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Singh S, Singh S, Trivedi M, Dwivedi M. An insight into MDR Acinetobacter baumannii infection and its pathogenesis: Potential therapeutic targets and challenges. Microb Pathog 2024; 192:106674. [PMID: 38714263 DOI: 10.1016/j.micpath.2024.106674] [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: 10/19/2023] [Revised: 04/22/2024] [Accepted: 05/01/2024] [Indexed: 05/09/2024]
Abstract
Acinetobacter baumannii is observed as a common species of Gram-negative bacteria that exist in soil and water. Despite being accepted as a typical component of human skin flora, it has become an important opportunistic pathogen, especially in healthcare settings. The pathogenicity of A. baumannii is attributed to its virulence factors, which include adhesins, pili, lipopolysaccharides, outer membrane proteins, iron uptake systems, autotransporter, secretion systems, phospholipases etc. These elements provide the bacterium the ability to cling to and penetrate host cells, get past the host immune system, and destroy tissue. Its infection is a major contributor to human pathophysiological conditions including pneumonia, bloodstream infections, urinary tract infections, and surgical site infections. It is challenging to treat infections brought on by this pathogen since this bacterium has evolved to withstand numerous drugs and further emergence of drug-resistant A. baumannii results in higher rates of morbidity and mortality. The long-term survival of this bacterium on surfaces of medical supplies and hospital furniture facilitates its frequent spread in humans from one habitat to another. There is a need for urgent investigations to find effective drug targets for A. baumannii as well as designing novel drugs to reduce the survival and spread of infection. In the current review, we represent the specific features, pathogenesis, and molecular intricacies of crucial drug targets of A. baumannii. This would also assist in proposing strategies and alternative therapies for the prevention and treatment of A. baumannii infections and their spread.
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Affiliation(s)
- Sukriti Singh
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, 226028, India
| | - Sushmita Singh
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, 226028, India
| | - Mala Trivedi
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, 226028, India
| | - Manish Dwivedi
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, 226028, India; Research Cell, Amity University Uttar Pradesh, Lucknow, 226028, India.
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Pelozo MF, Cordeiro CF, Inácio LF, de Cassia Alves Lemini R, Gonçalves Souza E Leite E, Benedetti MD, Tulha CA, Novaes RD, Caldas IS, Carvalho DT, Lavorato SN, Hawkes JA, Franco LL. Synthesis of new trypanocidal agents from the hybridisation of metronidazole and eugenol analogues. Bioorg Chem 2024; 146:107288. [PMID: 38521013 DOI: 10.1016/j.bioorg.2024.107288] [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: 12/05/2023] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 03/25/2024]
Abstract
Nitroimidazole compounds are well-known bioactive substances, and the structural activity relationship has been reported whereby the position of the nitro group within the imidazole ring has a large influence on the activity. This study focuses on synthesising new trypanocidal agents from the hybridisation of metronidazole with different natural phenols (eugenol, dihydroeugenol and guaiacol). Two different coupling methodologies have been explored in order to analyse the influence of the connector on bioactivity: i) classic direct esterification (AD compounds) and ii) "click" chemistry using a triazole connector (AC compounds). The in vitro trypanocidal tests show good results for both AC and AD hybrid compounds against both epimastigote and trypomastigote forms of T. cruzi. In silico studies showed positive data for most of the synthesised compounds and, in general present low toxicological risks. The AC compounds present lower ClogP (lipophilicity) values than those found for the AD series and higher TPSA (topological polar surface area) values, suggesting lower lipophilicity may be related to the presence of the triazole connector. The AD series compounds have higher Drug Score values than the AC series derivatives, suggesting better general properties for a pharmacological action.
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Affiliation(s)
| | | | - Letícia Fonseca Inácio
- Faculdade de Ciências Farmacêuticas, Universidade Federal de Alfenas, MG 37130-001, Brazil
| | | | | | - Monique Dias Benedetti
- Faculdade de Ciências Farmacêuticas, Universidade Federal de Alfenas, MG 37130-001, Brazil
| | - Cristiane Alves Tulha
- Faculdade de Ciências Farmacêuticas, Universidade Federal de Alfenas, MG 37130-001, Brazil
| | - Rômulo Dias Novaes
- Departamento de Biologia Estrutural, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, Alfenas 37130-001, Minas Gerais, Brazil
| | - Ivo Santana Caldas
- Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, MG 37130-001, Brazil
| | | | - Stefânia Neiva Lavorato
- Centro de Ciências Biológicas e Saúde, Universidade Federal do Oeste da Bahia, BA 47810-047 Brazil
| | - Jamie Anthony Hawkes
- Faculdade de Ciências Farmacêuticas, Universidade Federal de Alfenas, MG 37130-001, Brazil
| | - Lucas Lopardi Franco
- Faculdade de Ciências Farmacêuticas, Universidade Federal de Alfenas, MG 37130-001, Brazil.
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3
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Rajangam SL, Narasimhan MK. Current treatment strategies for targeting virulence factors and biofilm formation in Acinetobacter baumannii. Future Microbiol 2024. [PMID: 38683166 DOI: 10.2217/fmb-2023-0263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2024] Open
Abstract
A higher prevalence of Acinetobacter baumannii infections and mortality rate has been reported recently in hospital-acquired infections (HAI). The biofilm-forming capability of A. baumannii makes it an extremely dangerous pathogen, especially in device-associated hospital-acquired infections (DA-HAI), thereby it resists the penetration of antibiotics. Further, the transmission of the SARS-CoV-2 virus was exacerbated in DA-HAI during the epidemic. This review specifically examines the complex interconnections between several components and genes that play a role in the biofilm formation and the development of infections. The current review provides insights into innovative treatments and therapeutic approaches to combat A. baumannii biofilm-related infections, thereby ultimately improving patient outcomes and reducing the burden of HAI.
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Affiliation(s)
- Seetha Lakshmi Rajangam
- Department of Genetic Engineering, School of Bioengineering, College of Engineering & Technology, SRM Institute of Science & Technology, Kattankulathur, Chennai, Tamil Nadu, 603203, India
| | - Manoj Kumar Narasimhan
- Department of Genetic Engineering, School of Bioengineering, College of Engineering & Technology, SRM Institute of Science & Technology, Kattankulathur, Chennai, Tamil Nadu, 603203, India
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Wang Y, Wakelam MJO, Bankaitis VA, McDermott MI. The wide world of non-mammalian phospholipase D enzymes. Adv Biol Regul 2024; 91:101000. [PMID: 38081756 DOI: 10.1016/j.jbior.2023.101000] [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: 11/10/2023] [Accepted: 11/15/2023] [Indexed: 02/25/2024]
Abstract
Phospholipase D (PLD) hydrolyses phosphatidylcholine (PtdCho) to produce free choline and the critically important lipid signaling molecule phosphatidic acid (PtdOH). Since the initial discovery of PLD activities in plants and bacteria, PLDs have been identified in a diverse range of organisms spanning the taxa. While widespread interest in these proteins grew following the discovery of mammalian isoforms, research into the PLDs of non-mammalian organisms has revealed a fascinating array of functions ranging from roles in microbial pathogenesis, to the stress responses of plants and the developmental patterning of flies. Furthermore, studies in non-mammalian model systems have aided our understanding of the entire PLD superfamily, with translational relevance to human biology and health. Increasingly, the promise for utilization of non-mammalian PLDs in biotechnology is also being recognized, with widespread potential applications ranging from roles in lipid synthesis, to their exploitation for agricultural and pharmaceutical applications.
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Affiliation(s)
- Y Wang
- Department of Cell Biology & Genetics, Texas A&M Health Science Center, College Station, TX, 77843, USA; Department of Microbiology, University of Washington, Seattle, WA98109, USA
| | - M J O Wakelam
- Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, United Kingdom
| | - V A Bankaitis
- Department of Cell Biology & Genetics, Texas A&M Health Science Center, College Station, TX, 77843, USA; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843, USA; Department of Chemistry, Texas A&M University, College Station, TX, 77843, USA
| | - M I McDermott
- Department of Cell Biology & Genetics, Texas A&M Health Science Center, College Station, TX, 77843, USA.
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Weng Z, Yang N, Shi S, Xu Z, Chen Z, Liang C, Zhang X, Du X. Outer Membrane Vesicles from Acinetobacter baumannii: Biogenesis, Functions, and Vaccine Application. Vaccines (Basel) 2023; 12:49. [PMID: 38250862 PMCID: PMC10818702 DOI: 10.3390/vaccines12010049] [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: 11/16/2023] [Revised: 12/25/2023] [Accepted: 12/29/2023] [Indexed: 01/23/2024] Open
Abstract
This review focuses on Acinetobacter baumannii, a Gram-negative bacterium that causes various infections and whose multidrug resistance has become a significant challenge in clinical practices. There are multiple bacterial mechanisms in A. baumannii that participate in bacterial colonization and immune responses. It is believed that outer membrane vesicles (OMVs) budding from the bacteria play a significant role in mediating bacterial survival and the subsequent attack against the host. Most OMVs originate from the bacterial membranes and molecules are enveloped in them. Elements similar to the pathogen endow OMVs with robust virulence, which provides a new direction for exploring the pathogenicity of A. baumannii and its therapeutic pathways. Although extensive research has been carried out on the feasibility of OMV-based vaccines against pathogens, no study has yet summarized the bioactive elements, biological activity, and vaccine applicability of A. baumannii OMVs. This review summarizes the components, biogenesis, and function of OMVs that contribute to their potential as vaccine candidates and the preparation methods and future directions for their development.
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Affiliation(s)
- Zheqi Weng
- The Second Clinical Medical School, Nanjing Medical University, Nanjing 210011, China
| | - Ning Yang
- Department of Respiratory and Critical Care Medicine, The Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China
| | - Shujun Shi
- The Second Clinical Medical School, Nanjing Medical University, Nanjing 210011, China
| | - Zining Xu
- The Second Clinical Medical School, Nanjing Medical University, Nanjing 210011, China
| | - Zixu Chen
- The Second Clinical Medical School, Nanjing Medical University, Nanjing 210011, China
| | - Chen Liang
- The Second Clinical Medical School, Nanjing Medical University, Nanjing 210011, China
| | - Xiuwei Zhang
- Department of Respiratory and Critical Care Medicine, The Affiliated Jiangning Hospital with Nanjing Medical University, Nanjing 211100, China
| | - Xingran Du
- Department of Respiratory and Critical Care Medicine, The Affiliated Jiangning Hospital with Nanjing Medical University, Nanjing 211100, China
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Kori A, Negi N, Chandola I, Roy R, Gairola S, Gaur L. Prevalence of ventilator-associated events and antibiogram of bacterial isolates of ventilator-associated pneumonia in a tertiary care hospital of Uttarakhand. IRANIAN JOURNAL OF MICROBIOLOGY 2023; 15:765-770. [PMID: 38156309 PMCID: PMC10751612 DOI: 10.18502/ijm.v15i6.14137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2023]
Abstract
Background and Objectives Despite progress in diagnosing and managing ventilator-associated pneumonia (VAP), ongoing monitoring of ventilator-associated events (VAE) is crucial due to VAP's persistent prominence as the primary cause of Hospital-Acquired Infection (HAI) among Intensive Care unit patients. This study was done to illuminate the prevalence of VAE and antibiogram of bacterial isolates of VAP in a tertiary care hospital of Uttarakhand. Materials and Methods This cross-sectional study focused on ICU patients. Adult patients ventilated for > 2 days were monitored daily, with VAE data analyzed using Center of Disease Control & Prevention (CDC) criteria. Specimens were sent to the Microbiology Department and cultured on Blood agar and MacConkey agar. Identification and antimicrobial profiles of isolates were determined using Vitek-2 Compact. Results 1220 ventilated individuals were assessed in total. VAE was diagnosed in 6.4% (78/1220) of the patients, the same later developed ventilator associated condition (VAC), 74 developed the infection-related VAC (IVAC), and 60 developed the possible/probable VAP (PVAP) among the 78 VAE cases. Klebsiella pneumoniae (35%), Acinetobacter baumannii (33%), and Pseudomonas aeruginosa (16%) were the most common isolated organisms. Colistin (57%) was the most effective against Klebsiella pneumoniae, followed by amikacin (28.5%) and trimethoprim+sulfamethoxazole (24%). Pseudomonas aeruginosa was most susceptible to imipenem (70%), meropenem, cefoperazone+sulbactam, and colistin (60%). Acinetobacter baumannii was most susceptible to colistin (85%), tigecycline (65%), and trimethoprim+sulfamethoxazole (25%). Conclusion The most common cause of HAI is VAP. The purpose of this study is to determine the importance of starting suitable antibiotics early for prognosis and the difficulty of diagnosing VAP.
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Affiliation(s)
- Abhishek Kori
- Department of Microbiology, Himalayan Institute of Medical Sciences (HIMS), Swami Rama Himalayan University (SRHU), Jolly grant, Dehradun, Uttarakhand, India
| | - Nidhi Negi
- Department of Microbiology, Government Doon Medical College, Hemwati Nandan Bahuguna Uttarakhand Medical Education University, Dehradun, Uttarakhand, India
| | - Iva Chandola
- Department of Microbiology and Immunology, Shri Guru Ram Rai Institute of Medical and Health Sciences, Shri Guru Ram Rai University, Dehradun, Uttarakhand, India
| | - Reshmi Roy
- Department of Microbiology and Immunology, Shri Guru Ram Rai Institute of Medical and Health Sciences, Shri Guru Ram Rai University, Dehradun, Uttarakhand, India
| | - Shikha Gairola
- Department of Microbiology and Immunology, Shri Guru Ram Rai Institute of Medical and Health Sciences, Shri Guru Ram Rai University, Dehradun, Uttarakhand, India
| | - Lipika Gaur
- Department of Microbiology and Immunology, Shri Guru Ram Rai Institute of Medical and Health Sciences, Shri Guru Ram Rai University, Dehradun, Uttarakhand, India
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Maure A, Robino E, Van der Henst C. The intracellular life of Acinetobacter baumannii. Trends Microbiol 2023; 31:1238-1250. [PMID: 37487768 DOI: 10.1016/j.tim.2023.06.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 07/26/2023]
Abstract
Acinetobacter baumannii is a Gram-negative opportunistic bacterium responsible for nosocomial and community-acquired infections. This pathogen is globally disseminated and associated with high levels of antibiotic resistance, which makes it an important threat to human health. Recently, new evidence showed that several A. baumannii isolates can survive and proliferate within eukaryotic professional and/or nonprofessional phagocytic cells, with in vivo consequences. This review provides updated information and describes the tools that A. baumannii possesses to adhere, colonize, and replicate in host cells. Additionally, we emphasize the high genetic and phenotypic heterogeneity detected amongst A. baumannii isolates and its impact on the bacterial intracellular features. We also discuss the need for standardized methods to characterize this pathogen robustly and consequently consider some strains as facultative intracellular bacteria.
