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Faria NA, Touret T, Simões AS, Palos C, Bispo S, Cristino JM, Ramirez M, Carriço J, Pinto M, Toscano C, Gonçalves E, Gonçalves ML, Costa A, Araújo M, Duarte A, de Lencastre H, Serrano M, Sá-Leão R, Miragaia M. Genomic insights into the expansion of carbapenem-resistant Klebsiella pneumoniae within Portuguese hospitals. J Hosp Infect 2024; 148:62-76. [PMID: 38554808 DOI: 10.1016/j.jhin.2024.02.028] [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: 10/19/2023] [Revised: 01/31/2024] [Accepted: 02/19/2024] [Indexed: 04/02/2024]
Abstract
Carbapenem-resistant Klebsiella pneumoniae (CR-KP) are a public health concern, causing infections with a high mortality rate, limited therapeutic options and challenging infection control strategies. In Portugal, the CR-KP rate has increased sharply, but the factors associated with this increase are poorly explored. In order to address this question, phylogenetic and resistome analysis were used to compare the draft genomes of 200 CR-KP isolates collected in 2017-2019 from five hospitals in the Lisbon region, Portugal. Most CR-KP belonged to sequence type (ST) 13 (29%), ST17 (15%), ST348 (13%), ST231 (12%) and ST147 (7%). Carbapenem resistance was conferred mostly by the presence of KPC-3 (74%) or OXA-181 (18%), which were associated with IncF/IncN and IncX plasmids, respectively. Almost all isolates were multi-drug resistant, harbouring resistance determinants to aminoglycosides, beta-lactams, trimethoprim, fosfomycin, quinolones and sulphonamides. In addition, 11% of isolates were resistant to colistin. Colonizing and infecting isolates were highly related, and most colonized patients (89%) reported a previous hospitalization. Moreover, among the 171 events of cross-dissemination identified by core genome multi-locus sequence typing data analysis (fewer than five allelic differences), 41 occurred between different hospitals and 130 occurred within the same hospital. The results suggest that CR-KP dissemination in the Lisbon region results from acquisition of carbapenemases in mobile genetic elements, influx of CR-KP into the hospitals by colonized ambulatory patients, and transmission of CR-KP within and between hospitals. Prudent use of carbapenems, patient screening at hospital entry, and improvement of infection control are needed to decrease the burden of CR-KP infection in Portugal.
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Affiliation(s)
- N A Faria
- Laboratory of Bacterial Evolution and Molecular Epidemiology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Lisbon, Portugal; Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Lisbon, Portugal
| | - T Touret
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Lisbon, Portugal
| | - A S Simões
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Lisbon, Portugal
| | - C Palos
- Hospital Beatriz Ângelo, Lisbon, Portugal
| | - S Bispo
- Hospital Beatriz Ângelo, Lisbon, Portugal
| | - J M Cristino
- Centro Hospitalar Lisboa Norte, Lisbon, Portugal
| | - M Ramirez
- Centro Hospitalar Lisboa Norte, Lisbon, Portugal; Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - J Carriço
- Centro Hospitalar Lisboa Norte, Lisbon, Portugal; Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - M Pinto
- Centro Hospitalar Lisboa Central, Lisbon, Portugal
| | - C Toscano
- Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal
| | - E Gonçalves
- Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal
| | | | - A Costa
- Hospital dos SAMS, Lisbon, Portugal
| | - M Araújo
- Laboratory of Bacterial Evolution and Molecular Epidemiology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Lisbon, Portugal
| | - A Duarte
- Faculdade de Farmácia, Universidade de Lisboa, Lisbon, Portugal; Centro de investigação Interdisciplinar Egas Moniz, Instituto Universitário Egas Moniz, Almada, Portugal
| | - H de Lencastre
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Lisbon, Portugal; Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, USA
| | - M Serrano
- Laboratory of Microbial Development, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Lisbon, Portugal
| | - R Sá-Leão
- Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Lisbon, Portugal
| | - M Miragaia
- Laboratory of Bacterial Evolution and Molecular Epidemiology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Lisbon, Portugal.
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Escobar-Salom M, Barceló IM, Rojo-Molinero E, Jordana-Lluch E, Cabot G, Oliver A, Juan C. In vitro activity of human defensins HNP-1 and hBD-3 against multidrug-resistant ESKAPE Gram-negatives of clinical origin and selected peptidoglycan recycling-defective mutants. Microbiol Spectr 2024; 12:e0035824. [PMID: 38441982 PMCID: PMC10986477 DOI: 10.1128/spectrum.00358-24] [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: 02/09/2024] [Accepted: 02/20/2024] [Indexed: 03/07/2024] Open
Abstract
The use of immune compounds as antimicrobial adjuvants is a classic idea recovering timeliness in the current antibiotic resistance scenario. However, the activity of certain antimicrobial peptides against ESKAPE Gram-negatives has not been sufficiently investigated. The objective of this study was to determine the activities of human defensins HNP-1 and hBD-3 alone or combined with permeabilizing/peptidoglycan-targeting agents against clinical ESKAPE Gram-negatives [Acinetobacter baumannii (AB), Enterobacter cloacae (EC), Klebsiella pneumoniae (KP), and acute/chronic Pseudomonas aeruginosa (PA)]. Lethal concentrations (LCs) of HNP-1 and hBD-3 were determined in four collections of multidrug resistant EC, AB, KP, and PA clinical strains (10-36 isolates depending on the collection). These defensins act through membrane permeabilization plus peptidoglycan building blockade, enabling that alterations in peptidoglycan recycling may increase their activity, which is why different recycling-defective mutants were also included. Combinations with physiological lysozyme and subinhibitory colistin for bactericidal activities determination, and with meropenem for minimum inhibitory concentrations (MICs), were also assessed. HNP-1 showed undetectable activity (LC > 32 mg/L for all strains). hBD-3 showed appreciable activities: LC ranges 2-16, 8-8, 8->32, and 8->32 mg/L for AB, EC, KP, and PA, being PA strains from cystic fibrosis significantly more resistant than acute origin ones. None of the peptidoglycan recycling-defective mutants showed greater susceptibility to HNP-1/hBD-3. Combination with colistin or lysozyme did not change their bactericidal power, and virtually neither did meropenem + hBD-3 compared to meropenem MICs. This is the first study comparatively analyzing the HNP-1/hBD-3 activities against the ESKAPE Gram-negatives, and demonstrates interesting bactericidal capacities of hBD-3 mostly against AB and EC. IMPORTANCE In the current scenario of critical need for new antimicrobials against multidrug-resistant bacteria, all options must be considered, including classic ideas such as the use of purified immune compounds. However, information regarding the activity of certain human defensins against ESKAPE Gram-negatives was incomplete. This is the first study comparatively assessing the in vitro activity of two membrane-permeabilizing/peptidoglycan construction-blocking defensins (HNP-1 and hBD-3) against relevant clinical collections of ESKAPE Gram-negatives, alone or in combination with permeabilizers, additional peptidoglycan-targeting attacks, or the blockade of its recycling. Our data suggest that hBD-3 has a notable bactericidal activity against multidrug-resistant Acinetobacter baumannii and Enterobacter cloacae strains that should be considered as potential adjuvant option. Our results suggest for the first time an increased resistance of Pseudomonas aeruginosa strains from chronic infection compared to acute origin ones, and provide new clues about the predominant mode of action of hBD-3 against Gram-negatives (permeabilization rather than peptidoglycan-targeting).
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Affiliation(s)
- María Escobar-Salom
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- Microbiology Department, University Hospital Son Espases, Palma, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Isabel María Barceló
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- Microbiology Department, University Hospital Son Espases, Palma, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Estrella Rojo-Molinero
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- Microbiology Department, University Hospital Son Espases, Palma, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Elena Jordana-Lluch
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- Microbiology Department, University Hospital Son Espases, Palma, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Gabriel Cabot
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- Microbiology Department, University Hospital Son Espases, Palma, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Antonio Oliver
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- Microbiology Department, University Hospital Son Espases, Palma, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Carlos Juan
- Research Unit, University Hospital Son Espases-Health Research Institute of the Balearic Islands (IdISBa), Palma, Spain
- Microbiology Department, University Hospital Son Espases, Palma, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
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Gao S, Jin W, Quan Y, Li Y, Shen Y, Yuan S, Yi L, Wang Y, Wang Y. Bacterial capsules: Occurrence, mechanism, and function. NPJ Biofilms Microbiomes 2024; 10:21. [PMID: 38480745 PMCID: PMC10937973 DOI: 10.1038/s41522-024-00497-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 03/05/2024] [Indexed: 03/17/2024] Open
Abstract
In environments characterized by extended multi-stress conditions, pathogens develop a variety of immune escape mechanisms to enhance their ability to infect the host. The capsules, polymers that bacteria secrete near their cell wall, participates in numerous bacterial life processes and plays a crucial role in resisting host immune attacks and adapting to their niche. Here, we discuss the relationship between capsules and bacterial virulence, summarizing the molecular mechanisms of capsular regulation and pathogenesis to provide new insights into the research on the pathogenesis of pathogenic bacteria.
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Affiliation(s)
- Shuji Gao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Wenjie Jin
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yingying Quan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yue Li
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yamin Shen
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Shuo Yuan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Li Yi
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
- College of Life Science, Luoyang Normal University, Luoyang, 471934, China
| | - Yuxin Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China.
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China.
| | - Yang Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China.
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China.
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4
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Ra YE, Bang YJ. Balancing Act of the Intestinal Antimicrobial Proteins on Gut Microbiota and Health. J Microbiol 2024; 62:167-179. [PMID: 38630349 DOI: 10.1007/s12275-024-00122-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 05/15/2024]
Abstract
The human gut houses a diverse and dynamic microbiome critical for digestion, metabolism, and immune development, exerting profound effects on human health. However, these microorganisms pose a potential threat by breaching the gut barrier, entering host tissues, and triggering infections, uncontrolled inflammation, and even sepsis. The intestinal epithelial cells form the primary defense, acting as a frontline barrier against microbial invasion. Antimicrobial proteins (AMPs), produced by these cells, serve as innate immune effectors that regulate the gut microbiome by directly killing or inhibiting microbes. Abnormal AMP production, whether insufficient or excessive, can disturb the microbiome equilibrium, contributing to various intestinal diseases. This review delves into the complex interactions between AMPs and the gut microbiota and sheds light on the role of AMPs in governing host-microbiota interactions. We discuss the function and mechanisms of action of AMPs, their regulation by the gut microbiota, microbial evasion strategies, and the consequences of AMP dysregulation in disease. Understanding these complex interactions between AMPs and the gut microbiota is crucial for developing strategies to enhance immune responses and combat infections within the gut microbiota. Ongoing research continues to uncover novel aspects of this intricate relationship, deepening our understanding of the factors shaping gut health. This knowledge has the potential to revolutionize therapeutic interventions, offering enhanced treatments for a wide range of gut-related diseases.
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Affiliation(s)
- Ye Eun Ra
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Ye-Ji Bang
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.
- Department of Microbiology and Immunology, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.
- Institute of Infectious Diseases, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea.
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Nhu NTK, Rahman MA, Goh KGK, Kim SJ, Phan MD, Peters KM, Alvarez-Fraga L, Hancock SJ, Ravi C, Kidd TJ, Sullivan MJ, Irvine KM, Beatson SA, Sweet MJ, Irwin AD, Vukovic J, Ulett GC, Hasnain SZ, Schembri MA. A convergent evolutionary pathway attenuating cellulose production drives enhanced virulence of some bacteria. Nat Commun 2024; 15:1441. [PMID: 38383596 PMCID: PMC10881479 DOI: 10.1038/s41467-024-45176-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 01/16/2024] [Indexed: 02/23/2024] Open
Abstract
Bacteria adapt to selective pressure in their immediate environment in multiple ways. One mechanism involves the acquisition of independent mutations that disable or modify a key pathway, providing a signature of adaptation via convergent evolution. Extra-intestinal pathogenic Escherichia coli (ExPEC) belonging to sequence type 95 (ST95) represent a global clone frequently associated with severe human infections including acute pyelonephritis, sepsis, and neonatal meningitis. Here, we analysed a publicly available dataset of 613 ST95 genomes and identified a series of loss-of-function mutations that disrupt cellulose production or its modification in 55.3% of strains. We show the inability to produce cellulose significantly enhances ST95 invasive infection in a rat model of neonatal meningitis, leading to the disruption of intestinal barrier integrity in newborn pups and enhanced dissemination to the liver, spleen and brain. Consistent with these observations, disruption of cellulose production in ST95 augmented innate immune signalling and tissue neutrophil infiltration in a mouse model of urinary tract infection. Mutations that disrupt cellulose production were also identified in other virulent ExPEC STs, Shigella and Salmonella, suggesting a correlative association with many Enterobacteriaceae that cause severe human infection. Together, our findings provide an explanation for the emergence of hypervirulent Enterobacteriaceae clones.
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Affiliation(s)
- Nguyen Thi Khanh Nhu
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, QLD, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - M Arifur Rahman
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
- Immunopathology Group, Mater Research Institute, The University of Queensland, Translational Research Institute, Brisbane, Australia
- QIMR Berghofer Medical Research Institute, Brisbane QLD, Australia
| | - Kelvin G K Goh
- School of Pharmacy and Medical Sciences, Griffith University, Southport, QLD, Australia
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
| | - Seung Jae Kim
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Minh-Duy Phan
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, QLD, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Kate M Peters
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, QLD, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Laura Alvarez-Fraga
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
- INRAE, Univ Montpellier, LBE, 102 Avenue des Etangs, Narbonne, 11100, France
| | - Steven J Hancock
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK
| | - Chitra Ravi
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, QLD, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Timothy J Kidd
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
- Central Microbiology, Pathology Queensland, Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Matthew J Sullivan
- School of Pharmacy and Medical Sciences, Griffith University, Southport, QLD, Australia
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Katharine M Irvine
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
- Immunopathology Group, Mater Research Institute, The University of Queensland, Translational Research Institute, Brisbane, Australia
| | - Scott A Beatson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Matthew J Sweet
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, QLD, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
| | - Adam D Irwin
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia
- University of Queensland Centre for Clinical Research, Brisbane, Australia
- Queensland Children's Hospital, Brisbane, Australia
| | - Jana Vukovic
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.
| | - Glen C Ulett
- School of Pharmacy and Medical Sciences, Griffith University, Southport, QLD, Australia.
