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Santana de Cecco B, Grace Falconnier N, Chen W, Go YY, Peak L, Sasaki E, Walsh C, Mitchell MS, Carossino M, Del Piero F. Pathologic and genomic characterization of an outbreak of anthrax-like disease caused by Bacillus tropicus (formerly atypical Bacillus cereus) in red kangaroos ( Macropus rufus). Vet Pathol 2025; 62:332-342. [PMID: 40320846 DOI: 10.1177/03009858241306399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2025]
Abstract
Atypical Bacillus cereus strains (currently classified as Bacillus tropicus) capable of causing anthrax-like disease in humans and animals have emerged in the last 2 decades. These emerging strains are characterized by the acquisition of virulence plasmids pBCXO1 and pBC210, which are homologous to the pXO1 and pXO2 virulence plasmids of Bacillus anthracis, the agent of anthrax. The aim of this study was to describe the gross, histologic, microbiologic, and molecular features of an outbreak of anthrax-like septicemia caused by B. tropicus in red kangaroos (Macropus rufus). Three red kangaroos from a wild animal preserve were found dead with no premonitory clinical signs. No changes in husbandry were reported prior to the outbreak. The peracute disease process was characterized by severe splenomegaly, associated with fibrinonecrotizing splenitis in all affected animals, in addition to segmental suppurative enteritis in 2 kangaroos and cutaneous excoriations, with underlying necrotizing cellulitis and lymphadenitis, in 1 kangaroo. Numerous intralesional, gram-positive and capsulated bacilli were identified as the formerly known B. cereus group via bacteriologic culture. Whole-genome sequencing from one of the bacterial isolates (designated 11844) revealed numerous anthrax-like virulence factors, including the pBCXO1 and pBC210 virulence plasmids. This isolate also had a close phylogenetic relationship with other B. tropicus strains carrying these virulence plasmids, including B. tropicus (formerly B. cereus) G9241. This is the first report of B. tropicus leading to anthrax-like disease in kangaroos. This disease form carries significant public health risks due to potential zoonotic transmission.
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Affiliation(s)
- Bianca Santana de Cecco
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
| | - Naomi Grace Falconnier
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
| | - Weiyi Chen
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong SAR, China
| | - Yun Young Go
- College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea
| | - Laura Peak
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
| | - Emi Sasaki
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
| | - Christine Walsh
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
| | - Maria S Mitchell
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
| | - Mariano Carossino
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
| | - Fabio Del Piero
- Louisiana Animal Disease Diagnostic Laboratory, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
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Ferris AM, Dawson DG, Eyler AB, Yeager JJ, Bohannon JK, Boydston JA, Krause ML, Balzli CL, Wahl V, Jenkins TD, Rippeon SL, Miller JE, Miller SE, Clarke DW, Manan E, Harman AF, Rhodes KR, Sweeney TM, Cronin HD, Bowman RL, Winpigler MP, Zimmerman HA, Hail AS, Scorpio A. Bacillus cereus biovar anthracis causes inhalational anthrax-like disease in rabbits that is treatable with medical countermeasures. PLoS Negl Trop Dis 2025; 19:e0012973. [PMID: 40193393 PMCID: PMC12005533 DOI: 10.1371/journal.pntd.0012973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2025] [Revised: 04/17/2025] [Accepted: 03/11/2025] [Indexed: 04/09/2025] Open
Abstract
Bacillus anthracis is a zoonotic organism that causes the disease anthrax due to the activity of virulence factors harbored on plasmids pXO1 and pXO2. Inhalation of B. anthracis spores results in pneumonic disease that progresses quickly, and often results in lethality in the absence of medical countermeasure (MCM) intervention. Recently, reports have identified Bacillus cereus isolates that possess pXO1 and pXO2-like plasmids and cause an anthrax-like disease. These isolates have been named B. cereus biovar anthracis, or Bcbva. To evaluate disease course of Bcbva, the inhalational median lethal dose (INHLD50) was determined for two isolates, Bcbva Cameroon (CA) and Bcbva Cote d'Ivoire (CI), using the New Zealand white (NZW) rabbit inhalation anthrax model and compared to established B. anthracis inhalation data. Furthermore, disease progression and anthrax MCM efficacies were evaluated by quantifying temperature responses, bacteremia, and virulence factor production in both survivor and non-survivor animals. This study determined that the rabbit INHLD50 values for Bcbva CA and CI were similar to that published for B. anthracis Ames. The mean time to significant increase in body temperature (SIBT) and death were dose dependent for both Bcbva isolates, and all animals that succumbed to aerosol exposure displayed SIBT prior to death. Serum hyaluronic acid concentration increased prior to mortality in animals challenged with Bcbva and differences were observed in serum protective antigen concentration in animals challenged with Bcbva compared to B. anthracis. Pre-exposure vaccination with Anthrax Vaccine Adsorbed (AVA) and post-exposure prophylaxis of levofloxacin with or without AVA vaccination were effective against a challenge of ~200 INHLD50 of Bcbva CA or CI. Collectively, these data suggest that anthrax-like disease caused by Bcbva is similar to that caused by B. anthracis Ames 2084, and that currently available countermeasures are effective against inhalation exposure to Bcbva.
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Affiliation(s)
- Allison M. Ferris
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - David G. Dawson
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Andrea B. Eyler
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - John J. Yeager
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Jordan K. Bohannon
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Jeremy A. Boydston
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Melissa L. Krause
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Charles L. Balzli
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Victoria Wahl
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Tammy D. Jenkins
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Sherry L. Rippeon
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - James E. Miller
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Susan E. Miller
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - David W. Clarke
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Emmanuel Manan
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Ashley F. Harman
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Kim R. Rhodes
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Tina M. Sweeney
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Heather D. Cronin
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Ron L. Bowman
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Michael P. Winpigler
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Heather A. Zimmerman
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Alec S. Hail
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
| | - Angelo Scorpio
- National Biodefense Analysis and Countermeasures Center, Frederick, Maryland, United States of America
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Okutani A, Okugawa S, Fujimoto F, Ikeda M, Tsutsumi T, Moriya K, Maeda K. Genetic diversity and virulence of Bacillus cereus group isolates from bloodstream infections. Microbiol Spectr 2025; 13:e0240724. [PMID: 39873504 PMCID: PMC11878096 DOI: 10.1128/spectrum.02407-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2024] [Accepted: 12/06/2024] [Indexed: 01/30/2025] Open
Abstract
Bacillus cereus catheter-related bloodstream infections (CRBSIs) are an increasing concern in Japanese hospitals. Although their clinical characteristics have been explored, the genetic relationships and virulence profiles of B. cereus isolates from CRBSIs remain understudied. Here, using advanced genomic techniques, we investigated the genetic diversity, phylogenetic relationships, and virulence profiles of B. cereus isolates from patients with bloodstream infections. We analyzed 28 B. cereus group strains isolated from blood samples at the University of Tokyo Hospital between 2005 and 2017 using whole-genome sequencing, core-genome single-nucleotide polymorphism (SNP) typing, and virulence gene profiling. Core-genome SNP analysis revealed significant genetic diversity among the isolates, suggesting multiple independent sources of infection. The isolates predominantly belonged to panC clades III and IV, with distinct virulence gene profiles. All panC clade III isolates contained hbl operon genes, whereas four isolates from clade IV harbored cereulide synthetase genes (cesABCD). One isolate possessed a capsule gene operon (capBCADE), a rare finding among clinical B. cereus strains. Biofilm formation ability was observed in 50% of catheter-related isolates, although this ability was not significantly different from that of the noncatheter-related isolates.IMPORTANCEThis study provides novel insights into the genetic diversity and virulence potential of B. cereus strains causing bloodstream infections in a Japanese hospital setting. These findings suggest diverse infection pathways and highlight the importance of continuous molecular epidemiological surveillance for effective infection control.
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Affiliation(s)
- Akiko Okutani
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan
| | - Shu Okugawa
- Department of Infectious Diseases, The University of Tokyo Hospital, Tokyo, Japan
| | - Fumie Fujimoto
- Department of Infection Control and Prevention, The University of Tokyo Hospital, Tokyo, Japan
| | - Mahoko Ikeda
- Department of Infectious Diseases, The University of Tokyo Hospital, Tokyo, Japan
| | - Takeya Tsutsumi
- Department of Infectious Diseases, The University of Tokyo Hospital, Tokyo, Japan
| | - Kyoji Moriya
- Department of Infectious Diseases, The University of Tokyo Hospital, Tokyo, Japan
- Department of Infection Control and Prevention, The University of Tokyo Hospital, Tokyo, Japan
- Tokyo Healthcare University, Tokyo, Japan
| | - Ken Maeda
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan
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Jiranantasak T, Bluhm AP, Chabot DJ, Friedlander A, Bowen R, McMillan IA, Hadfield TL, Hartwig A, Blackburn JK, Norris MH. Toxin and capsule production by Bacillus cereus biovar anthracis influence pathogenicity in macrophages and animal models. PLoS Negl Trop Dis 2024; 18:e0012779. [PMID: 39715264 PMCID: PMC11706511 DOI: 10.1371/journal.pntd.0012779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 01/07/2025] [Accepted: 12/11/2024] [Indexed: 12/25/2024] Open
Abstract
Bacillus cereus biovar anthracis (Bcbva) causes anthrax-like disease in animals, particularly in the non-human primates and great apes of West and Central Africa. Genomic analyses revealed Bcbva as a member of the B. cereus species that carries two plasmids, pBCXO1 and pBCXO2, which have high sequence homology to the B. anthracis toxin and polyglutamate capsule encoding plasmids pXO1 and pXO2, respectively. To date, only a few studies have investigated the effect of variations in Bcbva sporulation, toxin, and capsule synthesis on animal and macrophage pathogenicity compared to B. anthracis, therefore more research is needed to gain a better understanding of the pathogenesis of this emerging infection. Here, we report that Bcbva can multiply and vegetatively survive on nutrient-rich media for a minimum of six days while generating spores. Sporulation of Bcbva occurred faster and more extensively than B. anthracis Ames. Bcbva tended to secrete less protective antigen (PA) than B. anthracis Ames when cultured in growth medium. We found Bcbva produced a substantially higher amount of attached poly-ƴ-D-glutamic acid (PDGA) capsule than B. anthracis Ames when grown in medium supplemented with human serum and CO2. In a phagocytosis assay, Bcbva spores showed reduced internalization by mouse macrophages compared to B. anthracis Ames. Our research demonstrated that Bcbva is more virulent than B. anthracis Ames using two in vivo models, Galleria mellonella larvae and guinea pigs. Following that, the efficacy of the veterinary vaccine Sterne strain 34F2 against anthrax-like disease was assessed in guinea pigs. Sterne vaccinated guinea pigs had significantly increased anti-PA titers compared to the unvaccinated control group. Toxin neutralizing antibody titers in vaccinated guinea pigs correlated with anti-PA titers. This indicates the Sterne vaccine provides adequate protection against Bcbva infection in laboratory animals.
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Affiliation(s)
- Treenate Jiranantasak
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Andrew P. Bluhm
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Donald J. Chabot
- United States Army Medical Research Institute of Infectious Disease, Fort Detrick, Maryland, United States of America
| | - Arthur Friedlander
- United States Army Medical Research Institute of Infectious Disease, Fort Detrick, Maryland, United States of America
| | - Richard Bowen
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Ian A. McMillan
- Pathogen Analysis and Translational Health Group, School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaiʻi, United States of America
| | - Ted L. Hadfield
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Airn Hartwig
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jason K. Blackburn
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Michael H. Norris
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- Pathogen Analysis and Translational Health Group, School of Life Sciences, University of Hawaiʻi at Mānoa, Honolulu, Hawaiʻi, United States of America
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Ochai SO, Hassim A, Dekker EH, Magome T, Lekota KE, Makgabo SM, de Klerk-Loris LM, van Schalkwyk LO, Kamath PL, Turner WC, van Heerden H. Comparing microbiological and molecular diagnostic tools for the surveillance of anthrax. PLoS Negl Trop Dis 2024; 18:e0012122. [PMID: 39571005 PMCID: PMC11620650 DOI: 10.1371/journal.pntd.0012122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 12/05/2024] [Accepted: 10/28/2024] [Indexed: 12/07/2024] Open
Abstract
The diagnosis of anthrax, a zoonotic disease caused by Bacillus anthracis can be complicated by detection of closely related species. Conventional diagnosis of anthrax involves microscopy, culture identification of bacterial colonies and molecular detection. Genetic markers used are often virulence gene targets such as B. anthracis protective antigen (pagA, also called BAPA, occurring on plasmid pXO1), lethal factor (lef, on pXO1), capsule-encoding capB/C (located on pXO2) as well as chromosomal Ba-1. Combinations of genetic markers using real-time/quantitative polymerase chain reaction (qPCR) are used to confirm B. anthracis from culture but can also be used directly on diagnostic samples to avoid propagation and its associated biorisks and for faster identification. We investigated how the presence of closely related species could complicate anthrax diagnoses with and without culture to standardise the use of genetic markers using qPCR for accurate anthrax diagnosis. Using blood smears from 2012-2020 from wildlife mortalities (n = 1708) in Kruger National Park in South Africa where anthrax is endemic, we contrasted anthrax diagnostic results based on qPCR, microscopy, and culture. From smears, 113/1708 grew bacteria in culture, from which 506 isolates were obtained. Of these isolates, only 24.7% (125 isolates) were positive for B. anthracis based on genetic markers or microscopy. However, among these, merely 4/125 (3.2%) were confirmed B. anthracis isolates (based on morphology, microscopy, and sensitivity testing to penicillin and gamma-phage) from the blood smear, likely due to poor survival of spores on stored smears. This study identified B. cereus sensu lato, which included B. cereus and B. anthracis, Peribacillus spp., and Priestia spp. clusters using gyrB gene in selected bacterial isolates positive for pagA region using BAPA probe. Using qPCR on blood smears, 52.1% (890 samples) tested positive for B. anthracis based on one or a combination of genetic markers which included the 25 positive controls. Notably, the standard lef primer set displayed the lowest specificity and accuracy. The Ba-1+BAPA+lef combination showed 100% specificity, sensitivity, and accuracy. Various marker combinations, such as Ba-1+capB, BAPA+capB, Ba-1+BAPA+capB+lef, and BAPA+lef+capB, all demonstrated 100.0% specificity and 98.7% accuracy, while maintaining a sensitivity of 96.6%. Using Ba-1+BAPA+lef+capB, as well as Ba-1+BAPA+lef with molecular diagnosis accurately detects B. anthracis in the absence of bacterial culture. Systematically combining microscopy and molecular markers holds promise for notably reducing false positives. This significantly enhances the detection and surveillance of diseases like anthrax in southern Africa and beyond and reduces the need for propagation of the bacteria in culture.