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Affiliation(s)
- Alexandra Maure
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Etienne Robino
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Charles Van der Henst
- Microbial Resistance and Drug Discovery, VIB-VUB Center for Structural Biology, VIB, Flanders Institute for Biotechnology, Brussels, Belgium; Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium.
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8
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Young M, Chojnacki M, Blanchard C, Cao X, Johnson WL, Flaherty D, Dunman PM. Genetic Determinants of Acinetobacter baumannii Serum-Associated Adaptive Efflux-Mediated Antibiotic Resistance. Antibiotics (Basel) 2023; 12:1173. [PMID: 37508269 PMCID: PMC10376123 DOI: 10.3390/antibiotics12071173] [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: 06/09/2023] [Revised: 07/05/2023] [Accepted: 07/06/2023] [Indexed: 07/30/2023] Open
Abstract
Acinetobacter baumannii is a nosocomial pathogen of serious healthcare concern that is becoming increasingly difficult to treat due to antibiotic treatment failure. Recent studies have revealed that clinically defined antibiotic-susceptible strains upregulate the expression of a repertoire of putative drug efflux pumps during their growth under biologically relevant conditions, e.g., in human serum, resulting in efflux-associated resistance to physiologically achievable antibiotic levels within a patient. This phenomenon, termed Adaptive Efflux Mediated Resistance (AEMR), has been hypothesized to account for one mechanism by which antibiotic-susceptible A. baumannii fails to respond to antibiotic treatment. In the current study, we sought to identify genetic determinants that contribute to A. baumannii serum-associated AEMR by screening a transposon mutant library for members that display a loss of the AEMR phenotype. Results revealed that mutation of a putative pirin-like protein, YhaK, results in a loss of AEMR, a phenotype that could be complemented by a wild-type copy of the yhaK gene and was verified in a second strain background. Ethidium bromide efflux assays confirmed that the loss of AEMR phenotype due to pirin-like protein mutation correlated with reduced overarching efflux capacity. Further, flow cytometry and confocal microscopy measures of a fluorophore 7-(dimethylamino)-coumarin-4-acetic acid (DMACA)-tagged levofloxacin isomer, ofloxacin, further verified that YhaK mutation reduces AEMR-mediated antibiotic efflux. RNA-sequencing studies revealed that YhaK may be required for the expression of multiple efflux-associated systems, including MATE and ABC families of efflux pumps. Collectively, the data indicate that the A. baumannii YhaK pirin-like protein plays a role in modulating the organism's adaptive efflux-mediated resistance phenotype.
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Affiliation(s)
- Mikaeel Young
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA; (M.Y.); (M.C.); (W.L.J.)
| | - Michaelle Chojnacki
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA; (M.Y.); (M.C.); (W.L.J.)
| | - Catlyn Blanchard
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA; (M.Y.); (M.C.); (W.L.J.)
| | - Xufeng Cao
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University College of Pharmacy, Lafayette, IN 47907, USA
| | - William L. Johnson
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA; (M.Y.); (M.C.); (W.L.J.)
| | - Daniel Flaherty
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University College of Pharmacy, Lafayette, IN 47907, USA
- Purdue Institute for Drug Discovery, West Lafayette, IN 47907, USA
- Purdue Institute of Inflammation, Immunology and Infectious Disease, West Lafayette, IN 47907, USA
| | - Paul M. Dunman
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA; (M.Y.); (M.C.); (W.L.J.)
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Cavallo I, Oliva A, Pages R, Sivori F, Truglio M, Fabrizio G, Pasqua M, Pimpinelli F, Di Domenico EG. Acinetobacter baumannii in the critically ill: complex infections get complicated. Front Microbiol 2023; 14:1196774. [PMID: 37425994 PMCID: PMC10325864 DOI: 10.3389/fmicb.2023.1196774] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/05/2023] [Indexed: 07/11/2023] Open
Abstract
Acinetobacter baumannii is increasingly associated with various epidemics, representing a serious concern due to the broad level of antimicrobial resistance and clinical manifestations. During the last decades, A. baumannii has emerged as a major pathogen in vulnerable and critically ill patients. Bacteremia, pneumonia, urinary tract, and skin and soft tissue infections are the most common presentations of A. baumannii, with attributable mortality rates approaching 35%. Carbapenems have been considered the first choice to treat A. baumannii infections. However, due to the widespread prevalence of carbapenem-resistant A. baumannii (CRAB), colistin represents the main therapeutic option, while the role of the new siderophore cephalosporin cefiderocol still needs to be ascertained. Furthermore, high clinical failure rates have been reported for colistin monotherapy when used to treat CRAB infections. Thus, the most effective antibiotic combination remains disputed. In addition to its ability to develop antibiotic resistance, A. baumannii is also known to form biofilm on medical devices, including central venous catheters or endotracheal tubes. Thus, the worrisome spread of biofilm-producing strains in multidrug-resistant populations of A. baumannii poses a significant treatment challenge. This review provides an updated account of antimicrobial resistance patterns and biofilm-mediated tolerance in A. baumannii infections with a special focus on fragile and critically ill patients.
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Affiliation(s)
- Ilaria Cavallo
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Alessandra Oliva
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Rebecca Pages
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Francesca Sivori
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Mauro Truglio
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Giorgia Fabrizio
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Martina Pasqua
- Department of Biology and Biotechnology "C. Darwin" Sapienza University of Rome, Rome, Italy
| | - Fulvia Pimpinelli
- Microbiology and Virology, San Gallicano Dermatological Institute, IRCCS, Rome, Italy
| | - Enea Gino Di Domenico
- Department of Biology and Biotechnology "C. Darwin" Sapienza University of Rome, Rome, Italy
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10
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Ren X, Palmer LD. Acinetobacter Metabolism in Infection and Antimicrobial Resistance. Infect Immun 2023:e0043322. [PMID: 37191522 DOI: 10.1128/iai.00433-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023] Open
Abstract
Acinetobacter infections have high rates of mortality due to an increasing incidence of infections by multidrug-resistant (MDR) and extensively-drug-resistant (XDR) strains. Therefore, new therapeutic strategies for the treatment of Acinetobacter infections are urgently needed. Acinetobacter spp. are Gram-negative coccobacilli that are obligate aerobes and can utilize a wide variety of carbon sources. Acinetobacter baumannii is the main cause of Acinetobacter infections, and recent work has identified multiple strategies A. baumannii uses to acquire nutrients and replicate in the face of host nutrient restriction. Some host nutrient sources also serve antimicrobial and immunomodulatory functions. Hence, understanding Acinetobacter metabolism during infection may provide new insights into novel infection control measures. In this review, we focus on the role of metabolism during infection and in resistance to antibiotics and other antimicrobial agents and discuss the possibility that metabolism may be exploited to identify novel targets to treat Acinetobacter infections.
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Affiliation(s)
- Xiaomei Ren
- Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, Illinois, USA
| | - Lauren D Palmer
- Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, Illinois, USA
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11
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Pulami D, Schwabe L, Blom J, Schwengers O, Wilharm G, Kämpfer P, Glaeser SP. Genomic plasticity and adaptive capacity of the quaternary alkyl-ammonium compound and copper tolerant Acinetobacter bohemicus strain QAC-21b isolated from pig manure. Antonie Van Leeuwenhoek 2023; 116:327-342. [PMID: 36642771 PMCID: PMC10024671 DOI: 10.1007/s10482-022-01805-w] [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: 09/12/2022] [Accepted: 12/26/2022] [Indexed: 01/17/2023]
Abstract
Here, we present the genomic characterization of an Acinetobacter bohemicus strain QAC-21b which was isolated in the presence of a quaternary alky-ammonium compound (QAAC) from manure of a conventional German pig farm. The genetic determinants for QAAC, heavy metal and antibiotic resistances are reported based of the whole genome shotgun sequence and physiological growth tests. A. bohemicus QAC-21b grew in a species typical manner well at environmental temperatures but not at 37 °C. The strain showed tolerance to QAACs and copper but was susceptible to antibiotics relevant for Acinetobacter treatments. The genome of QAC-21b contained several Acinetobacter typical QAAC and heavy metal transporting efflux pumps coding genes, but no key genes for acquired antimicrobial resistances. The high genomic content of transferable genetic elements indicates that this bacterium can be involved in the transmission of antimicrobial resistances, if it is released with manure as organic fertilizer on agricultural fields. The genetic content of the strain was compared to that of two other A. bohemicus strains, the type strain ANC 3994T, isolated from forest soil, and KCTC 42081, originally described as A. pakistanensis, a metal resistant strain isolated from a wastewater treatment pond. In contrast to the forest soil strain, both strains from anthropogenically impacted sources showed genetic features indicating their evolutionary adaptation to the anthropogenically impacted environments. Strain QAC-21b will be used as model strain to study the transmission of antimicrobial resistance to environmentally adapted Acinetobacter in agricultural environments receiving high content of pollutants with organic fertilizers from livestock husbandry.
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Affiliation(s)
- Dipen Pulami
- Institute of Applied Microbiology, Justus-Liebig University Giessen, 35392, Giessen, Germany
| | - Lina Schwabe
- Institute of Applied Microbiology, Justus-Liebig University Giessen, 35392, Giessen, Germany
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig University Giessen, 35392, Giessen, Germany
| | - Oliver Schwengers
- Bioinformatics and Systems Biology, Justus-Liebig University Giessen, 35392, Giessen, Germany
| | - Gottfried Wilharm
- Project Group P2, Robert Koch Institute, Wernigerode Branch, 38855, Wernigerode, Germany
| | - Peter Kämpfer
- Institute of Applied Microbiology, Justus-Liebig University Giessen, 35392, Giessen, Germany
| | - Stefanie P Glaeser
- Institute of Applied Microbiology, Justus-Liebig University Giessen, 35392, Giessen, Germany.
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12
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The Prevalence of Virulence Factor Genes among Carbapenem-Non-Susceptible Acinetobacter baumannii Clinical Strains and Their Usefulness as Potential Molecular Biomarkers of Infection. Diagnostics (Basel) 2023; 13:diagnostics13061036. [PMID: 36980344 PMCID: PMC10047099 DOI: 10.3390/diagnostics13061036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/25/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023] Open
Abstract
Healthcare-associated infections caused by multidrug-resistant Acinetobacter baumannii strains are a serious global threat. Therefore, it is important to expand the knowledge on the mechanisms of pathogenicity of these particular bacteria. The aim of this study was to assess the distribution of selected virulence factor genes (bap, surA1, omp33-36, bauA, bauS, and pld) among carbapenem-non-susceptible clinical A. baumannii isolates and to evaluate their potential usefulness as genetic markers for rapid diagnostics of A. baumannii infections. Moreover, we aimed to compare the virulence genes prevalence with the occurrence of carbapenemases genes. A total of 100 carbapenem-non-susceptible A. baumannii clinical isolates were included in the study. The presence of virulence factors and blaOXA genes was evaluated by real-time PCR. The occurrence of virulence factors genes was as follows: 100.0% for the bap and surA1 genes, 99.0% for the basD and pld genes. The bauA and omp33-36 genes were absent among the studied strains. The predominant genes (bap and surA1) are involved in biofilm formation and their presence among all clinical strains can be applied as a genetic marker to recognize A. baumannii infection. High frequencies of the basD gene—involved in siderophore biosynthesis and the gene encoding phospholipase D (pld)—were also noted among blaOXA-positive strains, showing their potential role in a pathogenicity of blaOXA-positive A. baumannii clinical strains.
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Mohamad F, Alzahrani RR, Alsaadi A, Alrfaei BM, Yassin AEB, Alkhulaifi MM, Halwani M. An Explorative Review on Advanced Approaches to Overcome Bacterial Resistance by Curbing Bacterial Biofilm Formation. Infect Drug Resist 2023; 16:19-49. [PMID: 36636380 PMCID: PMC9830422 DOI: 10.2147/idr.s380883] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 12/06/2022] [Indexed: 01/05/2023] Open
Abstract
The continuous emergence of multidrug-resistant pathogens evoked the development of innovative approaches targeting virulence factors unique to their pathogenic cascade. These approaches aimed to explore anti-virulence or anti-infective therapies. There are evident concerns regarding the bacterial ability to create a superstructure, the biofilm. Biofilm formation is a crucial virulence factor causing difficult-to-treat, localized, and systemic infections. The microenvironments of bacterial biofilm reduce the efficacy of antibiotics and evade the host's immunity. Producing a biofilm is not limited to a specific group of bacteria; however, Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus biofilms are exemplary models. This review discusses biofilm formation as a virulence factor and the link to antimicrobial resistance. In addition, it explores insights into innovative multi-targeted approaches and their physiological mechanisms to combat biofilms, including natural compounds, phages, antimicrobial photodynamic therapy (aPDT), CRISPR-Cas gene editing, and nano-mediated techniques.
