1
|
Shi J, Cheng J, Liu S, Zhu Y, Zhu M. Acinetobacter baumannii: an evolving and cunning opponent. Front Microbiol 2024; 15:1332108. [PMID: 38318341 PMCID: PMC10838990 DOI: 10.3389/fmicb.2024.1332108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 01/08/2024] [Indexed: 02/07/2024] Open
Abstract
Acinetobacter baumannii is one of the most common multidrug-resistant pathogens causing nosocomial infections. The prevalence of multidrug-resistant A. baumannii infections is increasing because of several factors, including unregulated antibiotic use. A. baumannii drug resistance rate is high; in particular, its resistance rates for tigecycline and polymyxin-the drugs of last resort for extensively drug-resistant A. baumannii-has been increasing annually. Patients with a severe infection of extensively antibiotic-resistant A. baumannii demonstrate a high mortality rate along with a poor prognosis, which makes treating them challenging. Through carbapenem enzyme production and other relevant mechanisms, A. baumannii has rapidly acquired a strong resistance to carbapenem antibiotics-once considered a class of strong antibacterials for A. baumannii infection treatment. Therefore, understanding the resistance mechanism of A. baumannii is particularly crucial. This review summarizes mechanisms underlying common antimicrobial resistance in A. baumannii, particularly those underlying tigecycline and polymyxin resistance. This review will serve as a reference for reasonable antibiotic use at clinics, as well as new antibiotic development.
Collapse
Affiliation(s)
- Jingchao Shi
- Open Laboratory Medicine, Hangzhou Xixi Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, China
- Department of Clinical Laboratory, Affiliated Jinhua Hospital, Zhejiang University School of Medicine, Jinhua, China
- Graduate School, Zhejiang Chinese Medical University, Hangzhou, China
| | - Jianghao Cheng
- Open Laboratory Medicine, Hangzhou Xixi Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, China
| | - Shourong Liu
- Department of Infectious Disease, Hangzhou Xixi Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, China
| | - Yufeng Zhu
- Open Laboratory Medicine, Hangzhou Xixi Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, China
| | - Mingli Zhu
- Open Laboratory Medicine, Hangzhou Xixi Hospital Affiliated to Zhejiang Chinese Medical University, Hangzhou, China
| |
Collapse
|
2
|
An T, Cai Y, Li G, Li S, Wong PK, Guo J, Zhao H. Prevalence and transmission risk of colistin and multidrug resistance in long-distance coastal aquaculture. ISME COMMUNICATIONS 2023; 3:115. [PMID: 37935916 PMCID: PMC10630474 DOI: 10.1038/s43705-023-00321-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 09/25/2023] [Accepted: 10/09/2023] [Indexed: 11/09/2023]
Abstract
Due to the wide use of antibiotics, intensive aquaculture farms have been recognized as a significant reservoir of antibiotic resistomes. Although the prevalence of colistin resistance genes and multidrug-resistant bacteria (MDRB) has been documented, empirical evidence for the transmission of colistin and multidrug resistance between bacterial communities in aquaculture farms through horizontal gene transfer (HGT) is lacking. Here, we report the prevalence and transmission risk of colistin and multidrug resistance in 27 aquaculture water samples from 9 aquaculture zones from over 5000 km of subtropical coastlines in southern China. The colistin resistance gene mcr-1, mobile genetic element (MGE) intl1 and 13 typical antibiotic resistance genes (ARGs) were prevalent in all the aquaculture water samples. Most types of antibiotic (especially colistin) resistance are transmissible in bacterial communities based on evidence from laboratory conjugation and transformation experiments. Diverse MDRB were detected in most of the aquaculture water samples, and a strain with high-level colistin resistance, named Ralstonia pickettii MCR, was isolated. The risk of horizontal transfer of the colistin resistance of R. pickettii MCR through conjugation and transformation was low, but the colistin resistance could be steadily transmitted to offspring through vertical transfer. The findings have important implications for the future regulation of antibiotic use in aquaculture farms globally to address the growing threat posed by antibiotic resistance to human health.
Collapse
Affiliation(s)
- Taicheng An
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China.
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China.
| | - Yiwei Cai
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Guiying Li
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Shaoting Li
- College of Biological and Pharmaceutical Science, Guangdong University of Technology, Guangzhou, 510006, China
| | - Po Keung Wong
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou, 510006, China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, 510006, China
| | - Jianhua Guo
- Australian Centre for Water and Environmental Biotechnology, The University of Queensland, St. Lucia, Brisbane, QLD, 4072, Australia.
