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Sun X, Qu S, Zhou F, Shi F, Wu Y, Gu L, Liu M, Bian Z, Shi L, Liu Z, Liu Y, Zen K. Monocytes serve as Shiga toxin carriers during the development of hemolytic uremic syndrome. Cell Mol Biol Lett 2025; 30:13. [PMID: 39871175 PMCID: PMC11773931 DOI: 10.1186/s11658-025-00689-8] [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: 07/23/2024] [Accepted: 01/08/2025] [Indexed: 01/29/2025] Open
Abstract
Shiga toxin (Stx)-induced hemolytic uremic syndrome (HUS) poses a life-threatening complication for which a definitive treatment remains elusive. To exert its cytotoxic effect on renal cells, Stx must be delivered from the infected intestines to the kidney. However, the mechanism underlying Stx delivery remains unclear. Here we pinpoint monocytes as the primary carriers responsible for transporting Stx2 to the renal region. Through single-cell sequencing analysis of Stx2-B-bound peripheral white blood cells sorted by flow cytometry, we observe that nearly all monocytes exhibit strong Stx2-B binding, whereas less than 10% of neutrophils are associated with Stx2-B, albeit with a lower affinity. Further examination of the single-cell dataset and cell binding assays suggest that monocytes likely bind to Stx2-B through the Toll-like receptor 4. Remarkably, Stx-laden monocytes demonstrate their ability to transport Stx2 to human renal glomerular endothelial cells (HRGEC), subsequently inducing apoptosis in HRGEC. In a mouse model of Stx1/2-positive EDL933 infection-induced HUS, the presence of Stx2-positive monocytes in peripheral blood and infiltrated kidney tissues was observed. Finally, depleting monocytes through the usage of a CD14 neutralizing antibody or blocking monocyte chemotaxis via inhibition of CCL2 notably mitigates kidney injury and dysfunction caused by lipopolysaccharide (LPS)/Stx2 treatment. Our findings unveil the pivotal role of monocytes in Stx delivery during STEC infection and offer a promising therapeutic approach for Stx-induced HUS.
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Affiliation(s)
- Xinlei Sun
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Gastroenterology, Drum Tower Hospital, Nanjing University Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Shuang Qu
- Geriatric Hospital of Nanjing Medical University, Nanjing, 210024, Jiangsu, China
| | - Fenglian Zhou
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Gastroenterology, Drum Tower Hospital, Nanjing University Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Fujie Shi
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Gastroenterology, Drum Tower Hospital, Nanjing University Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Yunfei Wu
- School of Life Science and Technology, China Pharmaceutical University, 639 Longmian Avenue, Nanjing, 211198, Jiangsu, China
| | - Lin Gu
- Jiangsu Provincial Central for Disease Prevention and Control, Nanjing, 210009, Jiangsu, China
| | - Minghui Liu
- School of Life Science and Technology, China Pharmaceutical University, 639 Longmian Avenue, Nanjing, 211198, Jiangsu, China
| | - Zhen Bian
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Gastroenterology, Drum Tower Hospital, Nanjing University Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Lei Shi
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Gastroenterology, Drum Tower Hospital, Nanjing University Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China
| | - Zhihong Liu
- National Clinical Research Center of Kidney Diseases, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, Jiangsu, China.
| | - Yuan Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Gastroenterology, Drum Tower Hospital, Nanjing University Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.
| | - Ke Zen
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Gastroenterology, Drum Tower Hospital, Nanjing University Medical School, Nanjing University, Nanjing, 210093, Jiangsu, China.
- Department of Emergency Medicine, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, 210093, China.
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Fang X, Miao S, Zhang Y, Chen Z, Lai Y, Yang Y, Cheng S, Fan S, Yang J, Zhang Y, Chen Z, Liu S. Green synthesis and characterization of an orally bioactive artemisinin-zinc nanoparticle with enhanced bactericidal activity. Colloids Surf B Biointerfaces 2024; 234:113660. [PMID: 38042107 DOI: 10.1016/j.colsurfb.2023.113660] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 10/19/2023] [Accepted: 11/19/2023] [Indexed: 12/04/2023]
Abstract
The occurrence of multidrug-resistant bacteria necessitates the development of new antibacterial agents. This study synthesized artemisinin-zinc nanoparticles (AZ NPs) using a simple green method and investigated their physicochemical properties, antibacterial activity, and oral biological activity. A spherical shape morphology of AZ NPs was observed by scanning and transmission electron microscopy, with a particle size of 73 ± 2.604 nm. Energy dispersive spectrometry analysis showed that the AZ NPs consisted mainly of Zn, C, N, and O elements. According to differential scanning calorimeter analysis, the AZ NPs were stable up to 450 °C. Fourier-transform infrared spectroscopy revealed that artemisinin successfully bound to zinc acetate. The AZ NPs showed antibacterial activity against Salmonella and Escherichia coli, with a minimum inhibitory concentration of 0.056 mg/mL for both and minimum bactericidal concentrations of 0.21 and 0.11 mg/mL, respectively. The mechanisms by which AZ NPs mediate membrane damage were revealed by the downregulation of gene expression, and potassium ion and protein leakage. In vivo safety trials of these drugs revealed low toxicity. After AZ NPs were administered to infected mice, the intestinal bacteria decreased significantly, liver and kidney function were restored, histopathological damage to the liver and spleen were reduced, and the expression of inflammatory cytokines decreased. Therefore, AZ NPs have the potential as an oral antibacterial agent and can be used in antibiotic development and in the pharmaceutical industry.