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Affiliation(s)
- F Mohamad
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Raghad R Alzahrani
- Nanomedicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia,Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Ahlam Alsaadi
- Infectious Diseases Research Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Bahauddeen M Alrfaei
- Stem Cells and Regenerative Medicine, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Alaa Eldeen B Yassin
- College of Pharmacy, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Manal M Alkhulaifi
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia,Manal M Alkhulaifi, P.O. Box 55670, Riyadh, 11544, Tel +966 (11) 805-1685, Email
| | - Majed Halwani
- Nanomedicine Department, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia,Correspondence: Majed Halwani, P.O. Box 3660, Mail Code 1515 (KAIMRC), Riyadh, 11481, Tel +966 (11) 429-4433, Fax +966 (11) 429-4440, Email ;
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Neutrophil trafficking to the site of infection requires Cpt1a-dependent fatty acid β-oxidation. Commun Biol 2022; 5:1366. [PMID: 36513703 PMCID: PMC9747976 DOI: 10.1038/s42003-022-04339-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 12/05/2022] [Indexed: 12/15/2022] Open
Abstract
Cellular metabolism influences immune cell function, with mitochondrial fatty acid β-oxidation and oxidative phosphorylation required for multiple immune cell phenotypes. Carnitine palmitoyltransferase 1a (Cpt1a) is considered the rate-limiting enzyme for mitochondrial metabolism of long-chain fatty acids, and Cpt1a deficiency is associated with infant mortality and infection risk. This study was undertaken to test the hypothesis that impairment in Cpt1a-dependent fatty acid oxidation results in increased susceptibility to infection. Screening the Cpt1a gene for common variants predicted to affect protein function revealed allele rs2229738_T, which was associated with pneumonia risk in a targeted human phenome association study. Pharmacologic inhibition of Cpt1a increases mortality and impairs control of the infection in a murine model of bacterial pneumonia. Susceptibility to pneumonia is associated with blunted neutrophilic responses in mice and humans that result from impaired neutrophil trafficking to the site of infection. Chemotaxis responsible for neutrophil trafficking requires Cpt1a-dependent mitochondrial fatty acid oxidation for amplification of chemoattractant signals. These findings identify Cpt1a as a potential host determinant of infection susceptibility and demonstrate a requirement for mitochondrial fatty acid oxidation in neutrophil biology.
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Acar MB, Ayaz-Güner Ş, Güner H, Dinç G, Ulu Kılıç A, Doğanay M, Özcan S. A subtractive proteomics approach for the identification of immunodominant Acinetobacter baumannii vaccine candidate proteins. Front Immunol 2022; 13:1001633. [DOI: 10.3389/fimmu.2022.1001633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 10/10/2022] [Indexed: 11/11/2022] Open
Abstract
BackgroundAcinetobacter baumannii is one of the most life-threatening multidrug-resistant pathogens worldwide. Currently, 50%–70% of clinical isolates of A. baumannii are extensively drug-resistant, and available antibiotic options against A. baumannii infections are limited. There is still a need to discover specific de facto bacterial antigenic proteins that could be effective vaccine candidates in human infection. With the growth of research in recent years, several candidate molecules have been identified for vaccine development. So far, no public health authorities have approved vaccines against A. baumannii.MethodsThis study aimed to identify immunodominant vaccine candidate proteins that can be immunoprecipitated specifically with patients’ IgGs, relying on the hypothesis that the infected person’s IgGs can capture immunodominant bacterial proteins. Herein, the outer-membrane and secreted proteins of sensitive and drug-resistant A. baumannii were captured using IgGs obtained from patient and healthy control sera and identified by Liquid Chromatography- Tandem Mass Spectrometry (LC-MS/MS) analysis.ResultsUsing the subtractive proteomic approach, we determined 34 unique proteins captured only in drug-resistant A. baumannii strain via patient sera. After extensively evaluating the predicted epitope regions, solubility, transverse membrane characteristics, and structural properties, we selected several notable vaccine candidates.ConclusionWe identified vaccine candidate proteins that triggered a de facto response of the human immune system against the antibiotic-resistant A. baumannii. Precipitation of bacterial proteins via patient immunoglobulins was a novel approach to identifying the proteins that could trigger a response in the patient immune system.
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Pérez Jorge G, Rodrigues dos Santos Goes IC, Gontijo MTP. Les misérables: a Parallel Between Antimicrobial Resistance and COVID-19 in Underdeveloped and Developing Countries. Curr Infect Dis Rep 2022; 24:175-186. [PMID: 36211535 PMCID: PMC9531231 DOI: 10.1007/s11908-022-00788-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2022] [Indexed: 12/02/2022]
Abstract
Purpose of Review The COVID-19 pandemic has been responsible for more than 6.3 million deaths worldwide. During the pandemic, the indiscriminate use of antibiotics has increased, contributing to the spread of multidrug-resistant bacteria. In this review, we aim to determine the spread and impact of antibiotic treatments in patients with COVID-19, focusing on underdeveloped and developing countries. Recent Findings Meta-analysis revealed that bacterial co-infections and secondary infections are relatively rare in COVID-19 patients, corresponding to less than 20% of hospitalized patients. Even so, most of these patients have received antibiotic treatments. Summary This review discusses how the COVID-19 pandemic could increase the emergence of multidrug-resistant strains to currently available antibiotics. Initially, we discussed the spread and impact of multidrug resistance of ESKAPE pathogens associated with nosocomial infections and analyzed their risk of secondary infections in patients with COVID-19. Then we highlight three factors related to the spread of resistant bacteria during the current pandemic: overprescription of antibiotics followed by self-medication. Finally, we discussed the lack of availability of diagnostic tests to discriminate the etiologic agent of a disease. All these factors lead to inappropriate use of antibiotics and, therefore, to an increase in the prevalence of resistance, which can have devastating consequences shortly. The data compiled in this study underscore the importance of epidemiological surveillance of hospital isolates to provide new strategies for preventing and controlling infections caused by multidrug-resistant bacteria. In addition, the bibliographic research also highlights the need for an improvement in antibiotic prescribing in the health system.
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Affiliation(s)
- Genesy Pérez Jorge
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas, Rua Monteiro Lobato 255, Campinas, SP 13083-862 Brazil
- Laboratorio de Investigaciones Biomédicas, Universidad de Sucre, Cra. 28 #5-267, Sincelejo, Sucre, Colômbia
| | - Isabella Carolina Rodrigues dos Santos Goes
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas, Rua Monteiro Lobato 255, Campinas, SP 13083-862 Brazil
| | - Marco Tulio Pardini Gontijo
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas, Rua Monteiro Lobato 255, Campinas, SP 13083-862 Brazil
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, 10 Duke Medicine Cir, Durham, NC 27710 USA
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Tobuse AJ, Ang CW, Yeong KY. Modern vaccine development via reverse vaccinology to combat antimicrobial resistance. Life Sci 2022; 302:120660. [PMID: 35642852 DOI: 10.1016/j.lfs.2022.120660] [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: 03/25/2022] [Revised: 05/02/2022] [Accepted: 05/19/2022] [Indexed: 10/18/2022]
Abstract
With the continuous evolution of bacteria, the global antimicrobial resistance health threat is causing millions of deaths yearly. While depending on antibiotics as a primary treatment has its merits, there are no effective alternatives thus far in the pharmaceutical market against some drug-resistant bacteria. In recent years, vaccinology has become a key topic in scientific research. Combining with the growth of technology, vaccine research is seeing a new light where the process is made faster and more efficient. Although less discussed, bacterial vaccine is a feasible strategy to combat antimicrobial resistance. Some vaccines have shown promising results with good efficacy against numerous multidrug-resistant strains of bacteria. In this review, we aim to discuss the findings from studies utilizing reverse vaccinology for vaccine development against some multidrug-resistant bacteria, as well as provide a summary of multi-year bacterial vaccine studies in clinical trials. The advantages of reverse vaccinology in the generation of new bacterial vaccines are also highlighted. Meanwhile, the limitations and future prospects of bacterial vaccine concludes this review.
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Affiliation(s)
- Asuka Joy Tobuse
- School of Science, Monash University Malaysia Campus, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia
| | - Chee Wei Ang
- School of Science, Monash University Malaysia Campus, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia
| | - Keng Yoon Yeong
- School of Science, Monash University Malaysia Campus, Jalan Lagoon Selatan, Bandar Sunway 47500, Selangor, Malaysia.
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Ries JI, Heß M, Nouri N, Wichelhaus TA, Göttig S, Falcone FH, Kraiczy P. CipA mediates complement resistance of Acinetobacter baumannii by formation of a factor I-dependent quadripartite assemblage. Front Immunol 2022; 13:942482. [PMID: 35958553 PMCID: PMC9361855 DOI: 10.3389/fimmu.2022.942482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/24/2022] [Indexed: 11/29/2022] Open
Abstract
Multidrug-resistant Acinetobacter baumannii is known to be one of the leading pathogens that cause severe nosocomial infections. To overcome eradication by the innate immune system during infection, A. baumannii developed a number of immune evasion strategies. Previously, we identified CipA as a plasminogen-binding and complement-inhibitory protein. Here we show that CipA inhibits all three complement activation pathways and interacts with key complement components C3, C3b, C4b, C5, Factor B, Factor D, and in particular Factor I. CipA also targets function of the C5 convertase as cleavage of C5 was impaired. Systematic screening of CipA variants identified two separate binding sites for C3b and a Factor I-interacting domain located at the C-terminus. Structure predictions using AlphaFold2 and binding analyses employing CipA variants lacking Factor I-binding capability confirmed that the orientation of the C-terminal domain is essential for the interaction with Factor I. Hence, our analyses point to a novel Factor I-dependent mechanisms of complement inactivation mediated by CipA of A. baumannii. Recruitment of Factor I by CipA initiates the assembly of a quadripartite complex following binding of either Factor H or C4b-binding protein to degrade C3b and C4b, respectively. Loss of Factor I binding in a CipA-deficient strain, or a strain producing a CipA variant lacking Factor I-binding capability, correlated with a higher susceptibility to human serum, indicating that recruitment of Factor I enables A. baumannii to resist complement-mediated killing.
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Affiliation(s)
- Julia I. Ries
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
| | - Marie Heß
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
| | - Noura Nouri
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
| | - Thomas A. Wichelhaus
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
| | - Stephan Göttig
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
| | - Franco H. Falcone
- Institute for Parasitology, Biomedical Research Center Seltersberg, Justus Liebig University Giessen, Giessen, Germany
| | - Peter Kraiczy
- Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Goethe University Frankfurt, Frankfurt, Germany
- *Correspondence: Peter Kraiczy,
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19
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Wijers CDM, Pham L, Douglass MV, Skaar EP, Palmer LD, Noto MJ. Gram-negative bacteria act as a reservoir for aminoglycoside antibiotics that interact with host factors to enhance bacterial killing in a mouse model of pneumonia. FEMS MICROBES 2022; 3:xtac016. [PMID: 35909464 PMCID: PMC9326624 DOI: 10.1093/femsmc/xtac016] [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: 01/26/2022] [Revised: 05/04/2022] [Accepted: 05/11/2022] [Indexed: 01/28/2023] Open
Abstract
In vitro exposure of multiple Gram-negative bacteria to an aminoglycoside (AG) antibiotic has previously been demonstrated to result in bacterial alterations that interact with host factors to suppress Gram-negative pneumonia. However, the mechanisms resulting in suppression are not known. Here, the hypothesis that Gram-negative bacteria bind and retain AGs, which are introduced into the lung and interact with host defenses to affect bacterial killing, was tested. Following in vitro exposure of one of several, pathogenic Gram-negative bacteria to the AG antibiotics kanamycin or gentamicin, AGs were detected in bacterial cell pellets (up to 208 μg/mL). Using inhibitors of AG binding and internalization, the bacterial outer membrane was implicated as the predominant kanamycin and gentamicin reservoir. Following intranasal administration of gentamicin-bound bacteria or gentamicin solution at the time of infection with live, AG-naïve bacteria, gentamicin was detected in the lungs of infected mice (up to 8 μg/g). Co-inoculation with gentamicin-bound bacteria resulted in killing of AG-naïve bacteria by up to 3-log10, mirroring the effects of intranasal gentamicin treatment. In vitro killing of AG-naïve bacteria mediated by kanamycin-bound bacteria required the presence of detergents or pulmonary surfactant, suggesting that increased bacterial killing inside the murine lung is facilitated by the detergent component of pulmonary surfactant. These findings demonstrate that Gram-negative bacteria bind and retain AGs that can interact with host-derived pulmonary surfactant to enhance bacterial killing in the lung. This may help explain why AGs appear to have unique efficacy in the lung and might expand their clinical utility.
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Affiliation(s)
- Christiaan D M Wijers
- Department of Pathology, Microbiology, and Immunology, Vanderbilt
University Medical Center, 1161 21st Avenue South, Nashville, TN 37232,
United States,Vanderbilt Institute for Infection, Immunology, and Inflammation,
Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville,
TN 37232, United States
| | - Ly Pham
- Department of Pathology, Microbiology, and Immunology, Vanderbilt
University Medical Center, 1161 21st Avenue South, Nashville, TN 37232,
United States,Vanderbilt Institute for Infection, Immunology, and Inflammation,
Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville,
TN 37232, United States
| | - Martin V Douglass
- Department of Pathology, Microbiology, and Immunology, Vanderbilt
University Medical Center, 1161 21st Avenue South, Nashville, TN 37232,
United States,Vanderbilt Institute for Infection, Immunology, and Inflammation,
Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville,
TN 37232, United States
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt
University Medical Center, 1161 21st Avenue South, Nashville, TN 37232,
United States,Vanderbilt Institute for Infection, Immunology, and Inflammation,
Vanderbilt University Medical Center, 1161 21st Avenue South, Nashville,
TN 37232, United States
| | - Lauren D Palmer
- Department of Microbiology and Immunology, University of Illinois
Chicago, 835 South Wolcott Avenue, Chicago, IL 60612, United States
| | - Michael J Noto
- Corresponding author: Room 205H Whitehead Biomedical Research Building, Emory
University, 615 Michael Street, Atlanta, GA 30322, United States. Tel: (+404)712-2988;
E-mail:
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Bacterial hydrophilins promote pathogen desiccation tolerance. Cell Host Microbe 2022; 30:975-987.e7. [PMID: 35413266 DOI: 10.1016/j.chom.2022.03.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 02/14/2022] [Accepted: 03/17/2022] [Indexed: 11/21/2022]
Abstract
Acinetobacter baumannii is a leading cause of hospital-acquired infections, where outbreaks are driven by its ability to persist on surfaces in a desiccated state. Here, we show that A. baumannii causes more virulent pneumonia following desiccation and profile the genetic requirements for desiccation. We find that desiccation tolerance is enhanced upon the disruption of Lon protease, which targets unfolded and aggregated proteins for degradation. Notably, two bacterial hydrophilins, DtpA and DtpB, are transcriptionally upregulated in Δlon via the two-component regulator, BfmR. These proteins, both hydrophilic and intrinsically disordered, promote desiccation tolerance in A. baumannii. Additionally, recombinant DtpA protects purified enzymes from inactivation and improves the desiccation tolerance of a probiotic bacterium when heterologously expressed. These results demonstrate a connection between environmental persistence and pathogenicity in A. baumannii, provide insight into the mechanisms of extreme desiccation tolerance, and reveal potential applications for bacterial hydrophilins in the preservation of protein- and live bacteria-based pharmaceuticals.