| | - Huijun Zhao
- Centre for Clean Environment and Energy, and Griffith School of Environment, Gold Coast Campus, Griffith University, Gold Coast, QLD, 4222, Australia
| |
Collapse
|
3
|
Boral J, Pınarlık F, Ekinci G, Can F, Ergönül Ö. Does Emerging Carbapenem Resistance in Acinetobacter baumannii Increase the Case Fatality Rate? Systematic Review and Meta-Analysis. Infect Dis Rep 2023; 15:564-575. [PMID: 37888136 PMCID: PMC10606343 DOI: 10.3390/idr15050055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 09/20/2023] [Accepted: 09/25/2023] [Indexed: 10/28/2023] Open
Abstract
BACKGROUND In the era of rising carbapenem resistance, we aimed to investigate the change in mortality rate and positivity of carbapenemase genes in Acinetobacter baumannii. METHODS Preferred Reporting Items for Systematic Review (PRISMA) guidelines were adopted in this systematic review. Our literature search included the Cochrane Library, Pubmed, Scopus, Web of Science, Medline, Tubitak TR Dizin, and Harman databases for studies dating back from 2003 to 2023 reporting bloodstream A. baumannii infections in Türkiye. A simple linear regression model was used to determine the association between resistance, mortality, and time. RESULTS A total of 1717 studies were identified through a literature search, and 21 articles were selected based on the availability of the data regarding mortality and resistance rate (four articles) or the molecular epidemiology of carbapenem-resistant A. baumannii (17 articles) in Türkiye. From 2007 to 2018, the carbapenem resistance rate increased (p = 0.025). The OXA-23 and OXA-58 positivities were inversely correlated (p = 0.025). CONCLUSIONS Despite the emergence of carbapenem resistance, mortality did not increase in parallel, which may be due to improved medical advancements or the fitness cost of bacteria upon prolonged antimicrobial exposure. Therefore, we suggest further global research with the foresight to assess clonal relatedness that might affect the carbapenem resistance rate.
Collapse
Affiliation(s)
- Jale Boral
- Graduate School of Health Sciences, Koç University, Istanbul 34010, Türkiye; (J.B.)
- Koç University İşBank Center for Infectious Diseases, Koç University Hospital (KUISCID), Istanbul 34010, Türkiye;
| | - Fatihan Pınarlık
- Graduate School of Health Sciences, Koç University, Istanbul 34010, Türkiye; (J.B.)
- Koç University İşBank Center for Infectious Diseases, Koç University Hospital (KUISCID), Istanbul 34010, Türkiye;
| | - Güz Ekinci
- Graduate School of Health Sciences, Koç University, Istanbul 34010, Türkiye; (J.B.)
- Koç University İşBank Center for Infectious Diseases, Koç University Hospital (KUISCID), Istanbul 34010, Türkiye;
| | - Füsun Can
- Koç University İşBank Center for Infectious Diseases, Koç University Hospital (KUISCID), Istanbul 34010, Türkiye;
- Department of Medical Microbiology, School of Medicine, Koç University, Istanbul 34010, Türkiye
| | - Önder Ergönül
- Koç University İşBank Center for Infectious Diseases, Koç University Hospital (KUISCID), Istanbul 34010, Türkiye;
- Department of Infectious Diseases and Clinical Microbiology, School of Medicine, Koç University, Istanbul 34010, Türkiye
| |
Collapse
|
4
|
Gadar K, de Dios R, Kadeřábková N, Prescott TAK, Mavridou DAI, McCarthy RR. Disrupting iron homeostasis can potentiate colistin activity and overcome colistin resistance mechanisms in Gram-Negative Bacteria. Commun Biol 2023; 6:937. [PMID: 37704838 PMCID: PMC10499790 DOI: 10.1038/s42003-023-05302-2] [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: 01/26/2023] [Accepted: 08/29/2023] [Indexed: 09/15/2023] Open
Abstract
Acinetobacter baumannii is a Gram-negative priority pathogen that can readily overcome antibiotic treatment through a range of intrinsic and acquired resistance mechanisms. Treatment of carbapenem-resistant A. baumannii largely relies on the use of colistin in cases where other treatment options have been exhausted. However, the emergence of resistance against this last-line drug has significantly increased amongst clinical strains. In this study, we identify the phytochemical kaempferol as a potentiator of colistin activity. When administered singularly, kaempferol has no effect on growth but does impact biofilm formation. Nonetheless, co-administration of kaempferol with sub-inhibitory concentrations of colistin exposes bacteria to a metabolic Achilles heel, whereby kaempferol-induced dysregulation of iron homeostasis leads to bacterial killing. We demonstrate that this effect is due to the disruption of Fenton's reaction, and therefore to a lethal build-up of toxic reactive oxygen species in the cell. Furthermore, we show that this vulnerability can be exploited to overcome both intrinsic and acquired colistin resistance in clinical strains of A. baumannii and E. coli in vitro and in the Galleria mellonella model of infection. Overall, our findings provide a proof-of-principle demonstration that targeting iron homeostasis is a promising strategy for enhancing the efficacy of colistin and overcoming colistin-resistant infections.
Collapse
Affiliation(s)
- Kavita Gadar
- Biosciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, UK
| | - Rubén de Dios
- Biosciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, UK
| | - Nikol Kadeřábková
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | | | - Despoina A I Mavridou
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, 78712, USA
- John Ring LaMontagne Centre for Infectious Diseases, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Ronan R McCarthy
- Biosciences, Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UB8 3PH, UK.
| |
Collapse
|
5
|
Colistin Resistance in Acinetobacter baumannii: Molecular Mechanisms and Epidemiology. Antibiotics (Basel) 2023; 12:antibiotics12030516. [PMID: 36978383 PMCID: PMC10044110 DOI: 10.3390/antibiotics12030516] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 02/17/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023] Open
Abstract
Acinetobacter baumannii is recognized as a clinically significant pathogen causing a wide spectrum of nosocomial infections. Colistin was considered a last-resort antibiotic for the treatment of infections caused by multidrug-resistant A. baumannii. Since the reintroduction of colistin, a number of mechanisms of colistin resistance in A. baumannii have been reported, including complete loss of LPS by inactivation of the biosynthetic pathway, modifications of target LPS driven by the addition of phosphoethanolamine (PEtN) moieties to lipid A mediated by the chromosomal pmrCAB operon and eptA gene-encoded enzymes or plasmid-encoded mcr genes and efflux of colistin from the cell. In addition to resistance to colistin, widespread heteroresistance is another feature of A. baumannii that leads to colistin treatment failure. This review aims to present a critical assessment of relevant published (>50 experimental papers) up-to-date knowledge on the molecular mechanisms of colistin resistance in A. baumannii with a detailed review of implicated mutations and the global distribution of colistin-resistant strains.