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Affiliation(s)
- Xue Fang
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China
| | - Shengnan Miao
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China
| | - Yan Zhang
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China
| | - Zhuo Chen
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China
| | - Yonghao Lai
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China
| | - Yumeng Yang
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China
| | - Siyuan Cheng
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China
| | - Shoudong Fan
- Dongwo Tongtai (Fengcheng) Bioengineering Co., Ltd, Dandong 118000, China
| | - Jiao Yang
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China
| | - Yi Zhang
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China.
| | - Zeliang Chen
- Key Laboratory of Livestock Infectious Diseases, Ministry of Education, Shenyang Agricultural University, Shenyang 110866, China; Laboratory of Ruminant Infectious Disease Prevention and Control (East), Ministry of Agriculture and Rural Affairs, Shenyang 110866, China.
| | - Shiwei Liu
- Department of Nephrology and Endocrinology, Wangjing Hospital, Chinese Academy of Chinese Medical Science, Beijing 100102, China.
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Ngoma NFN, Malahlela MN, Marufu MC, Cenci-Goga BT, Grispoldi L, Etter E, Kalake A, Karama M. Antimicrobial growth promoters approved in food-producing animals in South Africa induce shiga toxin-converting bacteriophages from Escherichia coli O157:H7. Gut Pathog 2023; 15:64. [PMID: 38057920 DOI: 10.1186/s13099-023-00590-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 11/23/2023] [Indexed: 12/08/2023] Open
Abstract
In this study, four antimicrobial growth promoters, including virginiamycin, josamycin, flavophospholipol, poly 2-propenal 2-propenoic acid and ultraviolet light, were tested for their capacity to induce stx-bacteriophages in 47 Shiga toxin-producing E. coli O157:H7 isolates. Induced bacteriophages were characterized for shiga toxin subtypes and structural genes by PCR, DNA restriction fragment length polymorphisms (RFLP) and morphological features by electron microscopy. Bacteriophages were induced from 72.3% (34/47) of the STEC O157:H7 isolates tested. Bacteriophage induction rates per induction method were as follows: ultraviolet light, 53.2% (25/47); poly 2-propenal 2-propenoic acid, 42.6% (20/47); virginiamycin, 34.0% (16/47); josamycin, 34.0% (16/47); and flavophospholipol, 29.8% (14/47). A total of 98 bacteriophages were isolated, but only 59 were digestible by NdeI, revealing 40 RFLP profiles which could be subdivided in 12 phylogenetic subgroups. Among the 98 bacteriophages, stx2a, stx2c and stx2d were present in 85.7%, 94.9% and 36.7% of bacteriophages, respectively. The Q, P, CIII, N1, N2 and IS1203 genes were found in 96.9%, 82.7%, 69.4%, 40.8%, 60.2% and 73.5% of the samples, respectively. Electron microscopy revealed four main representative morphologies which included three bacteriophages which all had long tails but different head morphologies: long hexagonal head, oval/oblong head and oval/circular head, and one bacteriophage with an icosahedral/hexagonal head with a short thick contractile tail. This study demonstrated that virginiamycin, josamycin, flavophospholipol and poly 2-propenal 2-propenoic acid induce genetically and morphologically diverse free stx-converting bacteriophages from STEC O157:H7. The possibility that these antimicrobial growth promoters may induce bacteriophages in vivo in animals and human hosts is a public health concern. Policies aimed at minimizing or banning the use of antimicrobial growth promoters should be promoted and implemented in countries where these compounds are still in use in animal agriculture.
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Affiliation(s)
- Nomonde F N Ngoma
- Department of Paraclinical Sciences, Faculty of Veterinary Science, Veterinary Public Health Section, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Mogaugedi N Malahlela
- Department of Paraclinical Sciences, Faculty of Veterinary Science, Veterinary Public Health Section, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Munyaradzi C Marufu
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa
| | - Beniamino T Cenci-Goga
- Department of Paraclinical Sciences, Faculty of Veterinary Science, Veterinary Public Health Section, University of Pretoria, Onderstepoort, 0110, South Africa
- Departimento di Medicina Veterinaria, Laboratorio di Ispezione Degli Alimenti di Origine Animale, University of Perugia, Perugia, 06126, Italy
| | - Luca Grispoldi
- Departimento di Medicina Veterinaria, Laboratorio di Ispezione Degli Alimenti di Origine Animale, University of Perugia, Perugia, 06126, Italy
| | - Eric Etter
- CIRAD, UMR ASTRE, Petit-Bourg, F-97170, France
- ASTRE, Université de Montpellier, CIRAD INRAE, Montpellier, France
| | - Alan Kalake
- Gauteng Department of Agriculture and Rural Development, Johannesburg, 2001, South Africa
| | - Musafiri Karama
- Department of Paraclinical Sciences, Faculty of Veterinary Science, Veterinary Public Health Section, University of Pretoria, Onderstepoort, 0110, South Africa.
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Pascal SB, Lorenzo R, Farías MVN, Rossen JW, Lucchesi PMA, Krüger A. Characterization of the flanking region of the Shiga toxin operon in Stx2a bacteriophages reveals a diversity of the NanS-p sialate O-acetylesterase gene. AIMS Microbiol 2023; 9:570-590. [PMID: 37649799 PMCID: PMC10462455 DOI: 10.3934/microbiol.2023030] [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: 06/05/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 09/01/2023] Open
Abstract
Shiga toxin-producing E. coli (STEC) are diarrheagenic strains that can cause bloody diarrhea and hemolytic-uremic syndrome. Their main virulence factor, the Shiga toxin (Stx), is encoded by phages integrated into the bacterial chromosome. Stx phages are widely diverse and carry many genes with limited or unknown function. As the toxin subtype Stx2a is associated with highly pathogenic strains, this study was mainly focused on the characterization of the stx flanking region of Stx2a phages. Of particular interest was a sialate O-acetylesterase (NanS-p), which has been described previously to be encoded downstream stx in some phage genomes and may confer a growth advantage for STEC. Complete DNA sequences of Stx2a phages and prophages were retrieved from the GenBank database, and the genomic regions from anti-terminator Q to holin S genes were bioinformatically analyzed. Predicted NanSp sequences from phages encoding other Stx subtypes were also studied. Additionally, expression of nanS-p was quantified by qPCR in strains selected from our laboratory collection. The analysis of Stx2a phage genomes showed that all carried the Q, stx2a, nanS-p and S genes, but with allele diversity and other sequence differences. In particular, sequence differences were detected in each of the three domains of NanS-p esterases encoded by Stx2a phages and other Stx phages; however, nanS-p was not identified in the Stx2e, Stx2f and Stx2g phages analyzed. The expression of nanS-p increased in most stx2a-positive strains under phage inducing conditions, as was previously shown for stx2a. As the present work showed diversity at the Q-S region among Stx phages, and particularly in the encoded NanS-p enzyme, future studies will be necessary to evaluate if NanS-p variants differ in their activity and to assess the impact of the absence of nanS-p in certain Stx phages.