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Gülbüz M, Saral Sariyer A. Combined in silico approach and whole genome sequencing: Acinetobacter baumannii ST218 isolate harboring ADC-73 β-lactamase which has a similar C-loop with ADC-56 and ADC-68 β-lactamase. J Mol Graph Model 2022; 114:108195. [DOI: 10.1016/j.jmgm.2022.108195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 04/07/2022] [Accepted: 04/11/2022] [Indexed: 11/28/2022]
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Liu X, Tang R, Li H, Wang L, Wan C. The physiological and ecological properties of bacterial persisters discovered from municipal sewage sludge and the potential risk. ENVIRONMENTAL RESEARCH 2022; 205:112481. [PMID: 34871595 DOI: 10.1016/j.envres.2021.112481] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/21/2021] [Accepted: 11/29/2021] [Indexed: 06/13/2023]
Abstract
Bacterial persisters are a special microbial population and are considered to be the bacterial reservoir of antibiotic-resistant bacteria. They can survive antibiotic treatment even in high concentrations of antibiotics and revive in the appropriate conditions. However, the characteristics of bacterial persisters in the municipal sewage sludge and their potential environmental risks have not yet been paid much attention to. In this study, bacterial persisters were discovered from the sludge of wastewater treatment plants in four different regions (Jilin, Lhasa, Shenzhen, and Yili), and the metagenomic analysis confirmed that bacterial persisters were ubiquitous in all four municipal sewage sludge and positively related to the protobacterium populations. At the taxonomic genus level, a total of 57 genera of bacterial persisters were shared by the four sewage sludge, and the genera with abundance exceeding 2% were Acinetobacter, Lysinibacillus, Aeromonas, Brevundimonas, Pseudomonas, and Alcaligenes, among which Acinetobacter accounted for 57.24%. Genus Lysinibacillus and Aeromonas were significant in Jilin and Lhasa, respectively. The persistence mechanism of bacterial persisters derived from sludge was also clarified, among which, Aeromonas, Brevundimonas, and Alcaligenes rely on the hipBA toxin-antitoxin system, while Acinetobacter enters the persistence state mainly through the stringent response system based on (p)ppGpp. Moreover, it was found that a typical bacterial persister originated from Acinetobacter, named T9-9, could tolerate a variety of antibiotics, such as 1000 μg/mL of kanamycin, 160 μg/mL of tetracycline, and 30 μg/mL of ciprofloxacin. Even if the ultraviolet intensity was 6-36 times the usual dosage of ultraviolet disinfection in wastewater treatment plants, it could not completely kill T9-9, but the killing efficiency by chlorine disinfection technology could reach 100%. This study pointed out an environmental risk of bacterial persisters that existed in sewage sludge that had been neglected and strongly recommended to improve the disinfection process in the wastewater treatment plant.
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Affiliation(s)
- Xiang Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China.
| | - Rui Tang
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China
| | - Huiqi Li
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China
| | - Li Wang
- Center of Analysis and Measurement, Fudan University, Shanghai, 200438, China
| | - Chunli Wan
- Department of Environmental Science and Engineering, Fudan University, Shanghai, 200438, China.
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Sadat MA, Ullah MW, Hossain MS, Ahmed B, Bashar KK. Genome-wide in silico identification of phospholipase D (PLD) gene family from Corchorus capsularis and Corchorus olitorius: reveals their responses to plant stress. J Genet Eng Biotechnol 2022; 20:28. [PMID: 35147846 PMCID: PMC8837719 DOI: 10.1186/s43141-022-00311-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 01/30/2022] [Indexed: 11/17/2022]
Abstract
Background Plant grows in nature facing various types of abiotic stresses for their normal growth and development. During abiotic stress, plants evolve different types of mechanisms to survive in a hostile environment. Phospholipase D (PLD) plays important role in the regulation of diverse cellular processes including stress responses in plants. Member of PLD genes are well studied in different model plants; however, their functions in the jute are not clear yet. Result In the present study, a total of 12 and 11 PLD genes were identified in the genome of C. capsularis and C. olitorius, respectively. The presence of the two conserved HKD motifs in PLD genes except for CoPLDδ-2 in jute suggests their strong lipase activity. Twenty different motifs were found in the identified PLD genes, and PLD-β1, PLD-γ1, and all members of PLD-δ1 of both jute species contained the highest number of motifs. Phylogenetic analysis showed the close evolutionary relationship among the five groups of jute PLD proteins along with the PLD proteins from Arabidopsis. Tissue-specific expression pattern of PLDα1-2, PLD-α2, PLDβ1, PLDγ1, and PLDδ1 of two jute species suggested their involvement in plant growth and development. However, the expression pattern of PLDα1-2, PLDα1-3, PLD-α4, PLDδ1, and PLDδ3 indicated their association during waterlogging stress. In addition, PLD-α2, PLDβ1, and PLDδ2 seemed to be involved in drought stress as well as salinity stress. Conclusion This genome-wide identification of jute PLD genes from C. capsularis and C. olitorius will help to further functional characterization of the PLD genes for developing stress-tolerant jute variety.
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Affiliation(s)
- Md Abu Sadat
- Basic and Applied Research on Jute Project, Bangladesh Jute Research Institute, Manik Mia Avenue, Dhaka, 1207, Bangladesh.
| | - Md Wali Ullah
- Basic and Applied Research on Jute Project, Bangladesh Jute Research Institute, Manik Mia Avenue, Dhaka, 1207, Bangladesh
| | - Md Sabbir Hossain
- Basic and Applied Research on Jute Project, Bangladesh Jute Research Institute, Manik Mia Avenue, Dhaka, 1207, Bangladesh
| | - Borhan Ahmed
- Basic and Applied Research on Jute Project, Bangladesh Jute Research Institute, Manik Mia Avenue, Dhaka, 1207, Bangladesh
| | - Kazi Khayrul Bashar
- Basic and Applied Research on Jute Project, Bangladesh Jute Research Institute, Manik Mia Avenue, Dhaka, 1207, Bangladesh
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Abstract
The spread of antibiotic-resistant Acinetobacter baumannii poses a significant threat to public health worldwide. This nosocomial bacterial pathogen can be associated with life-threatening infections, particularly in intensive care units. A. baumannii is mainly described as an extracellular pathogen with restricted survival within cells. This study shows that a subset of A. baumannii clinical isolates extensively multiply within nonphagocytic immortalized and primary cells without the induction of apoptosis and with bacterial clusters visible up to 48 h after infection. This phenotype was observed for the A. baumannii C4 strain associated with high mortality in a hospital outbreak and the A. baumannii ABC141 strain, which was isolated from the skin but was found to be hyperinvasive. Intracellular multiplication of these A. baumannii strains occurred within spacious single membrane-bound vacuoles, labeled with the lysosomal associate membrane protein (LAMP1). However, these compartments excluded lysotracker, an indicator of acidic pH, suggesting that A. baumannii can divert its trafficking away from the lysosomal degradative pathway. These compartments were also devoid of autophagy features. A high-content microscopy screen of 43 additional A. baumannii clinical isolates highlighted various phenotypes, and (i) the majority of isolates remained extracellular, (ii) a significant proportion was capable of invasion and limited persistence, and (iii) three more isolates efficiently multiplied within LAMP1-positive vacuoles, one of which was also hyperinvasive. These data identify an intracellular niche for specific A. baumannii clinical isolates that enables extensive multiplication in an environment protected from host immune responses and out of reach of many antibiotics. IMPORTANCE Multidrug-resistant Acinetobacter baumannii isolates are associated with significant morbidity and mortality in hospitals worldwide. Understanding their pathogenicity is critical for improving therapeutic management. Although A. baumannii can steadily adhere to surfaces and host cells, most bacteria remain extracellular. Recent studies have shown that a small proportion of bacteria can invade cells but present limited survival. We have found that some A. baumannii clinical isolates can establish a specialized intracellular niche that sustains extensive intracellular multiplication for a prolonged time without induction of cell death. We propose that this intracellular compartment allows A. baumannii to escape the cell’s normal degradative pathway, protecting bacteria from host immune responses and potentially hindering antibiotic accessibility. This may contribute to A. baumannii persistence, relapsing infections, and enhanced mortality in susceptible patients. A high-content microscopy-based screen confirmed that this pathogenicity trait is present in other clinical A. baumannii isolates. There is an urgent need for new antibiotics or alternative antimicrobial approaches, particularly to combat carbapenem-resistant A. baumannii. The discovery of an intracellular niche for this pathogen, as well as hyperinvasive isolates, may help guide the development of antimicrobial therapies and diagnostics in the future.
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Tansho-Nagakawa S, Sato Y, Ubagai T, Kikuchi-Ueda T, Kamoshida GO, Nishida S, Ono Y. Histopathological Analysis of Acinetobacter baumannii Lung Infection in a Mouse Model. Pol J Microbiol 2022; 70:469-477. [PMID: 35003278 PMCID: PMC8702610 DOI: 10.33073/pjm-2021-044] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/31/2021] [Indexed: 11/20/2022] Open
Abstract
Acinetobacter baumannii is the main causative pathogen of nosocomial infections that causes severe infections in the lungs. In this study, we analyzed the histopathological characteristics of lung infection with two strains of A. baumannii (ATCC 19606 and the clinical isolate TK1090) and Pseudomonas aeruginosa PAO-1 in C3H/HeN mice to evaluate the virulence of A. baumannii. Survival was evaluated over 14 days. At 1, 2, 5, or 14 days postinfection, mice of C3H/HeN were sacrificed, and histopathological analysis of lung specimens was also performed. Histopathological changes and accumulation of neutrophils and macrophages in the lungs after infection with A. baumannii and P. aeruginosa were analyzed. Following intratracheal inoculation, the lethality of ATCC 19606- and TK1090-infected mice was lower than that of PAO-1-infected mice. However, when mice were inoculated with a sub-lethal dose of A. baumannii, the lung bacterial burden remained in the mice until 14 days post-infection. Additionally, histopathological analysis revealed that macrophages infiltrated the lung foci of ATCC 19606-, TK1090-, and PAO-1-infected mice. Although neutrophils infiltrated the lung foci of ATCC 19606- and TK1090-infected mice, they poorly infiltrated the lung foci of PAO-1-infected mice. Accumulation of these cells in the lung foci of ATCC 19606- and TK1090-infected mice, but not PAO-1-infected mice, was observed for 14 days post-infection. These results suggest that A. baumannii is not completely eliminated despite the infiltration of immune cells in the lungs and that inflammation lasts for prolonged periods in the lungs. Further studies are required to understand the mechanism of A. baumannii infection, and novel drugs and vaccines should be developed to prevent A. baumannii infection.
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Affiliation(s)
- Shigeru Tansho-Nagakawa
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Yoshinori Sato
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Tsuneyuki Ubagai
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Takane Kikuchi-Ueda
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - G O Kamoshida
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Satoshi Nishida
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
| | - Yasuo Ono
- Department of Microbiology and Immunology, Teikyo University School of Medicine, Tokyo, Japan
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Kamuyu G, Ercoli G, Ramos-Sevillano E, Willcocks S, Kewcharoenwong C, Kiratisin P, Taylor PW, Wren BW, Lertmemongkolchai G, Stabler RA, Brown JS. Strain Specific Variations in Acinetobacter baumannii Complement Sensitivity. Front Immunol 2022; 13:853690. [PMID: 35812377 PMCID: PMC9258041 DOI: 10.3389/fimmu.2022.853690] [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: 01/12/2022] [Accepted: 05/27/2022] [Indexed: 12/02/2022] Open
Abstract
The complement system is required for innate immunity against Acinetobacter baumannii, an important cause of antibiotic resistant systemic infections. A. baumannii strains differ in their susceptibility to the membrane attack complex (MAC) formed from terminal complement pathway proteins, but the reasons for this variation remain poorly understood. We have characterized in detail the complement sensitivity phenotypes of nine A. baumannii clinical strains and some of the factors that might influence differences between strains. Using A. baumannii laboratory strains and flow cytometry assays, we first reconfirmed that both opsonization with the complement proteins C3b/iC3b and MAC formation were inhibited by the capsule. There were marked differences in C3b/iC3b and MAC binding between the nine clinical A. baumannii strains, but this variation was partially independent of capsule composition or size. Opsonization with C3b/iC3b improved neutrophil phagocytosis of most strains. Importantly, although C3b/iC3b binding and MAC formation on the bacterial surface correlated closely, MAC formation did not correlate with variations between A. baumannii strains in their levels of serum resistance. Genomic analysis identified only limited differences between strains in the distribution of genes required for serum resistance, but RNAseq data identified three complement-resistance genes that were differentially regulated between a MAC resistant and two MAC intermediate resistant strains when cultured in serum. These data demonstrate that clinical A. baumannii strains vary in their sensitivity to different aspects of the complement system, and that the serum resistance phenotype was influenced by factors in addition to the amount of MAC forming on the bacterial surface.