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Affiliation(s)
- Sunday Ochonu Ochai
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
- Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
- International Centre for Antimicrobial Resistance Solutions, Copenhagen S, 2300, Denmark
| | - Ayesha Hassim
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Edgar H. Dekker
- Office of the State Veterinarian, Department of Agriculture, Forestry and Fisheries, Government of South Africa, Skukuza, South Africa
| | - Thuto Magome
- Unit for Environmental Sciences and Management, Microbiology, North West University, Potchefstroom, South Africa
| | - Kgaugelo Edward Lekota
- Unit for Environmental Sciences and Management, Microbiology, North West University, Potchefstroom, South Africa
| | - S. Marcus Makgabo
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
- Department of Life and Consumer Sciences, College of Agriculture and Environmental Sciences, University of South Africa (UNISA), Florida Campus, Roodepoort, 1709, South Africa
| | - Lin-Mari de Klerk-Loris
- Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Louis O. van Schalkwyk
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
- Office of the State Veterinarian, Department of Agriculture, Forestry and Fisheries, Government of South Africa, Skukuza, South Africa
- Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany
| | - Pauline L. Kamath
- School of Food and Agriculture, University of Maine, Orono, Maine, United States of America
- Maine Center for Genetics in the Environment, University of Maine, Orono, Maine, United States of America
| | - Wendy C. Turner
- U.S. Geological Survey, Wisconsin Cooperative Wildlife Research Unit, Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
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Sabin SJ, Beesley CA, Marston CK, Paisie TK, Gulvik CA, Sprenger GA, Gee JE, Traxler RM, Bell ME, McQuiston JR, Weiner ZP. Investigating Anthrax-Associated Virulence Genes among Archival and Contemporary Bacillus cereus Group Genomes. Pathogens 2024; 13:884. [PMID: 39452755 PMCID: PMC11510535 DOI: 10.3390/pathogens13100884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2024] [Revised: 09/26/2024] [Accepted: 10/02/2024] [Indexed: 10/26/2024] Open
Abstract
Bacillus anthracis causes anthrax through virulence factors encoded on two plasmids. However, non-B. anthracis organisms within the closely related, environmentally ubiquitous Bacillus cereus group (BCG) may cause an anthrax-like disease in humans through the partial adoption of anthrax-associated virulence genes, challenging the definition of anthrax disease. To elucidate these phenomena and their evolutionary past, we performed whole-genome sequencing on non-anthracis BCG isolates, including 93 archival (1967-2003) and 5 contemporary isolates (2019-2023). We produced annotated genomic assemblies and performed a pan-genome analysis to identify evidence of virulence gene homology and virulence gene acquisition by linear inheritance or horizontal gene transfer. At least one anthrax-associated virulence gene was annotated in ten isolates. Most homologous sequences in archival isolates showed evidence of pseudogenization and subsequent gene loss. The presence or absence of accessory genes, including anthrax-associated virulence genes, aligned with the phylogenetic structure of the BCG core genome. These findings support the hypothesis that anthrax-associated virulence genes were inherited from a common ancestor in the BCG and were retained or lost across different lineages, and contribute to a growing body of work informing public health strategies related to anthrax surveillance and identification.
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Affiliation(s)
- Susanna J. Sabin
- Laboratory Leadership Service Fellow Assigned to the National Center for Emerging and Zoonotic Infectious Diseases, CDC, Atlanta, GA 30329, USA
| | - Cari A. Beesley
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of High-Consequence Pathogens and Pathology, Bacterial Special Pathogens Branch, 1600 Clifton Rd, Atlanta, GA 30329, USA
| | - Chung K. Marston
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of High-Consequence Pathogens and Pathology, Bacterial Special Pathogens Branch, 1600 Clifton Rd, Atlanta, GA 30329, USA
| | - Taylor K. Paisie
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Christopher A. Gulvik
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of High-Consequence Pathogens and Pathology, Bacterial Special Pathogens Branch, 1600 Clifton Rd, Atlanta, GA 30329, USA
| | | | - Jay E. Gee
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of High-Consequence Pathogens and Pathology, Bacterial Special Pathogens Branch, 1600 Clifton Rd, Atlanta, GA 30329, USA
| | - Rita M. Traxler
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of High-Consequence Pathogens and Pathology, Bacterial Special Pathogens Branch, 1600 Clifton Rd, Atlanta, GA 30329, USA
| | - Melissa E. Bell
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of High-Consequence Pathogens and Pathology, Bacterial Special Pathogens Branch, 1600 Clifton Rd, Atlanta, GA 30329, USA
| | - John R. McQuiston
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of High-Consequence Pathogens and Pathology, Bacterial Special Pathogens Branch, 1600 Clifton Rd, Atlanta, GA 30329, USA
| | - Zachary P. Weiner
- Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of High-Consequence Pathogens and Pathology, Bacterial Special Pathogens Branch, 1600 Clifton Rd, Atlanta, GA 30329, USA
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7
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Al-Shaarani AAQA, Pecoraro L. A review of pathogenic airborne fungi and bacteria: unveiling occurrence, sources, and profound human health implication. Front Microbiol 2024; 15:1428415. [PMID: 39364169 PMCID: PMC11446796 DOI: 10.3389/fmicb.2024.1428415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Accepted: 09/05/2024] [Indexed: 10/05/2024] Open
Abstract
Airborne fungi and bacteria have been extensively studied by researchers due to their significant effects on human health. We provided an overview of the distribution and sources of airborne pathogenic microbes, and a detailed description of the detrimental effects that these microorganisms cause to human health in both outdoor and indoor environments. By analyzing the large body of literature published in this field, we offered valuable insights into how airborne microbes influence our well-being. The findings highlight the harmful consequences associated with the exposure to airborne fungi and bacteria in a variety of natural and human-mediated environments. Certain demographic groups, including children and the elderly, immunocompromised individuals, and various categories of workers are particularly exposed and vulnerable to the detrimental effect on health of air microbial pollution. A number of studies performed up to date consistently identified Alternaria, Cladosporium, Penicillium, Aspergillus, and Fusarium as the predominant fungal genera in various indoor and outdoor environments. Among bacteria, Bacillus, Streptococcus, Micrococcus, Enterococcus, and Pseudomonas emerged as the dominant genera in air samples collected from numerous environments. All these findings contributed to expanding our knowledge on airborne microbe distribution, emphasizing the crucial need for further research and increased public awareness. Collectively, these efforts may play a vital role in safeguarding human health in the face of risks posed by airborne microbial contaminants.
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Affiliation(s)
- Amran A. Q. A. Al-Shaarani
- College of Pharmaceutical Science & Moganshan Research Institute at Deqing County, Zhejiang University of Technology, Hangzhou, China
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, China
| | - Lorenzo Pecoraro
- College of Pharmaceutical Science & Moganshan Research Institute at Deqing County, Zhejiang University of Technology, Hangzhou, China
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Magome TG, Ochai SO, Hassim A, Bezuidenhout CC, van Heerden H, Lekota KE. A genome-based investigation of the Priestia species isolated from anthrax endemic regions in Kruger National Park. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2024; 123:105649. [PMID: 39059732 DOI: 10.1016/j.meegid.2024.105649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2024] [Revised: 07/21/2024] [Accepted: 07/23/2024] [Indexed: 07/28/2024]
Abstract
Priestia is a genus that was renamed from the genus Bacillus based on the conserved signature indels (CSIs) in protein sequences that separate Priestia species from Bacillus, with the latter only including species closely related to B. subtilis and B. cereus. Diagnosis of anthrax, a zoonotic disease, is implicated by tripartite anthrax virulence genes (lef, pagA, and cya) and poly-γ-D-glutamic acid capsular genes cap-ABCDE of Bacillus anthracis. Due to the amplification of anthrax virulence genes in Priestia isolates, the search for homologous anthrax virulence genes within the Priestia genomes (n = 9) isolated from animal blood smears was embarked upon through whole genome sequencing. In silico taxonomic identification of the isolates was conducted using genome taxonomy database (GTDB), average nucleotide identity (ANI), and multi-locus sequence typing (MLST), which identified the genomes as P. aryabhattai (n = 5), P. endophytica (n = 2) and P. megaterium (n = 2). A pan-genome analysis was further conducted on the Priestia genomes, including the screening of virulence, antibiotic resistance genes and mobile genetic elements on the sequenced genomes. The oligoribonuclease NrnB protein sequences showed that Priestia spp. possess a unique CSI that is absent in other Bacillus species. Furthermore, the CSI in P. endophytica is unique from other Priestia spp. Pan-genomic analysis indicates that P. endophytica clusters separately from P. aryabhattai and P. megaterium. In silico BLASTn genome analysis using the SYBR primers, Taqman probes and primers that target the chromosomal marker (Ba-1), protective antigen (pagA), and lethal factor (lef) on B. anthracis, showed partial binding to Priestia regions encoding for hypothetical proteins, pyridoxine biosynthesis, hydrolase, and inhibitory proteins. The antibiotic resistance genes (ARG) profile of Priestia spp. showed that the genomes contained no more than two ARGs. This included genes conferring resistance to rifamycin and fosfomycin on P. endophytica, as well as clindamycin on P. aryabhattai and P. megaterium. Priestia genomes lacked B. anthracis plasmids and consisted of plasmid replicon types with unknown functions. Furthermore, the amplification of Priestia strains may result in false positives when qPCR is used to detect the virulence genes of B. anthracis in soil, blood smears, and/or environmental samples.
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Affiliation(s)
- Thuto Gomolemo Magome
- Unit for Environmental Sciences and Management, Microbiology, North-West University, Potchefstroom, South Africa.
| | - Sunday Ochonu Ochai
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa; International Centre for Antimicrobial Resistance Solutions, Copenhagen S, 2300, Denmark; Antimicrobial Research Unit, College of Health Sciences, University of KwaZulu-Natal, Durban, South Africa
| | - Ayesha Hassim
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | | | - Henriette van Heerden
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa
| | - Kgaugelo Edward Lekota
- Unit for Environmental Sciences and Management, Microbiology, North-West University, Potchefstroom, South Africa
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9
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Gogarten JF, Düx A, Gräßle T, Lumbu CP, Markert S, Patrono LV, Pléh KA, Singa FN, Tanga CTF, Tombolomako TB, Couacy-Hymann E, Kouadio L, Ahuka-Mundeke S, Makouloutou-Nzassi P, Calvignac-Spencer S, Leendertz FH. An ounce of prevention is better : Monitoring wildlife health as a tool for pandemic prevention. EMBO Rep 2024; 25:2819-2831. [PMID: 38849672 PMCID: PMC11239677 DOI: 10.1038/s44319-024-00156-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 04/30/2024] [Indexed: 06/09/2024] Open
Abstract
Long-term observations of wildlife are key to understanding the ecological foundations of disease emergence. They provide unique opportunities to detect pathogens with zoonotic potential that could threaten human health but also pose a threat for the animals.
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Affiliation(s)
- Jan Frederik Gogarten
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
- Department of Applied Zoology and Nature Conservation, University of Greifswald, Greifswald, Germany
| | - Ariane Düx
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
| | - Tobias Gräßle
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
| | - Christelle Patricia Lumbu
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
- Institut National de Recherche Biomedical, Kinshasa, Democratic Republic of the Congo
- Kokolopori Bonobo Research Project, Tshuapa, Democratic Republic of the Congo
| | - Stephanie Markert
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
| | - Livia Victoria Patrono
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
| | - Kamilla Anna Pléh
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
| | - Frederic Niatou Singa
- WWF Central African Republic Programme Office, Dzanga Sangha Protected Areas, Bangui, Central African Republic
| | - Coch Tanguy Floyde Tanga
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
- Institut de Recherche en Ecologie Tropicale, Libreville, Gabon
- Ozouga Chimpanzee Project, Loango National Park, Gabon
- Loango Gorilla Project, Loango National Park, Gabon
| | - Thais Berenger Tombolomako
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
- WWF Central African Republic Programme Office, Dzanga Sangha Protected Areas, Bangui, Central African Republic
| | | | - Leonce Kouadio
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
- Université Peleforo Gon Coulibaly, Korhogo, Côte d'Ivoire
- Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
| | - Steve Ahuka-Mundeke
- Service de Microbiologie, Departement de Biologie Médicale, Cliniques Universitaires de Kinshasa (CUK), Université de Kinshasa (UNIKIN), Kinshasa, Democratic Republic of the Congo
- Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
| | - Patrice Makouloutou-Nzassi
- Département de Biologie et Écologie Animale, Institut de Recherche en Écologie Tropicale (IRET/CENAREST), Libreville, Gabon
- Unité de Recherche en Écologie de la Santé, CIRMF, Franceville, Gabon
| | - Sébastien Calvignac-Spencer
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany
- Faculty of Mathematics and Natural Sciences, University of Greifswald, Greifswald, Germany
| | - Fabian Hubertus Leendertz
- Helmholtz Institute for One Health, Helmholtz-Centre for Infection Research (HZI), Greifswald, Germany.
- Taï Chimpanzee Project, Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire.
- Faculty of Mathematics and Natural Sciences, University of Greifswald, Greifswald, Germany.
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10
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Ogunleye SC, Olorunshola MM, Fasina KA, Aborode AT, Akinsulie OC, Amoo A, Olatoye BJ, Bakare A, Lawal MA, Adekanye O, Chinyere EC. Anthrax outbreak: exploring its biological agents and public health implications. FRONTIERS IN TROPICAL DISEASES 2024; 4. [DOI: 10.3389/fitd.2023.1297896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2024] Open
Abstract
The (re)emergence of several infectious zoonoses underlines the need for the re-evaluation of the transmission patterns and key players responsible for effective inter-species transfer of diseases. Anthrax is caused by Bacillus anthracis, a zoonotic rod-shaped, Gram-positive, spore-forming bacterium that is highly fatal to both human and animal populations. B. anthracis is widespread across several regions of the world, including Africa, Asia, southern Europe, North and South America, and Australia, and it has a remarkably high attendant impact on the sustainability and profitability of livestock. The current trend in the global distribution of anthrax necessitates an urgent contextual understanding of the key drivers of the spread of B. anthracis in different parts of the world toward the end goal of an anthrax-free world. The understanding of the drivers is integral for the development of control and preventive measures, and also the development of agents such as therapeutics and vaccines against B. anthracis. This review presents a holistic description of the transmission pattern and epidemiology of B. anthracis, and updates on the diagnostic techniques and approaches available for the detection of B. anthracis. In addition, this review highlights plausible prevention and control strategies for the bacterium. This review further underscores the need for participatory epidemiology, hygiene, and safety protocols, the establishment of comprehensive surveillance systems, and global collaborative efforts toward vaccine development as critical steps in controlling anthrax.