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.
| | - Sumaira Z Hasnain
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia.
- Immunopathology Group, Mater Research Institute, The University of Queensland, Translational Research Institute, Brisbane, Australia.
| | - Mark A Schembri
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, QLD, Australia.
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia.
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, QLD, Australia.
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Tiwari V, Sharma A, Braga R, Garcia E, Appiah R, Fleeman R, Abuaita BH, Patrauchan M, Doerrler WT. Klebsiella pneumoniae DedA family proteins have redundant roles in divalent cation homeostasis and resistance to phagocytosis. Microbiol Spectr 2024; 12:e0380723. [PMID: 38214522 PMCID: PMC10846249 DOI: 10.1128/spectrum.03807-23] [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: 11/21/2023] [Accepted: 12/04/2023] [Indexed: 01/13/2024] Open
Abstract
The DedA superfamily is a highly conserved family of membrane proteins. Deletion of Escherichia coli yqjA and yghB, encoding related DedA family proteins, results in sensitivity to elevated temperature, antibiotics, and alkaline pH. The human pathogen Klebsiella pneumoniae possesses genes encoding DedA family proteins with >90% amino acid identity to E. coli YqjA and YghB. We hypothesized that the deletion of K. pneumoniae yqjA and yghB will impact its physiology and may reduce its virulence. The K. pneumoniae ΔyqjA ΔyghB mutant (strain VT101) displayed a growth defect at 42°C and alkaline pH sensitivity, not unlike its E. coli counterpart. However, VT101 retained mostly wild-type resistance to antibiotics. We found VT101 was sensitive to the chelating agent EDTA, the anionic detergent SDS, and agents capable of alkalizing the bacterial cytoplasm such as bicarbonate or chloroquine. We could restore growth at alkaline pH and at elevated temperature by addition of 0.5-2 mM Ca2+ or Mg2+ to the culture media. VT101 displayed a slower uptake of calcium, which was dependent upon calcium channel activity. VT201, with similar deletions as VT101 but derived from a virulent K. pneumoniae strain, was highly susceptible to phagocytosis by alveolar macrophages and displayed a defect in the production of capsule. These findings suggest divalent cation homeostasis and virulence are interlinked by common functions of the DedA family.IMPORTANCEKlebsiella pneumoniae is a dangerous human pathogen. The DedA protein family is found in all bacteria and is a membrane transporter often required for virulence and antibiotic resistance. K. pneumoniae possesses homologs of E. coli YqjA and YghB, with 60% amino acid identity and redundant functions, which we have previously shown to be required for tolerance to biocides and alkaline pH. A K. pneumoniae strain lacking yqjA and yghB was found to be sensitive to alkaline pH, elevated temperature, and EDTA/SDS and displayed a defect in calcium uptake. Sensitivity to these conditions was reversed by addition of calcium or magnesium to the growth medium. Introduction of ΔyqjA and ΔyghB mutations into virulent K. pneumoniae resulted in the loss of capsule, increased phagocytosis by macrophages, and a partial loss of virulence. These results show that targeting the Klebsiella DedA family results in impaired divalent cation transport and, in turn, loss of virulence.
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Affiliation(s)
- Vijay Tiwari
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Amit Sharma
- Department of Pathobiological Sciences, LSU School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Reygan Braga
- Department of Microbiology and Molecular Genetics, College of Arts and Science, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Emily Garcia
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Ridhwana Appiah
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Renee Fleeman
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Basel H. Abuaita
- Department of Pathobiological Sciences, LSU School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Marianna Patrauchan
- Department of Microbiology and Molecular Genetics, College of Arts and Science, Oklahoma State University, Stillwater, Oklahoma, USA
| | - William T. Doerrler
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, USA
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7
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Anurag Anand A, Amod A, Anwar S, Sahoo AK, Sethi G, Samanta SK. A comprehensive guide on screening and selection of a suitable AMP against biofilm-forming bacteria. Crit Rev Microbiol 2023:1-20. [PMID: 38102871 DOI: 10.1080/1040841x.2023.2293019] [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: 10/04/2023] [Accepted: 11/30/2023] [Indexed: 12/17/2023]
Abstract
Lately, antimicrobial resistance (AMR) is increasing at an exponential rate making it important to search alternatives to antibiotics in order to combat multi-drug resistant (MDR) bacterial infections. Out of the several antibacterial and antibiofilm strategies being tested, antimicrobial peptides (AMPs) have shown to give better hopes in terms of a long-lasting solution to the problem. To select a desired AMP, it is important to make right use of available tools and databases that aid in identification, classification, and analysis of the physiochemical properties of AMPs. To identify the targets of these AMPs, it becomes crucial to understand their mode-of-action. AMPs can also be used in combination with other antibacterial and antibiofilm agents so as to achieve enhanced efficacy against bacteria and their biofilms. Due to concerns regarding toxicity, stability, and bioavailability, strategizing drug formulation at an early-stage becomes crucial. Although there are few concerns regarding development of bacterial resistance to AMPs, the evolution of resistance to AMPs occurs extremely slowly. This comprehensive review gives a deep insight into the selection of the right AMP, deciding the right target and combination strategy along with the type of formulation needed, and the possible resistance that bacteria can develop to these AMPs.
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Affiliation(s)
- Ananya Anurag Anand
- Department of Applied Sciences, Indian Institute of Information Technology Allahabad, Prayagraj, India
| | - Ayush Amod
- Department of Applied Sciences, Indian Institute of Information Technology Allahabad, Prayagraj, India
| | - Sarfraz Anwar
- Department of Bioinformatics, University of Allahabad, Prayagraj, India
| | - Amaresh Kumar Sahoo
- Department of Applied Sciences, Indian Institute of Information Technology Allahabad, Prayagraj, India
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Sintu Kumar Samanta
- Department of Applied Sciences, Indian Institute of Information Technology Allahabad, Prayagraj, India
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Savitskaya A, Masso-Silva J, Haddaoui I, Enany S. Exploring the arsenal of antimicrobial peptides: Mechanisms, diversity, and applications. Biochimie 2023; 214:216-227. [PMID: 37499896 DOI: 10.1016/j.biochi.2023.07.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 07/09/2023] [Accepted: 07/24/2023] [Indexed: 07/29/2023]
Abstract
Antimicrobial peptides (AMPs) are essential for defence against pathogens in all living organisms and possessed activities against bacteria, fungi, viruses, parasites and even cancer cells. AMPs are short peptides containing 12-100 amino acids conferring a net positive charge and an amphiphilic property in most cases. Although, anionic AMPs also exist. AMPs can be classified based on the types of secondary structures, charge, hydrophobicity, amino acid composition, length, etc. Their mechanism of action usually includes a membrane disruption process through pore formation (three different models have been described, barrel-stave, toroidal or carpet model) but AMPs can also penetrate and impair intracellular functions. Besides their activity against pathogens, they have also shown immunomodulatory properties in complex scenarios through many different interactions. The aim of this review to summarize knowledge about AMP's and discuss the potential application of AMPs as therapeutics, the challenges due to their limitations, including their susceptibility to degradation, the potential generation of AMP resistance, cost, etc. We also discuss the current FDA-approved drugs based on AMPs and strategies to circumvent natural AMPs' limitations.
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Affiliation(s)
- Anna Savitskaya
- Institute of Bioorganic Chemistry of Russian Academy of Science, Moscow, Russian Federation
| | - Jorge Masso-Silva
- Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, University of California San Diego, La Jolla, CA, USA
| | - Imen Haddaoui
- National Research Institute of Rural Engineering, Water and Forestry, University of Carthage, LR Valorization of Unconventional Waters, Ariana, Tunisia
| | - Shymaa Enany
- Microbiology and Immunology Department, Faculty of Pharmacy, Suez Canal University, Ismailia, Egypt; Biomedical Research Department, Armed Force College of Medicine, Cairo, Egypt.
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9
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Ruest MK, Supina BSI, Dennis JJ. Bacteriophage steering of Burkholderia cenocepacia toward reduced virulence and increased antibiotic sensitivity. J Bacteriol 2023; 205:e0019623. [PMID: 37791751 PMCID: PMC10601696 DOI: 10.1128/jb.00196-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 09/06/2023] [Indexed: 10/05/2023] Open
Abstract
Antibiotic resistance in bacteria is a growing global concern and has spurred increasing efforts to find alternative therapeutics, such as the use of bacterial viruses, or bacteriophages. One promising approach is to use phages that not only kill pathogenic bacteria but also select phage-resistant survivors that are newly sensitized to traditional antibiotics, in a process called "phage steering." Members of the bacterial genus Burkholderia, which includes various human pathogens, are highly resistant to most antimicrobial agents, including serum immune components, antimicrobial peptides, and polymixin-class antibiotics. However, the application of phages in combination with certain antibiotics can produce synergistic effects that more effectively kill pathogenic bacteria. Herein, we demonstrate that Burkholderia cenocepacia serum resistance is due to intact lipopolysaccharide (LPS) and membranes, and phage-induced resistance altering LPS structure can enhance bacterial sensitivity not only to immune components in serum but also to membrane-associated antibiotics such as colistin. IMPORTANCE Bacteria frequently encounter selection pressure from both antibiotics and lytic phages, but little is known about the interactions between antibiotics and phages. This study provides new insights into the evolutionary trade-offs between phage resistance and antibiotic sensitivity. The creation of phage resistance through changes in membrane structure or lipopolysaccharide composition can simultaneously be a major cause of antibiotic sensitivity. Our results provide evidence of synergistic therapeutic efficacy in phage-antibiotic interactions and have implications for the future clinical use of phage steering in phage therapy applications.
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Affiliation(s)
- Marta K. Ruest
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | | | - Jonathan J. Dennis
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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10
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Li H, Sun L, Qiao H, Sun Z, Wang P, Xie C, Hu X, Nie T, Yang X, Li G, Zhang Y, Wang X, Li Z, Jiang J, Li C, You X. Polymyxin resistance caused by large-scale genomic inversion due to IS 26 intramolecular translocation in Klebsiella pneumoniae. Acta Pharm Sin B 2023; 13:3678-3693. [PMID: 37719365 PMCID: PMC10501869 DOI: 10.1016/j.apsb.2023.06.003] [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: 04/13/2023] [Revised: 05/11/2023] [Accepted: 06/06/2023] [Indexed: 09/19/2023] Open
Abstract
Polymyxin B and polymyxin E (colistin) are presently considered the last line of defense against human infections caused by multidrug-resistant Gram-negative organisms such as carbapenemase-producer Enterobacterales, Acinetobacter baumannii, and Klebsiella pneumoniae. Yet resistance to this last-line drugs is a major public health threat and is rapidly increasing. Polymyxin S2 (S2) is a polymyxin B analogue previously synthesized in our institute with obviously high antibacterial activity and lower toxicity than polymyxin B and colistin. To predict the possible resistant mechanism of S2 for wide clinical application, we experimentally induced bacterial resistant mutants and studied the preliminary resistance mechanisms. Mut-S, a resistant mutant of K. pneumoniae ATCC BAA-2146 (Kpn2146) induced by S2, was analyzed by whole genome sequencing, transcriptomics, mass spectrometry and complementation experiment. Surprisingly, large-scale genomic inversion (LSGI) of approximately 1.1 Mbp in the chromosome caused by IS26 mediated intramolecular transposition was found in Mut-S, which led to mgrB truncation, lipid A modification and hence S2 resistance. The resistance can be complemented by plasmid carrying intact mgrB. The same mechanism was also found in polymyxin B and colistin induced drug-resistant mutants of Kpn2146 (Mut-B and Mut-E, respectively). This is the first report of polymyxin resistance caused by IS26 intramolecular transposition mediated mgrB truncation in chromosome in K. pneumoniae. The findings broaden our scope of knowledge for polymyxin resistance and enriched our understanding of how bacteria can manage to survive in the presence of antibiotics.
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Affiliation(s)
- Haibin Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Lang Sun
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Han Qiao
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Zongti Sun
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Penghe Wang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Chunyang Xie
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xinxin Hu
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Tongying Nie
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xinyi Yang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Guoqing Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Youwen Zhang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xiukun Wang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Zhuorong Li
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100050, China
| | - Jiandong Jiang
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100050, China
| | - Congran Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xuefu You
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
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11
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Fan Z, Fu T, Liu H, Li Z, Du B, Cui X, Zhang R, Feng Y, Zhao H, Xue G, Cui J, Yan C, Gan L, Feng J, Xu Z, Yu Z, Tian Z, Ding Z, Chen J, Chen Y, Yuan J. Glucose Induces Resistance to Polymyxins in High-Alcohol-Producing Klebsiella pneumoniae via Increasing Capsular Polysaccharide and Maintaining Intracellular ATP. Microbiol Spectr 2023; 11:e0003123. [PMID: 37338347 PMCID: PMC10434286 DOI: 10.1128/spectrum.00031-23] [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: 01/10/2023] [Accepted: 05/31/2023] [Indexed: 06/21/2023] Open
Abstract
High-alcohol-producing K. pneumoniae (HiAlc Kpn) causes nonalcoholic fatty liver disease (NAFLD) by producing excess endogenous alcohol in the gut of patients with NAFLD, using glucose as the main carbon source. The role of glucose in the response of HiAlc Kpn to environmental stresses such as antibiotics remains unclear. In this study, we found that glucose could enhance the resistance of HiAlc Kpn to polymyxins. First, glucose inhibited the expression of crp in HiAlc Kpn and promoted the increase of capsular polysaccharide (CPS), which promoted the drug resistance of HiAlc Kpn. Second, glucose maintained high ATP levels in HiAlc Kpn cells under the pressure of polymyxins, enhancing the resistance of the cells to the killing effect of antibiotics. Notably, the inhibition of CPS formation and the decrease of intracellular ATP levels could both effectively reverse glucose-induced polymyxins resistance. Our work demonstrated the mechanism by which glucose induces polymyxins resistance in HiAlc Kpn, thereby laying the foundation for developing effective treatments for NAFLD caused by HiAlc Kpn. IMPORTANCE HiAlc Kpn can use glucose to produce excess endogenous alcohol for promoting the development of NAFLD. Polymyxins are the last line of antibiotics and are commonly used to treat infections caused by carbapenem-resistant K. pneumoniae. In this study, we found that glucose increased bacterial resistance to polymyxins via increasing CPS and maintaining intracellular ATP; this increases the risk of failure to treat NAFLD caused by multidrug-resistant HiAlc Kpn infection. Further research revealed the important roles of glucose and the global regulator, CRP, in bacterial resistance and found that inhibiting CPS formation and decreasing intracellular ATP levels could effectively reverse glucose-induced polymyxins resistance. Our work reveals that glucose and the regulatory factor CRP can affect the resistance of bacteria to polymyxins, laying a foundation for the treatment of infections caused by multidrug-resistant bacteria.