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Affiliation(s)
- Gathoni Kamuyu
- Centre for Inflammation and Tissue Repair, UCL Respiratory, University College London, London, United Kingdom
| | - Giuseppe Ercoli
- Centre for Inflammation and Tissue Repair, UCL Respiratory, University College London, London, United Kingdom
| | - Elisa Ramos-Sevillano
- Centre for Inflammation and Tissue Repair, UCL Respiratory, University College London, London, United Kingdom
| | - Sam Willcocks
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Chidchamai Kewcharoenwong
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Cellular and Molecular Immunology Unit, Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Pattarachai Kiratisin
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Peter W. Taylor
- School of Pharmacy, University College London, London, United Kingdom
| | - Brendan W. Wren
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Ganjana Lertmemongkolchai
- Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Cellular and Molecular Immunology Unit, Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Richard A. Stabler
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Jeremy S. Brown
- Centre for Inflammation and Tissue Repair, UCL Respiratory, University College London, London, United Kingdom
- *Correspondence: Jeremy S. Brown,
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Abstract
Infection by multidrug-resistant (MDR) Acinetobacter baumannii is one of the major causes of hospital-acquired infections worldwide. The ability of A. baumannii to survive in adverse conditions as well as its extensive antimicrobial resistance make it one of the most difficult to treat pathogens associated with high mortality rates. The aim of this study was to investigate MDR A. baumannii that has spread among pediatric cancer patients in the Children’s Cancer Hospital Egypt 57357. Whole-genome sequencing was used to characterize 31 MDR A. baumannii clinical isolates. Phenotypically, the isolates were MDR, with four isolates showing resistance to the last-resort antibiotic colistin. Multilocus sequence typing showed the presence of eight clonal groups, two of which were previously reported to cause outbreaks in Egypt, and one novel sequence type (ST), Oxf-ST2246. Identification of the circulating plasmids showed the presence of two plasmid lineages in the isolates, strongly governed by sequence type. A large number of antimicrobial genes with a range of resistance mechanisms were detected in the isolates, including β-lactamases and antibiotic efflux pumps. Analysis of insertion sequences (ISs) revealed the presence of ISAba1 and ISAba125 in all the samples, which amplify β-lactamase expression, causing extensive carbapenem resistance. Mutation analysis was used to decipher underlying mutations responsible for colistin resistance and revealed novel mutations in several outer membrane proteins, in addition to previously reported mutations in pmrB. Altogether, understanding the transmissibility of A. baumannii as well as its resistance and virulence mechanisms will help develop novel treatment options for better management of hospital-acquired infections. IMPORTANCEAcinetobacter baumannii represents a major health threat, in particular among immunocompromised cancer patients. The rise in carbapenem-resistant A. baumannii, and the development of resistance to the last-resort antimicrobial agent colistin, complicates the management of A. baumannii outbreaks and increases mortality rates. Here, we investigate 31 multidrug resistant A. baumannii isolates from pediatric cancer patients in Children’s Cancer Hospital Egypt (CCHE) 57357 via whole-genome sequencing. Multilocus sequence typing (MLST) showed the presence of eight clonal groups including a novel sequence type. In silico detection of antimicrobial-resistant genes and virulence factors revealed a strong correlation between certain virulence genes and mortality as well as several point mutations in outer membrane proteins contributing to colistin resistance. Detection of CRISPR/Cas sequences in the majority of the samples was strongly correlated with the presence of prophage sequences and associated with failure of bacteriophage therapy. Altogether, understanding the genetic makeup of circulating A. baumannii is essential for better management of outbreaks.
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Bergamini G, Perico ME, Di Palma S, Sabatini D, Andreetta F, Defazio R, Felici A, Ferrari L. Mouse pneumonia model by Acinetobacter baumannii multidrug resistant strains: Comparison between intranasal inoculation, intratracheal instillation and oropharyngeal aspiration techniques. PLoS One 2021; 16:e0260627. [PMID: 34855837 PMCID: PMC8638993 DOI: 10.1371/journal.pone.0260627] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 11/12/2021] [Indexed: 11/18/2022] Open
Abstract
Infectious pneumonia induced by multidrug resistant (MDR) Acinetobacter baumannii strains is among the most common and deadly forms of healthcare acquired infections. Over the years, different strategies have been put in place to increase host susceptibility to MDR A. baumannii, since only a self-limiting pneumonia with no or limited local bacterial replication was frequently obtained in mouse models. Direct instillation into the trachea or intranasal inoculation of the bacterial suspension are the techniques used to induce the infection in most of the preclinical models of pneumonia developed to date. More recently, the oropharyngeal aspiration procedure has been widely described in the literature for a variety of purposes including pathogens administration. Aim of this study was to compare the oropharyngeal aspiration technique to the intranasal inoculation and intratracheal instillation in the ability of inducing a consistent lung infection with two MDR A. baumannii clinical isolates in immunocompromised mice. Moreover, pneumonia obtained by bacteria administration with two out of three techniques, intratracheal and oropharyngeal, was characterised in terms of histopathology of pulmonary lesions, biomarkers of inflammation level and leukocytes cells infiltration extent after mice treatment with either vehicle or the antibiotic tigecycline. The data generated clearly showed that both strains were not able to colonize the lungs when inoculated by intranasal route. By contrast, the bacterial load in lungs of mice intratracheally or oropharyngeally infected significantly increased during 26 hours of monitoring, thus highlighting the ability of these strains to generate the infection when directly instilled into the lower respiratory airways. Furthermore, the intragroup variability of mice was significantly reduced with respect to those intranasally administered. Tigecycline was efficacious in lung bacterial load and cytokines release reduction. Findings were supported by semi-quantitative histopathological evaluation of the pulmonary lesions and by inflammatory biomarkers analysis. To conclude, both intratracheal instillation and oropharyngeal aspiration techniques showed to be suitable methods for inducing a robust and consistent pneumonia infection in mice when difficult MDR A. baumannii clinical isolates were used. Noteworthy, oropharyngeal aspiration not requiring specific technical skills and dedicated equipment, was proven to be a safer, easier and faster technique in comparison to the intratracheal instillation.
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Affiliation(s)
- Gabriella Bergamini
- Translational Microbiology, Antibacterial Discovery, Aptuit (Verona) S.r.l., an Evotec Company DD&D Research Centre, Verona, Italy
- * E-mail:
| | - Maria Elisa Perico
- In vitro Pharmacology, Aptuit (Verona) S.r.l., an Evotec Company DD&D Research Centre, Verona, Italy
| | - Stefano Di Palma
- Pathology, Preclinical Development, Aptuit (Verona) S.r.l., an Evotec Company, DD&D Research Centre, Verona, Italy
| | - Daniela Sabatini
- In vitro Pharmacology, Microbiology Discovery, Aptuit (Verona) S.r.l., an Evotec Company, DD&D Research Centre, Verona, Italy
| | - Filippo Andreetta
- In vitro Pharmacology, Aptuit (Verona) S.r.l., an Evotec Company DD&D Research Centre, Verona, Italy
| | - Rossella Defazio
- Pathology, Preclinical Development, Aptuit (Verona) S.r.l., an Evotec Company, DD&D Research Centre, Verona, Italy
| | - Antonio Felici
- In vitro Pharmacology, Microbiology Discovery, Aptuit (Verona) S.r.l., an Evotec Company, DD&D Research Centre, Verona, Italy
| | - Livia Ferrari
- Translational Microbiology, Antibacterial Discovery, Aptuit (Verona) S.r.l., an Evotec Company DD&D Research Centre, Verona, Italy
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Identification of Two Variants of Acinetobacter baumannii Strain ATCC 17978 with Distinct Genotypes and Phenotypes. Infect Immun 2021; 89:e0045421. [PMID: 34460288 DOI: 10.1128/iai.00454-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Acinetobacter baumannii is a nosocomial pathogen that exhibits substantial genomic plasticity. Here, the identification of two variants of A. baumannii ATCC 17978 that differ based on the presence of a 44-kb accessory locus, named AbaAL44 (A. baumannii accessory locus 44 kb), is described. Analyses of existing deposited data suggest that both variants are found in published studies of A. baumannii ATCC 17978 and that American Type Culture Collection (ATCC)-derived laboratory stocks comprise a mix of these two variants. Yet, each variant exhibits distinct interactions with the host in vitro and in vivo. Infection with the variant that harbors AbaAL44 (A. baumannii 17978 UN) results in decreased bacterial burdens and increased neutrophilic lung inflammation in a mouse model of pneumonia, and affects the production of interleukin 1 beta (IL-1β) and IL-10 by infected macrophages. AbaAL44 harbors putative pathogenesis genes, including those predicted to encode a type I pilus cluster, a catalase, and a cardiolipin synthase. The accessory catalase increases A. baumannii resistance to oxidative stress and neutrophil-mediated killing in vitro. The accessory cardiolipin synthase plays a dichotomous role by promoting bacterial uptake and increasing IL-1β production by macrophages, but also by enhancing bacterial resistance to cell envelope stress. Collectively, these findings highlight the phenotypic consequences of the genomic dynamism of A. baumannii through the evolution of two variants of a common type strain with distinct infection-related attributes.
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Scholtz V, Vaňková E, Kašparová P, Premanath R, Karunasagar I, Julák J. Non-thermal Plasma Treatment of ESKAPE Pathogens: A Review. Front Microbiol 2021; 12:737635. [PMID: 34712211 PMCID: PMC8546340 DOI: 10.3389/fmicb.2021.737635] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 09/09/2021] [Indexed: 01/19/2023] Open
Abstract
The acronym ESKAPE refers to a group of bacteria consisting of Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. They are important in human medicine as pathogens that show increasing resistance to commonly used antibiotics; thus, the search for new effective bactericidal agents is still topical. One of the possible alternatives is the use of non-thermal plasma (NTP), a partially ionized gas with the energy stored particularly in the free electrons, which has antimicrobial and anti-biofilm effects. Its mechanism of action includes the formation of pores in the bacterial membranes; therefore, resistance toward it is not developed. This paper focuses on the current overview of literature describing the use of NTP as a new promising tool against ESKAPE bacteria, both in planktonic and biofilm forms. Thus, it points to the fact that NTP treatment can be used for the decontamination of different types of liquids, medical materials, and devices or even surfaces used in various industries. In summary, the use of diverse experimental setups leads to very different efficiencies in inactivation. However, Gram-positive bacteria appear less susceptible compared to Gram-negative ones, in general.
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Affiliation(s)
- Vladimír Scholtz
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, Czechia
| | - Eva Vaňková
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, Czechia.,Department of Biotechnology, University of Chemistry and Technology, Prague, Czechia
| | - Petra Kašparová
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, Czechia
| | - Ramya Premanath
- Nitte University, Nitte University Centre for Science Education and Research, Mangalore, India
| | - Iddya Karunasagar
- Nitte University, Nitte University Centre for Science Education and Research, Mangalore, India
| | - Jaroslav Julák
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, Czechia.,Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czechia
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Gedefie A, Demsis W, Ashagrie M, Kassa Y, Tesfaye M, Tilahun M, Bisetegn H, Sahle Z. Acinetobacter baumannii Biofilm Formation and Its Role in Disease Pathogenesis: A Review. Infect Drug Resist 2021; 14:3711-3719. [PMID: 34531666 PMCID: PMC8439624 DOI: 10.2147/idr.s332051] [Citation(s) in RCA: 78] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 09/02/2021] [Indexed: 01/01/2023] Open
Abstract
Acinetobacter species, particularly Acinetobacter baumannii, is the first pathogen on the critical priority list of pathogens for novel antibiotics to become a "red-alert" human pathogen. Acinetobacter baumannii is an emerging global antibiotic-resistant gram-negative bacteria that most typically causes biofilm-associated infections such as ventilator-associated pneumonia and catheter-related infection, both of which are resistant to antibiotic therapy. A. baumannii's capacity to develop antibiotic resistance mechanisms allows the organism to thrive in hospital settings, facilitating the global spread of multidrug-resistant strains. Although Acinetobacter infections are quickly expanding throughout hospital environments around the world, the highest concentration of infections occurs in intensive care units (ICUs). Biofilms are populations of bacteria on biotic or abiotic surfaces that are encased in the extracellular matrix and play a crucial role in pathogenesis, making treatment options more difficult. Even though a variety of biological and environmental elements are involved in the production of A. baumannii biofilms, glucose is the most important component. Biofilm-mediated A. baumannii infections are the most common type of A. baumannii infection associated with medical equipment, and they are extremely difficult to treat. As a result, health care workers (HCWs) should focus on infection prevention and safety actions to avoid A. baumannii biofilm-related infections caused by medical devices, and they should be very selective when using treatments in combination with anti-biofilms. Therefore, this review discusses biofilm formation in A. baumannii, its role in disease pathogenesis, and its antimicrobial resistance mechanism.
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Affiliation(s)
- Alemu Gedefie
- Department of Medical Laboratory Sciences, College of Medicine and Health Science, Wollo University, Dessie, Ethiopia
| | - Wondmagegn Demsis
- Department of Medical Laboratory Sciences, College of Medicine and Health Science, Wollo University, Dessie, Ethiopia
| | - Melaku Ashagrie
- Department of Medical Laboratory Sciences, College of Medicine and Health Science, Wollo University, Dessie, Ethiopia
| | - Yeshimebet Kassa
- Department of Medical Laboratory Sciences, College of Medicine and Health Science, Wollo University, Dessie, Ethiopia
| | - Melkam Tesfaye
- Department of Medical Laboratory Sciences, College of Medicine and Health Science, Wollo University, Dessie, Ethiopia
| | - Mihret Tilahun
- Department of Medical Laboratory Sciences, College of Medicine and Health Science, Wollo University, Dessie, Ethiopia
| | - Habtye Bisetegn
- Department of Medical Laboratory Sciences, College of Medicine and Health Science, Wollo University, Dessie, Ethiopia
| | - Zenawork Sahle
- Department of Medical Laboratory Sciences, Debre Birhan Health Science College, Debre Birhan, Ethiopia
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Badmasti F, Habibi M, Firoozeh F, Fereshteh S, Bolourchi N, Goodarzi NN. The combination of CipA and PBP-7/8 proteins contribute to the survival of C57BL/6 mice from sepsis of Acinetobacter baumannii. Microb Pathog 2021; 158:105063. [PMID: 34166729 DOI: 10.1016/j.micpath.2021.105063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/13/2021] [Accepted: 06/16/2021] [Indexed: 10/21/2022]
Abstract
Due to the emergence of multi-drug resistant Acinetobacter baumannii strains, there is an urgent need to develop several new strategies to control this bacterium. In this context, vaccination may be the best approach to reduce the morbidity and mortality associated with MDR isolates in vulnerable groups. Serum resistance factors have a key role in the pathogenesis of A. baumannii and can be considered as potential vaccine candidates. This project aimed to evaluate the immunological reactivity of CipA and PBP-7/8 as two serum resistance factors in a combination form against sepsis infections of A. baumannii. Recombinant proteins were obtained and immunological evaluations were performed against sepsis infection in the C57BL/6 mouse model. The data showed a statistically significant increase in total IgG levels in all three immunization regimens (CipA, PBP-7/8, and CipA + PBP-7/8) compared to the control group. The ratios of IgG2c/IgG1 in the CipA, PBP-7/8, and CipA + PBP-7/8 schedules were 8.7, 46.50, and 33.29, respectively. It appears that the immunization schedules developed a strong polarized Th1 response. The cytokine profiles of the three plans showed that IFN-γ was highly concentrated in the combination plan. However, the highest concentration of IL-17 belonged to the PBP-7/8 plan. In conclusion, the data of total IgG, survival rates and splenic bacterial loads showed that the CipA + PBP-7/8 plan was more effective than each protein individually.