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11
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Gummelt C, Dupke S, Howaldt S, Zimmermann F, Scholz HC, Laue M, Klee SR. Analysis of Sporulation in Bacillus cereus Biovar anthracis Which Contains an Insertion in the Gene for the Sporulation Factor σ K. Pathogens 2023; 12:1442. [PMID: 38133325 PMCID: PMC10745906 DOI: 10.3390/pathogens12121442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 12/23/2023] Open
Abstract
Bacillus cereus biovar anthracis (Bcbva) is an untypical pathogen causing a fatal anthrax-like disease in a variety of wildlife species in African rainforest areas. In contrast to Bacillus anthracis and most species of the B. cereus group, all strains of the Bcbva cluster contain a 22 kb insertion in the sigK gene which encodes the essential late sporulation sigma factor σK. This insertion is excised during sporulation in a site-specific recombination process resulting in an intact sigK gene and a circular molecule. The sporulation kinetics of two strains each of Bcbva and B. anthracis were compared by the expression analysis of eight sporulation-associated genes, including sigK, using reverse transcriptase quantitative real-time PCR. In addition, morphological sporulation stages were analyzed and quantified by electron microscopy. Our results indicated that the necessary excision of the insertion in Bcbva neither delayed nor inhibited its sporulation. In two spontaneous mutants of Bcbva, the excision of the sigK insertion and sporulation were impeded due to mutations in the spo0A and spoVG regulator genes, respectively. The spo0A frameshift mutation was overcome by intragenic suppression in a revertant which was able to sporulate normally, despite an M171S amino acid exchange in the global regulator Spo0A. A screening of the NCBI database identified further strains of the B. cereus group which possess unrelated insertions in the sigK gene, and two strains containing almost identical insertions at the same gene position. Some of the sigK insertions encode putative prophages, whereas the Bcbva insertion encoded a type I restriction-modification system. The function of these insertions and if they are possibly essential for sporulation remains to be assessed.
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Affiliation(s)
- Constanze Gummelt
- Highly Pathogenic Microorganisms (ZBS 2), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (C.G.); (S.D.); (S.H.); (H.C.S.)
| | - Susann Dupke
- Highly Pathogenic Microorganisms (ZBS 2), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (C.G.); (S.D.); (S.H.); (H.C.S.)
| | - Sabine Howaldt
- Highly Pathogenic Microorganisms (ZBS 2), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (C.G.); (S.D.); (S.H.); (H.C.S.)
| | - Fee Zimmermann
- Epidemiology of Highly Pathogenic Microorganisms (P3), Robert Koch Institute, 13353 Berlin, Germany;
| | - Holger C. Scholz
- Highly Pathogenic Microorganisms (ZBS 2), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (C.G.); (S.D.); (S.H.); (H.C.S.)
| | - Michael Laue
- Advanced Light and Electron Microscopy (ZBS 4), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany;
| | - Silke R. Klee
- Highly Pathogenic Microorganisms (ZBS 2), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany; (C.G.); (S.D.); (S.H.); (H.C.S.)
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12
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Millett P, Alexanian T, Brink KR, Carter SR, Diggans J, Palmer MJ, Ritterson R, Sandbrink JB, Wheeler NE. Beyond Biosecurity by Taxonomic Lists: Lessons, Challenges, and Opportunities. Health Secur 2023; 21:521-529. [PMID: 37856148 PMCID: PMC10733751 DOI: 10.1089/hs.2022.0109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023] Open
Affiliation(s)
- Piers Millett
- Piers Millett, PhD, is Executive Director, International Biosecurity and Biosafety Initiative for Science, Washington, DC
| | - Tessa Alexanian
- Tessa Alexanian is Safety and Security Program Officer, iGEM Foundation, Paris, France
| | - Kathryn R. Brink
- Kathryn R. Brink, PhD, is a Postdoctoral Fellow, Center for International Security and Cooperation, at Stanford University, Stanford, CA
| | - Sarah R. Carter
- Sarah R. Carter, PhD, is Principal, Science Policy Consulting LLC, Arlington, VA
| | - James Diggans
- James Diggans, PhD, is Head of Biosecurity, Twist Bioscience, San Francisco, CA
| | - Megan J. Palmer
- Megan J. Palmer, PhD, is Executive Director of Bio Policy & Leadership Initiatives and an Adjunct Professor, Department of Bioengineering; at Stanford University, Stanford, CA
| | - Ryan Ritterson
- Ryan Ritterson, PhD, is Executive Vice President of Research, Gryphon Scientific LLC, Takoma Park, MD
| | - Jonas B. Sandbrink
- Jonas B. Sandbrink is a Doctoral Researcher, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nicole E. Wheeler
- Nicole E. Wheeler, PhD, is a Turing Fellow, Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
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13
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Lablaine A, Chamot S, Serrano M, Billaudeau C, Bornard I, Carballido-López R, Carlin F, Henriques AO, Broussolle V. A new fluorescence-based approach for direct visualization of coat formation during sporulation in Bacillus cereus. Sci Rep 2023; 13:15136. [PMID: 37704668 PMCID: PMC10499802 DOI: 10.1038/s41598-023-42143-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 09/06/2023] [Indexed: 09/15/2023] Open
Abstract
The human pathogenic bacteria Bacillus cereus, Bacillus anthracis and the entomopathogenic Bacillus thuringiensis form spores encased in a protein coat surrounded by a balloon-like exosporium. These structures mediate spore interactions with its environment, including the host immune system, control the transit of molecules that trigger germination and thus are essential for the spore life cycle. Formation of the coat and exosporium has been traditionally visualized by transmission electronic microscopy on fixed cells. Recently, we showed that assembly of the exosporium can be directly observed in live B. cereus cells by super resolution-structured illumination microscopy (SR-SIM) using the membrane MitoTrackerGreen (MTG) dye. Here, we demonstrate that the different steps of coat formation can also be visualized by SR-SIM using MTG and SNAP-cell TMR-star dyes during B. cereus sporulation. We used these markers to characterize a subpopulation of engulfment-defective B. cereus cells that develops at a suboptimal sporulation temperature. Importantly, we predicted and confirmed that synthesis and accumulation of coat material, as well as synthesis of the σK-dependent protein BxpB, occur in cells arrested during engulfment. These results suggest that, unlike the well-studied model organism Bacillus subtilis, the activity of σK is not strictly linked to the state of forespore development in B. cereus.
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Affiliation(s)
- Armand Lablaine
- INRAE, Avignon Université, UMR SQPOV, 84000, Avignon, France
- MICALIS Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | | | - Mónica Serrano
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
| | - Cyrille Billaudeau
- MICALIS Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | | | - Rut Carballido-López
- MICALIS Institute, INRAE, AgroParisTech, Université Paris-Saclay, 78350, Jouy-en-Josas, France
| | - Frédéric Carlin
- INRAE, Avignon Université, UMR SQPOV, 84000, Avignon, France
| | - Adriano O Henriques
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157, Oeiras, Portugal
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14
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Norris MH, Zincke D, Daegling DJ, Krigbaum J, McGraw WS, Kirpich A, Hadfield TL, Blackburn JK. Genomic and Phylogenetic Analysis of Bacillus cereus Biovar anthracis Isolated from Archival Bone Samples Reveals Earlier Natural History of the Pathogen. Pathogens 2023; 12:1065. [PMID: 37624025 PMCID: PMC10457788 DOI: 10.3390/pathogens12081065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/15/2023] [Accepted: 08/17/2023] [Indexed: 08/26/2023] Open
Abstract
(1) Background: Bacillus cereus biovar anthracis (Bcbva) was the causative agent of an anthrax-like fatal disease among wild chimpanzees in 2001 in Côte d'Ivoire. Before this, there had not been any description of an anthrax-like disease caused by typically avirulent Bacillus cereus. Genetic analysis found that B. cereus had acquired two anthrax-like plasmids, one a pXO1-like toxin producing plasmid and the other a pXO2-like plasmid encoding capsule. Bcbva caused animal fatalities in Cameroon, Democratic Republic of Congo, and the Central African Republic between 2004 and 2012. (2) Methods: The pathogen had acquired plasmids in the wild and that was discovered as the cause of widespread animal fatalities in the early 2000s. Primate bones had been shipped out of the endemic zone for anthropological studies prior to the realized danger of contamination with Bcbva. Spores were isolated from the bone fragments and positively identified as Bcbva. Strains were characterized by classical microbiological methods and qPCR. Four new Bcbva isolates were whole-genome sequenced. Chromosomal and plasmid phylogenomic analysis was performed to provide temporal and spatial context to these new strains and previously sequenced Bcbva. Tau and principal component analyses were utilized to identify genetic and spatial case patterns in the Taï National Park anthrax zone. (3) Results: Preliminary studies positively identified Bcbva presence in several archival bone fragments. The animals in question died between 1994 and 2010. Previously, the earliest archival strains of Bcbva were identified in 1996. Though the pathogen has a homogeneous genome, spatial analyses of a subset of mappable isolates from Taï National Park revealed strains found closer together were generally more similar, with strains from chimpanzees and duikers having the widest distribution. Ancestral strains were located mostly in the west of the park and had lower spatial clustering compared to more recent isolates, indicating a local increase in genetic diversity of Bcbva in the park over space and time. Global clustering analysis indicates patterns of genetic diversity and distance are shared between the ancestral and more recently isolated type strains. (4) Conclusions: Our strains have the potential to unveil historical genomic information not available elsewhere. This information sheds light on the evolution and emergence of a dangerous anthrax-causing pathogen.
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Affiliation(s)
- Michael H. Norris
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL 32611, USA; (M.H.N.); (D.Z.); (T.L.H.)
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA
| | - Diansy Zincke
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL 32611, USA; (M.H.N.); (D.Z.); (T.L.H.)
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA
| | - David J. Daegling
- Department of Anthropology, University of Florida, Gainesville, FL 32611, USA; (D.J.D.); (J.K.)
| | - John Krigbaum
- Department of Anthropology, University of Florida, Gainesville, FL 32611, USA; (D.J.D.); (J.K.)
| | - W. Scott McGraw
- Department of Anthropology, Ohio State University, Columbus, OH 43210, USA;
| | - Alexander Kirpich
- Department of Population Health Sciences, Georgia State University, Atlanta, GA 30302, USA;
| | - Ted L. Hadfield
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL 32611, USA; (M.H.N.); (D.Z.); (T.L.H.)
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA
| | - Jason K. Blackburn
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL 32611, USA; (M.H.N.); (D.Z.); (T.L.H.)
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32611, USA
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15
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Cheng LW, Byadgi OV, Tsai CE, Wang PC, Chen SC. Pathogenicity and Genomic Characterization of a Novel Genospecies, Bacillus shihchuchen, of the Bacillus cereus Group Isolated from Chinese Softshell Turtle ( Pelodiscus sinensis). Int J Mol Sci 2023; 24:ijms24119636. [PMID: 37298593 DOI: 10.3390/ijms24119636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 05/25/2023] [Accepted: 05/27/2023] [Indexed: 06/12/2023] Open
Abstract
The Chinese softshell turtle (CST; Pelodiscus sinensis) is a freshwater aquaculture species of substantial economic importance that is commercially farmed across Asia, particularly in Taiwan. Although diseases caused by the Bacillus cereus group (Bcg) pose a major threat to commercial CST farming systems, information regarding its pathogenicity and genome remains limited. Here, we investigated the pathogenicity of Bcg strains isolated in a previous study and performed whole-genome sequencing. Pathogenicity analysis indicated that QF108-045 isolated from CSTs caused the highest mortality rate, and whole-genome sequencing revealed that it was an independent group distinct from other known Bcg genospecies. The average nucleotide identity compared to other known Bcg genospecies was below 95%, suggesting that QF108-045 belongs to a new genospecies, which we named Bacillus shihchuchen. Furthermore, genes annotation revealed the presence of anthrax toxins, such as edema factor and protective antigen, in QF108-045. Therefore, the biovar anthracis was assigned, and the full name of QF108-045 was Bacillus shihchuchen biovar anthracis. In addition to possessing multiple drug-resistant genes, QF108-045 demonstrated resistance to various types of antibiotics, including penicillins (amoxicillin and ampicillin), cephalosporins (ceftifour, cephalexin, and cephazolin), and polypeptides, such as vancomycin.
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Affiliation(s)
- Li-Wu Cheng
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Southern Taiwan Fish Diseases Research Centre, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
| | - Omkar Vijay Byadgi
- International Degree Program of Ornamental Fish Technology and Aquatic Animal Health, International College, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
| | - Chin-En Tsai
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
| | - Pei-Chi Wang
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Southern Taiwan Fish Diseases Research Centre, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- International Degree Program of Ornamental Fish Technology and Aquatic Animal Health, International College, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Research Centre for Fish Vaccine and Diseases, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
| | - Shih-Chu Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Southern Taiwan Fish Diseases Research Centre, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- International Degree Program of Ornamental Fish Technology and Aquatic Animal Health, International College, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Research Centre for Fish Vaccine and Diseases, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Research Centre for Animal Biologics, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
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16
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Tsai JM, Kuo HW, Cheng W. Retrospective Screening of Anthrax-like Disease Induced by Bacillus tropicus str. JMT from Chinese Soft-Shell Turtles in Taiwan. Pathogens 2023; 12:pathogens12050693. [PMID: 37242363 DOI: 10.3390/pathogens12050693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 04/19/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
Bacillus cereus is ubiquitous in the environment and a well-known causative agent of foodborne disease. Surprisingly, more and more emerging strains of atypical B. cereus have been identified and related to severe disease in humans and mammals such as chimpanzees, apes, and bovine. Recently, the atypical B. cereus isolates, which mainly derive from North America and Africa, have drawn great attention due to the potential risk of zoonosis. The cluster of B. cereus carries several anthrax-like virulent genes that are implicated in lethal disease. However, in non-mammals, the distribution of atypical B. cereus is still unknown. In this study, we conducted a retrospective screening of the 32 isolates of Bacillus spp. from diseased Chinese soft-shelled turtles from 2016 to 2020. To recognize the causative agent, we used various methods, such as sequencing analysis using PCR-amplification of the 16S rRNA gene, multiplex PCR for discriminating, and colony morphology by following previous studies. Furthermore, the digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values were calculated, respectively, below the 70 and 96% cutoff to define species boundaries. According to the summarized results, the pathogen is taxonomically classified as Bacillus tropicus str. JMT (previous atypical Bacillus cereus). Subsequently, analyses such as targeting the unique genes using PCR and visual observation of the bacteria under various staining techniques were implemented in our study. Our findings show that all (32/32, 100%) isolates in this retrospective screening share similar phenotypical properties and carry the protective antigen (PA), edema factor (EF), hyaluronic acid (HA), and exopolysaccharide (Bps) genes on their plasmids. In this study, the results indicate that the geographic distribution and host range of B. tropicus were previously underestimated.