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Affiliation(s)
- Stefanía B. Pascal
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, CISAPA, Tandil, Buenos Aires, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Tandil, Buenos Aires, Argentina
| | - Ramiro Lorenzo
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Tandil, Buenos Aires, Argentina
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - María Victoria Nieto Farías
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, CISAPA, Tandil, Buenos Aires, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Tandil, Buenos Aires, Argentina
| | - John W.A. Rossen
- Laboratory of Medical Microbiology and Infectious Diseases, Isala Hospital, Zwolle, The Netherlands
- Department of Medical Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Paula M. A. Lucchesi
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, CISAPA, Tandil, Buenos Aires, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Tandil, Buenos Aires, Argentina
| | - Alejandra Krüger
- Universidad Nacional del Centro de la Provincia de Buenos Aires (UNCPBA), Facultad de Ciencias Veterinarias, CISAPA, Tandil, Buenos Aires, Argentina
- Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Tandil, Buenos Aires, Argentina
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5
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Amadio A, Bono JL, Irazoqui M, Larzábal M, Marques da Silva W, Eberhardt MF, Riviere NA, Gally D, Manning SD, Cataldi A. Genomic analysis of shiga toxin-containing Escherichia coli O157:H7 isolated from Argentinean cattle. PLoS One 2021; 16:e0258753. [PMID: 34710106 PMCID: PMC8553066 DOI: 10.1371/journal.pone.0258753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 10/04/2021] [Indexed: 11/19/2022] Open
Abstract
Cattle are the main reservoir of Enterohemorrhagic Escherichia coli (EHEC), with O157:H7 the distinctive serotype. EHEC is the main causative agent of a severe systemic disease, Hemolytic Uremic Syndrome (HUS). Argentina has the highest pediatric HUS incidence worldwide with 12–14 cases per 100,000 children. Herein, we assessed the genomes of EHEC O157:H7 isolates recovered from cattle in the humid Pampas of Argentina. According to phylogenetic studies, EHEC O157 can be divided into clades. Clade 8 strains that were classified as hypervirulent. Most of the strains of this clade have a Shiga toxin stx2a-stx2c genotype. To better understand the molecular bases related to virulence, pathogenicity and evolution of EHEC O157:H7, we performed a comparative genomic analysis of these isolates through whole genome sequencing. The isolates classified as clade 8 (four strains) and clade 6 (four strains) contained 13 to 16 lambdoid prophages per genome, and the observed variability of prophages was analysed. An inter strain comparison show that while some prophages are highly related and can be grouped into families, other are unique. Prophages encoding for stx2a were highly diverse, while those encoding for stx2c were conserved. A cluster of genes exclusively found in clade 8 contained 13 genes that mostly encoded for DNA binding proteins. In the studied strains, polymorphisms in Q antiterminator, the Q-stx2A intergenic region and the O and P γ alleles of prophage replication proteins are associated with different levels of Stx2a production. As expected, all strains had the pO157 plasmid that was highly conserved, although one strain displayed a transposon interruption in the protease EspP gene. This genomic analysis may contribute to the understanding of the genetic basis of the hypervirulence of EHEC O157:H7 strains circulating in Argentine cattle. This work aligns with other studies of O157 strain variation in other populations that shows key differences in Stx2a-encoding prophages.
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Affiliation(s)
- Ariel Amadio
- Instituto de Investigación de la Cadena Láctea IDICaL (INTA-CONICET), Rafaela, Argentina
| | - James L. Bono
- U.S Meat Animal Research Center, Agricultural Research Service, U.S. Department of Agriculture, Clay Center, Nebraska, United States of America
| | - Matías Irazoqui
- Instituto de Investigación de la Cadena Láctea IDICaL (INTA-CONICET), Rafaela, Argentina
| | - Mariano Larzábal
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO)-CICVyA, Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET), Hurlingham, Argentina
| | - Wanderson Marques da Silva
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO)-CICVyA, Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET), Hurlingham, Argentina
| | | | - Nahuel A. Riviere
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO)-CICVyA, Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET), Hurlingham, Argentina
| | - David Gally
- Division of Immunity and Infection, The Roslin Institute and R(D)SVS, The University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Shannon D. Manning
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, United States of America
| | - Angel Cataldi
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO)-CICVyA, Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de investigaciones Científicas y Tecnológicas (CONICET), Hurlingham, Argentina
- * E-mail:
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Ramstad SN, Wasteson Y, Lindstedt BA, Taxt AM, Bjørnholt JV, Brandal LT, Bohlin J. Characterization of Shiga Toxin 2a Encoding Bacteriophages Isolated From High-Virulent O145:H25 Shiga Toxin-Producing Escherichia coli. Front Microbiol 2021; 12:728116. [PMID: 34566932 PMCID: PMC8456039 DOI: 10.3389/fmicb.2021.728116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 07/19/2021] [Indexed: 11/20/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) may cause severe disease mainly due to the ability to produce Shiga toxins (Stx) encoded on bacteriophages. In Norway, more than 30% of the reported cases with STEC O145:H25 develop hemolytic uremic syndrome (HUS), and most cases, with known travel history, acquired the infection domestically. To describe phage characteristics associated with high virulence, we extracted the Stx2a phage sequences from eight clinical Norwegian O145:H25 STEC to conduct in-depth molecular characterization using long and short read sequencing. The Stx2a phages were annotated, characterized, and compared with previously published Stx2a phages isolated from STEC of different serotypes. The Norwegian O145:H25 Stx2a phages showed high sequence identity (>99%) with 100% coverage. The Stx2a phages were located at the integration site yciD, were approximately 45 kbp long, and harbored several virulence-associated genes, in addition to stx2a, such as nanS and nleC. We observed high sequence identity (>98%) and coverage (≥94%) between Norwegian O145:H25 Stx2a phages and publicly available Stx2a phages from O145:H25 and O145:H28 STEC, isolated from HUS cases in the USA and a hemorrhagic diarrhea case from Japan, respectively. However, low similarity was seen when comparing the Norwegian O145:H25 Stx2a phage to Stx2a phages from STEC of other serotypes. In all the Norwegian O145:H25 STEC, we identified a second phage or remnants of a phage (a shadow phage, 61 kbp) inserted at the same integration site as the Stx2a phage. The shadow phage shared similarity with the Stx2a phage, but lacked stx2a and harbored effector genes not present in the Stx2a phage. We identified a conserved Stx2a phage among the Norwegian O145:H25 STEC that shared integration site with a shadow phage in all isolates. Both phage and shadow phage harbored several virulence-associated genes that may contribute to the increased pathogenicity of O145:H25 STEC.