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Affiliation(s)
- Farzad Badmasti
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran; Microbiology Research Center (MRC), Pasteur Institute of Iran, Iran.
| | - Mehri Habibi
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
| | - Farzaneh Firoozeh
- Department of Microbiology, School of Medicine, Alborz University of Medical Science, Karaj, Iran
| | | | - Negin Bolourchi
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Narjes Noori Goodarzi
- Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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Ma C, McClean S. Mapping Global Prevalence of Acinetobacter baumannii and Recent Vaccine Development to Tackle It. Vaccines (Basel) 2021; 9:vaccines9060570. [PMID: 34205838 PMCID: PMC8226933 DOI: 10.3390/vaccines9060570] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/16/2021] [Accepted: 05/22/2021] [Indexed: 12/23/2022] Open
Abstract
Acinetobacter baumannii is a leading cause of nosocomial infections that severely threaten public health. The formidable adaptability and resistance of this opportunistic pathogen have hampered the development of antimicrobial therapies which consequently leads to very limited treatment options. We mapped the global prevalence of multidrug-resistant A. baumannii and showed that carbapenem-resistant A. baumannii is widespread throughout Asia and the Americas. Moreover, when antimicrobial resistance rates of Acinetobacter spp. exceed a threshold level, the proportion of A. baumannii isolates from clinical samples surges. Therefore, vaccines represent a realistic alternative strategy to tackle this pathogen. Research into anti-A. baumannii vaccines have enhanced in the past decade and multiple antigens have been investigated preclinically with varying results. This review summarises the current knowledge of virulence factors relating to A. baumannii–host interactions and its implication in vaccine design, with a view to understanding the current state of A. baumannii vaccine development and the direction of future efforts.
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Mofolorunsho KC, Ocheni HO, Aminu RF, Omatola CA, Olowonibi OO. Prevalence and antimicrobial susceptibility of extended-spectrum beta lactamases-producing Escherichia coli and Klebsiella pneumoniae isolated in selected hospitals of Anyigba, Nigeria. Afr Health Sci 2021; 21:505-512. [PMID: 34795702 PMCID: PMC8568240 DOI: 10.4314/ahs.v21i2.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND Escherichia coli and Klebsiella pneumoniae are commonly implicated in urinary tract infections accounting for majority of the antimicrobial resistance encountered in hospitals. OBJECTIVES To determine the prevalence and antimicrobial susceptibility of extended-spectrum beta-lactamases (ESBLs) producing E. coli and K. pneumoniae among patients in Anyigba, Nigeria. METHODS This hospital-based cross-sectional study was conducted using urine samples from 200 patients of Grimmard Catholic hospital and Maria Goretti hospital. Urine samples were processed to identify ESBL-producing E. coli and K. pneumoniae using standard microbiological techniques. Isolates were then tested against antimicrobial agents. RESULTS A total of 156 bacterial isolates were recovered consisting 128 of E. coli and 28 of K. pneumoniae. Extended spectrum beta-lactamases production was observed in 69% of E. coli and 31% of K. pneumoniae. These pathogens were resistant to 3 or more antibiotics. Of the antimicrobials tested, cefotaxime demonstrated the highest rates of resistance (100%) for both ESBL-producing E. coli and K. pneumoniae. Fifty-four isolates of ESBL-producing E. coli showed a high level of resistance to amoxicillin clavulanic acid (83.3%), ciprofloxacin (83.3%), and ceftazidime (79.6%). ESBL-positive K. pneumoniae isolates were highly resistant to ciprofloxacin (75%), and amoxicillin clavulanic acid (83.3%). Cefoxitin (62.5%) and gentamicin (66.7%) showed substantially higher rates of resistance against these isolates while all 24 strains were resistant to imipenem. CONCLUSION This study indicated the prevalence of ESBL-positive Gram-negative pathogens in these study sites and also demonstrated their resistance to a few antibiotics. This highlights the need for new antimicrobials that are potent and improved policy on use of antibiotics.
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Affiliation(s)
| | - Hannah O Ocheni
- Kogi State University, Faculty of Natural Sciences, Department of Microbiology
| | - Ruth F Aminu
- Kogi State University, Faculty of Natural Sciences, Department of Microbiology
| | - Cornelius A Omatola
- Kogi State University, Faculty of Natural Sciences, Department of Microbiology
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Klebba PE, Newton SMC, Six DA, Kumar A, Yang T, Nairn BL, Munger C, Chakravorty S. Iron Acquisition Systems of Gram-negative Bacterial Pathogens Define TonB-Dependent Pathways to Novel Antibiotics. Chem Rev 2021; 121:5193-5239. [PMID: 33724814 PMCID: PMC8687107 DOI: 10.1021/acs.chemrev.0c01005] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Iron is an indispensable metabolic cofactor in both pro- and eukaryotes, which engenders a natural competition for the metal between bacterial pathogens and their human or animal hosts. Bacteria secrete siderophores that extract Fe3+ from tissues, fluids, cells, and proteins; the ligand gated porins of the Gram-negative bacterial outer membrane actively acquire the resulting ferric siderophores, as well as other iron-containing molecules like heme. Conversely, eukaryotic hosts combat bacterial iron scavenging by sequestering Fe3+ in binding proteins and ferritin. The variety of iron uptake systems in Gram-negative bacterial pathogens illustrates a range of chemical and biochemical mechanisms that facilitate microbial pathogenesis. This document attempts to summarize and understand these processes, to guide discovery of immunological or chemical interventions that may thwart infectious disease.
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Affiliation(s)
- Phillip E Klebba
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Salete M C Newton
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - David A Six
- Venatorx Pharmaceuticals, Inc., 30 Spring Mill Drive, Malvern, Pennsylvania 19355, United States
| | - Ashish Kumar
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Taihao Yang
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Brittany L Nairn
- Department of Biological Sciences, Bethel University, 3900 Bethel Drive, St. Paul, Minnesota 55112, United States
| | - Colton Munger
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Somnath Chakravorty
- Jacobs School of Medicine and Biomedical Sciences, SUNY Buffalo, Buffalo, New York 14203, United States
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Nutman A, Temkin E, Lellouche J, Rakovitsky N, Hameir A, Daikos G, Durante-Mangoni E, Pavleas I, Dishon Y, Petersiel N, Yahav D, Eliakim N, Bernardo M, Iossa D, Friberg LE, Theuretzbacher U, Leibovici L, Paul M, Carmeli Y. In vivo fitness of carbapenem-resistant Acinetobacter baumannii strains in murine infection is associated with treatment failure in human infections. Clin Microbiol Infect 2021; 28:73-78. [PMID: 33984488 DOI: 10.1016/j.cmi.2021.05.005] [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: 02/01/2021] [Revised: 04/14/2021] [Accepted: 05/01/2021] [Indexed: 12/01/2022]
Abstract
OBJECTIVES Mortality among patients with carbapenem-resistant Acinetobacter baumannii (CRAB) infections varies between studies. We examined whether in vivo fitness of CRAB strains is associated with clinical outcomes in patients with CRAB infections. METHODS Isolates were collected from patients enrolled in the AIDA trial with hospital-acquired pneumonia, bloodstream infections and/or urinary tract infections caused by CRAB. The primary outcome was 14-day clinical failure, defined as failure to meet all criteria: alive; haemodynamically stable; improved or stable Sequential Organ Failure Assessment (SOFA) score; improved or stable oxygenation; and microbiological cure of bacteraemia. The secondary outcome was 14-day mortality. We tested in vivo growth using a neutropenic murine thigh infection model. Fitness was defined based on the CFU count 24 hours after injection of an inoculum of 105 CFU. We used mixed-effects logistic regression to test the association between fitness and the two outcomes. RESULTS The sample included 266 patients; 215 (80.8%) experienced clinical failure. CRAB fitness ranged from 5.23 to 10.08 log CFU/g. The odds of clinical failure increased by 62% for every 1-log CFU/g increase in fitness (OR 1.62, 95% CI 1.04-2.52). After adjusting for age, Charlson score, SOFA score and acquisition in the intensive care unit, fitness remained significant (adjusted OR 1.63, 95% CI 1.03-2.59). CRAB fitness had a similar effect on 14-day mortailty, although the association was not statistically significant (OR 1.56, 95% CI 0.95-2.57). It became significant after adjusting for age, Charlson score, SOFA score and recent surgery (adjusted OR 1.88, 95% CI 1.09-3.25). CONCLUSIONS In vivo CRAB fitness was associated with clinical failure in patients with CRAB infection.
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Affiliation(s)
- Amir Nutman
- Division of Epidemiology and Preventive Medicine, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel; National Institute for Antibiotic Resistance and Infection Control, Israel Ministry of Health, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Elizabeth Temkin
- Division of Epidemiology and Preventive Medicine, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel; National Institute for Antibiotic Resistance and Infection Control, Israel Ministry of Health, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jonathan Lellouche
- National Institute for Antibiotic Resistance and Infection Control, Israel Ministry of Health, Tel Aviv, Israel
| | - Nadya Rakovitsky
- National Institute for Antibiotic Resistance and Infection Control, Israel Ministry of Health, Tel Aviv, Israel
| | - Amichay Hameir
- National Institute for Antibiotic Resistance and Infection Control, Israel Ministry of Health, Tel Aviv, Israel
| | - George Daikos
- First Department of Medicine, Laikon General Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Emanuele Durante-Mangoni
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", AORN Dei Colli-Monaldi Hospital, Napoli, Italy
| | - Ioannis Pavleas
- Intensive Care Unit, Laikon General Hospital, Athens, Greece
| | - Yael Dishon
- Institute of Infectious Diseases, Rambam Health Care Campus, Haifa, Israel; The Cheryl Spencer Institute for Nursing Research, University of Haifa, Haifa, Israel
| | - Neta Petersiel
- Institute of Infectious Diseases, Rambam Health Care Campus, Haifa, Israel
| | - Dafna Yahav
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Infectious Diseases Unit, Rabin Medical Centre, Beilinson Hospital, Petah Tikva, Israel
| | - Noa Eliakim
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Medicine E, Rabin Medical Centre, Beilinson Hospital, Petah Tikva, Israel
| | - Mariano Bernardo
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", AORN Dei Colli-Monaldi Hospital, Napoli, Italy
| | - Domenico Iossa
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", AORN Dei Colli-Monaldi Hospital, Napoli, Italy
| | - Lena E Friberg
- Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden
| | | | - Leonard Leibovici
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Medicine E, Rabin Medical Centre, Beilinson Hospital, Petah Tikva, Israel
| | - Mical Paul
- Institute of Infectious Diseases, Rambam Health Care Campus, Haifa, Israel; The Ruth and Bruce Rappaport Faculty of Medicine, Techion - Israel Institute of Technology, Haifa, Israel
| | - Yehuda Carmeli
- Division of Epidemiology and Preventive Medicine, Tel Aviv Sourasky Medical Centre, Tel Aviv, Israel; National Institute for Antibiotic Resistance and Infection Control, Israel Ministry of Health, Tel Aviv, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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López-Martín M, Dubern JF, Alexander MR, Williams P. AbaM Regulates Quorum Sensing, Biofilm Formation, and Virulence in Acinetobacter baumannii. J Bacteriol 2021; 203:e00635-20. [PMID: 33495249 PMCID: PMC8088503 DOI: 10.1128/jb.00635-20] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/08/2021] [Indexed: 12/31/2022] Open
Abstract
Acinetobacter baumannii possesses a single divergent luxR/luxRI-type quorum-sensing (QS) locus named abaR/abaI This locus also contains a third gene located between abaR and abaI, which we term abaM, that codes for an uncharacterized member of the RsaM protein family known to regulate N-acylhomoserine lactone (AHL)-dependent QS in other beta- and gammaproteobacteria. Here, we show that disruption of abaM via a T26 insertion in A. baumannii strain AB5075 resulted in increased production of N-(3-hydroxydodecanoyl)-l-homoserine lactone and enhanced surface motility and biofilm formation. In contrast to the wild type and the abaI::T26 mutant, the virulence of the abaM::T26 mutant was completely attenuated in a Galleria mellonella infection model. Transcriptomic analysis of the abaM::T26 mutant revealed that AbaM differentially regulates at least 76 genes, including the csu pilus operon and the acinetin 505 lipopeptide biosynthetic operon, that are involved in surface adherence, biofilm formation and virulence. A comparison of the wild type, abaM::T26 and abaI::T26 transcriptomes, indicates that AbaM regulates ∼21% of the QS regulon including the csu operon. Moreover, the QS genes (abaI and abaR) were among the most upregulated in the abaM::T26 mutant. A. baumanniilux-based abaM reporter gene fusions revealed that abaM expression is positively regulated by QS but negatively autoregulated. Overall, the data presented in this work demonstrates that AbaM plays a central role in regulating A. baumannii QS, virulence, surface motility, and biofilm formation.IMPORTANCEAcinetobacter baumannii is a multiantibiotic-resistant pathogen of global health care importance. Understanding Acinetobacter virulence gene regulation could aid the development of novel anti-infective strategies. In A. baumannii, the abaR and abaI genes that code for the receptor and synthase components of an N-acylhomoserine (AHL) lactone-dependent quorum sensing system (QS) are separated by abaM Here, we show that although mutation of abaM increased AHL production, surface motility, and biofilm development, it resulted in the attenuation of virulence. AbaM was found to control both QS-dependent and QS-independent genes. The significance of this work lies in the identification of AbaM, an RsaM ortholog known to control virulence in plant pathogens, as a modulator of virulence in a human pathogen.