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Affiliation(s)
- Jia-Ming Tsai
- Department of Aquaculture, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
- Fish Doctor Veterinary Clinic, Pingtung 94042, Taiwan
| | - Hsin-Wei Kuo
- General Research Service Center, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
| | - Winton Cheng
- Department of Aquaculture, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
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Manoharan S, Taylor-Joyce G, Brooker TA, Hernández Rodríguez CS, Hapeshi A, Baldwin V, Baillie L, Oyston PCF, Waterfield NR. From cereus to anthrax and back again: Assessment of the temperature-dependent phenotypic switching in the "cross-over" strain Bacillus cereus G9241. Front Microbiol 2023; 14:1113562. [PMID: 36937299 PMCID: PMC10017872 DOI: 10.3389/fmicb.2023.1113562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 02/07/2023] [Indexed: 03/06/2023] Open
Abstract
Bacillus cereus G9241 was isolated from a Louisiana welder suffering from an anthrax-like infection. The organism carries two transcriptional regulators that have previously been proposed to be incompatible with each other in Bacillus anthracis: the pleiotropic transcriptional regulator PlcR found in most members of the Bacillus cereus group but truncated in all B. anthracis isolates, and the anthrax toxin regulator AtxA found in all B. anthracis strains and a few B. cereus sensu stricto strains. Here we report cytotoxic and hemolytic activity of cell free B. cereus G9241 culture supernatants cultured at 25°C to various eukaryotic cells. However, this is not observed at the mammalian infection relevant temperature 37°C, behaving much like the supernatants generated by B. anthracis. Using a combination of genetic and proteomic approaches to understand this unique phenotype, we identified several PlcR-regulated toxins to be secreted highly at 25°C compared to 37°C. Furthermore, results suggest that differential expression of the protease involved in processing the PlcR quorum sensing activator molecule PapR appears to be the limiting step for the production of PlcR-regulated toxins at 37°C, giving rise to the temperature-dependent hemolytic and cytotoxic activity of the culture supernatants. This study provides an insight on how B. cereus G9241 is able to "switch" between B. cereus and B. anthracis-like phenotypes in a temperature-dependent manner, potentially accommodating the activities of both PlcR and AtxA.
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Affiliation(s)
- Shathviga Manoharan
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Grace Taylor-Joyce
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Thomas A. Brooker
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | | | - Alexia Hapeshi
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | | | - Les Baillie
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom
| | | | - Nicholas R. Waterfield
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, United Kingdom
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18
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Bacilli in the International Space Station. Microorganisms 2022; 10:microorganisms10122309. [PMID: 36557562 PMCID: PMC9782108 DOI: 10.3390/microorganisms10122309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022] Open
Abstract
Astronauts remote from Earth, not least those who will inhabit the Moon or Mars, are vulnerable to disease due to their reduced immunity, isolation from clinical support, and the disconnect from any buffering capacity provided by the Earth. Here, we explore potential risks for astronaut health, focusing on key aspects of the biology of Bacillus anthracis and other anthrax-like bacilli. We examine aspects of Bacillus cereus group genetics in relation to their evolutionary biology and pathogenicity; a new clade of the Bacillus cereus group, close related to B. anthracis, has colonized the International Space Station (ISS), is still present, and could in theory at least acquire pathogenic plasmids from the other B. cereus group strains. The main finding is that the genomic sequence alignments of the B. cereus group ISS strains revealed a high sequence identity, indicating they originated from the same strain and that a close look to the genetic variations among the strains suggesting they lived, or they are living, in a vegetative form in the ISS enough time to accumulate genetic variations unique for each single strains.
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Mondange L, Tessier É, Tournier JN. Pathogenic Bacilli as an Emerging Biothreat? Pathogens 2022; 11:pathogens11101186. [PMID: 36297243 PMCID: PMC9609551 DOI: 10.3390/pathogens11101186] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/11/2022] [Accepted: 10/11/2022] [Indexed: 11/16/2022] Open
Abstract
Bacillus anthracis, present as a very durable endospore in soil, causes zoonotic illness which is mainly associated with herbivores and domestic animals. Human cases are scarce and often involve populations close to infected livestock. If anthrax is no longer of public health concern in developed countries, B. anthracis is one of the top-tier biological weapon agents. It is classified by the CDC as a category A agent. Since 1994, emerging strains of Bacillus cereus have been associated with anthrax-like disease in mammals. Some clinical strains of B. cereus harbor anthrax-like plasmid genes (pXO1 and pXO2) associated with non-human primate and human infections, with the same clinical presentation of inhalation anthrax and mortality rates. Although currently restricted to certain limited areas of circulation, the emergence of these new strains of B. cereus extends the list of potential agents possibly usable for bioterrorism or as a biological weapon. It is therefore important to improve our knowledge of the phylogeny within the B. cereus sensu lato group to better understand the origin of these strains. We can then more efficiently monitor the emergence of new strains to better control the risk of infection and limit potentially malicious uses.
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Affiliation(s)
- Lou Mondange
- Bacteriology Unit, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France
- Yersinia Unit, Institut Pasteur, 75015 Paris, France
- Correspondence: (L.M.); (J.-N.T.)
| | - Émilie Tessier
- Immunopathology Unit, Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France
| | - Jean-Nicolas Tournier
- CNR-LE Charbon, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France
- Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France
- École du Val-de-Grâce, 75015 Paris, France
- Correspondence: (L.M.); (J.-N.T.)
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Strains Associated with Two 2020 Welder Anthrax Cases in the United States Belong to Separate Lineages within Bacillus cereus sensu lato. Pathogens 2022; 11:pathogens11080856. [PMID: 36014977 PMCID: PMC9413466 DOI: 10.3390/pathogens11080856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/22/2022] [Accepted: 07/27/2022] [Indexed: 12/04/2022] Open
Abstract
Anthrax-causing members of Bacillus cereus sensu lato (s.l.) pose a serious threat to public health. While most anthrax-causing strains resemble B. anthracis phenotypically, rare cases of anthrax-like illness caused by strains resembling “B. cereus” have been reported. Here, whole-genome sequencing was used to characterize three B. cereus s.l. isolates associated with two 2020 welder anthrax cases in the United States, which resembled “B. cereus” phenotypically. Comparison of the three genomes sequenced here to all publicly available, high-quality B. cereus s.l. genomes (n = 2890 total genomes) demonstrated that genomes associated with each case effectively belonged to separate species at the conventional 95% average nucleotide identity prokaryotic species threshold. Two PubMLST sequence type 78 (ST78) genomes affiliated with a case in Louisiana were most closely related to B. tropicus and possessed genes encoding the Bps exopolysaccharide capsule, as well as hemolysin BL (Hbl) and cytotoxin K (CytK). Comparatively, a ST108 genome associated with a case in Texas was most closely related to B. anthracis; however, like other anthrax-causing strains most closely related to B. anthracis, this genome did not possess Bps-, Hbl-, or CytK-encoding genes. Overall, results presented here provide insights into the evolution of anthrax-causing B. cereus s.l.
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21
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Hinnekens P, Mahillon J. Conjugation-mediated transfer of pXO16, a large plasmid from Bacillus thuringiensis sv. israelensis, across the Bacillus cereus group and its impact on host phenotype. Plasmid 2022; 122:102639. [PMID: 35842001 DOI: 10.1016/j.plasmid.2022.102639] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/27/2022] [Accepted: 07/10/2022] [Indexed: 11/17/2022]
Abstract
pXO16, the 350 kb-conjugative plasmid from Bacillus thuringiensis sv. israelensis promotes its own transfer at high efficiency, triggers the transfer of mobilizable and non-mobilizable plasmids, as well as the transfer of host chromosomal loci. Naturally found in B. thuringiensis sv. israelensis, pXO16 transfers to various strains of Bacillus cereus sensu lato (s.l.) at a wide range of frequencies. Despite this host diversity, a paradox remains between the relatively large host spectrum and the natural occurrence of pXO16, so far restricted to B. thuringiensis sv. israelensis. Proposing first insights exploring this paradox, we investigated the behaviour of pXO16 amongst different members of the B. cereus group. We first looked at the transfer of pXO16 to two new host clusters of B. cereus s.l., Bacillus mycoides and Bacillus anthracis clusters. This examination brought to light the impairment of the characteristic rhizoidal phenotype of B. mycoides in presence of pXO16. We also explored the stability of pXO16 at different temperatures as some B. cereus group members are well-known for their psychro- or thermo-tolerance. This shed light on the thermo-sensitivity of the plasmid. The influence of pXO16 on its host cell growth and on swimming capacity also revealed no or limited impact on its natural host B. thuringiensis sv. israelensis. On the contrary, pXO16 affected more strongly both the growth and swimming capacity of other B. cereus s.l. hosts. This reinforced the running hypothesis of a co-evolution between pXO16 and B. thuringiensis sv. israelensis, enabling the plasmid maintenance without impairing the host strain development.
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Affiliation(s)
- Pauline Hinnekens
- Laboratory of Food and Environmental Microbiology, Earth and Life Institute, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Jacques Mahillon
- Laboratory of Food and Environmental Microbiology, Earth and Life Institute, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium.
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Bower WA, Hendricks KA, Vieira AR, Traxler RM, Weiner Z, Lynfield R, Hoffmaster A. What Is Anthrax? Pathogens 2022; 11:690. [PMID: 35745544 PMCID: PMC9231248 DOI: 10.3390/pathogens11060690] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/12/2022] [Accepted: 06/13/2022] [Indexed: 11/29/2022] Open
Abstract
Anthrax has been feared for its high mortality in animals and humans for centuries. The etiologic agent is considered a potentially devastating bioweapon, and since 1876-when Robert Koch demonstrated that Bacillus anthracis caused anthrax-it has been considered the sole cause of the disease. Anthrax is, however, a toxin-mediated disease. The toxins edema toxin and lethal toxin are formed from protein components encoded for by the pXO1 virulence plasmid present in pathogenic B. anthracis strains. However, other members of the Bacillus cereus group, to which B. anthracis belongs, have recently been shown to harbor the pXO1 plasmid and produce anthrax toxins. Infection with these Bacillus cereus group organisms produces a disease clinically similar to anthrax. This suggests that anthrax should be defined by the exotoxins encoded for by the pXO1 plasmid rather than the bacterial species it has historically been associated with, and that the definition of anthrax should be expanded to include disease caused by any member of the B. cereus group containing the toxin-producing pXO1 plasmid or anthrax toxin genes specifically.
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Affiliation(s)
- William A. Bower
- Bacterial Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (K.A.H.); (A.R.V.); (R.M.T.); (Z.W.); (A.H.)
| | - Katherine A. Hendricks
- Bacterial Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (K.A.H.); (A.R.V.); (R.M.T.); (Z.W.); (A.H.)
| | - Antonio R. Vieira
- Bacterial Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (K.A.H.); (A.R.V.); (R.M.T.); (Z.W.); (A.H.)
| | - Rita M. Traxler
- Bacterial Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (K.A.H.); (A.R.V.); (R.M.T.); (Z.W.); (A.H.)
| | - Zachary Weiner
- Bacterial Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (K.A.H.); (A.R.V.); (R.M.T.); (Z.W.); (A.H.)
| | - Ruth Lynfield
- Minnesota Department of Health, Saint Paul, MN 55155, USA;
| | - Alex Hoffmaster
- Bacterial Special Pathogens Branch, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (K.A.H.); (A.R.V.); (R.M.T.); (Z.W.); (A.H.)
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23
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Calvigioni M, Cara A, Celandroni F, Mazzantini D, Panattoni A, Tirloni E, Bernardi C, Pinotti L, Stella S, Ghelardi E. Characterization of a Bacillus cereus strain associated with a large feed-related outbreak of severe infection in pigs. J Appl Microbiol 2022; 133:1078-1088. [PMID: 35611609 PMCID: PMC9543730 DOI: 10.1111/jam.15636] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/12/2022] [Accepted: 05/19/2022] [Indexed: 12/03/2022]
Abstract
Aims Bacillus cereus is often responsible for foodborne diseases and both local and systemic infections in humans. Cases of infection in other mammals are rather rare. In this study, we report a B. cereus feed‐related outbreak that caused the death of 6234 pigs in Italy. Methods and Results Massive doses of a Gram‐positive, spore‐forming bacterium were recovered from the animal feed, faeces of survived pigs and intestinal content of dead ones. The B. cereus MM1 strain was identified by MALDI‐TOF MS and typified by RAPD‐PCR. The isolate was tested for the production of PC‐PLC, proteases, hemolysins and biofilm, for motility, as well as for the presence of genes encoding tissue‐degrading enzymes and toxins. Antimicrobial resistance and pathogenicity in Galleria mellonella larvae were also investigated. Our results show that the isolated B. cereus strain is swimming‐proficient, produces PC‐PLC, proteases, hemolysins, biofilm and carries many virulence genes. The strain shows high pathogenicity in G. mellonella larvae. Conclusions The isolated B. cereus strain demonstrates an aggressive profile of pathogenicity and virulence, being able to produce a wide range of determinants potentially hazardous to pigs' health. Significance and Impact of Study This study highlights the proficiency of B. cereus to behave as a devastating pathogen in swine if ingested at high doses and underlines that more stringent quality controls are needed for livestock feeds and supplements.
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Affiliation(s)
- Marco Calvigioni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Alice Cara
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Francesco Celandroni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Diletta Mazzantini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Adelaide Panattoni
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy
| | - Erica Tirloni
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
| | - Cristian Bernardi
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
| | - Luciano Pinotti
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
| | - Simone Stella
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
| | - Emilia Ghelardi
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Italy.,Research Center Nutraceuticals and Food for Health-Nutrafood, University of Pisa, Italy
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24
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Chang JD, Vaughan EE, Liu CG, Jelinski JW, Terwilliger AL, Maresso AW. Metabolic profiling reveals nutrient preferences during carbon utilization in Bacillus species. Sci Rep 2021; 11:23917. [PMID: 34903830 PMCID: PMC8669014 DOI: 10.1038/s41598-021-03420-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 11/29/2021] [Indexed: 11/18/2022] Open
Abstract
The genus Bacillus includes species with diverse natural histories, including free-living nonpathogenic heterotrophs such as B. subtilis and host-dependent pathogens such as B. anthracis (the etiological agent of the disease anthrax) and B. cereus, a cause of food poisoning. Although highly similar genotypically, the ecological niches of these three species are mutually exclusive, which raises the untested hypothesis that their metabolism has speciated along a nutritional tract. Here, we developed a pipeline for quantitative total assessment of the use of diverse sources of carbon for general metabolism to better appreciate the "culinary preferences" of three distinct Bacillus species, as well as related Staphylococcus aureus. We show that each species has widely varying metabolic ability to utilize diverse sources of carbon that correlated to their ecological niches. This approach was applied to the growth and survival of B. anthracis in a blood-like environment and find metabolism shifts from sugar to amino acids as the preferred source of energy. Finally, various nutrients in broth and host-like environments are identified that may promote or interfere with bacterial metabolism during infection.
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Affiliation(s)
- James D Chang
- The Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Ellen E Vaughan
- The Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Carmen Gu Liu
- The Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Joseph W Jelinski
- The Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Austen L Terwilliger
- The Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Anthony W Maresso
- The Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA.