Collapse
|
6
|
Acinetobacter Baumannii: More Ways to Die. Microbiol Res 2022; 261:127069. [DOI: 10.1016/j.micres.2022.127069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/06/2022] [Accepted: 05/09/2022] [Indexed: 11/17/2022]
|
7
|
Ilangumaran Ponmalar I, Swain J, Basu JK. Escherichia coli response to subinhibitory concentrations of colistin: insights from a study of membrane dynamics and morphology. Biomater Sci 2022; 10:2609-2617. [PMID: 35411890 DOI: 10.1039/d2bm00037g] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Prevalence of widespread bacterial infections brings forth a critical need to understand the molecular mechanisms of the antibiotics as well as the bacterial response to those antibiotics. Improper use of antibiotics, which can be in sub-lethal concentrations is one among the multiple reasons for acquiring antibiotic resistance which makes it vital to understand the bacterial response towards sub-lethal concentrations of antibiotics. In this work, we have used colistin, a well-known membrane active antibiotic used to treat severe bacterial infections and explored the impact of its sub-minimum inhibitory concentration (MIC) on the lipid membrane dynamics and morphological changes of E. coli. Upon investigation of live cell membrane properties such as lipid dynamics using fluorescence correlation spectroscopy, we observed that colistin disrupts the lipid membrane at sub-MIC by altering the lipid diffusivity. Interestingly, filamentation-like cell elongation was observed upon colistin treatment which led to further exploration of surface morphology with the help of atomic force spectroscopy. The changes in the surface roughness upon colistin treatment provides additional insight on the colistin-membrane interaction corroborating with the altered lipid diffusion. Although altered lipid dynamics could be attributed to an outcome of lipid rearrangement due to direct disruption by antibiotic molecules on the membrane or an indirect consequence of disruptions in lipid biosynthetic pathways, we were able to ascertain that altered bacterial membrane dynamics is due to direct disruptions. Our results provide a broad overview on the consequence of the cyclic polypeptide colistin on membrane-specific lipid dynamics and morphology of a live Gram-negative bacterial cell.
Collapse
Affiliation(s)
| | - Jitendriya Swain
- Department of Physics, Indian Institute of Science, Bengaluru 560012, India.
| | - Jaydeep K Basu
- Department of Physics, Indian Institute of Science, Bengaluru 560012, India.
| |
Collapse
|
8
|
Badawy S, Baka ZAM, Abou-Dobara MI, El-Sayed AKA, Skurnik M. Biological and molecular characterization of fEg-Eco19, a lytic bacteriophage active against an antibiotic-resistant clinical Escherichia coli isolate. Arch Virol 2022; 167:1333-1341. [PMID: 35399144 PMCID: PMC9038960 DOI: 10.1007/s00705-022-05426-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 03/12/2022] [Indexed: 12/30/2022]
Abstract
Characterization of bacteriophages facilitates better understanding of their biology, host specificity, genomic diversity, and adaptation to their bacterial hosts. This, in turn, is important for the exploitation of phages for therapeutic purposes, as the use of uncharacterized phages may lead to treatment failure. The present study describes the isolation and characterization of a bacteriophage effective against the important clinical pathogen Escherichia coli, which shows increasing accumulation of antibiotic resistance. Phage fEg-Eco19, which is specific for a clinical E. coli strain, was isolated from an Egyptian sewage sample. Phage fEg-Eco19 formed clear, sharp-edged, round plaques. Electron microscopy showed that the isolated phage is tailed and therefore belongs to the order Caudovirales, and morphologically, it resembles siphoviruses. The diameter of the icosahedral head of fEg-Eco19 is 68 ± 2 nm, and the non-contractile tail length and diameter are 118 ± 0.2 and 13 ± 0.6 nm, respectively. The host range of the phage was found to be narrow, as it infected only two out of 137 clinical E. coli strains tested. The phage genome is 45,805 bp in length with a GC content of 50.3% and contains 76 predicted genes. Comparison of predicted and experimental restriction digestion patterns allowed rough mapping of the physical ends of the phage genome, which was confirmed using the PhageTerm tool. Annotation of the predicted genes revealed gene products belonging to several functional groups, including regulatory proteins, DNA packaging and phage structural proteins, host lysis proteins, and proteins involved in DNA/RNA metabolism and replication.