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Affiliation(s)
- Silje N Ramstad
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Yngvild Wasteson
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Bjørn-Arne Lindstedt
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Arne M Taxt
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway.,Department of Infectious Diseases and Prevention, Norwegian Institute of Public Health, Oslo, Norway
| | - Jørgen V Bjørnholt
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Lin T Brandal
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway.,ECDC Fellowship Programme, Public Health Microbiology Path (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Solna, Sweden
| | - Jon Bohlin
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
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Pinto G, Sampaio M, Dias O, Almeida C, Azeredo J, Oliveira H. Insights into the genome architecture and evolution of Shiga toxin encoding bacteriophages of Escherichia coli. BMC Genomics 2021; 22:366. [PMID: 34011288 PMCID: PMC8136144 DOI: 10.1186/s12864-021-07685-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 05/07/2021] [Indexed: 11/18/2022] Open
Abstract
Background A total of 179 Shiga toxin-producing Escherichia coli (STEC) complete genomes were analyzed in terms of serotypes, prophage coding regions, and stx gene variants and their distribution. We further examined the genetic diversity of Stx-converting phage genomes (Stx phages), focusing on the lysis-lysogeny decision and lytic cassettes. Results We show that most STEC isolates belong to non-O157 serotypes (73 %), regardless the sources and geographical regions. While the majority of STEC genomes contain a single stx gene (61 %), strains containing two (35 %), three (3 %) and four (1 %) stx genes were also found, being stx2 the most prevalent gene variant. Their location is exclusively found in intact prophage regions, indicating that they are phage-borne. We further demonstrate that Stx phages can be grouped into four clusters (A, B, C and D), three subclusters (A1, A2 and A3) and one singleton, based on their shared gene content. This cluster distribution is in good agreement with their predicted virion morphologies. Stx phage genomes are highly diverse with a vast number of 1,838 gene phamilies (phams) of related sequences (of which 677 are orphams i.e. unique genes) and, although having high mosaicism, they are generally organized into three major transcripts. While the mechanisms that guide lysis–lysogeny decision are complex, there is a strong selective pressure to maintain the stx genes location close to the lytic cassette composed of predicted SAR-endolysin and pin-holin lytic proteins. The evolution of STEC Stx phages seems to be strongly related to acquiring genetic material, probably from horizontal gene transfer events. Conclusions This work provides novel insights on the genetic structure of Stx phages, showing a high genetic diversity throughout the genomes, where the various lysis-lysogeny regulatory systems are in contrast with an uncommon, but conserved, lytic system always adjacent to stx genes. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07685-0.
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Affiliation(s)
- Graça Pinto
- CEB - Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.,INIAV, IP-National Institute for Agrarian and Veterinary Research, Rua dos Lagidos, Lugar da Madalena, Vairão, Vila do Conde, Portugal
| | - Marta Sampaio
- CEB - Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal
| | - Oscar Dias
- CEB - Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal
| | - Carina Almeida
- INIAV, IP-National Institute for Agrarian and Veterinary Research, Rua dos Lagidos, Lugar da Madalena, Vairão, Vila do Conde, Portugal
| | - Joana Azeredo
- CEB - Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
| | - Hugo Oliveira
- CEB - Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal.
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8
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Rodríguez-Rubio L, Haarmann N, Schwidder M, Muniesa M, Schmidt H. Bacteriophages of Shiga Toxin-Producing Escherichia coli and Their Contribution to Pathogenicity. Pathogens 2021; 10:404. [PMID: 33805526 PMCID: PMC8065619 DOI: 10.3390/pathogens10040404] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/18/2021] [Accepted: 03/24/2021] [Indexed: 12/25/2022] Open
Abstract
Shiga toxins (Stx) of Shiga toxin-producing Escherichia coli (STEC) are generally encoded in the genome of lambdoid bacteriophages, which spend the most time of their life cycle integrated as prophages in specific sites of the bacterial chromosome. Upon spontaneous induction or induction by chemical or physical stimuli, the stx genes are co-transcribed together with the late phase genes of the prophages. After being assembled in the cytoplasm, and after host cell lysis, mature bacteriophage particles are released into the environment, together with Stx. As members of the group of lambdoid phages, Stx phages share many genetic features with the archetypical temperate phage Lambda, but are heterogeneous in their DNA sequences due to frequent recombination events. In addition to Stx phages, the genome of pathogenic STEC bacteria may contain numerous prophages, which are either cryptic or functional. These prophages may carry foreign genes, some of them related to virulence, besides those necessary for the phage life cycle. Since the production of one or more Stx is considered the major pathogenicity factor of STEC, we aim to highlight the new insights on the contribution of Stx phages and other STEC phages to pathogenicity.