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Affiliation(s)
- Zheng Fan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Tongtong Fu
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Hongbo Liu
- School of Pharmaceutical Sciences, Jilin University, Changchun, China
| | - Zhoufei Li
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Bing Du
- University of Edinburgh, Edinburgh, United Kingdom
| | - Xiaohu Cui
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Rui Zhang
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
- Graduate School, Peking Union Medical College, Beijing, China
| | - Yanling Feng
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Hanqing Zhao
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Guanhua Xue
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Jinghua Cui
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Chao Yan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Lin Gan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Junxia Feng
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Ziying Xu
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Zihui Yu
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Ziyan Tian
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Zanbo Ding
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Jinfeng Chen
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Yujie Chen
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
| | - Jing Yuan
- Department of Bacteriology, Capital Institute of Pediatrics, Beijing, China
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12
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Roshini J, Patro LPP, Sundaresan S, Rathinavelan T. Structural diversity among Acinetobacter baumannii K-antigens and its implication in the in silico serotyping. Front Microbiol 2023; 14:1191542. [PMID: 37415807 PMCID: PMC10320297 DOI: 10.3389/fmicb.2023.1191542] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/30/2023] [Indexed: 07/08/2023] Open
Abstract
Acinetobacter baumannii is an emerging opportunistic pathogen. It exhibits multi-, extreme-, and pan-drug resistance against several classes of antibiotics. Capsular polysaccharide (CPS or K-antigen) is one of the major virulence factors which aids A. baumannii in evading the host immune system. K-antigens of A. baumannii exploit the Wzx/Wzy-dependent pathway that involves 13 different proteins for its assembly and transport onto the outer membrane. A total of 64 (out of 237 K-locus(KL) types) known K-antigen sugar repeating structures are discussed here and are classified into seven groups based on their initial sugars, QuiNAc4NAc, GalNAc, GlcNAc, Gal, QuiNAc/FucNAc, FucNAc, and GlcNAc along with Leg5Ac7Ac/Leg5Ac7R. Thus, the corresponding seven initializing glycosyltransferases (ItrA1, ItrA2, ItrA3, ItrA4, ItrB1, ItrB3, and ItrA3 along with ItrB2) exhibit serotype specificity. The modeled 3D-structural repository of the 64 K-antigens can be accessed at https://project.iith.ac.in/ABSD/k_antigen.html. The topology of K-antigens further reveals the presence of 2-6 and 0-4 sugar monomers in the main and side chains, respectively. The presence of negatively (predominant) or neutrally charged K-antigens is observed in A. baumannii. Such diversity in the K-antigen sugar composition provides the K-typing specificity (viz., 18-69% in terms of reliability) for Wza, Wzb, Wzc, Wzx, and Wzy proteins involved in the Wzx/Wzy-dependent pathway. Interestingly, the degree of uniqueness of these proteins among different K-types is estimated to be 76.79%, considering the 237 reference sequences. This article summarizes the A. baumannii K-antigen structural diversity and creation of a K-antigen digital repository and provides a systematic analysis of the K-antigen assembly and transportation marker proteins.
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13
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Arredondo-Alonso S, Blundell-Hunter G, Fu Z, Gladstone RA, Fillol-Salom A, Loraine J, Cloutman-Green E, Johnsen PJ, Samuelsen Ø, Pöntinen AK, Cléon F, Chavez-Bueno S, De la Cruz MA, Ares MA, Vongsouvath M, Chmielarczyk A, Horner C, Klein N, McNally A, Reis JN, Penadés JR, Thomson NR, Corander J, Taylor PW, McCarthy AJ. Evolutionary and functional history of the Escherichia coli K1 capsule. Nat Commun 2023; 14:3294. [PMID: 37322051 PMCID: PMC10272209 DOI: 10.1038/s41467-023-39052-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: 01/28/2023] [Accepted: 05/26/2023] [Indexed: 06/17/2023] Open
Abstract
Escherichia coli is a leading cause of invasive bacterial infections in humans. Capsule polysaccharide has an important role in bacterial pathogenesis, and the K1 capsule has been firmly established as one of the most potent capsule types in E. coli through its association with severe infections. However, little is known about its distribution, evolution and functions across the E. coli phylogeny, which is fundamental to elucidating its role in the expansion of successful lineages. Using systematic surveys of invasive E. coli isolates, we show that the K1-cps locus is present in a quarter of bloodstream infection isolates and has emerged in at least four different extraintestinal pathogenic E. coli (ExPEC) phylogroups independently in the last 500 years. Phenotypic assessment demonstrates that K1 capsule synthesis enhances E. coli survival in human serum independent of genetic background, and that therapeutic targeting of the K1 capsule re-sensitizes E. coli from distinct genetic backgrounds to human serum. Our study highlights that assessing the evolutionary and functional properties of bacterial virulence factors at population levels is important to better monitor and predict the emergence of virulent clones, and to also inform therapies and preventive medicine to effectively control bacterial infections whilst significantly lowering antibiotic usage.
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Affiliation(s)
- Sergio Arredondo-Alonso
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
| | | | - Zuyi Fu
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | - Rebecca A Gladstone
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
| | - Alfred Fillol-Salom
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | | | - Elaine Cloutman-Green
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Pål J Johnsen
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Ørjan Samuelsen
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
| | - Anna K Pöntinen
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
| | - François Cléon
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Susana Chavez-Bueno
- University of Missouri Kansas City, Kansas City, USA
- Division of Infectious Diseases, Children's Mercy Hospital Kansas City, UMKC School of Medicine, Kansas City, USA
| | - Miguel A De la Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Facultad de Medicina, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Miguel A Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Manivanh Vongsouvath
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
| | - Agnieszka Chmielarczyk
- Faculty of Medicine, Chair of Microbiology, Jagiellonian University Medical College, Czysta str. 18, 31-121, Kraków, Poland
| | - Carolyne Horner
- British Society for Antimicrobial Chemotherapy, Birmingham, UK
| | - Nigel Klein
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Alan McNally
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Joice N Reis
- Laboratory of Pathology and Molecular Biology (LPBM), Gonçalo Moniz Research Institute, Oswaldo Cruz Foundation, Salvador, Brazil
- Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, Brazil
| | - José R Penadés
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | - Nicholas R Thomson
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
- London School of Hygiene and Tropical Medicine, London, UK
| | - Jukka Corander
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway.
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK.
- Helsinki Institute of Information Technology, Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland.
| | - Peter W Taylor
- School of Pharmacy, University College London, London, UK.
| | - Alex J McCarthy
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK.
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14
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Seethalakshmi PS, Rajeev R, Prabhakaran A, Kiran GS, Selvin J. The menace of colistin resistance across globe: Obstacles and opportunities in curbing its spread. Microbiol Res 2023; 270:127316. [PMID: 36812837 DOI: 10.1016/j.micres.2023.127316] [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: 05/01/2022] [Revised: 11/27/2022] [Accepted: 02/01/2023] [Indexed: 02/11/2023]
Abstract
Colistin-resistance in bacteria is a big concern for public health, since it is a last resort antibiotic to treat infectious diseases of multidrug resistant and carbapenem resistant Gram-negative pathogens in clinical settings. The emergence of colistin resistance in aquaculture and poultry settings has escalated the risks associated with colistin resistance in environment as well. The staggering number of reports pertaining to the rise of colistin resistance in bacteria from clinical and non-clinical settings is disconcerting. The co-existence of colistin resistant genes with other antibiotic resistant genes introduces new challenges in combatting antimicrobial resistance. Some countries have banned the manufacture, sale and distribution of colistin and its formulations for food producing animals. However, to tackle the issue of antimicrobial resistance, a one health approach initiative, inclusive of human, animal, and environmental health needs to be developed. Herein, we review the recent reports in colistin resistance in bacteria of clinical and non-clinical settings, deliberating on the new findings obtained regarding the development of colistin resistance. This review also discusses the initiatives implemented globally in mitigating colistin resistance, their strength and weakness.
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Affiliation(s)
- P S Seethalakshmi
- Department of Microbiology, Pondicherry University, Puducherry 605014, India.
| | - Riya Rajeev
- Department of Microbiology, Pondicherry University, Puducherry 605014, India.
| | | | - George Seghal Kiran
- Department of Food Science and Technology, Pondicherry University, Puducherry 605014, India.
| | - Joseph Selvin
- Department of Microbiology, Pondicherry University, Puducherry 605014, India.
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15
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The Capsule Increases Susceptibility to Last-Resort Polymyxins, but Not to Other Antibiotics, in Klebsiella pneumoniae. Antimicrob Agents Chemother 2023; 67:e0012723. [PMID: 36912665 PMCID: PMC10112221 DOI: 10.1128/aac.00127-23] [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: 03/14/2023] Open
Abstract
The extracellular capsule is a virulence factor present in many facultative pathogens, but its role in antimicrobial resistance remains controversial. To shed light on this debate, we tested six antibiotics on four Klebsiella pneumoniae species complex strains. Noncapsulated strains exhibited increased tolerance to polymyxins, but not to other antibiotics, as measured using the MIC. Our results urge caution on the use of therapeutic agents that target the capsule and may result in selection for its inactivation.
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16
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Pertics BZ, Kovács T, Schneider G. Characterization of a Lytic Bacteriophage and Demonstration of Its Combined Lytic Effect with a K2 Depolymerase on the Hypervirulent Klebsiella pneumoniae Strain 52145. Microorganisms 2023; 11:microorganisms11030669. [PMID: 36985241 PMCID: PMC10051899 DOI: 10.3390/microorganisms11030669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/01/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Klebsiella pneumoniae is a nosocomial pathogen. Among its virulence factors is the capsule with a prominent role in defense and biofilm formation. Bacteriophages (phages) can evoke the lysis of bacterial cells. Due to the mode of action of their polysaccharide depolymerase enzymes, phages are typically specific for one bacterial strain and its capsule type. In this study, we characterized a bacteriophage against the capsule-defective mutant of the nosocomial K. pneumoniae 52145 strain, which lacks K2 capsule. The phage showed a relatively narrow host range but evoked lysis on a few strains with capsular serotypes K33, K21, and K24. Phylogenetic analysis showed that the newly isolated Klebsiella phage 731 belongs to the Webervirus genus in the Drexlerviridae family; it has a 31.084 MDa double-stranded, linear DNA with a length of 50,306 base pairs and a G + C content of 50.9%. Out of the 79 open reading frames (ORFs), we performed the identification of orf22, coding for a trimeric tail fiber protein with putative capsule depolymerase activity, along with the mapping of other putative depolymerases of phage 731 and homologous phages. Efficacy of a previously described recombinant K2 depolymerase (B1dep) was tested by co-spotting phage 731 on K. pneumoniae strains, and it was demonstrated that the B1dep-phage 731 combination allows the lysis of the wild type 52145 strain, originally resistant to the phage 731. With phage 731, we showed that B1dep is a promising candidate for use as a possible antimicrobial agent, as it renders the virulent strain defenseless against other phages. Phage 731 alone is also important due to its efficacy on K. pneumoniae strains possessing epidemiologically important serotypes.
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Affiliation(s)
- Botond Zsombor Pertics
- Department of Medical Microbiology and Immunology, Medical School, University of Pécs, Szigeti St. 12., H-7624 Pécs, Hungary
| | - Tamás Kovács
- Department of Biotechnology, Nanophagetherapy Center, Enviroinvest Corporation, Kertváros St. 2., H-7632 Pécs, Hungary
| | - György Schneider
- Department of Medical Microbiology and Immunology, Medical School, University of Pécs, Szigeti St. 12., H-7624 Pécs, Hungary
- Correspondence: ; Tel.: +36-72-536-200 (ext. 1908)
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17
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Modelling the Gastrointestinal Carriage of Klebsiella pneumoniae Infections. mBio 2023; 14:e0312122. [PMID: 36598189 PMCID: PMC9972987 DOI: 10.1128/mbio.03121-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Klebsiella pneumoniae is a leading cause of nosocomial and community acquired infections, making K. pneumoniae the pathogen that is associated with the second largest number of deaths attributed to any antibiotic resistant infection. K. pneumoniae colonizes the nasopharynx and the gastrointestinal tract in an asymptomatic manner without dissemination to other tissues. Importantly, gastrointestinal colonization is a requisite for infection. Our understanding of K. pneumoniae colonization is still based on interrogating mouse models in which animals are pretreated with antibiotics to disturb the colonization resistance imposed by the gut microbiome. In these models, infections disseminate to other tissues. Here, we report a murine model to allow for the study of the gastrointestinal colonization of K. pneumoniae without tissue dissemination. Hypervirulent and antibiotic resistant strains stably colonize the gastrointestinal tract of in an inbred mouse population without antibiotic treatment. The small intestine is the primary site of colonization and is followed by a transition to the colon over time, without dissemination to other tissues. Our model recapitulates the disease dynamics of the metastatic K. pneumoniae strains that are able to disseminate from the gastrointestinal tract to other sterile sites. Colonization is associated with mild to moderate histopathology, no significant inflammation, and no effect on the richness of the microbiome. Our model sums up the clinical scenario in which antibiotic treatment disturbs the colonization of K. pneumoniae and results in dissemination to other tissues. Finally, we establish that the capsule polysaccharide is necessary for the colonization of the large intestine, whereas the type VI secretion system contributes to colonization across the gastrointestinal tract. IMPORTANCE Klebsiella pneumoniae is one of the pathogens that is sweeping the world in the antibiotic resistance pandemic. Klebsiella colonizes the nasopharynx and the gut of healthy subjects in an asymptomatic manner, making gut colonization a requisite for infection. This makes it essential to understand the gastrointestinal carriage in preventing Klebsiella infections. Current research models rely on the perturbation of the gut microbiome by antibiotics, resulting in an invasive infection. Here, we report a new model of K. pneumoniae gut colonization that recapitulates key features of the asymptomatic human gastrointestinal tract colonization. In our model, there is no need to disturb the microbiota to achieve stable colonization, and there is no dissemination to other tissues. Our model sums up the clinical scenario in which antibiotic treatment triggers invasive infection. We envision that our model will be an excellent platform upon which to investigate factors enhancing colonization and invasive infections and to test therapeutics to eliminate Klebsiella asymptomatic colonization.