Collapse
Affiliation(s)
- Shimaa Badawy
- Department of Bacteriology and Immunology, Medicum, Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00014 UH Helsinki, Finland
- Department of Botany and Microbiology, Faculty of Science, Damietta University, New Damietta, 34517 Egypt
| | - Zakaria A. M. Baka
- Department of Botany and Microbiology, Faculty of Science, Damietta University, New Damietta, 34517 Egypt
| | - Mohamed I. Abou-Dobara
- Department of Botany and Microbiology, Faculty of Science, Damietta University, New Damietta, 34517 Egypt
| | - Ahmed K. A. El-Sayed
- Department of Botany and Microbiology, Faculty of Science, Damietta University, New Damietta, 34517 Egypt
| | - Mikael Skurnik
- Department of Bacteriology and Immunology, Medicum, Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00014 UH Helsinki, Finland
- Division of Clinical Microbiology, Helsinki University Hospital, HUSLAB, 00290 Helsinki, Finland
| |
Collapse
|
9
|
Colistin Resistance Onset Strategies and Genomic Mosaicism in Clinical Acinetobacter baumannii Lineages. Pathogens 2021; 10:pathogens10111516. [PMID: 34832671 PMCID: PMC8623500 DOI: 10.3390/pathogens10111516] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 11/16/2022] Open
Abstract
The treatment of multidrug-resistant Gram-negative infections is based on colistin. As result, COL-resistance (COL-R) can develop and spread. In Acinetobacter baumannii, a crucial step is to understand COL-R onset and stability, still far to be elucidated. COL-R phenotypic stability, onset modalities, and phylogenomics were investigated in a clinical A. baumannii sample showing a COL resistant (COLR) phenotype at first isolation. COL-R was confirmed by Minimum-Inhibitory-Concentrations as well as investigated by Resistance-Induction assays and Population-Analysis-Profiles (PAPs) to determine: (i) stability; (ii) inducibility; (iii) heteroresistance. Genomics was performed by Mi-Seq Whole-Genome-Sequencing, Phylogenesis, and Genomic Epidemiology by bioinformatics. COLRA. baumannii were subdivided as follows: (i) 3 A. baumannii with stable and high COL MICs defining the “homogeneous-resistant” onset phenotype; (ii) 6 A. baumannii with variable and lower COL MICs displaying a “COL-inducible” onset phenotype responsible for adaptive-resistance or a “subpopulation” onset phenotype responsible for COL-heteroresistance. COL-R stability and onset strategies were not uniquely linked to the amount of LPS and cell envelope charge. Phylogenomics categorized 3 lineages clustering stable and/or unstable COL-R phenotypes with increasing genomic complexity. Likewise, different nsSNP profiling in genes already associated with COL-R marked the stable and/or unstable COL-R phenotypes. Our investigation finds out that A. baumannii can range through unstable or stable COLR phenotypes emerging via different “onset strategies” within phylogenetic lineages displaying increasing genomic mosaicism.
Collapse
|
10
|
de Kraker MEA, Lipsitch M. Burden of Antimicrobial Resistance: Compared to What? Epidemiol Rev 2021; 43:53-64. [PMID: 33710259 PMCID: PMC8763122 DOI: 10.1093/epirev/mxab001] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 03/03/2021] [Accepted: 03/09/2021] [Indexed: 02/07/2023] Open
Abstract
The increased focus on the public health burden of antimicrobial resistance (AMR) raises conceptual challenges, such as determining how much harm multidrug-resistant organisms do compared to what, or how to establish the burden. Here, we present a counterfactual framework and provide guidance to harmonize methodologies and optimize study quality. In AMR-burden studies, 2 counterfactual approaches have been applied: the harm of drug-resistant infections relative to the harm of the same drug-susceptible infections (the susceptible-infection counterfactual); and the total harm of drug-resistant infections relative to a situation where such infections were prevented (the no-infection counterfactual). We propose to use an intervention-based causal approach to determine the most appropriate counterfactual. We show that intervention scenarios, species of interest, and types of infections influence the choice of counterfactual. We recommend using purpose-designed cohort studies to apply this counterfactual framework, whereby the selection of cohorts (patients with drug-resistant, drug-susceptible infections, and those with no infection) should be based on matching on time to infection through exposure density sampling to avoid biased estimates. Application of survival methods is preferred, considering competing events. We conclude by advocating estimation of the burden of AMR by using the no-infection and susceptible-infection counterfactuals. The resulting numbers will provide policy-relevant information about the upper and lower bound of future interventions designed to control AMR. The counterfactuals should be applied in cohort studies, whereby selection of the unexposed cohorts should be based on exposure density sampling, applying methods avoiding time-dependent bias and confounding.