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Affiliation(s)
- Lorena Rodríguez-Rubio
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Diagonal 643, 08028 Barcelona, Spain; (L.R.-R.); (M.M.)
| | - Nadja Haarmann
- Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany; (N.H.); (M.S.)
| | - Maike Schwidder
- Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany; (N.H.); (M.S.)
| | - Maite Muniesa
- Department of Genetics, Microbiology and Statistics, University of Barcelona, Diagonal 643, 08028 Barcelona, Spain; (L.R.-R.); (M.M.)
| | - Herbert Schmidt
- Department of Food Microbiology and Hygiene, Institute of Food Science and Biotechnology, University of Hohenheim, 70599 Stuttgart, Germany; (N.H.); (M.S.)
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Mechanisms involved in the adaptation of Escherichia coli O157:H7 to the host intestinal microenvironment. Clin Sci (Lond) 2020; 134:3283-3301. [PMID: 33346356 DOI: 10.1042/cs20200971] [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: 08/03/2020] [Revised: 11/24/2020] [Accepted: 12/01/2020] [Indexed: 11/17/2022]
Abstract
Host adaptation of pathogens may increase intra- and interspecies transmission. We showed previously that the passage of a clinically isolated enterohemorrhagic Escherichia coli (EHEC) O157 strain (125/99) through the gastrointestinal tract of mice increases its pathogenicity in the same host. In this work, we aimed to elucidate the underlying mechanism(s) involved in the patho-adaptation of the stool-recovered (125RR) strain. We assessed the global transcription profile by microarray and found almost 100 differentially expressed genes in 125RR strain compared with 125/99 strain. We detected an overexpression of Type Three Secretion System (TTSS) proteins at the mRNA and protein levels and demonstrated increased adhesion to epithelial cell lines for the 125RR strain. Additional key attributes of the 125RR strain were: increased motility on semisolid agar, which correlated with an increased fliC mRNA level; reduced Stx2 production at the mRNA and protein levels; increased survival at pH 2.5, as determined by acid resistance assays. We tested whether the overexpression of the LEE-encoded regulator (ler) in trans in the 125/99 strain could recreate the increased pathogenicity observed in the 125RR strain. As anticipated ler overexpression led to increased expression of TTSS proteins and bacterial adhesion to epithelial cells in vitro but also increased mortality and intestinal colonization in vivo. We conclude that this host-adaptation process required changes in several mechanisms that improved EHEC O157 fitness in the new host. The research highlights some of the bacterial mechanisms required for horizontal transmission of these zoonotic pathogens between their animal and human populations.
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Ramstad SN, Taxt AM, Naseer U, Wasteson Y, Bjørnholt JV, Brandal LT. Effects of antimicrobials on Shiga toxin production in high-virulent Shiga toxin-producing Escherichia coli. Microb Pathog 2020; 152:104636. [PMID: 33242644 DOI: 10.1016/j.micpath.2020.104636] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 11/10/2020] [Accepted: 11/16/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE Antimicrobial treatment of Shiga toxin-producing Escherichia coli (STEC) infections is controversial because antimicrobials may stimulate Shiga toxin (Stx) production, and thereby increase the risk of developing haemolytic uremic syndrome (HUS). Previous in vitro studies have shown this mainly in infections caused by STEC serotype O157:H7. The aim of this study was to investigate induction of Stx transcription and production in different serotypes of STEC isolated from severely ill patients, following their exposure in vitro to six different classes of antimicrobials. METHODS We investigated Stx transcription and production in 12 high-virulent STEC strains, all carrying the stx2a gene, of six different serotypes following their exposure to six classes of antimicrobials. Liquid cultures of the STEC strains were incubated with sub-inhibitory concentrations of the antimicrobials. We used reverse-transcription quantitative PCR to measure the relative expression of Stx2a mRNA and an enzyme-linked immunosorbent assay to quantify Stx production. RESULTS In general the antibiotics tested showed only minor effects on transcriptional levels of Stx2a. Ciprofloxacin caused an increase of Stx production in all but two strains, while gentamicin, meropenem and azithromycin did not induce Stx production in any of the STEC strains examined. STEC O104:H4 was the serotype that in greatest extent responded to antimicrobial exposure with an increase of stx2a transcription and Stx production. CONCLUSION Gentamicin, meropenem and azithromycin exposure did not result in elevated Stx production. We recommend that this finding is investigated further in the search for candidates for future antimicrobial treatment of STEC.