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25
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Detection of Bacillus cereus sensu lato Isolates Posing Potential Health Risks in Mexican Chili Powder. Microorganisms 2021; 9:microorganisms9112226. [PMID: 34835349 PMCID: PMC8618785 DOI: 10.3390/microorganisms9112226] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 01/10/2023] Open
Abstract
The potential presence of spore-forming bacteria related to the Bacillus cereus group in Mexican chili powder elaborated from Capsicum annuum L. is of commercial and clinical interest, because chili powder is an essential spice in the Mexican diet and in diets around the globe. To facilitate detection and isolation of members of this group of spore-forming bacteria from Mexican chili powder samples, we identified colonies that grew on agar medium selective for Bacillus cereus sensu lato, supplemented with polymyxin B (10 µg/mL) and ampicillin (10 to 100 µg/mL). The presumptive B. cereus (s.l.) isolates were tested using a tRNACys-PCR-based approach and the results identified species related phylogenetically to B. cereus, B. thuringiensis, and B. toyonensis. Their toxigenic potential was assessed by serological tests to detect enterotoxins (Nhe and Hbl) and by PCR targeting the hemolysin BL (hbl) component C (hblC) and non-hemolytic enterotoxin component A (nheA). The antibiotic profiles of the isolates showed a high resistance to β-lactams (100% of the isolates), trimethoprim-sulfamethoxazole (100%), tetracycline (90%), erythromycin (77%), clindamycin (74%), and chloramphenicol (42%). Our results indicate the presence of B. cereus s.l. with toxigenic characteristics in Mexican chili powder. Because of the potential for these organisms to cause disease through their production of various toxins, and resistance to antibiotics, we recommend that a microbiological risk assessment must be considered in the Mexican regulatory requirements.
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Zorigt T, Furuta Y, Simbotwe M, Ochi A, Tsujinouchi M, Shawa M, Shimizu T, Isoda N, Enkhtuya J, Higashi H. Development of ELISA based on Bacillus anthracis capsule biosynthesis protein CapA for naturally acquired antibodies against anthrax. PLoS One 2021; 16:e0258317. [PMID: 34634075 PMCID: PMC8504768 DOI: 10.1371/journal.pone.0258317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/23/2021] [Indexed: 11/30/2022] Open
Abstract
Anthrax is a zoonotic disease caused by the gram-positive spore-forming bacterium Bacillus anthracis. Detecting naturally acquired antibodies against anthrax sublethal exposure in animals is essential for anthrax surveillance and effective control measures. Serological assays based on protective antigen (PA) of B. anthracis are mainly used for anthrax surveillance and vaccine evaluation. Although the assay is reliable, it is challenging to distinguish the naturally acquired antibodies from vaccine-induced immunity in animals because PA is cross-reactive to both antibodies. Although additional data on the vaccination history of animals could bypass this problem, such data are not readily accessible in many cases. In this study, we established a new enzyme-linked immunosorbent assay (ELISA) specific to antibodies against capsule biosynthesis protein CapA antigen of B. anthracis, which is non-cross-reactive to vaccine-induced antibodies in horses. Using in silico analyses, we screened coding sequences encoded on pXO2 plasmid, which is absent in the veterinary vaccine strain Sterne 34F2 but present in virulent strains of B. anthracis. Among the 8 selected antigen candidates, capsule biosynthesis protein CapA (GBAA_RS28240) and peptide ABC transporter substrate-binding protein (GBAA_RS28340) were detected by antibodies in infected horse sera. Of these, CapA has not yet been identified as immunoreactive in other studies to the best of our knowledge. Considering the protein solubility and specificity of B. anthracis, we prepared the C-terminus region of CapA, named CapA322, and developed CapA322-ELISA based on a horse model. Comparative analysis of the CapA322-ELISA and PAD1-ELISA (ELISA uses domain one of the PA) showed that CapA322-ELISA could detect anti-CapA antibodies in sera from infected horses but was non-reactive to sera from vaccinated horses. The CapA322-ELISA could contribute to the anthrax surveillance in endemic areas, and two immunoreactive proteins identified in this study could be additives to the improvement of current or future vaccine development.
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Affiliation(s)
- Tuvshinzaya Zorigt
- Division of Infection and Immunity, International Institute for Zoonosis Control (Former Research Center for Zoonosis Control), Hokkaido University, Sapporo, Japan
- Graduate School of Infectious Diseases, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Yoshikazu Furuta
- Division of Infection and Immunity, International Institute for Zoonosis Control (Former Research Center for Zoonosis Control), Hokkaido University, Sapporo, Japan
- Graduate School of Infectious Diseases, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Manyando Simbotwe
- Division of Infection and Immunity, International Institute for Zoonosis Control (Former Research Center for Zoonosis Control), Hokkaido University, Sapporo, Japan
| | - Akihiro Ochi
- Equine Research Institute, Japan Racing Association, Shimotsuke, Tochigi, Japan
| | - Mai Tsujinouchi
- Division of Infection and Immunity, International Institute for Zoonosis Control (Former Research Center for Zoonosis Control), Hokkaido University, Sapporo, Japan
| | - Misheck Shawa
- Division of Infection and Immunity, International Institute for Zoonosis Control (Former Research Center for Zoonosis Control), Hokkaido University, Sapporo, Japan
- Graduate School of Infectious Diseases, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | - Tomoko Shimizu
- Division of Infection and Immunity, International Institute for Zoonosis Control (Former Research Center for Zoonosis Control), Hokkaido University, Sapporo, Japan
| | - Norikazu Isoda
- Laboratory of Microbiology, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
| | | | - Hideaki Higashi
- Division of Infection and Immunity, International Institute for Zoonosis Control (Former Research Center for Zoonosis Control), Hokkaido University, Sapporo, Japan
- Graduate School of Infectious Diseases, School of Veterinary Medicine, Hokkaido University, Sapporo, Japan
- * E-mail:
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27
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Carroll LM, Cheng RA, Wiedmann M, Kovac J. Keeping up with the Bacillus cereus group: taxonomy through the genomics era and beyond. Crit Rev Food Sci Nutr 2021; 62:7677-7702. [PMID: 33939559 DOI: 10.1080/10408398.2021.1916735] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The Bacillus cereus group, also known as B. cereus sensu lato (s.l.), is a species complex that contains numerous closely related lineages, which vary in their ability to cause illness in humans and animals. The classification of B. cereus s.l. isolates into species-level taxonomic units is thus essential for informing public health and food safety efforts. However, taxonomic classification of these organisms is challenging. Numerous-often conflicting-taxonomic changes to the group have been proposed over the past two decades, making it difficult to remain up to date. In this review, we discuss the major nomenclatural changes that have accumulated in the B. cereus s.l. taxonomic space prior to 2020, particularly in the genomic sequencing era, and outline the resulting problems. We discuss several contemporary taxonomic frameworks as applied to B. cereus s.l., including (i) phenotypic, (ii) genomic, and (iii) hybrid nomenclatural frameworks, and we discuss the advantages and disadvantages of each. We offer suggestions as to how readers can avoid B. cereus s.l. taxonomic ambiguities, regardless of the nomenclatural framework(s) they choose to employ. Finally, we discuss future directions and open problems in the B. cereus s.l. taxonomic realm, including those that cannot be solved by genomic approaches alone.
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Affiliation(s)
- Laura M Carroll
- Structural and Computational Biology Unit, EMBL, Heidelberg, Germany
| | - Rachel A Cheng
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Jasna Kovac
- Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania, USA
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Smith V, Josefsen M, Lindbäck T, Hegna IK, Finke S, Tourasse NJ, Nielsen-LeRoux C, Økstad OA, Fagerlund A. MogR Is a Ubiquitous Transcriptional Repressor Affecting Motility, Biofilm Formation and Virulence in Bacillus thuringiensis. Front Microbiol 2020; 11:610650. [PMID: 33424814 PMCID: PMC7793685 DOI: 10.3389/fmicb.2020.610650] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 12/01/2020] [Indexed: 12/16/2022] Open
Abstract
Flagellar motility is considered an important virulence factor in different pathogenic bacteria. In Listeria monocytogenes the transcriptional repressor MogR regulates motility in a temperature-dependent manner, directly repressing flagellar- and chemotaxis genes. The only other bacteria known to carry a mogR homolog are members of the Bacillus cereus group, which includes motile species such as B. cereus and Bacillus thuringiensis as well as the non-motile species Bacillus anthracis, Bacillus mycoides and Bacillus pseudomycoides. Furthermore, the main motility locus in B. cereus group bacteria, carrying the genes for flagellar synthesis, appears to be more closely related to L. monocytogenes than to Bacillus subtilis, which belongs to a separate phylogenetic group of Bacilli and does not carry a mogR ortholog. Here, we show that in B. thuringiensis, MogR overexpression results in non-motile cells devoid of flagella. Global gene expression profiling showed that 110 genes were differentially regulated by MogR overexpression, including flagellar motility genes, but also genes associated with virulence, stress response and biofilm lifestyle. Accordingly, phenotypic assays showed that MogR also affects cytotoxicity and biofilm formation in B. thuringiensis. Overexpression of a MogR variant mutated in two amino acids within the putative DNA binding domain restored phenotypes to those of an empty vector control. In accordance, introduction of these mutations resulted in complete loss in MogR binding to its candidate flagellar locus target site in vitro. In contrast to L. monocytogenes, MogR appears to be regulated in a growth-phase dependent and temperature-independent manner in B. thuringiensis 407. Interestingly, mogR was found to be conserved also in non-motile B. cereus group species such as B. mycoides and B. pseudomycoides, which both carry major gene deletions in the flagellar motility locus and where in B. pseudomycoides mogR is the only gene retained. Furthermore, mogR is expressed in non-motile B. anthracis. Altogether this provides indications of an expanded set of functions for MogR in B. cereus group species, beyond motility regulation. In conclusion, MogR constitutes a novel B. thuringiensis pleiotropic transcriptional regulator, acting as a repressor of motility genes, and affecting the expression of a variety of additional genes involved in biofilm formation and virulence.
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Affiliation(s)
- Veronika Smith
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
- Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Malin Josefsen
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Toril Lindbäck
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, Oslo, Norway
| | - Ida K Hegna
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Sarah Finke
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
- Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Nicolas J Tourasse
- CNRS, INSERM, ARNA, UMR 5320, U1212, University of Bordeaux, Bordeaux, France
| | | | - Ole Andreas Økstad
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
- Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Annette Fagerlund
- Laboratory for Microbial Dynamics (LaMDa), Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, Oslo, Norway
- Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Ås, Norway
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TaqMan Assays for Simultaneous Detection of Bacillus anthracis and Bacillus cereus biovar anthracis. Pathogens 2020; 9:pathogens9121074. [PMID: 33371332 PMCID: PMC7767396 DOI: 10.3390/pathogens9121074] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/12/2020] [Accepted: 12/16/2020] [Indexed: 11/22/2022] Open
Abstract
Anthrax is a worldwide zoonotic disease caused by the spore-forming bacterium Bacillus anthracis. Primarily a disease of herbivores, human infections often result from direct contact with contaminated animal products (cutaneous and inhalational anthrax) or through consumption of infected meat (gastrointestinal anthrax). The genetic near neighbor, Bacillus cereus biovar anthracis (Bcbva), causes an anthrax-like illness in the wildlife and livestock of west and central Africa due to the presence and expression of B. anthracis-specific virulence factors in this background. While Bcbva infections have not been reported in humans, a recent seroprevalence study detected Bcbva antibodies in the rural population around Taï National Park. This work describes the development of new TaqMan multiplex PCRs for the simultaneous detection of B. anthracis and Bcbva. The assays are designed to amplify Ba-1, capB, and lef markers in B. anthracis and genomic island IV (GI4), capB, and lef in Bcbva. Our assays allow for the rapid discrimination of B. anthracis and Bcbva and will provide insights into the molecular epidemiology of these two important pathogens that share an overlapping geographical range in west and central Africa.
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Attieh Z, Mouawad C, Rejasse A, Jehanno I, Perchat S, Hegna IK, Økstad OA, Kallassy Awad M, Sanchis-Borja V, El Chamy L. The fliK Gene Is Required for the Resistance of Bacillus thuringiensis to Antimicrobial Peptides and Virulence in Drosophila melanogaster. Front Microbiol 2020; 11:611220. [PMID: 33391240 PMCID: PMC7775485 DOI: 10.3389/fmicb.2020.611220] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/18/2020] [Indexed: 11/13/2022] Open
Abstract
Antimicrobial peptides (AMPs) are essential effectors of the host innate immune system and they represent promising molecules for the treatment of multidrug resistant microbes. A better understanding of microbial resistance to these defense peptides is thus prerequisite for the control of infectious diseases. Here, using a random mutagenesis approach, we identify the fliK gene, encoding an internal molecular ruler that controls flagella hook length, as an essential element for Bacillus thuringiensis resistance to AMPs in Drosophila. Unlike its parental strain, that is highly virulent to both wild-type and AMPs deficient mutant flies, the fliK deletion mutant is only lethal to the latter's. In agreement with its conserved function, the fliK mutant is non-flagellated and exhibits highly compromised motility. However, comparative analysis of the fliK mutant phenotype to that of a fla mutant, in which the genes encoding flagella proteins are interrupted, indicate that B. thuringiensis FliK-dependent resistance to AMPs is independent of flagella assembly. As a whole, our results identify FliK as an essential determinant for B. thuringiensis virulence in Drosophila and provide new insights on the mechanisms underlying bacteria resistance to AMPs.
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Affiliation(s)
- Zaynoun Attieh
- UR-EGP, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Carine Mouawad
- UR-EGP, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
| | - Agnès Rejasse
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Isabelle Jehanno
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Stéphane Perchat
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Ida K. Hegna
- Department of Pharmacy, Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Ole A. Økstad
- Department of Pharmacy, Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | | | - Vincent Sanchis-Borja
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Laure El Chamy
- UR-EGP, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
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Upadhyay L, Chaturvedi VK, Gupta PK, Sunita SC, Sumithra TG, Prusty BR, Yadav AK. Development of a visible loop mediated isothermal amplification assay for rapid detection of Bacillus anthracis. Biologicals 2020; 69:59-65. [PMID: 33309531 DOI: 10.1016/j.biologicals.2020.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 11/09/2020] [Accepted: 11/17/2020] [Indexed: 11/30/2022] Open
Abstract
Distressing effects on animal and human health with lethal progression, being used as bioweapon and shared features with non-pathogenic bacteria demands sensitive, specific, safe, cost effective and rapid detection methods for anthrax causing organisms. Conventional microbiology based diagnostics for anthrax are time consuming and need sophisticated equipment, while molecular diagnostics require less time and labor. The Loop mediated isothermal amplification assay (LAMP) is rapid, sensitive and specific assay and requires no specialized equipment. In the present study, we developed a LAMP assay for rapid as well as specific detection of Bacillus anthracis. The optimized assay produced positive results with the Sterne strain and one field isolate of B. anthracis and, negative results with other bacteria of the same and different genera within 2 h. Sensitivity was 500 fg of total DNA of B. anthracis, which was 100 times more sensitive than conventional PCR. The present study also demonstrated that the simple method of total DNA extraction by repeated boiling and freezing will not adversely affect the LAMP results. In conclusion, the optimized LAMP assay is a promising tool for the specific, sensitive, less time-consuming diagnosis for anthrax causing bacteria and also, for detecting the virulence of suspected B. anthracis cultures.