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18
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Dual-Uptake Mode of the Antibiotic Phazolicin Prevents Resistance Acquisition by Gram-Negative Bacteria. mBio 2023; 14:e0021723. [PMID: 36802165 PMCID: PMC10128002 DOI: 10.1128/mbio.00217-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Phazolicin (PHZ) is a peptide antibiotic exhibiting narrow-spectrum activity against rhizobia closely related to its producer, Rhizobium sp. strain Pop5. Here, we show that the frequency of spontaneous PHZ-resistant mutants in Sinorhizobium meliloti is below the detection limit. We find that PHZ can enter S. meliloti cells through two distinct promiscuous peptide transporters, BacA and YejABEF, which belong to the SLiPT (SbmA-like peptide transporter) and ABC (ATP-binding cassette) transporter families, respectively. The dual-uptake mode explains the lack of observed resistance acquisition because the simultaneous inactivation of both transporters is necessary for resistance to PHZ. Since both BacA and YejABEF are essential for the development of functional symbiosis of S. meliloti with leguminous plants, the unlikely acquisition of PHZ resistance via the inactivation of these transporters is further disfavored. A whole-genome transposon sequencing screen did not reveal additional genes that can provide strong PHZ resistance when inactivated. However, it was found that the capsular polysaccharide KPS, the novel putative envelope polysaccharide PPP (PHZ-protecting polysaccharide), as well as the peptidoglycan layer jointly contribute to the sensitivity of S. meliloti to PHZ, most likely serving as barriers that reduce the amount of PHZ transported inside the cell. IMPORTANCE Many bacteria produce antimicrobial peptides to eliminate competitors and create an exclusive niche. These peptides act either by membrane disruption or by inhibiting essential intracellular processes. The Achilles' heel of the latter type of antimicrobials is their dependence on transporters to enter susceptible cells. Transporter inactivation results in resistance. Here, we show that a rhizobial ribosome-targeting peptide, phazolicin (PHZ), uses two different transporters, BacA and YejABEF, to enter the cells of a symbiotic bacterium, Sinorhizobium meliloti. This dual-entry mode dramatically reduces the probability of the appearance of PHZ-resistant mutants. Since these transporters are also crucial for S. meliloti symbiotic associations with host plants, their inactivation in natural settings is strongly disfavored, making PHZ an attractive lead for the development of biocontrol agents for agriculture.
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19
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Dai P, Hu D. The making of hypervirulent Klebsiella pneumoniae. J Clin Lab Anal 2022; 36:e24743. [PMID: 36347819 PMCID: PMC9757020 DOI: 10.1002/jcla.24743] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/01/2022] [Accepted: 10/09/2022] [Indexed: 10/08/2023] Open
Abstract
Klebsiella pneumoniae is a notorious bacterium in clinical practice. Virulence, carbapenem-resistance and their convergence among K. pneumoniae are extensively discussed in this article. Hypervirulent K. pneumoniae (HvKP) has spread from the Asian Pacific Rim to the world, inducing various invasive infections, such as pyogenic liver abscess, endophthalmitis, and meningitis. Furthermore, HvKP has acquired more and more drug resistance. Among multidrug-resistant HvKP, hypervirulent carbapenem-resistant K. pneumoniae (Hv-CRKP), and carbapenem-resistant hypervirulent K. pneumoniae (CR-HvKP) are both devastating for their extreme drug resistance and virulence. The hypervirulence of HvKP is primarily attributed to hypercapsule, macromolecular exopolysaccharides, or excessive siderophores, although it has many other factors, for example, lipopolysaccharides, fimbriae, and porins. In contrast with classical determination of HvKP, that is, animal lethality test, molecular determination could be an optional and practical method after improvement. HvKP, including Hv-CRKP and CR-HvKP, has been progressing. R-M and CRISPR-Cas systems may play pivotal roles in such evolutions. Hv-CRKP and CR-HvKP, in particular the former, should be of severe concern due to their being more and more prevalent.
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Affiliation(s)
- Piaopiao Dai
- Department of Laboratory MedicineTaizhou Municipal HospitalTaizhouChina
| | - Dakang Hu
- Department of Laboratory MedicineTaizhou Municipal HospitalTaizhouChina
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20
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Dumigan A, Cappa O, Morris B, Sá Pessoa J, Calderon‐Gonzalez R, Mills G, Lancaster R, Simpson D, Kissenpfennig A, Bengoechea JA. In vivo single-cell transcriptomics reveal Klebsiella pneumoniae skews lung macrophages to promote infection. EMBO Mol Med 2022; 14:e16888. [PMID: 36337046 PMCID: PMC9727930 DOI: 10.15252/emmm.202216888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 11/09/2022] Open
Abstract
The strategies deployed by antibiotic-resistant bacteria to counteract host defences are poorly understood. Here, we elucidate a novel host-pathogen interaction resulting in skewing lung macrophage polarisation by the human pathogen Klebsiella pneumoniae. We identify interstitial macrophages (IMs) as the main population of lung macrophages associated with Klebsiella. Single-cell transcriptomics and trajectory analysis of cells reveal type I IFN and IL10 signalling, and macrophage polarisation are characteristic of infected IMs, whereas Toll-like receptor (TLR) and Nod-like receptor signalling are features of infected alveolar macrophages. Klebsiella-induced macrophage polarisation is a singular M2-type we termed M(Kp). To rewire macrophages, Klebsiella hijacks a TLR-type I IFN-IL10-STAT6 axis. Absence of STAT6 limits Klebsiella intracellular survival and facilitates the clearance of the pathogen in vivo. Glycolysis characterises M(Kp) metabolism, and inhibition of glycolysis results in clearance of intracellular Klebsiella. Capsule polysaccharide governs M(Kp). Klebsiella also skews human macrophage polarisation towards M(Kp) in a type I IFN-IL10-STAT6-dependent manner. Klebsiella induction of M(Kp) represents a novel strategy to overcome host restriction, and identifies STAT6 as target to boost defences against Klebsiella.
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Affiliation(s)
- Amy Dumigan
- Wellcome‐Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical SciencesQueen's University BelfastBelfastUK
| | - Oisin Cappa
- Wellcome‐Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical SciencesQueen's University BelfastBelfastUK
| | - Brenda Morris
- Wellcome‐Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical SciencesQueen's University BelfastBelfastUK
| | - Joana Sá Pessoa
- Wellcome‐Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical SciencesQueen's University BelfastBelfastUK
| | - Ricardo Calderon‐Gonzalez
- Wellcome‐Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical SciencesQueen's University BelfastBelfastUK
| | - Grant Mills
- Wellcome‐Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical SciencesQueen's University BelfastBelfastUK
| | - Rebecca Lancaster
- Wellcome‐Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical SciencesQueen's University BelfastBelfastUK
| | - David Simpson
- Wellcome‐Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical SciencesQueen's University BelfastBelfastUK
| | - Adrien Kissenpfennig
- Wellcome‐Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical SciencesQueen's University BelfastBelfastUK
| | - Jose A Bengoechea
- Wellcome‐Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical SciencesQueen's University BelfastBelfastUK
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21
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Zhang W, Yao Y, Zhou H, He J, Wang J, Li L, Gao M, Liu X, Shi Y, Lin J, Liu J, Chen H, Feng Y, Zhou Z, Yu Y, Hua X. Interactions between host epithelial cells and Acinetobacter baumannii promote the emergence of highly antibiotic resistant and highly mucoid strains. Emerg Microbes Infect 2022; 11:2556-2569. [PMID: 36227610 PMCID: PMC9621264 DOI: 10.1080/22221751.2022.2136534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Acinetobacter baumannii is an important nosocomial pathogen. Upon colonizing a host, A. baumannii are subjected to selective pressure by immune defenses as they adapt to the host environment. However, the mechanism of this pathoadaptation is unknown. Here, we established an in vitro system to evolve A. baumannii driven by the continuous selective pressure exerted by epithelial cells, and we used a combination of experimental evolution, phenotypic characterization and multi-omics analysis to address the underlying mechanism. When continuously exposed to selective pressure by pulmonary epithelial cells, A. baumannii showed ptk mutation-mediated mucoid conversion (reduced adhesion and increased anti-phagocytic ability) by enhancement of capsular exopolysaccharide chain length; rsmG mutation-mediated deficiency of 7-methylguanosine modification in the 524th nucleotide of 16S rRNA, which increased ribosome translation efficiency; and rnaseI mutation-mediated changes in outer membrane permeability and efflux pump expression. Together, these mutations altered susceptibility to a variety of antimicrobial agents, including the novel antibiotic cefiderocol, by regulating siderophore and siderophore-receptor biosynthesis. In conclusion, pulmonary epithelial cells modulate A. baumannii pathoadaptation, implicating the host–microbe interaction in the survival and persistence of A. baumannii.
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Affiliation(s)
- Wang Zhang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Yue Yao
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Hua Zhou
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jintao He
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Jingfen Wang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Li Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Minsong Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaochen Liu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Ya Shi
- Hangzhou Digital-Micro Biotech Co., Ltd., Hangzhou, Zhejiang, China
| | - Jinzhong Lin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jianzhao Liu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, China.,Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang, China
| | - Huan Chen
- Hangzhou Digital-Micro Biotech Co., Ltd., Hangzhou, Zhejiang, China
| | - Yu Feng
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Department of Biophysics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Zhihui Zhou
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
| | - Xiaoting Hua
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Regional Medical Center for National Institute of Respiratory Diseases, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Hangzhou, China
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22
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O’Brien DK, Ribot WJ, Chabot DJ, Scorpio A, Tobery SA, Jelacic TM, Wu Z, Friedlander AM. The capsule of Bacillus anthracis protects it from the bactericidal activity of human defensins and other cationic antimicrobial peptides. PLoS Pathog 2022; 18:e1010851. [PMID: 36174087 PMCID: PMC9560598 DOI: 10.1371/journal.ppat.1010851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 10/13/2022] [Accepted: 09/04/2022] [Indexed: 12/04/2022] Open
Abstract
During infection, Bacillus anthracis bacilli encounter potent antimicrobial peptides (AMPs) such as defensins. We examined the role that B. anthracis capsule plays in protecting bacilli from defensins and other cationic AMPs by comparing their effects on a fully virulent encapsulated wild type (WT) strain and an isogenic capsule-deficient capA mutant strain. We identified several human defensins and non-human AMPs that were capable of killing B. anthracis. The human alpha defensins 1–6 (HNP-1-4, HD-5-6), the human beta defensins 1–4 (HBD-1-4), and the non-human AMPs, protegrin, gramicidin D, polymyxin B, nisin, and melittin were all capable of killing both encapsulated WT and non-encapsulated capA mutant B. anthracis. However, non-encapsulated capA mutant bacilli were significantly more susceptible than encapsulated WT bacilli to killing by nearly all of the AMPs tested. We demonstrated that purified capsule bound HBD-2, HBD-3, and HNP-1 in an electrophoretic mobility shift assay. Furthermore, we determined that the capsule layer enveloping WT bacilli bound and trapped HBD-3, substantially reducing the amount reaching the cell wall. To assess whether released capsule might also play a protective role, we pre-incubated HBD-2, HBD-3, or HNP-1 with purified capsule before their addition to non-encapsulated capA mutant bacilli. We found that free capsule completely rescued the capA mutant bacilli from killing by HBD-2 and -3 while killing by HNP-1 was reduced to the level observed with WT bacilli. Together, these results suggest an immune evasion mechanism by which the capsule, both that enveloping the bacilli and released fragments, contributes to virulence by binding to and inhibiting the antimicrobial activity of cationic AMPs. Bacillus anthracis causes anthrax after spores infect the skin, respiratory tract, or gastrointestinal tract. Antimicrobial peptides (AMPs), such as defensins, are a first line of host defense that B. anthracis encounters in all of these tissues. B. anthracis bacteria are covered by a capsule that protects them from being engulfed and destroyed by phagocytic immune cells. In this study, we found that the capsule also provides protection from AMPs. An encapsulated B. anthracis strain is resistant to killing by multiple AMPs from humans and other species compared to an otherwise identical strain that is not encapsulated. By binding defensins the capsule surrounding the bacilli reduces the amount that gets to the bacterial cell wall where it can do damage. B. anthracis bacteria release large fragments of capsule in the host during infection and during growth in culture. We found that purified released capsule can bind defensins and reduce killing of non-encapsulated B. anthracis. Thus, both capsule covering the bacteria and capsule shed by the bacteria can contribute to the pathogenicity of B. anthracis by providing protection from AMPs. Our study reveals a new mechanism by which B. anthracis capsule contributes to virulence.