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Affiliation(s)
- Silje N Ramstad
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, PB 4956 Nydalen, 0424, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
| | - Arne M Taxt
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, PB 4956 Nydalen, 0424, Oslo, Norway
| | - Umaer Naseer
- Department of Infectious Diseases and Prevention, Norwegian Institute of Public Health, Oslo, Norway
| | - Yngvild Wasteson
- Department of Paraclinical Sciences, Norwegian University of Life Sciences, Oslo, Norway
| | - Jørgen V Bjørnholt
- Department of Microbiology, Division of Laboratory Medicine, Oslo University Hospital, PB 4956 Nydalen, 0424, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Lin T Brandal
- Department of Infectious Diseases and Prevention, Norwegian Institute of Public Health, Oslo, Norway
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11
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Burgán J, Krüger A, Lucchesi PMA. Comparable stx 2a expression and phage production levels between Shiga toxin-producing Escherichia coli strains from human and bovine origin. Zoonoses Public Health 2019; 67:44-53. [PMID: 31868306 DOI: 10.1111/zph.12653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/21/2019] [Accepted: 09/06/2019] [Indexed: 01/13/2023]
Abstract
Shiga toxin-producing Escherichia coli (STEC) can cause diarrhoea and severe diseases in humans, such as haemolytic uraemic syndrome. STEC virulence is considered to correlate with the amount of Shiga toxins (Stx) produced, especially Stx2, whose subtype Stx2a is most frequently associated with high virulence. Stx are encoded in prophages, which play an important role in STEC pathogenesis. The aim of this study was to evaluate stx2a expression levels and Stx2a phage production using qPCR and the double-agar-layer method in 29 STEC strains, corresponding to serotypes O26:H11 (6), O91:H21 (1), O145:H- (11) and O157:H7 (11), isolated from cattle and humans. Results were then tested for possible associations with serotype, origin or some genetic features. We observed heterogeneous levels of stx2a expression and Stx2a phage production. However, statistical comparisons identified a higher stx2a expression in response to mitomycin C in strains isolated from cattle than in those from humans. At the same time, compared to stx2a /stx2c strains, stx2a strains showed a higher increase in phage production under induced conditions. Notably, most of the strains studied, regardless of serotype and origin, carried inducible Stx2a phages and evidenced expression of stx2a that increased along with phage production levels under induced conditions.
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Affiliation(s)
- Julia Burgán
- Laboratorio de Inmunoquímica y Biotecnología, Centro de Investigación Veterinaria de Tandil (CIVETAN), (CONICET-CIC-UNCPBA) Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Buenos Aires, Argentina
| | - Alejandra Krüger
- Laboratorio de Inmunoquímica y Biotecnología, Centro de Investigación Veterinaria de Tandil (CIVETAN), (CONICET-CIC-UNCPBA) Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Buenos Aires, Argentina
| | - Paula M A Lucchesi
- Laboratorio de Inmunoquímica y Biotecnología, Centro de Investigación Veterinaria de Tandil (CIVETAN), (CONICET-CIC-UNCPBA) Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Buenos Aires, Argentina
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12
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Manage DP, Lauzon J, Jones CM, Ward PJ, Pilarski LM, Pilarski PM, McMullen LM. Detection of pathogenic Escherichia coli on potentially contaminated beef carcasses using cassette PCR and conventional PCR. BMC Microbiol 2019; 19:175. [PMID: 31362696 PMCID: PMC6668150 DOI: 10.1186/s12866-019-1541-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 07/11/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Over a one year period, swabs of 820 beef carcasses were tested for the presence of Shiga toxin-producing Escherichia coli by performing Polymerase Chain Reaction (PCR) in a novel technology termed "cassette PCR", in comparison to conventional liquid PCR. Cassette PCR is inexpensive and ready-to-use. The operator need only add the sample and press "go". Cassette PCR can simultaneously test multiple samples for multiple targets. Carcass swab samples were first tested for the presence of STEC genes (O157, eae, stx1 and stx2). Samples were considered to be pathogenic if positive for eae plus stx1 and/or stx2. For samples scored as pathogenic, further testing screened for 6 additional high frequency O-antigens (O26, O45, O103, O111, O121, and O145). RESULTS Of the 820 samples, 41% were pathogenic and 30% were O157 positive. Of these, 19% of samples were positive for O157 and carried potentially pathogenic E. coli (eae plus stx1 and/or stx2). Of all samples identified as carrying pathogenic E. coli, 18.9, 38.8, 41.4, 0, 36.1, and 4.1% respectively were positive for O26, O45, O103, O111, O121, and O145. To validate cassette PCR testing, conventional PCR using STEC primers was performed on each of the 820 samples. Only 148 of 3280 cassette PCR tests were discordant with conventional PCR results. However, further fractional testing showed that 110 of these 148 PCRs reflected low numbers of E. coli in the enrichment broth and could be explained as due to Poisson limiting dilution of the template, affecting both cassette PCR and conventional PCR. Of the remaining 38 discordant tests, 27 initial capillary PCRs and 10 initial conventional tests were nominally discordant between cassette and conventional PCR, perhaps reflecting human/technical error on both sides of the comparison. CONCLUSIONS Contaminated beef carcass swabs were often complex, likely harboring more than one strain of pathogenic E. coli. Cassette PCR had 98.8% concordance with parallel conventional PCR for detection of STEC genes. This indicates that cassette PCR is highly reliable for detecting multiple pathogens in beef carcass swabs from processing plants.
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Affiliation(s)
- Dammika P Manage
- Department of Oncology, University of Alberta and Cross Cancer Institute, 11560 University Ave, Edmonton, AB, T6G 1Z2, Canada
| | - Jana Lauzon
- Department of Oncology, University of Alberta and Cross Cancer Institute, 11560 University Ave, Edmonton, AB, T6G 1Z2, Canada
| | - Christina M Jones
- Department of Oncology, University of Alberta and Cross Cancer Institute, 11560 University Ave, Edmonton, AB, T6G 1Z2, Canada
| | - Patrick J Ward
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada
| | - Linda M Pilarski
- Department of Oncology, University of Alberta and Cross Cancer Institute, 11560 University Ave, Edmonton, AB, T6G 1Z2, Canada
| | - Patrick M Pilarski
- Division of Physical Medicine & Rehabilitation, Department of Medicine, University of Alberta, 5-005 Katz Group Centre for Pharmacy and Health Research, Edmonton, AB, T6G 2E1, Canada
| | - Lynn M McMullen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, T6G 2P5, Canada.