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Affiliation(s)
- L Upadhyay
- Division of Biological Products, ICAR-Indian Veterinary Research Institute, Izatnagar, 243122, Uttar Pradesh, India.
| | - V K Chaturvedi
- Division of Biological Products, ICAR-Indian Veterinary Research Institute, Izatnagar, 243122, Uttar Pradesh, India.
| | - P K Gupta
- Division of Biotechnology, ICAR-Indian Veterinary Research Institute, Izatnagar, 243122, Uttar Pradesh, India.
| | - S C Sunita
- Division of Biological Products, ICAR-Indian Veterinary Research Institute, Izatnagar, 243122, Uttar Pradesh, India
| | - T G Sumithra
- ICAR-Central Marine Fisheries Research Institute, Kochi, 682 018, India.
| | - B R Prusty
- Division of Biotechnology, ICAR-Indian Veterinary Research Institute, Izatnagar, 243122, Uttar Pradesh, India
| | - A K Yadav
- ICAR-National Research Centre on Pig, Rani, Guwahati, 781131, Assam, India.
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Complete Genome Sequence of an Environmental Bacillus cereus Isolate Belonging to the Bacillus anthracis Clade. Microbiol Resour Announc 2020; 9:9/47/e00917-20. [PMID: 33214297 PMCID: PMC7679090 DOI: 10.1128/mra.00917-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We report here the complete genome sequence of a Bacillus cereus isolate identified in a soil sample from Namibia. This isolate is closely related to the B. anthracis clade. While the plasmids (500 and 12 kb) carry no detectable B. anthracis virulence gene, the large plasmid shares a 50-kb continuous region similar to plasmid pXO1. We report here the complete genome sequence of a Bacillus cereus isolate identified in a soil sample from Namibia. This isolate is closely related to the B. anthracis clade. While the plasmids (500 and 12 kb) carry no detectable B. anthracis virulence gene, the large plasmid shares a 50-kb continuous region similar to plasmid pXO1.
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Jessberger N, Dietrich R, Granum PE, Märtlbauer E. The Bacillus cereus Food Infection as Multifactorial Process. Toxins (Basel) 2020; 12:E701. [PMID: 33167492 PMCID: PMC7694497 DOI: 10.3390/toxins12110701] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 02/06/2023] Open
Abstract
The ubiquitous soil bacterium Bacillus cereus presents major challenges to food safety. It is responsible for two types of food poisoning, the emetic form due to food intoxication and the diarrheal form emerging from food infections with enteropathogenic strains, also known as toxico-infections, which are the subject of this review. The diarrheal type of food poisoning emerges after production of enterotoxins by viable bacteria in the human intestine. Basically, the manifestation of the disease is, however, the result of a multifactorial process, including B. cereus prevalence and survival in different foods, survival of the stomach passage, spore germination, motility, adhesion, and finally enterotoxin production in the intestine. Moreover, all of these processes are influenced by the consumed foodstuffs as well as the intestinal microbiota which have, therefore, to be considered for a reliable prediction of the hazardous potential of contaminated foods. Current knowledge regarding these single aspects is summarized in this review aiming for risk-oriented diagnostics for enteropathogenic B. cereus.
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Affiliation(s)
- Nadja Jessberger
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
| | - Richard Dietrich
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
| | - Per Einar Granum
- Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, P.O. Box 5003 NMBU, 1432 Ås, Norway;
| | - Erwin Märtlbauer
- Department of Veterinary Sciences, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Schönleutnerstr. 8, 85764 Oberschleißheim, Germany; (R.D.); (E.M.)
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Carroll LM, Cheng RA, Kovac J. No Assembly Required: Using BTyper3 to Assess the Congruency of a Proposed Taxonomic Framework for the Bacillus cereus Group With Historical Typing Methods. Front Microbiol 2020; 11:580691. [PMID: 33072050 PMCID: PMC7536271 DOI: 10.3389/fmicb.2020.580691] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 08/25/2020] [Indexed: 12/19/2022] Open
Abstract
The Bacillus cereus group, also known as B. cereus sensu lato (s.l.), is a species complex comprising numerous closely related lineages, which vary in their ability to cause illness in humans and animals. The classification of B. cereus s.l. isolates into species-level taxonomic units is essential for facilitating communication between and among microbiologists, clinicians, public health officials, and industry professionals, but is not always straightforward. A recently proposed genomospecies-subspecies-biovar taxonomic framework aims to provide a standardized nomenclature for this species complex but relies heavily on whole-genome sequencing (WGS). It thus is unclear whether popular, low-cost typing methods (e.g., single- and multi-locus sequence typing) remain congruent with the proposed taxonomy. Here, we characterize 2,231 B. cereus s.l. genomes using a combination of in silico (i) average-nucleotide identity (ANI)-based genomospecies assignment, (ii) ANI-based subspecies assignment, (iii) seven-gene multi-locus sequence typing (MLST), (iv) single-locus panC group assignment, (v) rpoB allelic typing, and (vi) virulence factor detection. We show that sequence types (STs) assigned using MLST can be used for genomospecies assignment, and we provide a comprehensive list of ST/genomospecies associations. For panC group assignment, we show that an adjusted, eight-group framework is largely, albeit not perfectly, congruent with the proposed eight-genomospecies taxonomy, as panC alone may not distinguish (i) B. luti from Group II B. mosaicus and (ii) B. paramycoides from Group VI B. mycoides. We additionally provide a list of loci that capture the topology of the whole-genome B. cereus s.l. phylogeny that may be used in future sequence typing efforts. For researchers with access to WGS, MLST, and/or panC data, we showcase how our recently released software, BTyper3 (https://github.com/lmc297/BTyper3), can be used to assign B. cereus s.l. isolates to taxonomic units within this proposed framework with little-to-no user intervention or domain-specific knowledge of B. cereus s.l. taxonomy. We additionally outline a novel method for assigning B. cereus s.l. genomes to pseudo-gene flow units within proposed genomospecies. The results presented here highlight the backward-compatibility and accessibility of the recently proposed genomospecies-subspecies-biovar taxonomic framework and illustrate that WGS is not a necessity for microbiologists who want to use the proposed nomenclature effectively.
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Affiliation(s)
- Laura M. Carroll
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Rachel A. Cheng
- Department of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
| | - Jasna Kovac
- Department of Food Science, College of Agricultural Sciences, The Pennsylvania State University, University Park, PA, United States
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Alameh S, Bartolo G, O’Brien S, Henderson EA, Gonzalez LO, Hartmann S, Klimko CP, Shoe JL, Cote CK, Grill LK, Levitin A, Martchenko Shilman M. Anthrax toxin component, Protective Antigen, protects insects from bacterial infections. PLoS Pathog 2020; 16:e1008836. [PMID: 32866212 PMCID: PMC7458312 DOI: 10.1371/journal.ppat.1008836] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 07/24/2020] [Indexed: 01/23/2023] Open
Abstract
Anthrax is a major zoonotic disease of wildlife, and in places like West Africa, it can be caused by Bacillus anthracis in arid nonsylvatic savannahs, and by B. cereus biovar anthracis (Bcbva) in sylvatic rainforests. Bcbva-caused anthrax has been implicated in as much as 38% of mortality in rainforest ecosystems, where insects can enhance the transmission of anthrax-causing bacteria. While anthrax is well-characterized in mammals, its transmission by insects points to an unidentified anthrax-resistance mechanism in its vectors. In mammals, a secreted anthrax toxin component, 83 kDa Protective Antigen (PA83), binds to cell-surface receptors and is cleaved by furin into an evolutionary-conserved PA20 and a pore-forming PA63 subunits. We show that PA20 increases the resistance of Drosophila flies and Culex mosquitoes to bacterial challenges, without directly affecting the bacterial growth. We further show that the PA83 loop known to be cleaved by furin to release PA20 from PA63 is, in part, responsible for the PA20-mediated protection. We found that PA20 binds directly to the Toll activating peptidoglycan-recognition protein-SA (PGRP-SA) and that the Toll/NF-κB pathway is necessary for the PA20-mediated protection of infected flies. This effect of PA20 on innate immunity may also exist in mammals: we show that PA20 binds to human PGRP-SA ortholog. Moreover, the constitutive activity of Imd/NF-κB pathway in MAPKK Dsor1 mutant flies is sufficient to confer the protection from bacterial infections in a manner that is independent of PA20 treatment. Lastly, Clostridium septicum alpha toxin protects flies from anthrax-causing bacteria, showing that other pathogens may help insects resist anthrax. The mechanism of anthrax resistance in insects has direct implications on insect-mediated anthrax transmission for wildlife management, and with potential for applications, such as reducing the sensitivity of pollinating insects to bacterial pathogens.
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Affiliation(s)
- Saleem Alameh
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, California, United States of America
| | - Gloria Bartolo
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, California, United States of America
| | - Summer O’Brien
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, California, United States of America
| | - Elizabeth A. Henderson
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, California, United States of America
| | - Leandra O. Gonzalez
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, California, United States of America
| | - Stella Hartmann
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, California, United States of America
| | - Christopher P. Klimko
- Bacteriology Division, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, United States of America
| | - Jennifer L. Shoe
- Bacteriology Division, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, United States of America
| | - Christopher K. Cote
- Bacteriology Division, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, Maryland, United States of America
| | - Laurence K. Grill
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, California, United States of America
| | - Anastasia Levitin
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, California, United States of America
- * E-mail: (AL); (MMS)
| | - Mikhail Martchenko Shilman
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, California, United States of America
- * E-mail: (AL); (MMS)
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36
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Baldwin VM. You Can't B. cereus - A Review of Bacillus cereus Strains That Cause Anthrax-Like Disease. Front Microbiol 2020; 11:1731. [PMID: 32973690 PMCID: PMC7468541 DOI: 10.3389/fmicb.2020.01731] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 07/02/2020] [Indexed: 12/15/2022] Open
Abstract
Emerging strains of Bacillus cereus, traditionally considered a self-limiting foodborne pathogen, have been associated with anthrax-like disease in mammals, including humans. The strains have emerged by divergent evolution and, as exchange of genetic material in the Bacillus genus occurs naturally, it is possible that further isolates will be identified in the future. The strains vary in their genotypes and phenotypes, combining traits of both B. cereus and B. anthracis species. Cases of anthrax-like disease associated with these strains result in similar symptoms and mortality rates as those caused by B. anthracis. The strains are susceptible to frontline antibiotics used in the treatment of anthrax and existing vaccines provide protection in animal models. The emergence of these strains has reignited the debate surrounding classification of the B. cereus sensu lato group and serves as a reminder that the field of medical microbiology is constantly changing and remains an important and ongoing area of research.
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Hassim A, Lekota KE, van Dyk DS, Dekker EH, van Heerden H. A Unique Isolation of a Lytic Bacteriophage Infected Bacillus anthracis Isolate from Pafuri, South Africa. Microorganisms 2020; 8:microorganisms8060932. [PMID: 32575780 PMCID: PMC7356010 DOI: 10.3390/microorganisms8060932] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/04/2020] [Accepted: 06/11/2020] [Indexed: 11/24/2022] Open
Abstract
Bacillus anthracis is a soil-borne, Gram-positive endospore-forming bacterium and the causative agent of anthrax. It is enzootic in Pafuri, Kruger National Park in South Africa. The bacterium is amplified in a wild ungulate host, which then becomes a source of infection to the next host upon its death. The exact mechanisms involving the onset (index case) and termination of an outbreak are poorly understood, in part due to a paucity of information about the soil-based component of the bacterium’s lifecycle. In this study, we present the unique isolation of a dsDNA bacteriophage from a wildebeest carcass site suspected of having succumbed to anthrax. The aggressively lytic bacteriophage hampered the initial isolation of B. anthracis from samples collected at the carcass site. Classic bacteriologic methods were used to test the isolated phage on B. anthracis under different conditions to simulate deteriorating carcass conditions. Whole genome sequencing was employed to determine the relationship between the bacterium isolated on site and the bacteriophage-dubbed Bacillus phage Crookii. The 154,012 bp phage belongs to Myoviridae and groups closely with another African anthrax carcass-associated Bacillus phage WPh. Bacillus phage Crookii was lytic against B. cereus sensu lato group members but demonstrated a greater affinity for encapsulated B. anthracis at lower concentrations (<1 × 108 pfu) of bacteriophage. The unusual isolation of this bacteriophage demonstrates the phage’s role in decreasing the inoculum in the environment and impact on the life cycle of B. anthracis at a carcass site.
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Affiliation(s)
- Ayesha Hassim
- Department of Veterinary Tropical diseases, University of Pretoria, Faculty of Veterinary Science, Pretoria 0110, South Africa; (K.E.L); (H.v.H.)
- Correspondence: ; Tel.: +27-125-298-339
| | - Kgaugelo Edward Lekota
- Department of Veterinary Tropical diseases, University of Pretoria, Faculty of Veterinary Science, Pretoria 0110, South Africa; (K.E.L); (H.v.H.)
- Unit for Environmental Sciences and Management: Microbiology, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom 2520, South Africa
| | - David Schalk van Dyk
- Department of Agriculture Fisheries and Forestry, Office of the State Veterinarian, Skukuza 1350, South Africa; (D.S.v.D.); (E.H.D.)
| | - Edgar Henry Dekker
- Department of Agriculture Fisheries and Forestry, Office of the State Veterinarian, Skukuza 1350, South Africa; (D.S.v.D.); (E.H.D.)
| | - Henriette van Heerden
- Department of Veterinary Tropical diseases, University of Pretoria, Faculty of Veterinary Science, Pretoria 0110, South Africa; (K.E.L); (H.v.H.)
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Dupke S, Schubert G, Beudjé F, Barduhn A, Pauly M, Couacy-Hymann E, Grunow R, Akoua-Koffi C, Leendertz FH, Klee SR. Serological evidence for human exposure to Bacillus cereus biovar anthracis in the villages around Taï National Park, Côte d'Ivoire. PLoS Negl Trop Dis 2020; 14:e0008292. [PMID: 32407387 PMCID: PMC7224451 DOI: 10.1371/journal.pntd.0008292] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/14/2020] [Indexed: 02/06/2023] Open
Abstract
Bacillus cereus biovar anthracis (Bcbva) is an untypical anthrax-causing pathogen responsible for high wildlife mortality in Taï National Park (TNP), Côte d’Ivoire. However, nothing is known about its effect on the rural population living in the region bordering TNP. Contact to bushmeat is a known risk factor for exposure to a variety of zoonotic pathogens, but no human infections with Bcbva were noted so far. Therefore, we performed a retrospective seroprevalence analysis with sera from 1,386 study volunteers. We used assays which detect antibodies against the protective antigen PA, which is synthesized by both Bcbva and classic B. anthracis, and against the recently described antigen pXO2-60, a 35-kDa protein only produced by Bcbva. We found a high seroprevalence (22.37%) of antibodies against PA, and approximately half of those sera (10.46%) were also positive for the Bcbva-specific antigen pXO2-60. All sera negative for PA were also negative for antibodies against pXO2-60, confirming specificity and suitability of the PA/pXO2-60 combined serological assay. The fact that a large fraction of sera was positive for PA but negative for pXO2-60 can most likely be explained by lower immunogenicity of pXO2-60, but exposure to classic B. anthracis cannot be excluded. As only Bcbva has been detected in the TNP area so far, exposure to Bcbva can be suspected from the presence of antibodies against PA alone. In a questionnaire, most study participants reported contact to bushmeat and livestock carcasses. Unfortunately, risk factor analysis indicated that neither animal contacts, sex, age, nor country of origin were significant predictors of Bcbva seroprevalence. Nevertheless, our study added to an assessment of the distribution of Bcbva and its impact on the human population, and our data can serve to raise awareness of anthrax in the affected regions. Anthrax is a zoonotic disease transmitted from animals to humans and normally caused by B. anthracis mainly in savanna regions. However, untypical bacteria named Bacillus cereus biovar anthracis (Bcbva) were detected in a variety of wild animals in the rain forest region of the Taï National Park (TNP) in Côte d’Ivoire. No anthrax infections in humans living in the region around TNP were reported until now. Therefore, we assessed exposure to the pathogen by analysis of sera from human volunteers for the presence of antibodies against the protective antigen (PA), which is produced by B. anthracis and Bcbva, and against the Bcbva-specific protein pXO2-60. We found antibodies against PA in more than 20% of sera from humans living in the TNP region, and around 10% possessed also antibodies against pXO2-60, confirming exposure to Bcbva. As only Bcbva, but not classic B. anthracis was found in TNP, we assume that the majority of humans had contact with Bcbva and that pXO2-60 is less immunogenic than PA. Although most people reported animal contacts, there was no statistically significant correlation with the presence of antibodies against Bcbva. Nevertheless, our study confirmed that Bcbva represents a danger for humans living in the affected area.