Collapse
Affiliation(s)
- Marlieke E A de Kraker
- Correspondence to Dr. Marlieke E.A. de Kraker, Infection Control Program, Geneva University Hospitals and Faculty of Medicine, Rue Gabrielle Perret Gentil 4, CH-1205 Geneva, Switzerland (e-mail: )
| | | |
Collapse
|
11
|
Ghahraman MRK, Hosseini-Nave H, Azizi O, Shakibaie MR, Mollaie HR, Shakibaie S. Molecular characterization of lpxACD and pmrA/B two-component regulatory system in the colistin resistance Acinetobacter baumannii clinical isolates. GENE REPORTS 2020. [DOI: 10.1016/j.genrep.2020.100952] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|
12
|
Ghahraman MRK, Hosseini-Nave H, Azizi O, Shakibaie MR, Mollaie HR, Shakibaie S. Molecular characterization of lpxACD and pmrA/B two-component regulatory system in the colistin resistance Acinetobacter baumannii clinical isolates. GENE REPORTS 2020. [DOI: https:/doi.org/10.1016/j.genrep.2020.100952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
13
|
Ghahraman MRK, Hosseini-Nave H, Azizi O, Shakibaie MR, Mollaie HR, Shakibaie S. Molecular characterization of lpxACD and pmrA/B two-component regulatory system in the colistin resistance Acinetobacter baumannii clinical isolates. GENE REPORTS 2020. [DOI: https://doi.org/10.1016/j.genrep.2020.100952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
14
|
Sharma S, Banerjee T, Yadav G, Palandurkar K. Mutations at Novel Sites in pmrA/B and lpxA/D Genes and Absence of Reduced Fitness in Colistin-Resistant Acinetobacter baumannii from a Tertiary Care Hospital, India. Microb Drug Resist 2020; 27:628-636. [PMID: 33085934 DOI: 10.1089/mdr.2020.0023] [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] [Indexed: 10/23/2022] Open
Abstract
Background: Colistin resistance in Acinetobacter baumannii, the last resort drug for serious infections, is emerging worldwide. There has been paucity of data on this aspect from India, which is one of the largest producers of colistin. We studied colistin resistance in A. baumannii and characterized the isolates with respect to resistance mechanisms and virulence. Methods: A total of 365 A. baumannii isolates were studied. Antimicrobial susceptibility testing was performed as per standards. Colistin resistance mechanisms were studied by mutation detection in pmrA/B and lpxA/C/D genes, phenotypic loss of lipopolysaccharide, presence of mcr1-5 genes, and carbonyl cyanide 3-chlorophenylhydrazone (CCCP) effects. Biofilm formation, desiccation survival, and growth kinetics were studied and statistically analyzed for colistin-resistant and colistin-susceptible isolates. Results: All the colistin-resistant isolates (9, 2.5%) showed multiple mutations at novel sites in pmrA/B and/or lpxA/D genes with reversion of resistance with CCCP. Majority of these isolates (6, 66.6%) were from patients without prior colistin therapy. All received prior carbapenems. The resistant isolates demonstrated no significant difference in biofilm formation and desiccation survival but were slow growers. Conclusion: Mutations in pmrA/B and/or lpxA/D genes were the main resistance mechanism in these colistin-resistant isolates that showed no reduction in fitness.
Collapse
Affiliation(s)
- Swati Sharma
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Tuhina Banerjee
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Ghanshyam Yadav
- Department of Anesthesiology, and Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | - Kamlesh Palandurkar
- Department of Biochemistry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| |
Collapse
|
15
|
Yang Q, Pogue JM, Li Z, Nation RL, Kaye KS, Li J. Agents of Last Resort: An Update on Polymyxin Resistance. Infect Dis Clin North Am 2020; 34:723-750. [PMID: 33011049 DOI: 10.1016/j.idc.2020.08.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Polymyxin resistance is a major public health threat, because the polymyxins represent last-line therapeutics for gram-negative pathogens resistant to essentially all other antibiotics. Minimizing any potential emergence and dissemination of polymyxin resistance relies on an improved understanding of mechanisms of and risk factors for polymyxin resistance, infection prevention and stewardship strategies, together with optimization of dosing of polymyxins (eg, combination regimens).
Collapse
Affiliation(s)
- Qiwen Yang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, No.9 Dongdan Santiao, Dongcheng District, Beijing, China.
| | - Jason M Pogue
- Department of Clinical Pharmacy, University of Michigan College of Pharmacy, 428 Church Street, Ann Arbor, MI 48109, USA
| | - Zekun Li
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, No.9 Dongdan Santiao, Dongcheng District, Beijing, China
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Victoria 3052, Australia
| | - Keith S Kaye
- Department of Internal Medicine, University of Michigan Medical School, 1301 Catherine Street, Ann Arbor, MI 48109, USA
| | - Jian Li
- Laboratory of Antimicrobial Systems Pharmacology, Department of Microbiology, Monash University, Victoria 3800, Australia
| |
Collapse
|
16
|
Impey RE, Hawkins DA, Sutton JM, Soares da Costa TP. Overcoming Intrinsic and Acquired Resistance Mechanisms Associated with the Cell Wall of Gram-Negative Bacteria. Antibiotics (Basel) 2020; 9:E623. [PMID: 32961699 PMCID: PMC7558195 DOI: 10.3390/antibiotics9090623] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/16/2020] [Accepted: 09/17/2020] [Indexed: 12/19/2022] Open
Abstract
The global increase in multi-drug-resistant bacteria is severely impacting our ability to effectively treat common infections. For Gram-negative bacteria, their intrinsic and acquired resistance mechanisms are heightened by their unique cell wall structure. The cell wall, while being a target of some antibiotics, represents a barrier due to the inability of most antibacterial compounds to traverse and reach their intended target. This means that its composition and resulting mechanisms of resistance must be considered when developing new therapies. Here, we discuss potential antibiotic targets within the most well-characterised resistance mechanisms associated with the cell wall in Gram-negative bacteria, including the outer membrane structure, porins and efflux pumps. We also provide a timely update on the current progress of inhibitor development in these areas. Such compounds could represent new avenues for drug discovery as well as adjuvant therapy to help us overcome antibiotic resistance.