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Rodrigues-Jesus MJ, Fotoran WL, Cardoso RM, Araki K, Wunderlich G, Ferreira LCS. Nano-multilamellar lipid vesicles (NMVs) enhance protective antibody responses against Shiga toxin (Stx2a) produced by enterohemorrhagic Escherichia coli strains (EHEC). Braz J Microbiol 2019; 50:67-77. [PMID: 30637647 PMCID: PMC6863297 DOI: 10.1007/s42770-018-0035-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/24/2018] [Indexed: 01/08/2023] Open
Abstract
Microlipid vesicles (MLV) have a broad spectrum of applications for the delivery of molecules, ranging from chemical compounds to proteins, in both in vitro and in vivo conditions. In the present study, we developed a new set of nanosize multilayer lipid vesicles (NMVs) containing a unique combination of lipids. The NMVs enable the adsorption of histidine-tagged proteins at the vesicle surface and were demonstrated to be suitable for the in vivo delivery of antigens. The NMVs contained a combination of neutral (DOPC) and anionic (DPPG) lipids in the inner membrane and an external layer composed of DOPC, cholesterol, and a nickel-containing lipid (DGS-NTA [Ni]). NMVs combined with a recombinant form of the B subunit of the Shiga toxin (rStx2B) produced by certain enterohemorragic Escherichia coli (EHEC) strains enhanced the immunogenicity of the antigen after parenteral administration to mice. Mice immunized with rStx2B-loaded NMVs elicited serum antibodies capable of neutralizing the toxic activities of the native toxin; this result was demonstrated both in vitro and in vivo. Taken together, these results demonstrated that the proposed NMVs represent an alternative for the delivery of antigens, including recombinant proteins, generated in different expression systems.
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Affiliation(s)
- M J Rodrigues-Jesus
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, 05508-900, Brazil
| | - W L Fotoran
- Unit for Drug Development and Plasmodium Molecular Biology, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - R M Cardoso
- Supramolecular Chemistry and Nanotechnology Laboratory, Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - K Araki
- Supramolecular Chemistry and Nanotechnology Laboratory, Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - G Wunderlich
- Unit for Drug Development and Plasmodium Molecular Biology, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Luís C S Ferreira
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Lineu Prestes, 1374, Cidade Universitária, São Paulo, SP, 05508-900, Brazil.
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Zhang LX, Simpson DJ, McMullen LM, Gänzle MG. Comparative Genomics and Characterization of the Late Promoter pR' from Shiga Toxin Prophages in Escherichia coli. Viruses 2018; 10:v10110595. [PMID: 30384416 PMCID: PMC6266700 DOI: 10.3390/v10110595] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 10/26/2018] [Accepted: 10/27/2018] [Indexed: 02/02/2023] Open
Abstract
Shiga-toxin producing Escherichia coli (STEC) causes human illness ranging from mild diarrhea to death. The bacteriophage encoded stx genes are located in the late transcription region, downstream of the antiterminator Q. The transcription of the stx genes is directly under the control of the late promoter pR’, thus the sequence diversity of the region between Q and stx, here termed the pR’ region, may affect Stx toxin production. Here, we compared the gene structure of the pR’ region and the stx subtypes of nineteen STECs. The sequence alignment and phylogenetic analysis suggested that the pR’ region tends to be more heterogeneous than the promoter itself, even if the prophages harbor the same stx subtype. Furthermore, we established and validated transcriptional fusions of the pR’ region to the DsRed reporter gene using mitomycin C (MMC) induction. Finally, these constructs were transformed into native and non-native strains and examined with flow cytometry. The results showed that induction levels changed when pR’ regions were placed under different regulatory systems. Moreover, not every stx gene could be induced in its native host bacteria. In addition to the functional genes, the diversity of the pR’ region plays an important role in determining the level of toxin induction.
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Affiliation(s)
- Ling Xiao Zhang
- Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada.
| | - David J Simpson
- Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada.
| | - Lynn M McMullen
- Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada.
| | - Michael G Gänzle
- Department of Agriculture, Food and Nutritional Science, University of Alberta, Edmonton, AB T6G 2P5, Canada.
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15
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Khatibi SA, Misaghi A, Moosavy MH, Akhondzadeh Basti A, Mohamadian S, Khanjari A. Effect of nanoliposomes containing Zataria multiflora Boiss. essential oil on gene expression of Shiga toxin 2 in Escherichia coli O157:H7. J Appl Microbiol 2018; 124:389-397. [PMID: 29152837 DOI: 10.1111/jam.13641] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 11/06/2017] [Accepted: 11/13/2017] [Indexed: 11/29/2022]
Abstract
AIMS Enterohaemorrhagic Escherichia coli serotype O157:H7 as a major human pathogen is responsible for food borne outbreaks, bloody diarrhoea, haemorrhagic colitis and haemolytic uraemic syndrome and even death. In this study, the antibacterial activity of the Zataria multiflora essential oil (ZMEO) and nanoliposome-encapsulated ZMEO was evaluated on the pathogenicity of E. coli O157:H7. METHODS AND RESULTS The minimum inhibitory concentrations (MIC) of essential oil (EO) were determined against the bacterium before and after encapsulation into nanoliposome. Then, the effect of subinhibitory concentrations was evaluated on Shiga toxin 2 (Stx2) production. The effect of free and nanoliposomal EO was also studied on the gene expression of Stx2 by real-time PCR. It was found that inhibitory activity of EO was improved after incorporation into nanoliposomes (P < 0·05). The MIC of free EO against E. coli O157:H7 was 0·03% (v/v), while this value decreased to 0·015%, after encapsulation of EO into nanoliposomes. Furthermore, subinhibitory concentrations of liposomal EO (50 and 75% MIC) had significantly higher inhibitory effect on Stx2 titre than its free form (P < 0·05). Sub-MICs of nanoencapsulated EO also showed a better activity in reduction of Stx2A gene expression than free EO. Using 75% MIC of nanoliposomal EO, the relative transcriptional level of Stx2A gene was decreased from 0·721 to 0·646. CONCLUSIONS The findings of present study suggest that application of nanoliposomes can improve the antibacterial effect of EOs like ZMEO. SIGNIFICANCE AND IMPACT OF THE STUDY Due to the enhancement of antimicrobial activity, nanoencapsulation of plant EOs and extracts may increase their commercial application not only in food area but also in the pharmaceutics, cosmetics and health products.