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Affiliation(s)
- Susann Dupke
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens, ZBS 2: Highly Pathogenic Microorganisms, Berlin, Germany
| | - Grit Schubert
- Robert Koch Institute, P3: Epidemiology of Highly Pathogenic Microorganisms, Berlin, Germany
| | - Félicité Beudjé
- Laboratoire National d’Appui au Développement Agricole/Laboratoire central de Pathologie Animale, Bingerville, Côte d’Ivoire
| | - Anne Barduhn
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens, ZBS 2: Highly Pathogenic Microorganisms, Berlin, Germany
| | - Maude Pauly
- Robert Koch Institute, P3: Epidemiology of Highly Pathogenic Microorganisms, Berlin, Germany
| | - Emmanuel Couacy-Hymann
- Laboratoire National d’Appui au Développement Agricole/Laboratoire central de Pathologie Animale, Bingerville, Côte d’Ivoire
| | - Roland Grunow
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens, ZBS 2: Highly Pathogenic Microorganisms, Berlin, Germany
| | - Chantal Akoua-Koffi
- Centre de Recherche pour le Développement, Université Alassane Ouattara, Bouaké, Côte d’Ivoire
| | - Fabian H. Leendertz
- Robert Koch Institute, P3: Epidemiology of Highly Pathogenic Microorganisms, Berlin, Germany
- * E-mail:
| | - Silke R. Klee
- Robert Koch Institute, Centre for Biological Threats and Special Pathogens, ZBS 2: Highly Pathogenic Microorganisms, Berlin, Germany
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Phylogenetic Analysis of Bacillus cereus sensu lato Isolates from Commercial Bee Pollen Using tRNA Cys-PCR. Microorganisms 2020; 8:microorganisms8040524. [PMID: 32268545 PMCID: PMC7232370 DOI: 10.3390/microorganisms8040524] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 03/25/2020] [Accepted: 04/03/2020] [Indexed: 01/06/2023] Open
Abstract
Endospore-forming bacteria related to the Bacillus cereus group produce toxins that cause illnesses in organisms from invertebrates to mammals, including foodborne illnesses in humans. As commercial bee pollen can be contaminated with these bacteria, a comprehensive microbiological risk assessment of commercial bee pollen must be incorporated into the relevant regulatory requirements, including those that apply in Mexico. To facilitate detection of members of this group of bacteria, we have developed a PCR strategy that is based on the amplification of the single-copy tRNACys gene and specific genes associated with tRNACys to detect Bacillus cereus sensu lato (B. cereus s.l.). This tRNACys-PCR-based approach was used to examine commercial bee pollen for endospore-forming bacteria. Our analysis revealed that 3% of the endospore-forming colonies isolated from a commercial source of bee pollen were related to B. cereus s.l., and this result was corroborated by phylogenetic analysis, bacterial identification via MALDI-TOF MS, and detection of enterotoxin genes encoding the HBL and NHE complexes. The results show that the isolated colonies are closely related phylogenetically to B. cereus, B. thuringiensis, and B. bombysepticus. Our results indicate that the tRNACys-PCR, combined with other molecular tools, will be a useful approach for identifying B. cereus s.l. and will assist in controlling the spread of potential pathogens.
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Li S, Ma Q, Chen H, Liu Y, Yao G, Tang G, Wang D. Epidemiological Investigation and Etiological Analysis of a Cutaneous Anthrax Epidemic Caused by Butchering Sick Cattle in Guizhou, China. Front Public Health 2020; 8:65. [PMID: 32269982 PMCID: PMC7109284 DOI: 10.3389/fpubh.2020.00065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 02/20/2020] [Indexed: 11/13/2022] Open
Abstract
A suspected human cutaneous anthrax epidemic caused by butchering sick cattle occurred in Zhijin County of Guizhou Province, Southwest of China, in 2016. Epidemiological investigation and etiological analysis were performed to provide a scientific basis for the source tracking of the epidemic. The epidemic was epidemiologically investigated, and skin blister samples collected from patients and soil samples collected from the butchering spots were used for Bacillus anthracis isolation. The suspicious B. anthracis isolates were identified using conventional methods and PCR, followed by genotyping using multiple-locus variable-number tandem repeats (VNTRs) analysis (MLVA-15) and canonical single-nucleotide polymorphism (canSNP). The genetic relationship of epidemic strains and isolates collected from other regions was analyzed. Epidemiological investigation results showed that the patients may be infected by B. anthracis during butchering sick cattle. Two suspected B. anthracis strains were isolated from blood samples and blister fluids, respectively. Conventional methods identified the two suspected isolates as B. anthracis, while PCR results showed that anti-protective antigen (PA) and capsule (CAP) gene were positive in the two isolates. MLVA-15 showed that the MLVA profiles of the two isolates were 9-20-12-53-16-2-8-8-8-4-4-4-4-10-4, which is different from the MLVA profiles of representative strains from other regions. CanSNP analysis showed that the two strains belonged to cluster A.Br.001/002. Clustering analysis and minimum spanning tree (MST) demonstrated that the two isolates were clustered with strains previously isolated from Guizhou Province. The results indicated that B. anthracis was the pathogen for this epidemic, and the patients were infected during butchering the sick. The genetic characteristics and the relationship of the B. anthracis isolates to strains from other regions indicated that the epidemic was a local occurrence.
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Affiliation(s)
- Shijun Li
- Laboratory of Bacterial Disease, Experiment Center, Guizhou Provincial Center for Disease Control and Prevention, Guiyang, China
| | - Qing Ma
- Laboratory of Bacterial Disease, Experiment Center, Guizhou Provincial Center for Disease Control and Prevention, Guiyang, China
| | - Hong Chen
- Guiyang Centre for Animal Disease Control and Prevention, Guiyang, China
| | - Ying Liu
- Laboratory of Bacterial Disease, Experiment Center, Guizhou Provincial Center for Disease Control and Prevention, Guiyang, China
| | - Guanghai Yao
- Guizhou Provincial Center for Disease Control and Prevention, Institute for Communicable Disease Control and Prevention, Guiyang, China
| | - Guangpeng Tang
- Guizhou Provincial Center for Disease Control and Prevention, Institute for Communicable Disease Control and Prevention, Guiyang, China
| | - Dingming Wang
- Guizhou Provincial Center for Disease Control and Prevention, Institute for Communicable Disease Control and Prevention, Guiyang, China
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41
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Romero-Alvarez D, Peterson AT, Salzer JS, Pittiglio C, Shadomy S, Traxler R, Vieira AR, Bower WA, Walke H, Campbell LP. Potential distributions of Bacillus anthracis and Bacillus cereus biovar anthracis causing anthrax in Africa. PLoS Negl Trop Dis 2020; 14:e0008131. [PMID: 32150557 PMCID: PMC7082064 DOI: 10.1371/journal.pntd.0008131] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 03/19/2020] [Accepted: 02/11/2020] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Bacillus cereus biovar anthracis (Bcbva) is an emergent bacterium closely related to Bacillus anthracis, the etiological agent of anthrax. The latter has a worldwide distribution and usually causes infectious disease in mammals associated with savanna ecosystems. Bcbva was identified in humid tropical forests of Côte d'Ivoire in 2001. Here, we characterize the potential geographic distributions of Bcbva in West Africa and B. anthracis in sub-Saharan Africa using an ecological niche modeling approach. METHODOLOGY/PRINCIPAL FINDINGS Georeferenced occurrence data for B. anthracis and Bcbva were obtained from public data repositories and the scientific literature. Combinations of temperature, humidity, vegetation greenness, and soils values served as environmental variables in model calibrations. To predict the potential distribution of suitable environments for each pathogen across the study region, parameter values derived from the median of 10 replicates of the best-performing model for each pathogen were used. We found suitable environments predicted for B. anthracis across areas of confirmed and suspected anthrax activity in sub-Saharan Africa, including an east-west corridor from Ethiopia to Sierra Leone in the Sahel region and multiple areas in eastern, central, and southern Africa. The study area for Bcbva was restricted to West and Central Africa to reflect areas that have likely been accessible to Bcbva by dispersal. Model predicted values indicated potential suitable environments within humid forested environments. Background similarity tests in geographic space indicated statistical support to reject the null hypothesis of similarity when comparing environments associated with B. anthracis to those of Bcbva and when comparing humidity values and soils values individually. We failed to reject the null hypothesis of similarity when comparing environments associated with Bcbva to those of B. anthracis, suggesting that additional investigation is needed to provide a more robust characterization of the Bcbva niche. CONCLUSIONS/SIGNIFICANCE This study represents the first time that the environmental and geographic distribution of Bcbva has been mapped. We document likely differences in ecological niche-and consequently in geographic distribution-between Bcbva and typical B. anthracis, and areas of possible co-occurrence between the two. We provide information crucial to guiding and improving monitoring efforts focused on these pathogens.
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Affiliation(s)
- Daniel Romero-Alvarez
- Department of Ecology & Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, Kansas, United States of America
| | - A. Townsend Peterson
- Department of Ecology & Evolutionary Biology and Biodiversity Institute, University of Kansas, Lawrence, Kansas, United States of America
| | - Johanna S. Salzer
- Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Claudia Pittiglio
- Food and Agriculture Organization of the United Nations, Animal Health Service, Animal Production and Health Division, Rome, Italy
| | - Sean Shadomy
- Food and Agriculture Organization of the United Nations, Animal Health Service, Animal Production and Health Division, Rome, Italy
- One Health Office, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Rita Traxler
- Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Antonio R. Vieira
- Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - William A. Bower
- Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Henry Walke
- Bacterial Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Lindsay P. Campbell
- Florida Medical Entomology Laboratory, Department of Entomology and Nematology, IFAS | University of Florida, Vero Beach, Florida, United States of America
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42
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Carroll LM, Wiedmann M, Kovac J. Proposal of a Taxonomic Nomenclature for the Bacillus cereus Group Which Reconciles Genomic Definitions of Bacterial Species with Clinical and Industrial Phenotypes. mBio 2020; 11:e00034-20. [PMID: 32098810 PMCID: PMC7042689 DOI: 10.1128/mbio.00034-20] [Citation(s) in RCA: 112] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 01/15/2020] [Indexed: 02/07/2023] Open
Abstract
The Bacillus cereus group comprises numerous closely related species, including bioterrorism agent B. anthracis, foodborne pathogen B. cereus, and biopesticide B. thuringiensis Differentiating organisms capable of causing illness or death from those used in industry is essential for risk assessment and outbreak preparedness. However, current species definitions facilitate species-phenotype incongruences, particularly when horizontally acquired genes are responsible for a phenotype. Using all publicly available B. cereus group genomes (n = 2,231), we show that current species definitions lead to overlapping genomospecies clusters, in which 66.2% of genomes belong to multiple genomospecies at a conventional 95 average nucleotide identity (ANI) genomospecies threshold. A genomospecies threshold of ≈92.5 ANI is shown to reflect a natural gap in genome similarity for the B. cereus group, and medoid genomes identified at this threshold are shown to yield resolvable genomospecies clusters with minimal overlap (six of 2,231 genomes assigned to multiple genomospecies; 0.269%). We thus propose a nomenclatural framework for the B. cereus group which accounts for (i) genomospecies using resolvable genomospecies clusters obtained at ≈92.5 ANI, (ii) established lineages of medical importance using a formal collection of subspecies names, and (iii) heterogeneity of clinically and industrially important phenotypes using a formalized and extended collection of biovar terms. We anticipate that the proposed nomenclature will remain interpretable to clinicians, without sacrificing genomic species definitions, which can in turn aid in pathogen surveillance; early detection of emerging, high-risk genotypes; and outbreak preparedness.IMPORTANCE Historical species definitions for many prokaryotes, including pathogens, have relied on phenotypic characteristics that are inconsistent with genome evolution. This scenario forces microbiologists and clinicians to face a tradeoff between taxonomic rigor and clinical interpretability. Using the Bacillus cereus group as a model, a conceptual framework for the taxonomic delineation of prokaryotes which reconciles genomic definitions of species with clinically and industrially relevant phenotypes is presented. The nomenclatural framework outlined here serves as a model for genomics-based bacterial taxonomy that moves beyond arbitrarily set genomospecies thresholds while maintaining congruence with phenotypes and historically important species names.
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Affiliation(s)
- Laura M Carroll
- Structural and Computational Biology Unit, EMBL, Heidelberg, Germany
| | - Martin Wiedmann
- Department of Food Science, Cornell University, Ithaca, New York, USA
| | - Jasna Kovac
- Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania, USA
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Zasada AA. Detection and Identification of Bacillus anthracis: From Conventional to Molecular Microbiology Methods. Microorganisms 2020; 8:E125. [PMID: 31963339 PMCID: PMC7023132 DOI: 10.3390/microorganisms8010125] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 01/13/2020] [Accepted: 01/15/2020] [Indexed: 02/06/2023] Open
Abstract
Rapid and reliable identification of Bacillus anthracis is of great importance, especially in the event of suspected deliberate release of anthrax spores. However, the identification of B. anthracis is challenging due to its high similarity to closely related species. Since Amerithrax in 2001, a lot of effort has been made to develop rapid methods for detection and identification of this microorganism with special focus on easy-to-perform rapid tests for first-line responders. This article presents an overview of the evolution of B. anthracis identification methods from the time of the first description of the microorganism until the present day.