Collapse
Affiliation(s)
- Rachael E. Impey
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia; (R.E.I.); (D.A.H.)
| | - Daniel A. Hawkins
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia; (R.E.I.); (D.A.H.)
| | - J. Mark Sutton
- National Infection Service, Research and Development Institute, Public Health England, Porton Down, Salisbury, Wiltshire SP4 0JG, UK;
| | - Tatiana P. Soares da Costa
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia; (R.E.I.); (D.A.H.)
| |
Collapse
|
17
|
Wand ME, Sutton JM. Mutations in the two component regulator systems PmrAB and PhoPQ give rise to increased colistin resistance in Citrobacter and Enterobacter spp. J Med Microbiol 2020; 69:521-529. [PMID: 32125265 DOI: 10.1099/jmm.0.001173] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Introduction. Colistin is a last resort antibiotic for treating infections caused by carbapenem-resistant isolates. Mechanisms of resistance to colistin have been widely described in Klebsiella pneumoniae and Escherichia coli but have yet to be characterized in Citrobacter and Enterobacter species.Aim. To identify the causative mutations leading to generation of colistin resistance in Citrobacter and Enterobacter spp.Methodology. Colistin resistance was generated by culturing in increasing concentrations of colistin or by direct culture in a lethal (above MIC) concentration. Whole-genome sequencing was used to identify mutations. Fitness of resistant strains was determined by changes in growth rate, and virulence in Galleria mellonella.Results. We were able to generate colistin resistance upon exposure to sub-MIC levels of colistin, in several but not all strains of Citrobacter and Enterobacter resulting in a 16-fold increase in colistin MIC values for both species. The same individual strains also developed resistance to colistin after a single exposure at 10× MIC, with a similar increase in MIC. Genetic analysis revealed that this increased resistance was attributed to mutations in PmrB for Citrobacter and PhoP in Enterobacter, although we were not able to identify causative mutations in all strains. Colistin-resistant mutants showed little difference in growth rate, and virulence in G. mellonella, although there were strain-to-strain differences.Conclusions. Stable colistin resistance may be acquired with no loss of fitness in these species. However, only select strains were able to adapt suggesting that acquisition of colistin resistance is dependent upon individual strain characteristics.
Collapse
Affiliation(s)
- Matthew E Wand
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
| | - J Mark Sutton
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
| |
Collapse
|
18
|
Badawy S, Pajunen MI, Haiko J, Baka ZAM, Abou-Dobara MI, El-Sayed AKA, Skurnik M. Identification and Functional Analysis of Temperate Siphoviridae Bacteriophages of Acinetobacter baumannii. Viruses 2020; 12:v12060604. [PMID: 32486497 PMCID: PMC7354433 DOI: 10.3390/v12060604] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/25/2020] [Accepted: 05/29/2020] [Indexed: 02/07/2023] Open
Abstract
Acinetobacter baumannii is an opportunistic pathogen that presents a serious clinical challenge due to its increasing resistance to all available antibiotics. Phage therapy has been introduced recently to treat antibiotic-incurable A. baumannii infections. In search for new A. baumannii specific bacteriophages, 20 clinical A. baumannii strains were used in two pools in an attempt to enrich phages from sewage. The enrichment resulted in induction of resident prophage(s) and three temperate bacteriophages, named vB_AbaS_fEg-Aba01, vB_AbaS_fLi-Aba02 and vB_AbaS_fLi-Aba03, all able to infect only one strain (#6597) of the 20 clinical strains, were isolated. Morphological characteristics obtained by transmission electron microscopy together with the genomic information revealed that the phages belong to the family Siphoviridae. The ca. 35 kb genomic sequences of the phages were >99% identical to each other. The linear ds DNA genomes of the phages contained 10 nt cohesive end termini, 52–54 predicted genes, an attP site and one tRNA gene each. A database search revealed an >99% identical prophage in the genome of A. baumannii strain AbPK1 (acc. no. CP024576.1). Over 99% identical prophages were also identified from two of the original 20 clinical strains (#5707 and #5920) and both were shown to be spontaneously inducible, thus very likely being the origins of the isolated phages. The phage vB_AbaS_fEg-Aba01 was also able to lysogenize the susceptible strain #6597 demonstrating that it was fully functional. The phages showed a very narrow host range infecting only two A. baumannii strains. In conclusion, we have isolated and characterized three novel temperate Siphoviridae phages that infect A.baumannii.
Collapse
Affiliation(s)
- Shimaa Badawy
- Department of Bacteriology and Immunology, Medicum, Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00014 UH Helsinki, Finland; (S.B.); (M.I.P.)
- Department of Botany and Microbiology, Faculty of Science, Damietta University, 34511 New Damietta, Egypt; (Z.A.M.B.); (M.I.A.-D.); (A.K.A.E.-S.)
| | - Maria I. Pajunen
- Department of Bacteriology and Immunology, Medicum, Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00014 UH Helsinki, Finland; (S.B.); (M.I.P.)
| | - Johanna Haiko
- Division of Clinical Microbiology, Helsinki University Hospital, HUSLAB, 00290 Helsinki, Finland;
| | - Zakaria A. M. Baka
- Department of Botany and Microbiology, Faculty of Science, Damietta University, 34511 New Damietta, Egypt; (Z.A.M.B.); (M.I.A.-D.); (A.K.A.E.-S.)
| | - Mohamed I. Abou-Dobara
- Department of Botany and Microbiology, Faculty of Science, Damietta University, 34511 New Damietta, Egypt; (Z.A.M.B.); (M.I.A.-D.); (A.K.A.E.-S.)
| | - Ahmed K. A. El-Sayed
- Department of Botany and Microbiology, Faculty of Science, Damietta University, 34511 New Damietta, Egypt; (Z.A.M.B.); (M.I.A.-D.); (A.K.A.E.-S.)
| | - Mikael Skurnik
- Department of Bacteriology and Immunology, Medicum, Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, 00014 UH Helsinki, Finland; (S.B.); (M.I.P.)