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Affiliation(s)
- Mario López-Martín
- Biodiscovery Institute, National Biofilms Innovation Centre, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Jean-Frédéric Dubern
- Biodiscovery Institute, National Biofilms Innovation Centre, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Morgan R Alexander
- Advanced Materials and Healthcare Technologies, School of Pharmacy, University of Nottingham, Nottingham, United Kingdom
| | - Paul Williams
- Biodiscovery Institute, National Biofilms Innovation Centre, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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Wang P, Li RQ, Wang L, Yang WT, Zou QH, Xiao D. Proteomic Analyses of Acinetobacter baumannii Clinical Isolates to Identify Drug Resistant Mechanism. Front Cell Infect Microbiol 2021; 11:625430. [PMID: 33718272 PMCID: PMC7943614 DOI: 10.3389/fcimb.2021.625430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/11/2021] [Indexed: 12/25/2022] Open
Abstract
Acinetobacter baumannii is one of the main causes of nosocomial infections. Increasing numbers of multidrug-resistant Acinetobacter baumannii cases have been reported in recent years, but its antibiotic resistance mechanism remains unclear. We studied 9 multidrug-resistant (MDR) and 10 drug-susceptible Acinetobacter baumannii clinical isolates using Label free, TMT labeling approach and glycoproteomics analysis to identify proteins related to drug resistance. Our results showed that 164 proteins exhibited different expressions between MDR and drug-susceptible isolates. These differential proteins can be classified into six groups: a. proteins related to antibiotic resistance, b. membrane proteins, membrane transporters and proteins related to membrane formation, c. Stress response-related proteins, d. proteins related to gene expression and protein translation, e. metabolism-related proteins, f. proteins with unknown function or other functions containing biofilm formation and virulence. In addition, we verified seven proteins at the transcription level in eight clinical isolates by using quantitative RT-PCR. Results showed that four of the selected proteins have positive correlations with the protein level. This study provided an insight into the mechanism of antibiotic resistance of multidrug-resistant Acinetobacter baumannii.
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Affiliation(s)
- Ping Wang
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Ren-Qing Li
- Institute for Control of Infectious Diseases and Endemic Diseases, Beijing Center for Disease Prevention and Control, Beijing, China
| | - Lei Wang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Wen-Tao Yang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Qing-Hua Zou
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Di Xiao
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
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Time-Resolved Transcriptional Profiling of Epithelial Cells Infected by Intracellular Acinetobacter baumannii. Microorganisms 2021; 9:microorganisms9020354. [PMID: 33670223 PMCID: PMC7916935 DOI: 10.3390/microorganisms9020354] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/01/2021] [Accepted: 02/06/2021] [Indexed: 12/22/2022] Open
Abstract
The rise in the number of antibiotic-resistant bacteria has become a serious threat to health, making it important to identify, characterize and optimize new molecules to help us to overcome the infections they cause. It is well known that Acinetobacter baumannii has a significant capacity to evade the actions of antibacterial drugs, leading to its emergence as one of the bacteria responsible for hospital and community-acquired infections. Nonetheless, how this pathogen infects and survives inside the host cell is unclear. In this study, we analyze the time-resolved transcriptional profile changes observed in human epithelial HeLa cells after infection by A. baumannii, demonstrating how it survives in host cells and starts to replicate 4 h post infection. These findings were achieved by sequencing RNA to obtain a set of Differentially Expressed Genes (DEGs) to understand how bacteria alter the host cells’ environment for their own benefit. We also determine common features observed in this set of genes and identify the protein–protein networks that reveal highly-interacted proteins. The combination of these findings paves the way for the discovery of new antimicrobial candidates for the treatment of multidrug-resistant bacteria.
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40
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Yu K, Zeng W, Xu Y, Liao W, Xu W, Zhou T, Cao J, Chen L. Bloodstream infections caused by ST2 Acinetobacter baumannii: risk factors, antibiotic regimens, and virulence over 6 years period in China. Antimicrob Resist Infect Control 2021; 10:16. [PMID: 33461617 PMCID: PMC7814448 DOI: 10.1186/s13756-020-00876-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/22/2020] [Indexed: 12/16/2022] Open
Abstract
Background Bloodstream infection (BSI) caused by multidrug-resistant Acinetobacter baumannii (MDR-AB) has been increasingly observed among hospitalized patients. The following study analyzed the epidemiology and microbiological characteristics of MDR-AB, as well as the clinical features, antimicrobial treatments, and outcomes in patients over a six years period in China. Methods This retrospective study was conducted in a large tertiary hospital in China between January 2013 and December 2018. The clinical and microbiological data of all consecutive hospitalized patients with MDR-AB induced bloodstream infection were included and analyzed. Results A total of 108 BSI episodes were analyzed. All MDR isolates belonged to ST2, a sequence type that has spread all over the world. Overall, ST2 strains showed strong biofilm formation ability, high serum resistance, and high pathogenicity. As for the clinical characteristics of the patient, 30-day mortality was 69.4% (75/108). The three main risk factors included mechanical ventilation, intensive care unit (ICU) stay, and thrombocytopenia; three protective factors included a change of antimicrobial regimen within 48 h after positive blood culture, use of the antibacterial agent combination, and more inpatient days. The most effective antibacterial regimen was the combination of cefoperazone/sulbactam and tigecycline. Conclusions BSI caused by ST2 A.baumannii represents a difficult challenge for physicians, considering the high mortality associated with this infection. The combination of cefoperazone/sulbactam and tigecycline may be an effective treatment option.
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Affiliation(s)
- Kaihang Yu
- Department of Clinical Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Weiliang Zeng
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, 325000, China
| | - Ye Xu
- Department of Clinical Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Wenli Liao
- Department of Clinical Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Wenya Xu
- Department of Clinical Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Tieli Zhou
- Department of Clinical Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Jianming Cao
- School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, 325000, China.
| | - Lijiang Chen
- Department of Clinical Laboratory, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
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41
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Niu T, Guo L, Luo Q, Zhou K, Yu W, Chen Y, Huang C, Xiao Y. Wza gene knockout decreases Acinetobacter baumannii virulence and affects Wzy-dependent capsular polysaccharide synthesis. Virulence 2021; 11:1-13. [PMID: 31878839 PMCID: PMC6961727 DOI: 10.1080/21505594.2019.1700659] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
To investigate the virulence of capsular polysaccharide export protein (Wza) in carbapenem-resistant Acinetobacter baumannii and its effect on capsule formation. wza gene knockout and complementation strains were constructed, and changes in bacterial virulence were observed using in vitro adhesion, antiserum complement killing, anti-oxidation experiments, and infections in Galleria mellonella and mice. The effect of wza knockout on the genes wzb and wzc and wzi were assessed by RT-PCR. We successfully constructed wza knockout and complementation strains. Compared with wild-type (WT) strains, wza knockout strains displayed lower adhesion to A549 cells (p = 0.044), lower antiserum complement killing ability (p = 0.001), and lower mortality of G. mellonella (p = 0.010) and mice (p = 0.033). Expression levels of wzb, wzc and wzi were decreased in wza knockout strains. The antioxidant capacity of Wza knockout bacteria was only slightly decreased. Complementation of the wza gene returned the adhesion ability, antiserum complement killing ability, and mortality of G. mellonella and mice to WT levels. Expression of wzb, wzc and wzi was also returned to WT levels following wza complementation. The results clearly demonstrate that Wza is toxic. Wza affects the expression of other proteins of the Wzy capsule polysaccharide synthesis pathway, which affects the assembly, export, and extracellular fixation of capsular polysaccharide, resulting in synergistic effects that decrease bacterial virulence.
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Affiliation(s)
- Tianshui Niu
- Collaborative Initiative Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis & Treatment of Infectious Diseases, the First Affiliated Hospital, college of Medicine, Zhejiang University, Hangzhou, China.,Hangzhou Red Cross Hospital/Zhe Jiang Chinese Medcine and Western Medcine Integrated Hospital, Hangzhou, China
| | - Lihua Guo
- Collaborative Initiative Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis & Treatment of Infectious Diseases, the First Affiliated Hospital, college of Medicine, Zhejiang University, Hangzhou, China
| | - Qixia Luo
- Collaborative Initiative Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis & Treatment of Infectious Diseases, the First Affiliated Hospital, college of Medicine, Zhejiang University, Hangzhou, China
| | - Kai Zhou
- Collaborative Initiative Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis & Treatment of Infectious Diseases, the First Affiliated Hospital, college of Medicine, Zhejiang University, Hangzhou, China
| | - Wei Yu
- Zhejiang Provincial People's Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China
| | - Yunbo Chen
- Collaborative Initiative Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis & Treatment of Infectious Diseases, the First Affiliated Hospital, college of Medicine, Zhejiang University, Hangzhou, China
| | - Chen Huang
- Collaborative Initiative Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis & Treatment of Infectious Diseases, the First Affiliated Hospital, college of Medicine, Zhejiang University, Hangzhou, China
| | - Yonghong Xiao
- Collaborative Initiative Center for Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for Diagnosis & Treatment of Infectious Diseases, the First Affiliated Hospital, college of Medicine, Zhejiang University, Hangzhou, China
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Xie R, Shao N, Zheng J. Integrated Co-functional Network Analysis on the Resistance and Virulence Features in Acinetobacter baumannii. Front Microbiol 2020; 11:598380. [PMID: 33224132 PMCID: PMC7667040 DOI: 10.3389/fmicb.2020.598380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/06/2020] [Indexed: 12/12/2022] Open
Abstract
Acinetobacter baumannii is one of the most troublesome bacterial pathogens that pose major public health threats due to its rapidly increasing drug resistance property. It is not only derived from clinic setting but also emerges from aquaculture as a fish pathogen, which could pass the resistant genes in the food chain. Understanding the mechanism of antibiotic resistance development and pathogenesis will aid our battle with the infections caused by A. baumannii. In this study, we constructed a co-functional network by integrating multiple sources of data from A. baumannii and then used the k-shell decomposition to analyze the co-functional network. We found that genes involving in basic cellular physiological function, including genes for antibiotic resistance, tended to have high k-shell values and locate in the internal layer of our network. In contrast, the non-essential genes, such as genes associated with virulence, tended to have lower k-shell values and locate in the external layer. This finding allows us to fish out the potential antibiotic resistance factors and virulence factors. In addition, we constructed an online platform ABviresDB (https://acba.shinyapps.io/ABviresDB/) for visualization of the network and features of each gene in A. baumannii. The network analysis in this study will not only aid the study on A. baumannii but also could be referenced for the research of antibiotic resistance and pathogenesis in other bacteria.
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Affiliation(s)
- Ruiqiang Xie
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Ningyi Shao
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Jun Zheng
- Faculty of Health Sciences, University of Macau, Macau, China.,Institute of Translational Medicine, University of Macau, Macau, China
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Pfefferle K, Lopalco P, Breisch J, Siemund A, Corcelli A, Averhoff B. In vivo synthesis of monolysocardiolipin and cardiolipin by Acinetobacter baumannii phospholipase D and effect on cationic antimicrobial peptide resistance. Environ Microbiol 2020; 22:5300-5308. [PMID: 32929857 DOI: 10.1111/1462-2920.15231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 09/02/2020] [Accepted: 09/10/2020] [Indexed: 12/29/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen, which has become a rising threat in healthcare facilities worldwide due to increasing antibiotic resistances and optimal adaptation to clinical environments and the human host. We reported in a former publication on the identification of three phopholipases of the phospholipase D (PLD) superfamily in A. baumannii ATCC 19606T acting in concerted manner as virulence factors in Galleria mellonella infection and lung epithelial cell invasion. This study focussed on the function of the three PLDs. A Δpld1-3 mutant was defect in biosynthesis of the phospholipids cardiolipin (CL) and monolysocardiolipin (MLCL), whereas the deletion of pld2 and pld3 abolished the production of MLCL. Complementation of the Δpld1-3 mutant with pld1 restored CL biosynthesis demonstrating that the PLD1 is implicated in CL biosynthesis. Complementation of the Δpld1-3 mutant with either pld2 or pld3 restored MLCL and CL production leading to the conclusion that PLD2 and PLD3 are implicated in CL and MLCL production. Mutant studies revealed that two catalytic motifs are essential for the PLD3-mediated biosynthesis of CL and MLCL. The Δpld1-3 mutant exhibited a decreased colistin and polymyxin B resistance indicating a role of CL in cationic antimicrobial peptides (CAMPs) resistance.
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Affiliation(s)
- Katharina Pfefferle
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
| | - Patrizia Lopalco
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari Aldo Moro, Bari, Italy
| | - Jennifer Breisch
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
| | - Anna Siemund
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
| | - Angela Corcelli
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari Aldo Moro, Bari, Italy
| | - Beate Averhoff
- Department of Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences, Goethe-University Frankfurt am Main, Germany
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Chen W. Host Innate Immune Responses to Acinetobacter baumannii Infection. Front Cell Infect Microbiol 2020; 10:486. [PMID: 33042864 PMCID: PMC7521131 DOI: 10.3389/fcimb.2020.00486] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 08/05/2020] [Indexed: 12/23/2022] Open
Abstract
Acinetobacter baumannii has emerged as a major threat to global public health and is one of the key human pathogens in healthcare (nosocomial and community-acquired)-associated infections. Moreover, A. baumannii rapidly develops resistance to multiple antibiotics and is now globally regarded as a serious multidrug resistant pathogen. There is an urgent need to develop novel vaccines and immunotherapeutics as alternatives to antibiotics for clinical management of A. baumannii infection. However, our knowledge of host immune responses to A. baumannii infection and the identification of novel therapeutic targets are significantly lacking. This review highlights the recent advances and critical gaps in our understanding how A. baumannii interacts with the host innate pattern-recognition receptors, induces a cascade of inflammatory cytokine and chemokine responses, and recruits innate immune effectors (such as neutrophils and macrophages) to the site of infection for effective control of the infection. Such knowledge will facilitate the identification of new targets for the design and development of effective therapeutics and vaccines to fight this emerging threat.