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Affiliation(s)
- David K. O’Brien
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Wilson J. Ribot
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Donald J. Chabot
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Angelo Scorpio
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Steven A. Tobery
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Tanya M. Jelacic
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Zhibin Wu
- Institute of Human Virology, University of Maryland Biotechnology Institute, Baltimore, Maryland, United States of America
| | - Arthur M. Friedlander
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
- Department of Medicine, Uniformed University of Health Services, Bethesda, Maryland, United States of America
- * E-mail: ,
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23
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Coya JM, Fraile-Ágreda V, de Tapia L, García-Fojeda B, Sáenz A, Bengoechea JA, Kronqvist N, Johansson J, Casals C. Cooperative action of SP-A and its trimeric recombinant fragment with polymyxins against Gram-negative respiratory bacteria. Front Immunol 2022; 13:927017. [PMID: 36159837 PMCID: PMC9493720 DOI: 10.3389/fimmu.2022.927017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 08/10/2022] [Indexed: 11/19/2022] Open
Abstract
The exploration of therapies combining antimicrobial lung proteins and conventional antibiotics is important due to the growing problem of multidrug-resistant bacteria. The aim of this study was to investigate whether human SP-A and a recombinant trimeric fragment (rfhSP-A) have cooperative antimicrobial activity with antibiotics against pathogenic Gram-negative bacteria. We found that SP-A bound the cationic peptide polymyxin B (PMB) with an apparent dissociation constant (K D) of 0.32 ± 0.04 µM. SP-A showed synergistic microbicidal activity with polymyxin B and E, but not with other antibiotics, against three SP-A-resistant pathogenic bacteria: Klebsiella pneumoniae, non-typable Haemophilus influenzae (NTHi), and Pseudomonas aeruginosa. SP-A was not able to bind to K. pneumoniae, NTHi, or to mutant strains thereof expressing long-chain lipopolysaccharides (or lipooligosaccharides) and/or polysaccharide capsules. In the presence of PMB, SP-A induced the formation of SP-A/PMB aggregates that enhance PMB-induced bacterial membrane permeabilization. Furthermore, SP-A bound to a molecular derivative of PMB lacking the acyl chain (PMBN) with a K D of 0.26 ± 0.02 μM, forming SP-A/PMBN aggregates. PMBN has no bactericidal activity but can bind to the outer membrane of Gram-negative bacteria. Surprisingly, SP-A and PMBN showed synergistic bactericidal activity against Gram-negative bacteria. Unlike native supratrimeric SP-A, the trimeric rfhSP-A fragment had small but significant direct bactericidal activity against K. pneumoniae, NTHi, and P. aeruginosa. rfhSP-A did not bind to PMB under physiological conditions but acted additively with PMB and other antibiotics against these pathogenic bacteria. In summary, our results significantly improve our understanding of the antimicrobial actions of SP-A and its synergistic action with PMB. A peptide based on SP-A may aid the therapeutic use of PMB, a relatively cytotoxic antibiotic that is currently being reintroduced into clinics due to the global problem of antibiotic resistance.
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Affiliation(s)
- Juan Manuel Coya
- Department of Biochemistry and Molecular Biology, Complutense University of Madrid, Madrid, Spain
| | - Víctor Fraile-Ágreda
- Department of Biochemistry and Molecular Biology, Complutense University of Madrid, Madrid, Spain
| | - Lidia de Tapia
- Department of Biochemistry and Molecular Biology, Complutense University of Madrid, Madrid, Spain
| | - Belén García-Fojeda
- Department of Biochemistry and Molecular Biology, Complutense University of Madrid, Madrid, Spain
| | - Alejandra Sáenz
- Department of Biochemistry and Molecular Biology, Complutense University of Madrid, Madrid, Spain
| | - José A. Bengoechea
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast, United Kingdom
| | - Nina Kronqvist
- Department of Biosciences and Nutrition, Neo, Karolinska Institutet, Huddinge, Sweden
| | - Jan Johansson
- Department of Biosciences and Nutrition, Neo, Karolinska Institutet, Huddinge, Sweden
| | - Cristina Casals
- Department of Biochemistry and Molecular Biology, Complutense University of Madrid, Madrid, Spain
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24
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Rescuing humanity by antimicrobial peptides against colistin-resistant bacteria. Appl Microbiol Biotechnol 2022; 106:3879-3893. [PMID: 35604438 PMCID: PMC9125544 DOI: 10.1007/s00253-022-11940-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 04/18/2022] [Accepted: 04/21/2022] [Indexed: 12/03/2022]
Abstract
Abstract
It has been about a century since the discovery of the first antibiotic, and during this period, several antibiotics were produced and marketed. The production of high-potency antibiotics against infections led to victories, but these victories were temporary. Overuse and misuse of antibiotics have continued to the point that humanity today is almost helpless in the fight against infection. Researchers have predicted that by the middle of the new century, there will be a dark period after the production of antibiotics that doctors will encounter antibiotic-resistant infections for which there is no cure. Accordingly, researchers are looking for new materials with antimicrobial properties that will strengthen their ammunition to fight antibiotic-resistant infections. One of the most important alternatives to antibiotics introduced in the last three decades is antimicrobial peptides (AMPs), which affect a wide range of microbes. Due to their different antimicrobial properties from antibiotics, AMPs can fight and kill MDR, XDR, and colistin-resistant bacteria through a variety of mechanisms. Therefore, in this study, we intend to use the latest studies to give a complete description of AMPs, the importance of colistin-resistant bacteria, and their resistance mechanisms, and represent impact of AMPs on colistin-resistant bacteria. Key points • AMPs as limited options to kill colistin-resistant bacteria. • Challenge of antibiotics resistance, colistin resistance, and mechanisms. • What is AMPs in the war with colistin-resistant bacteria?
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25
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Waz NT, Oliveira S, Girardello R, Lincopan N, Barazzone G, Parisotto T, Hakansson AP, Converso TR, Darrieux M. Influence of the Polysaccharide Capsule on the Bactericidal Activity of Indolicidin on Streptococcus pneumoniae. Front Microbiol 2022; 13:898815. [PMID: 35633685 PMCID: PMC9136410 DOI: 10.3389/fmicb.2022.898815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 04/28/2022] [Indexed: 11/13/2022] Open
Abstract
Streptococcus pneumoniae is a pathogen responsible for high morbidity and mortality worldwide. The polysaccharide capsule confers protection against phagocytosis and influences many aspects of pneumococcal pathogenesis. The capsular polysaccharides (CPS) are highly immunogenic and exhibit great structural variability, with more than 100 serotypes described so far. Antimicrobial peptides (AMPs) are an important part of the innate defense mechanisms against many pathogens. Indolicidin is a cationic AMP produced by bovine neutrophils, with bactericidal effects against several bacteria. CPS has been shown to interfere with the ability of AMPs to kill pneumococci, but the effects of capsule variability on susceptibility to indolicidin have not been explored. The present work determined the effects of capsule on resistance to indolicidin in vitro. Using a bactericidal plate assay, we observed that different pneumococcal serotypes exhibited variable resistance to indolicidin, which correlated with the capsule net charge. Interestingly, the effect of capsule expression on resistance to indolicidin was dependent on the serotype; bacteria with lower zeta potential were more resistant to indolicidin when capsule was present, while those with less negative surface charge were more resistant in the absence of capsule. The addition of purified CPS partially rescued the bacteria from the bactericidal effects of indolicidin, while the addition of anticapsular antibodies accentuated the peptide’s bactericidal action, suggesting a possible new protective mechanism induced by polysaccharide-based pneumococcal vaccines.
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Affiliation(s)
- Natalha T. Waz
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Sheila Oliveira
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Raquel Girardello
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Nilton Lincopan
- Laboratório de Resistoma e Alternativas Terapêuticas, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Giovana Barazzone
- Laboratório de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil
| | - Thais Parisotto
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Anders P. Hakansson
- Division of Experimental Infection Medicine, Department of Translational Medicine, Lund University, Malmo, Sweden
| | - Thiago Rojas Converso
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Michelle Darrieux
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
- *Correspondence: Michelle Darrieux,
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26
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Fleeman RM, Davies BW. Polyproline Peptide Aggregation with Klebsiella pneumoniae Extracellular Polysaccharides Exposes Biofilm Associated Bacteria. Microbiol Spectr 2022; 10:e0202721. [PMID: 35254120 PMCID: PMC9045188 DOI: 10.1128/spectrum.02027-21] [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: 10/25/2021] [Accepted: 02/14/2022] [Indexed: 11/20/2022] Open
Abstract
Klebsiella pneumoniae produces a thick capsule layer composed of extracellular polysaccharides protecting the bacterial cells from clearance by innate host immunity during infection. Here we characterize the interactions of a structurally diverse set of host defense peptides with K. pneumoniae extracellular polysaccharides. Remarkably, we found that all host defense peptides were active against a diverse set of K. pneumoniae strains, including hypermucoviscous strains with extensive capsule production, and aggregated with extracted capsule. Interestingly, the polyproline peptide bac7 (1-35), was the most potent antimicrobial and induced the most capsule aggregation. In addition to capsule aggregation, we found that bac7 (1-35) could also disrupt pre-formed hypermucoviscous K. pneumoniae biofilm. Further analysis using scanning electron microscopy revealed the biofilm matrix of a hypermucoviscous strain is removed by bac7 (1-35) exposing associated bacterial cells. This is the first description of a host defense peptide interacting with capsular and biofilm extracellular polysaccharides to expose cells from a K. pneumoniae biofilm matrix and suggests that features of polyproline peptides may be uniquely suited for extracellular polysaccharide interactions. IMPORTANCE Klebsiella pneumoniae bacterial infections are a major threat to human health as mortality rates are steadily on the rise. A defining characteristic of K. pneumoniae is the robust polysaccharide capsule that aids in resistance to the human immune system. We have previously discovered that a synthetic peptide could aggregate with capsule polysaccharides and disrupt the capsule of K. pneumoniae. Here we describe that host defense peptides also aggregate with capsule produced from hypermucoviscous K. pneumoniae, revealing this mechanism is shared by natural peptides. We found the polyproline peptide bac7 (1-35) had the greatest antimicrobial activity and caused the most capsule aggregation. Interestingly, bac7 (1-35) also removed the biofilm matrix of hypermucoviscous K. pneumoniae exposing the associated bacterial cells. This is the first description of a polyproline peptide interacting with capsular and biofilm polysaccharides to expose cells from a K. pneumoniae biofilm matrix.
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Affiliation(s)
- Renee M. Fleeman
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Bryan W. Davies
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, Texas, USA
- John Ring LaMontagne Center for Infectious Diseases, The University of Texas at Austin, Austin, Texas, USA
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Gaurivaud P, Tardy F. The Mycoplasma spp. ‘Releasome’: A New Concept for a Long-Known Phenomenon. Front Microbiol 2022; 13:853440. [PMID: 35495700 PMCID: PMC9051441 DOI: 10.3389/fmicb.2022.853440] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 03/14/2022] [Indexed: 11/13/2022] Open
Abstract
The bacterial secretome comprises polypeptides expressed at the cell surface or released into the extracellular environment as well as the corresponding secretion machineries. Despite their reduced coding capacities, Mycoplasma spp. are able to produce and release several components into their environment, including polypeptides, exopolysaccharides and extracellular vesicles. Technical difficulties in purifying these elements from the complex broth media used to grow mycoplasmas have recently been overcome by optimizing growth conditions and switching to chemically defined culture media. However, the secretion pathways responsible for the release of these structurally varied elements are still poorly described in mycoplasmas. We propose the use of the term ‘releasome,’ instead of secretome, to refer to molecules released by mycoplasmas into their environment. The aim of this review is to more precisely delineate the elements that should be considered part of the mycoplasmal releasome and their role in the interplay of mycoplasmas with host cells and tissues.
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Lee IM, Huang TY, Yang FL, Johansson V, Hsu CR, Hsieh PF, Chen ST, Yang YJ, Konradsson P, Sheu JH, Wang JT, Wu SH. A hexasaccharide from capsular polysaccharide of carbapenem-resistant Klebsiella pneumoniae KN2 is a ligand of Toll-like receptor 4. Carbohydr Polym 2022; 278:118944. [PMID: 34973762 DOI: 10.1016/j.carbpol.2021.118944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 11/19/2022]
Abstract
Klebsiella pneumoniae serotype KN2 is a carbapenem-resistant strain and leads to the health care-associated infections, such as bloodstream infections. Its capsular polysaccharide (CPS) was isolated and cleaved by a specific enzyme from a bacteriophage into a hexasaccharide-repeating unit. With GC-MS, NMR, and Mass analyses, the structure of KN2 CPS was determined to be {→3)-β-D-Glcp-(1→3)-[α-D-GlcpA-(1→4)-β-D-Glcp-(1→6)]-α-D-Galp-(1→6)-β-D-Galp-(1→3)-β-D-Galp-(1→}n. We demonstrated that 1 μg/mL CPS could stimulate J774A.1 murine macrophages to release tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in vitro. Also, we proved that KN2 CPS induced the immune response through Toll-like receptor 4 (TLR4) in the human embryonic kidney (HEK)-293 cells. Strikingly, the hexasaccharide alone shows the same immune response as the CPS, suggesting that the hexasaccharide can shape the adaptive immunity to be a potential vaccine adjuvant. The glucuronic acid (GlcA) on other polysaccharides can affect the immune response, but the GlcA-reduced KN2 CPS and hexasaccharide still maintain their immunomodulatory activities.
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Affiliation(s)
- I-Ming Lee
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Tzu-Yin Huang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Feng-Ling Yang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Victor Johansson
- Department of Physics, Chemistry, and Biology, Linköping University, Sweden
| | - Chun-Ru Hsu
- Department of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan
| | - Pei-Fang Hsieh
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Shin-Tai Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yen-Ju Yang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Peter Konradsson
- Department of Physics, Chemistry, and Biology, Linköping University, Sweden
| | - Jyh-Horng Sheu
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan; Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Jin-Town Wang
- Department of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Shih-Hsiung Wu
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan; Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, Taiwan.