- Division of Clinical Microbiology, Helsinki University Hospital, HUSLAB, 00290 Helsinki, Finland;
- Correspondence: ; Tel.: +358-2941-26464
| |
Collapse
|
19
|
Choi Y, Lee JY, Lee H, Park M, Kang K, Lim SK, Shin D, Ko KS. Comparison of Fitness Cost and Virulence in Chromosome- and Plasmid-Mediated Colistin-Resistant Escherichia coli. Front Microbiol 2020; 11:798. [PMID: 32477288 PMCID: PMC7238749 DOI: 10.3389/fmicb.2020.00798] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/03/2020] [Indexed: 12/13/2022] Open
Abstract
Five types of Escherichia coli strains were obtained and sequenced: colistin-susceptible (CL-S) strains, in vitro induced colistin-resistant (CL-IR) strains, mcr-1-negative colistin-resistant strains from livestock (CL-chrR), mcr-1-positive colistin-resistant strains (CL-mcrR), and mcr-1-transferred transconjugants (TC-mcr). Amino acid alterations of PmrAB, PhoPQ, and EptA were identified, and their mRNA expression was measured. Their growth rate was evaluated, and an in vitro competition assay was performed. Virulence was compared through serum resistance and survival in macrophages and Drosophila melanogaster. CL-IR and CL-chrR strains were colistin-resistant due to amino acid alterations in PmrAB, PhoPQ, or EptA, and their overexpression. All colistin-resistant strains did not show reduced growth rates compared with CL-S strains. CL-IR and CL-chrR strains were less competitive than the susceptible strain, but CL-mcrR strains were not. In addition, TC-mcr strains were also significantly more competitive than their respective parental susceptible strain. CL-IR strains had similar or decreased survival rates in human serum, macrophages, and fruit flies, compared with their parental, susceptible strains. CL-chrR strains were also less virulent than CL-S strains. Although CL-mcrR strains showed similar survival rates in human serum and fruit fly to CL-S strains, the survival rates of TC-mcr strains decreased significantly in human serum, macrophages, and fruit flies, compared with their susceptible recipient strain (J53). Chromosome-mediated, colistin-resistant E. coli strains have a fitness cost, but plasmids bearing mcr-1 do not increase the fitness burden of E. coli. Along with high usage of polymyxins, the no fitness cost of mcr-1-positive strains may facilitate rapid spread of colistin resistance.
Collapse
Affiliation(s)
- Yujin Choi
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Ji-Young Lee
- Division of Antimicrobial Resistance, Korea Centers for Disease Control and Prevention, Cheongju, South Korea
| | - Haejeong Lee
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Myungseo Park
- Department of Integrative Biotechnology, College of Biotechnology and Bioengineering, Sungkyunkwan University, Suwon, South Korea
| | - KyeongJin Kang
- Department of Anatomy and Cell Biology, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Suk-Kyung Lim
- Bacterial Disease Division, Animal and Plant Quarantine Agency, Gimcheon, South Korea
| | - Dongwoo Shin
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Kwan Soo Ko
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, South Korea
| |
Collapse
|
20
|
Huang J, Li C, Song J, Velkov T, Wang L, Zhu Y, Li J. Regulating polymyxin resistance in Gram-negative bacteria: roles of two-component systems PhoPQ and PmrAB. Future Microbiol 2020; 15:445-459. [PMID: 32250173 DOI: 10.2217/fmb-2019-0322] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Polymyxins (polymyxin B and colistin) are last-line antibiotics against multidrug-resistant Gram-negative pathogens. Polymyxin resistance is increasing worldwide, with resistance most commonly regulated by two-component systems such as PmrAB and PhoPQ. This review discusses the regulatory mechanisms of PhoPQ and PmrAB in mediating polymyxin resistance, from receiving an external stimulus through to activation of genes responsible for lipid A modifications. By analyzing the reported nonsynonymous substitutions in each two-component system, we identified the domains that are critical for polymyxin resistance. Notably, for PmrB 71% of resistance-conferring nonsynonymous mutations occurred in the HAMP (present in histidine kinases, adenylate cyclases, methyl accepting proteins and phosphatase) linker and DHp (dimerization and histidine phosphotransfer) domains. These results enhance our understanding of the regulatory mechanisms underpinning polymyxin resistance and may assist with the development of new strategies to minimize resistance emergence.