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Affiliation(s)
- Aleksandra A Zasada
- Department of Sera and Vaccines Evaluation, National Institute of Public Health-National Institute of Hygiene, Chocimska 24, 00-791 Warsaw, Poland
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44
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Zincke D, Norris MH, Kurmanov B, Hadfield TL, Blackburn JK. Nucleotide polymorphism assay for the identification of west African group Bacillus anthracis: a lineage lacking anthrose. BMC Microbiol 2020; 20:6. [PMID: 31910798 PMCID: PMC6947953 DOI: 10.1186/s12866-019-1693-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 12/24/2019] [Indexed: 11/14/2022] Open
Abstract
Background The exosporium of the anthrax-causing Bacillus anthracis endospores display a tetrasaccharide composed of three rhamnose residues and an unusual sugar termed anthrose. Anthrose is a proposed potential target for immunotherapy and for specific detection of B. anthracis. Although originally thought to be ubiquitous in B. anthracis, previous work identified an anthrose negative strain from a West African lineage isolated from cattle that could represent a vaccine escape mutant. These strains carry genes required for expression of the anthrose operon but premature stop codons resulting from an 8-bp insertion in BAS3320 (an amino-transferase) and a C/T substitution at position 892 of the BAS3321 (a glycosyltransferase) gene prevent anthrose expression. Various other single nucleotide polymorphisms (SNPs) have been identified throughout the operon and could be the basis for detection of anthrose-deficient strains. Results In this study, we evaluated rhAmp genotypic assays based on SNPs at positions 892 and 1352 of BAS3321 for detection and differentiation of anthrose negative (Ant−) West African strains. Discrimination of anthrose negative West African isolates was achieved with as low as 100 fg of DNA, whereas consistent genotyping of Sterne necessitated at least 1 pg of DNA. Conclusions Screening of a global panel of B. anthracis isolates showed anthrose-expressing alleles are prevalent worldwide whereas the anthrose-deficient phenotype is to date limited to West Africa. Our work also revealed a third, previously unreported anthrose genotype in which the operon is altogether missing from a Polish B. anthracis isolate.
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Affiliation(s)
- Diansy Zincke
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL, USA.,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Michael H Norris
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL, USA.,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Berzhan Kurmanov
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL, USA.,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Ted L Hadfield
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL, USA.,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA
| | - Jason K Blackburn
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL, USA. .,Emerging Pathogens Institute, University of Florida, Gainesville, FL, USA.
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45
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Okutani A, Inoue S, Noguchi A, Kaku Y, Morikawa S. Whole-genome sequence-based comparison and profiling of virulence-associated genes of Bacillus cereus group isolates from diverse sources in Japan. BMC Microbiol 2019; 19:296. [PMID: 31842760 PMCID: PMC6915864 DOI: 10.1186/s12866-019-1678-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 12/09/2019] [Indexed: 02/07/2023] Open
Abstract
Background The complete genome sequences of 44 Bacillus cereus group isolates collected from diverse sources in Japan were analyzed to determine their genetic backgrounds and diversity levels in Japan. Multilocus sequence typing (MLST) and core-genome single-nucleotide polymorphism (SNP) typing data from whole-genome sequences were analyzed to determine genetic diversity levels. Virulence-associated gene profiles were also used to evaluate the genetic backgrounds and relationships among the isolates. Results The 44 B. cereus group isolates, including soil- and animal-derived isolates and isolates recovered from hospitalized patients and food poisoning cases, were genotyped by MLST and core-genome SNP typing. Genetic variation among the isolates was identified by the MLST and core-genome SNP phylogeny comparison against reference strains from countries outside of Japan. Exploratory principal component analysis and nonmetric multidimensional scaling (NMDS) analyses were used to assess the genetic similarities among the isolates using gene presence and absence information and isolate origins as the metadata. A significant correlation was seen between the principal components and the presence of genes encoding hemolysin BL and emetic genetic determinants in B. cereus, and the capsule proteins in B. anthracis. NMDS showed that the cluster of soil isolates overlapped with the cluster comprising animal-derived and clinical isolates. Conclusions Molecular and epidemiological analyses of B. cereus group isolates in Japan suggest that the soil- and animal-derived bacteria from our study are not a significant risk to human health. However, because several of the clinical isolates share close genetic relationships with the environmental isolates, both molecular and epidemiological surveillance studies could be used effectively to estimate virulence in these important pathogens.
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Affiliation(s)
- Akiko Okutani
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan.
| | - Satoshi Inoue
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan
| | - Akira Noguchi
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan
| | - Yoshihiro Kaku
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan
| | - Shigeru Morikawa
- Department of Veterinary Science, National Institute of Infectious Diseases, Tokyo, Japan.,Faculty of Veterinary Medicine, Okayama University of Science, Imabari, Ehime, Japan
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Fan C, Li Y, Liu P, Mu F, Xie Z, Lu R, Qi Y, Wang B, Jin C. Characteristics of airborne opportunistic pathogenic bacteria during autumn and winter in Xi'an, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 672:834-845. [PMID: 30978545 DOI: 10.1016/j.scitotenv.2019.03.412] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 03/25/2019] [Accepted: 03/26/2019] [Indexed: 05/23/2023]
Abstract
Bacteria are ubiquitous throughout the earth's lower atmosphere. Bacteria, especially pathogenic bacteria, play an important role in human health. The diversity, composition, and dynamics of airborne bacteria has been widely studied; however, the characteristics of pathogenic bacteria remain poorly understood. In this study, a high throughput sequencing method was used to explore the airborne opportunistic pathogenic bacteria during autumn and winter in Xi'an, China. An aggregated boosted tree (ABT) was developed to determine the relative influence of environmental factors on the proportions of opportunistic pathogenic bacteria. Results showed that significantly more opportunistic pathogenic bacteria were found in winter than in autumn, and more opportunistic pathogenic bacteria were found in fine particulate matters (<2.5 μm) than in PM10 (<10 μm). However, the composition of opportunistic pathogenic bacteria varied in autumn and winter. PM was the main factor affecting the proportions of opportunistic pathogenic bacteria, and air contaminants (PM, sulfur dioxide, nitrogen oxide, carbon monoxide, and ozone) influenced the proportion of opportunistic pathogenic bacteria more than meteorological factors (relative humidity, temperature, and wind speed). Different factors may be responsible for the variances in opportunistic pathogenic bacterial communities in different seasons. This study may provide a reference to support the control of pathogenic bacteria in urban environments during haze events.
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Affiliation(s)
- Chunlan Fan
- School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Yanpeng Li
- School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China; Key Laboratory of Subsurface Hydrology and Ecology in Arid Areas, Ministry of Education, Xi'an 710054, PR China.
| | - Pengxia Liu
- School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Feifei Mu
- School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Zhengsheng Xie
- School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Rui Lu
- School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Yuzhen Qi
- School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Beibei Wang
- School of Environmental Science and Engineering, Chang'an University, Xi'an 710054, China
| | - Cheng Jin
- School of Architecture, Chang'an University, Xi'an 710054, China
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Nasko DJ, Koren S, Phillippy AM, Treangen TJ. RefSeq database growth influences the accuracy of k-mer-based lowest common ancestor species identification. Genome Biol 2018; 19:165. [PMID: 30373669 PMCID: PMC6206640 DOI: 10.1186/s13059-018-1554-6] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 10/01/2018] [Indexed: 12/05/2022] Open
Abstract
In order to determine the role of the database in taxonomic sequence classification, we examine the influence of the database over time on k-mer-based lowest common ancestor taxonomic classification. We present three major findings: the number of new species added to the NCBI RefSeq database greatly outpaces the number of new genera; as a result, more reads are classified with newer database versions, but fewer are classified at the species level; and Bayesian-based re-estimation mitigates this effect but struggles with novel genomes. These results suggest a need for new classification approaches specially adapted for large databases.
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Affiliation(s)
- Daniel J Nasko
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, MD, USA
| | - Sergey Koren
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, Bethesda, MD, USA
| | - Adam M Phillippy
- Genome Informatics Section, Computational and Statistical Genomics Branch, National Human Genome Research Institute, Bethesda, MD, USA
| | - Todd J Treangen
- Department of Computer Science, Rice University, Houston, TX, USA.
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Dupke S, Barduhn A, Franz T, Leendertz FH, Couacy-Hymann E, Grunow R, Klee SR. Analysis of a newly discovered antigen of Bacillus cereus biovar anthracis for its suitability in specific serological antibody testing. J Appl Microbiol 2018; 126:311-323. [PMID: 30253024 DOI: 10.1111/jam.14114] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/31/2018] [Accepted: 09/12/2018] [Indexed: 12/21/2022]
Abstract
AIMS The aim of this work was to identify a protein which can be used for specific detection of antibodies against Bacillus cereus biovar anthracis (Bcbva), an anthrax-causing pathogen that so far has been described in African rainforest areas. METHODS AND RESULTS Culture supernatants of Bcbva and classic Bacillus anthracis (Ba) were analysed by gel electrophoresis, and a 35-kDa protein secreted only by Bcbva and not Ba was detected. The protein was identified as pXO2-60 by mass spectrometry. Sequence analysis showed that Ba is unable to secrete this protein due to a premature stop codon in the sequence for the signal peptide. Immunization of five outbred mice with sterile bacterial culture supernatants of Bcbva revealed an immune response in ELISA against pXO2-60 (three mice positive, one borderline) and the protective antigen (PA; four mice). When supernatants of classic Ba were injected into mice or human sera from anthrax patients were analysed, only antibodies against PA were detected. CONCLUSIONS In combination with PA, the pXO2-60 protein can be used for the detection of antibodies specific against Bcbva and discriminating from Ba. SIGNIFICANCE AND IMPACT OF THE STUDY After further validation, serological assays based on pXO2-60 can be used to perform seroprevalence studies to determine the epidemiology of B. cereus bv anthracis in affected countries and assess its impact on the human population.
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Affiliation(s)
- S Dupke
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens (ZBS2), Berlin, Germany
| | - A Barduhn
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens (ZBS2), Berlin, Germany
| | - T Franz
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens (ZBS2), Berlin, Germany
| | - F H Leendertz
- Robert Koch-Institute, Epidemiology of Highly Pathogenic Microorganisms (P3), Berlin, Germany
| | - E Couacy-Hymann
- Laboratoire National d'Appui au Développement Agricole (LANADA), Laboratoire Central Vétérinaire de Bingerville (LCVB), Bingerville, Côte d'Ivoire
| | - R Grunow
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens (ZBS2), Berlin, Germany
| | - S R Klee
- Robert Koch-Institute, Centre for Biological Threats and Special Pathogens (ZBS2), Berlin, Germany
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Petit III RA, Hogan JM, Ezewudo MN, Joseph SJ, Read TD. Fine-scale differentiation between Bacillus anthracis and Bacillus cereus group signatures in metagenome shotgun data. PeerJ 2018; 6:e5515. [PMID: 30155371 PMCID: PMC6109372 DOI: 10.7717/peerj.5515] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 08/03/2018] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND It is possible to detect bacterial species in shotgun metagenome datasets through the presence of only a few sequence reads. However, false positive results can arise, as was the case in the initial findings of a recent New York City subway metagenome project. False positives are especially likely when two closely related are present in the same sample. Bacillus anthracis, the etiologic agent of anthrax, is a high-consequence pathogen that shares >99% average nucleotide identity with Bacillus cereus group (BCerG) genomes. Our goal was to create an analysis tool that used k-mers to detect B. anthracis, incorporating information about the coverage of BCerG in the metagenome sample. METHODS Using public complete genome sequence datasets, we identified a set of 31-mer signatures that differentiated B. anthracis from other members of the B. cereus group (BCerG), and another set which differentiated BCerG genomes (including B. anthracis) from other Bacillus strains. We also created a set of 31-mers for detecting the lethal factor gene, the key genetic diagnostic of the presence of anthrax-causing bacteria. We created synthetic sequence datasets based on existing genomes to test the accuracy of a k-mer based detection model. RESULTS We found 239,503 B. anthracis-specific 31-mers (the Ba31 set), 10,183 BCerG 31-mers (the BCerG31 set), and 2,617 lethal factor k-mers (the lef31 set). We showed that false positive B. anthracis k-mers-which arise from random sequencing errors-are observable at high genome coverages of B. cereus. We also showed that there is a "gray zone" below 0.184× coverage of the B. anthracis genome sequence, in which we cannot expect with high probability to identify lethal factor k-mers. We created a linear regression model to differentiate the presence of B. anthracis-like chromosomes from sequencing errors given the BCerG background coverage. We showed that while shotgun datasets from the New York City subway metagenome project had no matches to lef31 k-mers and hence were negative for B. anthracis, some samples showed evidence of strains very closely related to the pathogen. DISCUSSION This work shows how extensive libraries of complete genomes can be used to create organism-specific signatures to help interpret metagenomes. We contrast "specialist" approaches to metagenome analysis such as this work to "generalist" software that seeks to classify all organisms present in the sample and note the more general utility of a k-mer filter approach when taxonomic boundaries lack clarity or high levels of precision are required.
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Affiliation(s)
- Robert A. Petit III
- Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Atlanta, GA, United States of America
| | - James M. Hogan
- Queensland University of Technology, Brisbane, Australia
| | - Matthew N. Ezewudo
- Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Sandeep J. Joseph
- Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Atlanta, GA, United States of America
| | - Timothy D. Read
- Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Atlanta, GA, United States of America
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Scarff JM, Seldina YI, Vergis JM, Ventura CL, O’Brien AD. Expression and contribution to virulence of each polysaccharide capsule of Bacillus cereus strain G9241. PLoS One 2018; 13:e0202701. [PMID: 30133532 PMCID: PMC6105005 DOI: 10.1371/journal.pone.0202701] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 08/06/2018] [Indexed: 12/03/2022] Open
Abstract
Bacillus cereus strain G9241 was isolated from a patient with pneumonia who had an anthrax-like illness. Like Bacillus anthracis, the virulence of G9241 is dependent on two large plasmids. In G9241 those plasmids are pBCXO1 and pBC210. There is a multi-gene capsule locus on each of these virulence plasmids, and both capsules are produced by G9241 in vitro and in mice. The hasACB operon on pBCXO1 is responsible for production of a hyaluronic acid (HA) capsule. The locus on pBC210 encodes a putative tetrasaccharide (TS) capsule that assembles in a Wzy-dependent manner. We found that the pBC210 capsule locus is transcribed as two operons and identified the promoter regions responsible for transcription. We constructed isogenic mutants to assess the role of genes in the two TS capsule operons in production of the capsule. Spores of strains deficient in production of either the HA or TS capsule were inoculated subcutaneously or intranasally into A/J and C57BL/6 mice to determine the lethal dose 50% of each bacterial mutant by each route of infection. The loss of the HA capsule attenuated G9241 more than the loss of the TS capsule for both infection routes in both mouse strains. Overall, our data further characterize the unique TS capsule on pBC210 and demonstrate that the two capsules do not have the same impact on virulence of G9241.
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Affiliation(s)
- Jennifer M. Scarff
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America
| | - Yuliya I. Seldina
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America
| | - James M. Vergis
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America
| | - Christy L. Ventura
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America
| | - Alison D. O’Brien
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America
- * E-mail:
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