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29
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Prevalence of polymyxin resistance through the food chain, the global crisis. J Antibiot (Tokyo) 2022; 75:185-198. [PMID: 35079146 DOI: 10.1038/s41429-022-00502-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 09/30/2021] [Accepted: 10/10/2021] [Indexed: 12/24/2022]
Abstract
Antimicrobial resistance is one of the vital challenges facing global health today. Multi-drug resistant (MDR) infections are often treated with the narrow-spectrum drugs, colistin (polymyxin E) or polymyxin B, which are last-resort antibiotics for human therapeutics that are effective against Gram-negative bacteria. Unfortunately, resistance to these polymyxins has occurred because of selective pressure caused by the inappropriate use of those antibiotics, especially in farming. The mechanisms of resistance to polymyxins are mediated through intrinsic, mutational, or genetic alteration in chromosomal genes. The mechanism includes the regulatory network controlling chemical modifications of lipid A moiety of lipopolysaccharide, reducing the negative charge of lipid A and its affinity for polymyxins. Additionally, the unique mobile colistin/polymyxin B resistance (mcr) gene reported in Enterobacteriales is responsible for the horizontal dissemination of resistance to polymyxins via the food chain. There is now an urgent need to increase surveillance for detecting resistance to polymyxins. Therefore, this review presents an overview of presently available scientific literature on the mechanism of resistance to polymyxins, with their associated gene variants, evaluation methods, resistance transmission through the food chain via food bacteria, and related risk factors. We further focus on the significant implications of polymyxins usage in India and future views for food safety to preserve polymyxin activity.
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Duong L, Gross SP, Siryaporn A. Developing Antimicrobial Synergy With AMPs. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 3:640981. [PMID: 35047912 PMCID: PMC8757689 DOI: 10.3389/fmedt.2021.640981] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 02/12/2021] [Indexed: 12/03/2022] Open
Abstract
Antimicrobial peptides (AMPs) have been extensively studied due to their vast natural abundance and ability to kill microbes. In an era critically lacking in new antibiotics, manipulating AMPs for therapeutic application is a promising option. However, bacterial pathogens resistant to AMPs remain problematic. To improve AMPs antimicrobial efficacy, their use in conjunction with other antimicrobials has been proposed. How might this work? AMPs kill bacteria by forming pores in bacterial membranes or by inhibiting bacterial macromolecular functions. What remains unknown is the duration for which AMPs keep bacterial pores open, and the extent to which bacteria can recover by repairing these pores. In this mini-review, we discuss various antimicrobial synergies with AMPs. Such synergies might arise if the antimicrobial agents helped to keep bacterial pores open for longer periods of time, prevented pore repair, perturbed bacterial intracellular functions at greater levels, or performed other independent bacterial killing mechanisms. We first discuss combinations of AMPs, and then focus on histones, which have antimicrobial activity and co-localize with AMPs on lipid droplets and in neutrophil extracellular traps (NETs). Recent work has demonstrated that histones can enhance AMP-induced membrane permeation. It is possible that histones, histone fragments, and histone-like peptides could amplify the antimicrobial effects of AMPs, giving rise to antimicrobial synergy. If so, clarifying these mechanisms will thus improve our overall understanding of the antimicrobial processes and potentially contribute to improved drug design.
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Affiliation(s)
- Leora Duong
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, United States
| | - Steven P Gross
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA, United States.,Department of Physics & Astronomy, University of California, Irvine, Irvine, CA, United States
| | - Albert Siryaporn
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, United States.,Department of Physics & Astronomy, University of California, Irvine, Irvine, CA, United States
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Escobar‐Salom M, Torrens G, Jordana‐Lluch E, Oliver A, Juan C. Mammals' humoral immune proteins and peptides targeting the bacterial envelope: from natural protection to therapeutic applications against multidrug‐resistant
Gram
‐negatives. Biol Rev Camb Philos Soc 2022; 97:1005-1037. [PMID: 35043558 PMCID: PMC9304279 DOI: 10.1111/brv.12830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 12/12/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022]
Abstract
Mammalian innate immunity employs several humoral ‘weapons’ that target the bacterial envelope. The threats posed by the multidrug‐resistant ‘ESKAPE’ Gram‐negative pathogens (Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) are forcing researchers to explore new therapeutic options, including the use of these immune elements. Here we review bacterial envelope‐targeting (peptidoglycan and/or membrane‐targeting) proteins/peptides of the mammalian immune system that are most likely to have therapeutic applications. Firstly we discuss their general features and protective activity against ESKAPE Gram‐negatives in the host. We then gather, integrate, and discuss recent research on experimental therapeutics harnessing their bactericidal power, based on their exogenous administration and also on the discovery of bacterial and/or host targets that improve the performance of this endogenous immunity, as a novel therapeutic concept. We identify weak points and knowledge gaps in current research in this field and suggest areas for future work to obtain successful envelope‐targeting therapeutic options to tackle the challenge of antimicrobial resistance.
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Affiliation(s)
- María Escobar‐Salom
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Gabriel Torrens
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Elena Jordana‐Lluch
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Antonio Oliver
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
| | - Carlos Juan
- Department of Microbiology University Hospital Son Espases‐Health Research Institute of the Balearic Islands (IdISBa) Carretera de Valldemossa 79 Palma Balearic Islands 07010 Spain
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Zhang S, Abbas M, Rehman MU, Wang M, Jia R, Chen S, Liu M, Zhu D, Zhao X, Gao Q, Tian B, Cheng A. Updates on the global dissemination of colistin-resistant Escherichia coli: An emerging threat to public health. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 799:149280. [PMID: 34364270 DOI: 10.1016/j.scitotenv.2021.149280] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/22/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
Colistin drug resistance is an emerging public health threat worldwide. The adaptability, existence and spread of colistin drug resistance in multiple reservoirs and ecological environmental settings is significantly increasing the rate of occurrence of multidrug resistant (MDR) bacteria such as Escherichia coli (E. coli). Here, we summarized the reports regarding molecular and biological characterization of mobile colistin resistance gene (mcr)-positive E. coli (MCRPEC), originating from diverse reservoirs, including but not limited to humans, environment, waste water treatment plants, wild, pets, and food producing animals. The MCRPEC revealed the abundance of clinically important resistance genes, which are responsible for MDR profile. A number of plasmid replicon types such as IncI2, IncX4, IncP, IncX, and IncFII with a predominance of IncI2 were facilitating the spread of colistin resistance. This study concludes the distribution of multiple sequence types of E. coli carrying mcr gene variants, which are possible threat to "One Health" perspective. In addition, we have briefly explained the newly known mechanisms of colistin resistance i.e. plasmid-encoded resistance determinant as well as presented the chromosomally-encoded resistance mechanisms. The transposition of ISApl1 into the chromosome and existence of intact Tn6330 are important for transmission and stability for mcr gene. Further, genetic environment of co-localized mcr gene with carbapenem-resistance or extended-spectrum β-lactamases genes has also been elaborated, which is limiting human beings to choose last resort antibiotics. Finally, environmental health and safety control measures along with spread mechanisms of mcr genes are discussed to avoid further propagation and environmental hazards of colistin resistance.
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Affiliation(s)
- Shaqiu Zhang
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China
| | - Muhammad Abbas
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China; Livestock and Dairy Development Department Lahore, Punjab 54000, Pakistan
| | - Mujeeb Ur Rehman
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China; Disease Investigation Laboratory, Livestock & Dairy Development Department, Zhob 85200, Balochistan, Pakistan
| | - Mingshu Wang
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China
| | - Renyong Jia
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China
| | - Shun Chen
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China
| | - Mafeng Liu
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China
| | - Dekang Zhu
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China
| | - Xinxin Zhao
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China
| | - Qun Gao
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China
| | - Bin Tian
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China
| | - Anchun Cheng
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu 611130, PR China; Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, PR China.
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Enantioselectivity of Chiral Derivatives of Xanthones in Virulence Effects of Resistant Bacteria. Pharmaceuticals (Basel) 2021; 14:ph14111141. [PMID: 34832923 PMCID: PMC8623869 DOI: 10.3390/ph14111141] [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: 10/20/2021] [Revised: 11/04/2021] [Accepted: 11/09/2021] [Indexed: 12/04/2022] Open
Abstract
Antimicrobial peptides are one of the lines of defense produced by several hosts in response to bacterial infections. Inspired by them and recent discoveries of xanthones as bacterial efflux pump inhibitors, chiral amides with a xanthone scaffold were planned to be potential antimicrobial adjuvants. The chiral derivatives of xanthones were obtained by peptide coupling reactions between suitable xanthones with enantiomerically pure building blocks, yielding derivatives with high enantiomeric purity. Among 18 compounds investigated for their antimicrobial activity against reference strains of bacteria and fungi, antibacterial activity for the tested strains was not found. Selected compounds were also evaluated for their potential to inhibit bacterial efflux pumps. Compound (R,R)-8 inhibited efflux pumps in the Gram-positive model tested and three compounds, (S,S)-8, (R)-17 and (R,S)-18, displayed the same activity in the Gram-negative strain used. Studies were performed on the inhibition of biofilm formation and quorum-sensing, to which the enantiomeric pair 8 displayed activity for the latter. To gain a better understanding of how the active compounds bind to the efflux pumps, docking studies were performed. Hit compounds were proposed for each activity, and it was shown that enantioselectivity was noticeable and must be considered, as enantiomers displayed differences in activity.
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34
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The bacterial tyrosine kinase system CpsBCD governs the length of capsule polymers. Proc Natl Acad Sci U S A 2021; 118:2103377118. [PMID: 34732571 DOI: 10.1073/pnas.2103377118] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2021] [Indexed: 12/17/2022] Open
Abstract
Many pathogenic bacteria are encased in a layer of capsular polysaccharide (CPS). This layer is important for virulence by masking surface antigens, preventing opsonophagocytosis, and avoiding mucus entrapment. The bacterial tyrosine kinase (BY-kinase) regulates capsule synthesis and helps bacterial pathogens to survive different host niches. BY-kinases autophosphorylate at the C-terminal tyrosine residues upon external stimuli, but the role of phosphorylation is still unclear. Here, we report that the BY-kinase CpsCD is required for growth in Streptococcus pneumoniae Cells lacking a functional cpsC or cpsD accumulated low molecular weight CPS and lysed because of the lethal sequestration of the lipid carrier undecaprenyl phosphate, resulting in inhibition of peptidoglycan (PG) synthesis. CpsC interacts with CpsD and the polymerase CpsH. CpsD phosphorylation reduces the length of CPS polymers presumably by controlling the activity of CpsC. Finally, pulse-chase experiments reveal the spatiotemporal coordination between CPS and PG synthesis. This coordination is dependent on CpsC and CpsD. Together, our study provides evidence that BY-kinases regulate capsule polymer length by fine-tuning CpsC activity through autophosphorylation.
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35
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Zheng M, Zheng M, Epstein S, Harnagel AP, Kim H, Lupoli TJ. Chemical Biology Tools for Modulating and Visualizing Gram-Negative Bacterial Surface Polysaccharides. ACS Chem Biol 2021; 16:1841-1865. [PMID: 34569792 DOI: 10.1021/acschembio.1c00341] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Bacterial cells present a wide diversity of saccharides that decorate the cell surface and help mediate interactions with the environment. Many Gram-negative cells express O-antigens, which are long sugar polymers that makeup the distal portion of lipopolysaccharide (LPS) that constitutes the surface of the outer membrane. This review highlights chemical biology tools that have been developed in recent years to facilitate the modulation of O-antigen synthesis and composition, as well as related bacterial polysaccharide pathways, and the detection of unique glycan sequences. Advances in the biochemistry and structural biology of O-antigen biosynthetic machinery are also described, which provide guidance for the design of novel chemical and biomolecular probes. Many of the tools noted here have not yet been utilized in biological systems and offer researchers the opportunity to investigate the complex sugar architecture of Gram-negative cells.
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Affiliation(s)
- Meng Zheng
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Maggie Zheng
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Samuel Epstein
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Alexa P. Harnagel
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Hanee Kim
- Department of Chemistry, New York University, New York, 10003 New York, United States
| | - Tania J. Lupoli
- Department of Chemistry, New York University, New York, 10003 New York, United States
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Mousavi SM, Babakhani S, Moradi L, Karami S, Shahbandeh M, Mirshekar M, Mohebi S, Moghadam MT. Bacteriophage as a Novel Therapeutic Weapon for Killing Colistin-Resistant Multi-Drug-Resistant and Extensively Drug-Resistant Gram-Negative Bacteria. Curr Microbiol 2021; 78:4023-4036. [PMID: 34633487 PMCID: PMC8503728 DOI: 10.1007/s00284-021-02662-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/10/2021] [Indexed: 02/05/2023]
Abstract
Colistin-resistant multidrug-resistant (MDR), extensively drug-resistant (XDR), and pan-drug-resistant (PDR) bacteria are highly lethal and many researchers have tried hard to combat these microorganisms around the world. Infections caused by these bacteria are resistant to the last resort of antibiotic therapy and have posed a major challenge in clinical and public health. Since the production of new antibiotics is very expensive and also very slow compared to the increasing rate of antibiotic resistance, researchers are suggesting the use of natural substances with high antibacterial potential. Bacteriophages are one of the most effective therapeutic measures that are known to exist for use for incurable and highly resistant infections. Phages are highly taken into consideration due to the lack of side effects, potential spread to various body organs, distinct modes of action from antibiotics, and proliferation at the site of infection. Although the effects of phages on MDR and XDR bacteria have been demonstrated in various studies, only a few have investigated the effect of phage therapy on colistin-resistant isolates. Therefore, in this review, we discuss the problems caused by colistin-resistant MDR and XDR bacteria in the clinics, explain the different mechanisms associated with colistin resistance, introduce bacteriophage therapy as a powerful remedy, and finally present new studies that have used bacteriophages against colistin-resistant isolates.
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Affiliation(s)
| | - Sajad Babakhani
- Department of Microbiology, Tehran North Branch, Islamic Azad University, Tehran, Iran
| | - Leila Moradi
- Department of Microbiology, Zanjan Branch, Islamic Azad University, Zanjan, Iran
| | - Saina Karami
- Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mahsa Shahbandeh
- Young Researchers and Elite Club, Saveh Branch, Islamic Azad University, Saveh, Iran
| | - Maryam Mirshekar
- Department of Microbiology, Iran University of Medical Sciences, Tehran, Iran
| | - Samane Mohebi
- Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Majid Taati Moghadam
- Department of Microbiology, Iran University of Medical Sciences, Tehran, Iran.
- Student Research Committee, Iran University of Medical Sciences, Tehran, Iran.