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Affiliation(s)
- S A Khatibi
- Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - A Misaghi
- Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - M H Moosavy
- Department of Food Hygiene and Aquatic, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
| | - A Akhondzadeh Basti
- Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - S Mohamadian
- Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - A Khanjari
- Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
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16
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Cheng K, Sloan A, Li X, Armstrong GD, Wang G. Mass spectrometry-based Shiga toxin identification: An optimized approach. J Proteomics 2017; 180:36-40. [PMID: 28602982 DOI: 10.1016/j.jprot.2017.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 05/25/2017] [Accepted: 06/02/2017] [Indexed: 10/19/2022]
Abstract
Toxin expression is a key factor in Shiga toxin (Stx)-producing E. coli, a common pathogen involved in foodborne disease outbreaks. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) based approach has been used in this study to identify commonly reported E. coli toxins, with a focus on Shiga toxins (Stxs). Different sample preparation methods using variable culture conditions and concentrations of mitomycin C (MMC), a common antibiotic/chemotherapy agent capable of stimulating Stx production, were first tested on reference strains EDL933 and 90-2380 by LC-MS/MS detection of tryptic digests of receptor-analogue affinity binding enriched Stx preparations from culture supernatants and lysates. A curated E. coli protein toxin database was also used for faster and more straightforward toxin identification. With eight more genetically confirmed E. coli strains examined to verify the method, this preliminary study indicates that receptor-analogue based affinity enrichment on cell lysate or supernatant is a sensitive and accurate method for Stx identification. BIOLOGICAL SIGNIFICANCE The existence of Stx is very important for identifying Stx-producing E. coli and implementing a clinical treatment regime. This study demonstrates for the first time that using a curated E. coli toxin database, together with receptor-analogue-based affinity enrichment of Stxs after MMC treatment of E. coli, is an easy and appropriate approach for fast and accurate Stx identification through LC-MS/MS.
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Affiliation(s)
- Keding Cheng
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada; Department of Human Anatomy and Cell Sciences, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
| | - Angela Sloan
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Xingle Li
- Henan Center for Disease Control, Henan, PR China
| | - Glen D Armstrong
- Department of Microbiology, Immunology & Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Gehua Wang
- National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
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Amigo N, Zhang Q, Amadio A, Zhang Q, Silva WM, Cui B, Chen Z, Larzabal M, Bei J, Cataldi A. Overexpressed Proteins in Hypervirulent Clade 8 and Clade 6 Strains of Escherichia coli O157:H7 Compared to E. coli O157:H7 EDL933 Clade 3 Strain. PLoS One 2016; 11:e0166883. [PMID: 27880834 PMCID: PMC5120812 DOI: 10.1371/journal.pone.0166883] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 11/04/2016] [Indexed: 11/19/2022] Open
Abstract
Escherichia coli O157:H7 is responsible for severe diarrhea and hemolytic uremic syndrome (HUS), and predominantly affects children under 5 years. The major virulence traits are Shiga toxins, necessary to develop HUS and the Type III Secretion System (T3SS) through which bacteria translocate effector proteins directly into the host cell. By SNPs typing, E. coli O157:H7 was separated into nine different clades. Clade 8 and clade 6 strains were more frequently associated with severe disease and HUS. In this study, we aimed to identify differentially expressed proteins in two strains of E. coli O157:H7 (clade 8 and clade 6), obtained from cattle and compared them with the well characterized reference EDL933 strain (clade 3). Clade 8 and clade 6 strains show enhanced pathogenicity in a mouse model and virulence-related properties. Proteins were extracted and analyzed using the TMT-6plex labeling strategy associated with two dimensional liquid chromatography and mass spectrometry in tandem. We detected 2241 proteins in the cell extract and 1787 proteins in the culture supernatants. Attention was focused on the proteins related to virulence, overexpressed in clade 6 and 8 strains compared to EDL933 strain. The proteins relevant overexpressed in clade 8 strain were the curli protein CsgC, a transcriptional activator (PchE), phage proteins, Stx2, FlgM and FlgD, a dienelactone hydrolase, CheW and CheY, and the SPATE protease EspP. For clade 6 strain, a high overexpression of phage proteins was detected, mostly from Stx2 encoding phage, including Stx2, flagellin and the protease TagA, EDL933_p0016, dienelactone hydrolase, and Haemolysin A, amongst others with unknown function. Some of these proteins were analyzed by RT-qPCR to corroborate the proteomic data. Clade 6 and clade 8 strains showed enhanced transcription of 10 out of 12 genes compared to EDL933. These results may provide new insights in E. coli O157:H7 mechanisms of pathogenesis.
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Affiliation(s)
- Natalia Amigo
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology. Hurlingham, Buenos Aires, Argentina
| | - Qi Zhang
- AGRO-Biological Gene Research Center, Guangdong `Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Ariel Amadio
- Rafaela Experimental Station, National Institute of Agricultural Technology. Rafaela, Santa Fe, Argentina
| | - Qunjie Zhang
- AGRO-Biological Gene Research Center, Guangdong `Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Wanderson M. Silva
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology. Hurlingham, Buenos Aires, Argentina
| | - Baiyuan Cui
- AGRO-Biological Gene Research Center, Guangdong `Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Zhongjian Chen
- AGRO-Biological Gene Research Center, Guangdong `Academy of Agricultural Sciences (GDAAS), Guangzhou, China
| | - Mariano Larzabal
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology. Hurlingham, Buenos Aires, Argentina
| | - Jinlong Bei
- AGRO-Biological Gene Research Center, Guangdong `Academy of Agricultural Sciences (GDAAS), Guangzhou, China
- * E-mail:
| | - Angel Cataldi
- Institute of Biotechnology, CICVyA, National Institute of Agricultural Technology. Hurlingham, Buenos Aires, Argentina
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