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Affiliation(s)
- Wangxue Chen
- Human Health and Therapeutics (HHT) Research Center, National Research Council Canada, Ottawa, ON, Canada.,Department of Biology, Brock University, St. Catharines, ON, Canada
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45
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Nutman A, Lellouche J, Lifshitz Z, Glick R, Carmeli Y. In vivo Fitness of Acinetobacter baumannii Strains in Murine Infection Is Associated with International Lineage II-rep-2 and International Lineage III Clones Showing High Case Fatality Rates in Human Infections. Microorganisms 2020; 8:microorganisms8060847. [PMID: 32512869 PMCID: PMC7356693 DOI: 10.3390/microorganisms8060847] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 05/31/2020] [Accepted: 06/02/2020] [Indexed: 11/04/2022] Open
Abstract
We previously reported that the 14-day case fatality rate (CFR) in patients with carbapenem-resistant Acinetobacter baumannii (CRAB) bacteremia varied between infecting clones. Here, we evaluated the in vitro and in vivo fitness of CRAB blood isolates belonging to clones with low CFR (< 32% 14-day mortality) and high CFR (65% 14-day mortality). Fitness was measured in vitro using a growth curve assay and in vivo using murine thigh muscle and septicemia models of infection. Our sample included 38 CRAB isolates belonging to two clones with low CFR (international lineage (IL)-II-rep-1, n = 13 and IL-79, n = 6) and two clones with high CFR (IL-III, n = 9 and IL-II-rep-2, n = 10). In in vitro growth curves, mean lag time, generation time and maximal growth varied between clones but could not discriminate between the high and low CFR clones. In the in vivo models, bacterial burdens were higher in mice infected with high CFR clones than in those infected with low CFR clones: in thigh muscle, 8.78 ± 0.25 vs. 7.53 ± 0.25 log10CFU/g, p < 0.001; in infected spleen, 5.53 ± 0.38 vs. 3.71 ± 0.35 log10CFU/g, p < 0.001. The thigh muscle and septicemia model results were closely correlated (r = 0.93, p < 0.01). These results suggest that in vivo but not in vitro fitness is associated with high CFR clones.
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Affiliation(s)
- Amir Nutman
- National Institute for Infection Control and Antibiotic Resistance, Tel-Aviv Sourasky Medical Center, 6423906 Tel-Aviv, Israel; (J.L.); (Z.L.); (R.G.); (Y.C.)
- Sackler Faculty of Medicine, Tel-Aviv University, 6997801 Tel-Aviv, Israel
- Correspondence:
| | - Jonathan Lellouche
- National Institute for Infection Control and Antibiotic Resistance, Tel-Aviv Sourasky Medical Center, 6423906 Tel-Aviv, Israel; (J.L.); (Z.L.); (R.G.); (Y.C.)
| | - Ziv Lifshitz
- National Institute for Infection Control and Antibiotic Resistance, Tel-Aviv Sourasky Medical Center, 6423906 Tel-Aviv, Israel; (J.L.); (Z.L.); (R.G.); (Y.C.)
| | - Rivka Glick
- National Institute for Infection Control and Antibiotic Resistance, Tel-Aviv Sourasky Medical Center, 6423906 Tel-Aviv, Israel; (J.L.); (Z.L.); (R.G.); (Y.C.)
| | - Yehuda Carmeli
- National Institute for Infection Control and Antibiotic Resistance, Tel-Aviv Sourasky Medical Center, 6423906 Tel-Aviv, Israel; (J.L.); (Z.L.); (R.G.); (Y.C.)
- Sackler Faculty of Medicine, Tel-Aviv University, 6997801 Tel-Aviv, Israel
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Vázquez-López R, Solano-Gálvez SG, Juárez Vignon-Whaley JJ, Abello Vaamonde JA, Padró Alonzo LA, Rivera Reséndiz A, Muleiro Álvarez M, Vega López EN, Franyuti-Kelly G, Álvarez-Hernández DA, Moncaleano Guzmán V, Juárez Bañuelos JE, Marcos Felix J, González Barrios JA, Barrientos Fortes T. Acinetobacter baumannii Resistance: A Real Challenge for Clinicians. Antibiotics (Basel) 2020; 9:antibiotics9040205. [PMID: 32340386 PMCID: PMC7235888 DOI: 10.3390/antibiotics9040205] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 01/29/2020] [Accepted: 02/05/2020] [Indexed: 12/21/2022] Open
Abstract
Acinetobacter baumannii (named in honor of the American bacteriologists Paul and Linda Baumann) is a Gram-negative, multidrug-resistant (MDR) pathogen that causes nosocomial infections, especially in intensive care units (ICUs) and immunocompromised patients with central venous catheters. A. baumannii has developed a broad spectrum of antimicrobial resistance, associated with a higher mortality rate among infected patients compared with other non-baumannii species. In terms of clinical impact, resistant strains are associated with increases in both in-hospital length of stay and mortality. A. baumannii can cause a variety of infections; most involve the respiratory tract, especially ventilator-associated pneumonia, but bacteremia and skin wound infections have also been reported, the latter of which has been prominently observed in the context of war-related trauma. Cases of meningitis associated with A. baumannii have been documented. The most common risk factor for the acquisition of MDR A baumannii is previous antibiotic use, following by mechanical ventilation, length of ICU/hospital stay, severity of illness, and use of medical devices. Current efforts focus on addressing all the antimicrobial resistance mechanisms described in A. baumannii, with the objective of identifying the most promising therapeutic scheme. Bacteriophage- and artilysin-based therapeutic approaches have been described as effective, but further research into their clinical use is required.
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Affiliation(s)
- Rosalino Vázquez-López
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
- Correspondence: or ; Tel.: +52-56-270210 (ext. 7302)
| | - Sandra Georgina Solano-Gálvez
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de Mexico 04510, Mexico;
| | - Juan José Juárez Vignon-Whaley
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Jorge Andrés Abello Vaamonde
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Luis Andrés Padró Alonzo
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Andrés Rivera Reséndiz
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Mauricio Muleiro Álvarez
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Eunice Nabil Vega López
- Medical IMPACT, Infectious Diseases Department, Mexico City 53900, Mexico; (E.N.V.L.); (G.F.-K.)
| | - Giorgio Franyuti-Kelly
- Medical IMPACT, Infectious Diseases Department, Mexico City 53900, Mexico; (E.N.V.L.); (G.F.-K.)
| | - Diego Abelardo Álvarez-Hernández
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Valentina Moncaleano Guzmán
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - Jorge Ernesto Juárez Bañuelos
- Departamento de Microbiología del Centro de Investigación en Ciencias de la Salud (CICSA), FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico; (J.J.J.V.-W.); (J.A.A.V.); (L.A.P.A.); (A.R.R.); (M.M.Á.); (D.A.Á.-H.); (V.M.G.); (J.E.J.B.)
| | - José Marcos Felix
- Coordinación Ciclos Clínicos Medicina, FCS, Universidad Anáhuac México Norte, Huixquilucan 52786, Mexico;
| | - Juan Antonio González Barrios
- Laboratorio de Medicina Genómica, Hospital Regional “1º de Octubre”, ISSSTE, Av. Instituto Politécnico Nacional 1669, Lindavista, Gustavo A. Madero, Ciudad de Mexico 07300, Mexico;
| | - Tomás Barrientos Fortes
- Dirección Sistema Universitario de Salud de la Universidad Anáhuac México (SUSA), Huixquilucan 52786, Mexico;
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47
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Genetic mechanisms of antibiotic resistance and virulence in Acinetobacter baumannii: background, challenges and future prospects. Mol Biol Rep 2020; 47:4037-4046. [PMID: 32303957 DOI: 10.1007/s11033-020-05389-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 03/24/2020] [Indexed: 01/18/2023]
Abstract
With the advent of the multidrug-resistant era, many opportunistic pathogens including the species Acinetobacter baumannii have gained prominence and pose a major global threat to clinical health care. Pathogenicity in bacteria is genetically regulated by a complex network of transcription and virulence factors and a brief overview of the major investigations on comprehending these processes over the past few decades in A. baumanni are compiled here. Many investigators have employed genome sequencing techniques to identify the regions that contribute to antibiotic resistance and comparative genomics to study sequence similarities to understand evolutionary trends of resistance gene transfers between isolates. A summary of these studies given here provides an insight into the invasion and successful colonization of the species. The individual roles played by different genes, regulators & promoters, enzymes, metal ions as well as mobile elements in influencing antibiotic resistance are briefly discussed. Precautionary measures and prospects for developing future strategies by exploring promising new research targets in effective control of multidrug resistant A. baumannii are also analyzed.
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48
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Loraine J, Heinz E, Soontarach R, Blackwell GA, Stabler RA, Voravuthikunchai SP, Srimanote P, Kiratisin P, Thomson NR, Taylor PW. Genomic and Phenotypic Analyses of Acinetobacter baumannii Isolates From Three Tertiary Care Hospitals in Thailand. Front Microbiol 2020; 11:548. [PMID: 32328045 PMCID: PMC7153491 DOI: 10.3389/fmicb.2020.00548] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 03/13/2020] [Indexed: 12/24/2022] Open
Abstract
Antibiotic resistant strains of Acinetobacter baumannii are responsible for a large and increasing burden of nosocomial infections in Thailand and other countries of Southeast Asia. New approaches to their control and treatment are urgently needed and an attractive strategy is to remove the bacterial polysaccharide capsule, and thus the protection from the host's immune system. To examine phylogenetic relationships, distribution of capsule chemotypes, acquired antibiotic resistance determinants, susceptibility to complement and other traits associated with systemic infection, we sequenced 191 isolates from three tertiary referral hospitals in Thailand and used phenotypic assays to characterize key aspects of infectivity. Several distinct lineages were circulating in three hospitals and the majority belonged to global clonal group 2 (GC2). Very high levels of resistance to carbapenems and other front-line antibiotics were found, as were a number of widespread plasmid replicons. A high diversity of capsule genotypes was encountered, with only three of these (KL6, KL10, and KL47) showing more than 10% frequency. Almost 90% of GC2 isolates belonged to the most common capsule genotypes and were fully resistant to the bactericidal action of human serum complement, most likely protected by their polysaccharide capsule, which represents a key determinant of virulence for systemic infection. Our study further highlights the importance to develop therapeutic strategies to remove the polysaccharide capsule from extensively drug-resistant A. baumanii during the course of systemic infection.
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Affiliation(s)
- Jessica Loraine
- School of Pharmacy, University College London, London, United Kingdom
| | - Eva Heinz
- Liverpool School of Tropical Medicine, Liverpool, United Kingdom.,Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom
| | | | - Grace A Blackwell
- Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom.,European Bioinformatics Institute, European Molecular Biology Laboratory, Hinxton, Cambridge, United Kingdom
| | - Richard A Stabler
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Potjanee Srimanote
- Faculty of Allied Health Sciences, Thammasat University, Pathumtanee, Thailand
| | | | - Nicholas R Thomson
- Wellcome Sanger Institute, Hinxton, Cambridge, United Kingdom.,London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Peter W Taylor
- School of Pharmacy, University College London, London, United Kingdom
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49
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Hood-Pishchany MI, Pham L, Wijers CD, Burns WJ, Boyd KL, Palmer LD, Skaar EP, Noto MJ. Broad-spectrum suppression of bacterial pneumonia by aminoglycoside-propagated Acinetobacter baumannii. PLoS Pathog 2020; 16:e1008374. [PMID: 32168364 PMCID: PMC7094866 DOI: 10.1371/journal.ppat.1008374] [Citation(s) in RCA: 3] [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: 08/13/2019] [Revised: 03/25/2020] [Accepted: 01/31/2020] [Indexed: 12/29/2022] Open
Abstract
Antimicrobial resistance is increasing in pathogenic bacteria. Yet, the effect of antibiotic exposure on resistant bacteria has been underexplored and may affect pathogenesis. Here we describe the discovery that propagation of the human pathogen Acinetobacter baumannii in an aminoglycoside antibiotic results in alterations to the bacterium that interact with lung innate immunity resulting in enhanced bacterial clearance. Co-inoculation of mice with A. baumannii grown in the presence and absence of the aminoglycoside, kanamycin, induces enhanced clearance of a non-kanamycin-propagated strain. This finding can be replicated when kanamycin-propagated A. baumannii is killed prior to co-inoculation of mice, indicating the enhanced bacterial clearance results from interactions with innate host defenses in the lung. Infection with kanamycin-propagated A. baumannii alters the kinetics of phagocyte recruitment to the lung and reduces pro- and anti-inflammatory cytokine and chemokine production in the lung and blood. This culminates in reduced histopathologic evidence of lung injury during infection despite enhanced bacterial clearance. Further, the antibacterial response induced by killed aminoglycoside-propagated A. baumannii enhances the clearance of multiple clinically relevant Gram-negative pathogens from the lungs of infected mice. Together, these findings exemplify cooperation between antibiotics and the host immune system that affords protection against multiple antibiotic-resistant bacterial pathogens. Further, these findings highlight the potential for the development of a broad-spectrum therapeutic that exploits a similar mechanism to that described here and acts as an innate immunity modulator. Preserving the ability to treat infectious diseases with antibiotics in the face of the rapid proliferation of drug-resistant bacterial pathogens is among the greatest challenges facing medicine. Efforts to combat antimicrobial resistance may include strategies to maximize the utility of existing antibiotics while also identifying new therapeutic targets to treat bacterial infections. Acinetobacter baumannii is a human pathogen and strains of A. baumannii have acquired multi- and pan-antibiotic resistance. Here, we demonstrate that A. baumannii that is resistant to the aminoglycoside class of antibiotics is rapidly cleared from the lungs of mice when exposed to aminoglycoside antibiotics. Exposure to aminoglycosides induces changes in A. baumannii that interact with mouse antibacterial defenses, leading to rapid clearance of the infection. Further, killed aminoglycoside-exposed A. baumannii interacts with innate immunity in the lung to enhance the clearance of other pathogenic bacteria. These findings indicate that pneumonia caused by aminoglycoside-resistant A. baumannii may be effectively treated with aminoglycoside antibiotics and also suggests that the host immune response can be targeted to enhance the clearance of bacterial infections.
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Affiliation(s)
- M. Indriati Hood-Pishchany
- Department of Pediatrics, Division of Infectious Diseases, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Ly Pham
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Christiaan D. Wijers
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - William J. Burns
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Kelli L. Boyd
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Lauren D. Palmer
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Eric P. Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Tennessee Valley Healthcare System, US Department of Veterans Affairs, Nashville, Tennessee, United States of America
- * E-mail: (EPS); (MJN)
| | - Michael J. Noto
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
- * E-mail: (EPS); (MJN)
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50
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Khazaal SS, Al-Kadmy IM, Aziz SN. Mechanism of pathogenesis in multidrug resistant Acinetobacter baumannii isolated from intensive care unit. GENE REPORTS 2020. [DOI: 10.1016/j.genrep.2019.100557] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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