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Binsker U, Käsbohrer A, Hammerl JA. Global colistin use: A review of the emergence of resistant Enterobacterales and the impact on their genetic basis. FEMS Microbiol Rev 2021; 46:6382128. [PMID: 34612488 PMCID: PMC8829026 DOI: 10.1093/femsre/fuab049] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 10/04/2021] [Indexed: 02/06/2023] Open
Abstract
The dramatic global rise of MDR and XDR Enterobacterales in human medicine forced clinicians to the reintroduction of colistin as last-resort drug. Meanwhile, colistin is used in the veterinary medicine since its discovery, leading to a steadily increasing prevalence of resistant isolates in the livestock and meat-based food sector. Consequently, transmission of resistant isolates from animals to humans, acquisition via food and exposure to colistin in the clinic are reasons for the increased prevalence of colistin-resistant Enterobacterales in humans in the last decades. Initially, resistance mechanisms were caused by mutations in chromosomal genes. However, since the discovery in 2015, the focus has shifted exclusively to mobile colistin resistances (mcr). This review will advance the understanding of chromosomal-mediated resistance mechanisms in Enterobacterales. We provide an overview about genes involved in colistin resistance and the current global situation of colistin-resistant Enterobacterales. A comparison of the global colistin use in veterinary and human medicine highlights the effort to reduce colistin sales in veterinary medicine under the One Health approach. In contrast, it uncovers the alarming rise in colistin consumption in human medicine due to the emergence of MDR Enterobacterales, which might be an important driver for the increasing emergence of chromosome-mediated colistin resistance.
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Affiliation(s)
- Ulrike Binsker
- Department Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Annemarie Käsbohrer
- Department Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany.,Department for Farm Animals and Veterinary Public Health, Institute of Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Jens A Hammerl
- Department Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
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Gogry FA, Siddiqui MT, Sultan I, Haq QMR. Current Update on Intrinsic and Acquired Colistin Resistance Mechanisms in Bacteria. Front Med (Lausanne) 2021; 8:677720. [PMID: 34476235 PMCID: PMC8406936 DOI: 10.3389/fmed.2021.677720] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 07/09/2021] [Indexed: 01/07/2023] Open
Abstract
Colistin regained global interest as a consequence of the rising prevalence of multidrug-resistant Gram-negative Enterobacteriaceae. In parallel, colistin-resistant bacteria emerged in response to the unregulated use of this antibiotic. However, some Gram-negative species are intrinsically resistant to colistin activity, such as Neisseria meningitides, Burkholderia species, and Proteus mirabilis. Most identified colistin resistance usually involves modulation of lipid A that decreases or removes early charge-based interaction with colistin through up-regulation of multistep capsular polysaccharide expression. The membrane modifications occur by the addition of cationic phosphoethanolamine (pEtN) or 4-amino-l-arabinose on lipid A that results in decrease in the negative charge on the bacterial surface. Therefore, electrostatic interaction between polycationic colistin and lipopolysaccharide (LPS) is halted. It has been reported that these modifications on the bacterial surface occur due to overexpression of chromosomally mediated two-component system genes (PmrAB and PhoPQ) and mutation in lipid A biosynthesis genes that result in loss of the ability to produce lipid A and consequently LPS chain, thereafter recently identified variants of plasmid-borne genes (mcr-1 to mcr-10). It was hypothesized that mcr genes derived from intrinsically resistant environmental bacteria that carried chromosomal pmrC gene, a part of the pmrCAB operon, code three proteins viz. pEtN response regulator PmrA, sensor kinase protein PmrAB, and phosphotransferase PmrC. These plasmid-borne mcr genes become a serious concern as they assist in the dissemination of colistin resistance to other pathogenic bacteria. This review presents the progress of multiple strategies of colistin resistance mechanisms in bacteria, mainly focusing on surface changes of the outer membrane LPS structure and other resistance genetic determinants. New handier and versatile methods have been discussed for rapid detection of colistin resistance determinants and the latest approaches to revert colistin resistance that include the use of new drugs, drug combinations and inhibitors. Indeed, more investigations are required to identify the exact role of different colistin resistance determinants that will aid in developing new less toxic and potent drugs to treat bacterial infections. Therefore, colistin resistance should be considered a severe medical issue requiring multisectoral research with proper surveillance and suitable monitoring systems to report the dissemination rate of these resistant genes.
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Affiliation(s)
| | | | - Insha Sultan
- Department of Biosciences, Jamia Millia Islamia, New Delhi, India
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Mohapatra SS, Dwibedy SK, Padhy I. Polymyxins, the last-resort antibiotics: Mode of action, resistance emergence, and potential solutions. J Biosci 2021. [PMID: 34475315 PMCID: PMC8387214 DOI: 10.1007/s12038-021-00209-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Infections caused by multi-drug resistant (MDR) bacterial pathogens are a leading cause of mortality and morbidity across the world. Indiscriminate use of broad-spectrum antibiotics has seriously affected this situation. With the diminishing discovery of novel antibiotics, new treatment methods are urgently required to combat MDR pathogens. Polymyxins, the cationic lipopeptide antibiotics, discovered more than half a century ago, are considered to be the last-line of antibiotics available at the moment. This antibiotic shows a great bactericidal effect against Gram-negative bacteria. Polymyxins primarily target the bacterial membrane and disrupt them, causing lethality. Because of their membrane interacting mode of action, polymyxins cause nephrotoxicity and neurotoxicity in humans, limiting their usability. However, recent modifications in their chemical structure have been able to reduce the toxic effects. The development of better dosing regimens has also helped in getting better clinical outcomes in the infections caused by MDR pathogens. Since the mid-1990s the use of polymyxins has increased manifold in clinical settings, resulting in the emergence of polymyxin-resistant strains. The risk posed by the polymyxin-resistant nosocomial pathogens such as the Enterobacteriaceae group, Pseudomonas aeruginosa, and Acinetobacter baumannii, etc. is very serious considering these pathogens are resistant to almost all available antibacterial drugs. In this review article, the mode of action of the polymyxins and the genetic regulatory mechanism responsible for the emergence of resistance are discussed. Specifically, this review aims to update our current understanding in the field and suggest possible solutions that can be pursued for future antibiotic development. As polymyxins primarily target the bacterial membranes, resistance to polymyxins arises primarily by the modification of the lipopolysaccharides (LPS) in the outer membrane (OM). The LPS modification pathways are largely regulated by the bacterial two-component signal transduction (TCS) systems. Therefore, targeting or modulating the TCS signalling mechanisms can be pursued as an alternative to treat the infections caused by polymyxin-resistant MDR pathogens. In this review article, this aspect is also highlighted.
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Affiliation(s)
- Saswat S Mohapatra
- Molecular Microbiology Lab, Department of Bioscience and Bioinformatics, Khallikote University, Konisi, Berhampur, 761 008 Odisha India
| | - Sambit K Dwibedy
- Molecular Microbiology Lab, Department of Bioscience and Bioinformatics, Khallikote University, Konisi, Berhampur, 761 008 Odisha India
| | - Indira Padhy
- Molecular Microbiology Lab, Department of Bioscience and Bioinformatics, Khallikote University, Konisi, Berhampur, 761 008 Odisha India
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Rodríguez-Santiago J, Cornejo-Juárez P, Silva-Sánchez J, Garza-Ramos U. Polymyxin resistance in Enterobacterales: overview and epidemiology in the Americas. Int J Antimicrob Agents 2021; 58:106426. [PMID: 34419579 DOI: 10.1016/j.ijantimicag.2021.106426] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 08/07/2021] [Accepted: 08/15/2021] [Indexed: 12/30/2022]
Abstract
The worldwide spread of carbapenem- and polymyxin-resistant Enterobacterales represents an urgent public-health threat. However, for most countries in the Americas, the available data are limited, although Latin America has been suggested as a silent spreading reservoir for isolates carrying plasmid-mediated polymyxin resistance mechanisms. This work provides an overall update on polymyxin and polymyxin resistance and focuses on uses, availability and susceptibility testing. Moreover, a comprehensive review of the current polymyxin resistance epidemiology in the Americas is provided. We found that reports in the English and Spanish literature show widespread carbapenemase-producing and colistin-resistant Klebsiella pneumoniae in the Americas determined by the clonal expansion of the pandemic clone ST258 and mgrB-mediated colistin resistance. In addition, widespread IncI2 and IncX4 plasmids carrying mcr-1 in Escherichia coli come mainly from human sources; however, plasmid-mediated colistin resistance in the Americas is underreported in the veterinary sector. These findings demonstrate the urgent need for the implementation of polymyxin resistance surveillance in Enterobacterales as well as appropriate regulatory measures for antimicrobial use in veterinary medicine.
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Affiliation(s)
- J Rodríguez-Santiago
- Instituto Nacional de Salud Pública (INSP), Centro de Investigación sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Cuernavaca, Morelos, México; Programa de Doctorado en Ciencias Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - P Cornejo-Juárez
- Departamento de Infectología, Instituto Nacional de Cancerología (INCan), Ciudad de México, México
| | - J Silva-Sánchez
- Instituto Nacional de Salud Pública (INSP), Centro de Investigación sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Cuernavaca, Morelos, México
| | - U Garza-Ramos
- Instituto Nacional de Salud Pública (INSP), Centro de Investigación sobre Enfermedades Infecciosas (CISEI), Laboratorio de Resistencia Bacteriana, Cuernavaca, Morelos, México.
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Kobayashi K. Diverse LXG toxin and antitoxin systems specifically mediate intraspecies competition in Bacillus subtilis biofilms. PLoS Genet 2021; 17:e1009682. [PMID: 34280190 PMCID: PMC8321402 DOI: 10.1371/journal.pgen.1009682] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 07/29/2021] [Accepted: 06/25/2021] [Indexed: 12/14/2022] Open
Abstract
Biofilms are multispecies communities, in which bacteria constantly compete with one another for resources and niches. Bacteria produce many antibiotics and toxins for competition. However, since biofilm cells exhibit increased tolerance to antimicrobials, their roles in biofilms remain controversial. Here, we showed that Bacillus subtilis produces multiple diverse polymorphic toxins, called LXG toxins, that contain N-terminal LXG delivery domains and diverse C-terminal toxin domains. Each B. subtilis strain possesses a distinct set of LXG toxin–antitoxin genes, the number and variation of which is sufficient to distinguish each strain. The B. subtilis strain NCIB3610 possesses six LXG toxin–antitoxin operons on its chromosome, and five of the toxins functioned as DNase. In competition assays, deletion mutants of any of the six LXG toxin–antitoxin operons were outcompeted by the wild-type strain. This phenotype was suppressed when the antitoxins were ectopically expressed in the deletion mutants. The fitness defect of the mutants was only observed in solid media that supported biofilm formation. Biofilm matrix polymers, exopolysaccharides and TasA protein polymers were required for LXG toxin function. These results indicate that LXG toxin-antitoxin systems specifically mediate intercellular competition between B. subtilis strains in biofilms. Mutual antagonism between some LXG toxin producers drove the spatial segregation of two strains in a biofilm, indicating that LXG toxins not only mediate competition in biofilms, but may also help to avoid warfare between strains in biofilms. LXG toxins from strain NCIB3610 were effective against some natural isolates, and thus LXG toxin–antitoxin systems have ecological impact. B. subtilis possesses another polymorphic toxin, WapA. WapA had toxic effects under planktonic growth conditions but not under biofilm conditions because exopolysaccharides and TasA protein polymers inhibited WapA function. These results indicate that B. subtilis uses two types of polymorphic toxins for competition, depending on the growth mode. Biofilms are surface-associated multispecies communities, in which bacteria are protected by self-produced extracellular polymeric substances. In biofilms, bacteria constantly engage in intra- and interspecies competition. To minimize exploitation by competitors, bacteria produce a variety of antibiotics and toxins for competition. However, since biofilm cells exhibit increased tolerance to antimicrobials, the function of antibiotics and toxins in biofilms remains controversial. Therefore, the mechanisms underlying bacterial competition in biofilms remain to be investigated. We found that the soil bacterium B. subtilis produces polymorphic toxins, termed LXG toxins. LXG toxins are highly diversified among B. subtilis strains, and each B. subtilis strain possesses three to nine different LXG toxins. LXG toxins specifically mediate intraspecies competition in biofilms. Competition between some LXG toxin producers resulted in the spatial segregation of strains in biofilms, indicating that LXG toxins not only mediate competition, but also help to minimize warfare in biofilms. LXG toxins were effective against natural isolates of B. subtilis, suggesting that LXG toxin–antitoxin systems have ecological impact. Our results provide new insights into how bacteria survive competition in biofilms.
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Affiliation(s)
- Kazuo Kobayashi
- Division of Biological Science, Department of Science and Technology, Nara Institute of Science & Technology, Ikoma, Nara, Japan
- * E-mail:
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Gan BH, Gaynord J, Rowe SM, Deingruber T, Spring DR. The multifaceted nature of antimicrobial peptides: current synthetic chemistry approaches and future directions. Chem Soc Rev 2021; 50:7820-7880. [PMID: 34042120 PMCID: PMC8689412 DOI: 10.1039/d0cs00729c] [Citation(s) in RCA: 162] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Indexed: 12/13/2022]
Abstract
Bacterial infections caused by 'superbugs' are increasing globally, and conventional antibiotics are becoming less effective against these bacteria, such that we risk entering a post-antibiotic era. In recent years, antimicrobial peptides (AMPs) have gained significant attention for their clinical potential as a new class of antibiotics to combat antimicrobial resistance. In this review, we discuss several facets of AMPs including their diversity, physicochemical properties, mechanisms of action, and effects of environmental factors on these features. This review outlines various chemical synthetic strategies that have been applied to develop novel AMPs, including chemical modifications of existing peptides, semi-synthesis, and computer-aided design. We will also highlight novel AMP structures, including hybrids, antimicrobial dendrimers and polypeptides, peptidomimetics, and AMP-drug conjugates and consider recent developments in their chemical synthesis.
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Affiliation(s)
- Bee Ha Gan
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Josephine Gaynord
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Sam M Rowe
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Tomas Deingruber
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - David R Spring
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
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A Molecular Perspective on Colistin and Klebsiella pneumoniae: Mode of Action, Resistance Genetics, and Phenotypic Susceptibility. Diagnostics (Basel) 2021; 11:diagnostics11071165. [PMID: 34202395 PMCID: PMC8305994 DOI: 10.3390/diagnostics11071165] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/11/2021] [Accepted: 06/16/2021] [Indexed: 12/26/2022] Open
Abstract
Klebsiella pneumoniae is a rod-shaped, encapsulated, Gram-negative bacteria associated with multiple nosocomial infections. Multidrug-resistant (MDR) K. pneumoniae strains have been increasing and the therapeutic options are increasingly limited. Colistin is a long-used, polycationic, heptapeptide that has regained attention due to its activity against Gram-negative bacteria, including the MDR K. pneumoniae strains. However, this antibiotic has a complex mode of action that is still under research along with numerous side-effects. The acquisition of colistin resistance is mainly associated with alteration of lipid A net charge through the addition of cationic groups synthesized by the gene products of a multi-genic regulatory network. Besides mutations in these chromosomal genes, colistin resistance can also be achieved through the acquisition of plasmid-encoded genes. Nevertheless, the diversity of molecular markers for colistin resistance along with some adverse colistin properties compromises the reliability of colistin-resistance monitorization methods. The present review is focused on the colistin action and molecular resistance mechanisms, along with specific limitations on drug susceptibility testing for K. pneumoniae.
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Janssen AB, van Hout D, Bonten MJM, Willems RJL, van Schaik W. Microevolution of acquired colistin resistance in Enterobacteriaceae from ICU patients receiving selective decontamination of the digestive tract. J Antimicrob Chemother 2021; 75:3135-3143. [PMID: 32712659 DOI: 10.1093/jac/dkaa305] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 06/11/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Colistin is an antibiotic that targets the LPS molecules present in the membranes of Gram-negative bacteria. It is used as a last-resort drug to treat infections with MDR strains. Colistin is also used in selective decontamination of the digestive tract (SDD), a prophylactic therapy used in patients hospitalized in ICUs to selectively eradicate opportunistic pathogens in the oropharyngeal and gut microbiota. OBJECTIVES To unravel the mechanisms of acquired colistin resistance in Gram-negative opportunistic pathogens obtained from SDD-treated patients. RESULTS Routine surveillance of 428 SDD-treated patients resulted in 13 strains with acquired colistin resistance (Escherichia coli, n = 9; Klebsiella aerogenes, n = 3; Enterobacter asburiae, n = 1) from 5 patients. Genome sequence analysis showed that these isolates represented multiple distinct colistin-resistant clones but that colistin-resistant strains within the same patient were clonally related. We identified previously described mechanisms that lead to colistin resistance, i.e. a G53 substitution in the response regulator PmrA/BasR and the acquisition of the mobile colistin resistance gene mcr-1.1, but we also observed novel variants of basR with an 18 bp deletion and a G19E substitution in the sensor histidine kinase BasS. We experimentally confirmed that these variants contribute to reduced colistin susceptibility. In a single patient, we observed that colistin resistance in a single E. coli clone evolved through two unique variants in basRS. CONCLUSIONS We show that prophylactic use of colistin during SDD can select for colistin resistance in species that are not intrinsically colistin resistant. This highlights the importance of continued surveillance for strains with acquired colistin resistance in patients treated with SDD.
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Affiliation(s)
- Axel B Janssen
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584CX Utrecht, The Netherlands
| | - Denise van Hout
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584CX Utrecht, The Netherlands
| | - Marc J M Bonten
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584CX Utrecht, The Netherlands.,Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584CX Utrecht, The Netherlands
| | - Rob J L Willems
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584CX Utrecht, The Netherlands
| | - Willem van Schaik
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Heidelberglaan 100, 3584CX Utrecht, The Netherlands.,Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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Taati Moghadam M, Mirzaei M, Fazel Tehrani Moghaddam M, Babakhani S, Yeganeh O, Asgharzadeh S, Farahani HE, Shahbazi S. The Challenge of Global Emergence of Novel Colistin-Resistant Escherichia coli ST131. Microb Drug Resist 2021; 27:1513-1524. [PMID: 33913748 DOI: 10.1089/mdr.2020.0505] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Escherichia coli ST131 is one of the high-risk multidrug-resistant clones with a global distribution and the ability to persist and colonize in a variety of niches. Carbapenemase-producing E. coli ST131 strains with the ability to resist last-line antibiotics (i.e., colistin) have been recently considered a significant public health. Colistin is widely used in veterinary medicine and therefore, colistin-resistant bacteria can be transmitted from livestock to humans through food. There are several mechanisms of resistance to colistin, which include chromosomal mutations and plasmid-transmitted mcr genes. E. coli ST131 is a great model organism to investigate the emergence of superbugs. This microorganism has the ability to cause intestinal and extraintestinal infections, and its accurate identification as well as its antibiotic resistance patterns are vitally important for a successful treatment strategy. Therefore, further studies are required to understand the evolution of this resistant organism for drug design, controlling the evolution of other nascent emerging pathogens, and developing antibiotic stewardship programs. In this review, we will discuss the importance of E. coli ST131, the mechanisms of resistance to colistin as the last-resort antibiotic against resistant Gram-negative bacteria, reports from different regions regarding E. coli ST131 resistance to colistin, and the most recent therapeutic approaches against colistin-resistance bacteria.
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Affiliation(s)
- Majid Taati Moghadam
- Student Research Committee, Iran University of Medical Sciences, Tehran, Iran
- Department of Microbiology, Iran University of Medical Sciences, Tehran, Iran
| | - Mehrnaz Mirzaei
- Department of Microbiology, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran
| | | | - Sajad Babakhani
- Department of Microbiology, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Omid Yeganeh
- Department of Microbiology, North Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Sajad Asgharzadeh
- Department of Microbiology, Iran University of Medical Sciences, Tehran, Iran
| | | | - Shahla Shahbazi
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
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Lytic bacteriophages facilitate antibiotic sensitization of Enterococcus faecium. Antimicrob Agents Chemother 2021; 65:AAC.00143-21. [PMID: 33649110 PMCID: PMC8092871 DOI: 10.1128/aac.00143-21] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Enterococcus faecium, a commensal of the human intestine, has emerged as a hospital-adapted, multi-drug resistant (MDR) pathogen. Bacteriophages (phages), natural predators of bacteria, have regained attention as therapeutics to stem the rise of MDR bacteria. Despite their potential to curtail MDR E. faecium infections, the molecular events governing E. faecium-phage interactions remain largely unknown. Such interactions are important to delineate because phage selective pressure imposed on E. faecium will undoubtedly result in phage resistance phenotypes that could threaten the efficacy of phage therapy. In an effort to understand the emergence of phage resistance in E. faecium, three newly isolated lytic phages were used to demonstrate that E. faecium phage resistance is conferred through an array of cell wall-associated molecules, including secreted antigen A (SagA), enterococcal polysaccharide antigen (Epa), wall teichoic acids, capsule, and an arginine-aspartate-aspartate (RDD) protein of unknown function. We find that capsule and Epa are important for robust phage adsorption and that phage resistance mutations in sagA, epaR, and epaX enhance E. faecium susceptibility to ceftriaxone, an antibiotic normally ineffective due to its low affinity for enterococcal penicillin binding proteins. Consistent with these findings, we provide evidence that phages potently synergize with cell wall (ceftriaxone and ampicillin) and membrane-acting (daptomycin) antimicrobials to slow or completely inhibit the growth of E. faecium Our work demonstrates that the evolution of phage resistance comes with fitness defects resulting in drug sensitization and that lytic phages could serve as effective antimicrobials for the treatment of E. faecium infections.
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The KbvR Regulator Contributes to Capsule Production, Outer Membrane Protein Biosynthesis, Antiphagocytosis, and Virulence in Klebsiella pneumoniae. Infect Immun 2021; 89:IAI.00016-21. [PMID: 33593891 DOI: 10.1128/iai.00016-21] [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: 01/09/2021] [Accepted: 01/27/2021] [Indexed: 01/17/2023] Open
Abstract
Klebsiella pneumoniae is an opportunistic pathogen that mostly affects patients with weakened immune systems, but a few serotypes (especially K1 and K2) are highly invasive and result in systemic infection in healthy persons. The ability to evade and survive the components of the innate immune system is critical in infection. To investigate the role and mechanism of transcription regulator KP1_RS12260 (KbvR) in virulence and defense against the innate immune response, kbvR deletion mutant and complement strains were constructed. The in vivo animal infection assay and in vitro antiphagocytosis assay demonstrate K. pneumoniae KbvR is an important regulator that contributes to virulence and the defense against phagocytosis of macrophages. The transcriptome analysis and phenotype experiments demonstrated that deletion of kbvR decreased production of capsular polysaccharide (CPS) and biosynthesis of partly outer membrane proteins (OMPs). The findings suggest that KbvR is a global regulator that confers pathoadaptive phenotypes, which provide several implications for improving our understanding of the pathogenesis of K. pneumoniae.
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Yaeger LN, Coles VE, Chan DCK, Burrows LL. How to kill Pseudomonas-emerging therapies for a challenging pathogen. Ann N Y Acad Sci 2021; 1496:59-81. [PMID: 33830543 DOI: 10.1111/nyas.14596] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/08/2021] [Accepted: 03/11/2021] [Indexed: 12/16/2022]
Abstract
As the number of effective antibiotics dwindled, antibiotic resistance (AR) became a pressing concern. Some Pseudomonas aeruginosa isolates are resistant to all available antibiotics. In this review, we identify the mechanisms that P. aeruginosa uses to evade antibiotics, including intrinsic, acquired, and adaptive resistance. Our review summarizes many different approaches to overcome resistance. Antimicrobial peptides have potential as therapeutics with low levels of resistance evolution. Rationally designed bacteriophage therapy can circumvent and direct evolution of AR and virulence. Vaccines and monoclonal antibodies are highlighted as immune-based treatments targeting specific P. aeruginosa antigens. This review also identifies promising drug combinations, antivirulence therapies, and considerations for new antipseudomonal discovery. Finally, we provide an update on the clinical pipeline for antipseudomonal therapies and recommend future avenues for research.
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Affiliation(s)
- Luke N Yaeger
- Department of Biochemistry and Biomedical Sciences and M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Victoria E Coles
- Department of Biochemistry and Biomedical Sciences and M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Derek C K Chan
- Department of Biochemistry and Biomedical Sciences and M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Lori L Burrows
- Department of Biochemistry and Biomedical Sciences and M.G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
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Abstract
Antibiotic resistance is a major global health challenge and, worryingly, several key Gram negative pathogens can become resistant to most currently available antibiotics. Polymyxins have been revived as a last-line therapeutic option for the treatment of infections caused by multidrug-resistant Gram negative bacteria, in particular Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacterales. Polymyxins were first discovered in the late 1940s but were abandoned soon after their approval in the late 1950s as a result of toxicities (e.g., nephrotoxicity) and the availability of "safer" antibiotics approved at that time. Therefore, knowledge on polymyxins had been scarce until recently, when enormous efforts have been made by several research teams around the world to elucidate the chemical, microbiological, pharmacokinetic/pharmacodynamic, and toxicological properties of polymyxins. One of the major achievements is the development of the first scientifically based dosage regimens for colistin that are crucial to ensure its safe and effective use in patients. Although the guideline has not been developed for polymyxin B, a large clinical trial is currently being conducted to optimize its clinical use. Importantly, several novel, safer polymyxin-like lipopeptides are developed to overcome the nephrotoxicity, poor efficacy against pulmonary infections, and narrow therapeutic windows of the currently used polymyxin B and colistin. This review discusses the latest achievements on polymyxins and highlights the major challenges ahead in optimizing their clinical use and discovering new-generation polymyxins. To save lives from the deadly infections caused by Gram negative "superbugs," every effort must be made to improve the clinical utility of the last-line polymyxins. SIGNIFICANCE STATEMENT: Antimicrobial resistance poses a significant threat to global health. The increasing prevalence of multidrug-resistant (MDR) bacterial infections has been highlighted by leading global health organizations and authorities. Polymyxins are a last-line defense against difficult-to-treat MDR Gram negative pathogens. Unfortunately, the pharmacological information on polymyxins was very limited until recently. This review provides a comprehensive overview on the major achievements and challenges in polymyxin pharmacology and clinical use and how the recent findings have been employed to improve clinical practice worldwide.
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Affiliation(s)
- Sue C Nang
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Mohammad A K Azad
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Tony Velkov
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Qi Tony Zhou
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
| | - Jian Li
- Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Victoria, Australia (S.C.N., M.A.K.A., J.L.); Department of Pharmacology and Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, Victoria, Australia (T.V.); and Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana (Q.T.Z.)
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Isolation and Characterization of a Novel Lytic Bacteriophage against the K2 Capsule-Expressing Hypervirulent Klebsiella pneumoniae Strain 52145, and Identification of Its Functional Depolymerase. Microorganisms 2021; 9:microorganisms9030650. [PMID: 33801047 PMCID: PMC8003838 DOI: 10.3390/microorganisms9030650] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/16/2021] [Accepted: 03/18/2021] [Indexed: 12/30/2022] Open
Abstract
Klebsiella pneumoniae is among the leading bacteria that cause nosocomial infections. The capsule of this Gram-negative bacterium is a dominant virulence factor, with a prominent role in defense and biofilm formation. Bacteriophages, which are specific for one bacterial strain and its capsule type, can evoke the lysis of bacterial cells, aided by polysaccharide depolymerase enzymes. In this study, we isolated and characterized a bacteriophage against the nosocomial K. pneumoniae 52145 strain with K2 capsular serotype. The phage showed a narrow host range and stable lytic activity, even when exposed to different temperatures or detergents. Preventive effect of the phage in a nasal colonization model was investigated in vivo. Phlyogenetic analysis showed that the newly isolated Klebsiella phage B1 belongs to the Webervirus genus in Drexlerviridae family. We identified the location of the capsule depolymerase gene of the new phage, which was amplified, cloned, expressed, and purified. The efficacy of the recombinant B1dep depolymerase was tested by spotting on K. pneumoniae strains and it was confirmed that the extract lowers the thickness of the bacterium lawn as it degrades the protective capsule on bacterial cells. As K. pneumoniae strains possessing the K2 serotype have epidemiological importance, the B1 phage and its depolymerase are promising candidates for use as possible antimicrobial agents.
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