Collapse
Affiliation(s)
- Jiayuan Huang
- Biomedicine Discovery Institute & Department of Microbiology, Monash University, Melbourne 3800, Australia
| | - Chen Li
- Biomedicine Discovery Institute & Department of Biochemistry & Molecular Biology, Monash University, Melbourne 3800, Australia.,Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich 8093, Switzerland
| | - Jiangning Song
- Biomedicine Discovery Institute & Department of Biochemistry & Molecular Biology, Monash University, Melbourne 3800, Australia
| | - Tony Velkov
- Department of Pharmacology & Therapeutics, School of Biomedical Sciences, Faculty of Medicine, Dentistry & Health Sciences, The University of Melbourne, Melbourne 3010, Australia
| | - Lushan Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yan Zhu
- Biomedicine Discovery Institute & Department of Microbiology, Monash University, Melbourne 3800, Australia
| | - Jian Li
- Biomedicine Discovery Institute & Department of Microbiology, Monash University, Melbourne 3800, Australia
| |
Collapse
|
21
|
Yu P, Zhou X, Li Z, Yan Y. Inactivation and change of tetracycline-resistant Escherichia coli in secondary effluent by visible light-driven photocatalytic process using Ag/AgBr/g-C 3N 4. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 705:135639. [PMID: 31841919 DOI: 10.1016/j.scitotenv.2019.135639] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 11/05/2019] [Accepted: 11/18/2019] [Indexed: 05/27/2023]
Abstract
Control of antibiotic-resistant bacteria (ARB) and their related genes in secondary effluents has become a serious issue because of increased awareness of their health risks. A considerable number of techniques have been developed in recent years, particularly in relation to advanced oxidation. However, limited information is known about cellular behavior and resistance characteristic change during photocatalytic treatment. In this study, the inactivation of tetracycline (TC)-resistant Escherichia coli (TC-E. coli), removal of TC-resistant genes (TC-RGs), and antibiotic susceptibility were evaluated by employing photocatalytic treatment using Ag/AgBr/g-C3N4 with visible light irradiation. The effects of light intensity, photocatalyst dosage, and reaction ambient temperature on photocatalysis were modelled and investigated. The rate of TC-E. coli removal was also optimized. Results demonstrated that the optimal conditions for TC-E. coli removal included light intensity of 96.0 mW/cm2, photocatalyst dosage of 211.0 mg/L, and reaction ambient temperature of 23.7 °C. Under such conditions, the ARB removal rate was 6.1 log after 90 min and the related TC-RG removal rates were 49%, 86%, 69%, and 86% for tetA, tetM, tetQ, and intl1, respectively. The minimum inhibitory concentration test after photocatalysis shows that the antibiotic resistance of TC-E. coli was enhanced, which may be mainly due to the changes in the membrane potential and resulted in difficulty in destroying the bacteria through antibiotic contact. Hence, photocatalytic treatment could be an ideal method for ARB and antibiotic-resistant gene (ARG) control in wastewater, but the health risks of the remaining ARB and ARG should be investigated further.
Collapse
Affiliation(s)
- Peng Yu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, PR China
| | - Xiaoqin Zhou
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, PR China.
| | - Zifu Li
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, PR China.
| | - Yichang Yan
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, PR China; Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, University of Science and Technology Beijing, Beijing 100083, PR China
| |
Collapse
|
22
|
Huang J, Dai X, Ge L, Shafiq M, Shah JM, Sun J, Yi S, Wang L. Sequence Duplication Within pmrB Gene Contribute to High-Level Colistin Resistance in Avian Pathogenic Escherichia coli. Microb Drug Resist 2019; 26:1442-1451. [PMID: 31770069 DOI: 10.1089/mdr.2019.0290] [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: 11/13/2022] Open
Abstract
Beyond the emergence of plasmid-encoded mechanisms, mutation within the pmrAB genes remains one of the primary colistin resistance mechanisms in Escherichia coli. However, the mechanisms of high-level colistin resistance (HLCR) have not been elucidated. In this study, we evaluated the HLCR mechanisms in five colistin-susceptible Avian pathogenic Escherichia coli (APEC) isolates after colistin exposure. Three PmrB substitutions (G19R, L167P, V88E) and two PmrB sequence duplication (PmrB-sd) mutations (68-77dup and 94-156dup) were detected. Chromosomal replacement and deletion mutagenesis revealed the two PmrB-sd mutations contribute to, but are not fully responsible for, HLCR in APEC strains. Quantitative reverse transcription/polymerase chain reaction (qRT-PCR) revealed that the PmrB-sd induction mutants showed an increased pmrAB transcript level and the PmrB-sd reversion mutants exhibited a reduction of pmrAB expression. All five induction mutants exhibited decreased minimum inhibitory concentrations to florfenicol and tetracycline. In addition, four mutants (G19R, L167P, V88E, and 94-156dup) and two mutants (68-77dup and 94-156dup) also displayed increased sensitivity to ceftiofur and gentamicin, respectively. Zeta potential measurement of the induction mutants showed that there was less negative charge on the cell surface compared with its parental strains in the absence of colistin. The induction mutants also showed an increase of lag time and decrease of fitness. In summary, the identification of novel PmrB-sd mutations contributing to HLCR is helpful to broaden the knowledge of colistin resistance. Attention should be paid to the use of colistin for the treatment of infections caused by APEC strains.
Collapse
Affiliation(s)
- Jinhu Huang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xingyang Dai
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Lin Ge
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Muhammad Shafiq
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Jan Mohammad Shah
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Junjie Sun
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Sida Yi
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Liping Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| |
Collapse
|
23
|
Bock LJ. Bacterial biocide resistance: a new scourge of the infectious disease world? Arch Dis Child 2019; 104:1029-1033. [PMID: 30705078 DOI: 10.1136/archdischild-2018-315090] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 12/27/2018] [Accepted: 01/04/2019] [Indexed: 12/17/2022]
|
24
|
Gazel D, Tatman Otkun M, Akçalı A. In vitro activity of methylene blue and eosin methylene blue agar on colistin-resistant A. baumannii: an experimental study. J Med Microbiol 2019; 68:1607-1613. [PMID: 31535963 DOI: 10.1099/jmm.0.001078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Introduction. Colistin is a last-resort antibiotic used against carbapenem-resistant Acinetobacter baumannii (AB); however, colistin resistance has been reported recently. Methylene blue (MB) is used in microbiology for staining, and in medicine as an antidote drug.Aim. We aimed to investigate the antimicrobial effects of MB and eosin methylene blue (EMB) agar against colistin-resistant AB strains.Methodology. Firstly, a standard strain and AB clinical isolate were included in the study. After determining MICs, two strains were transformed into colistin-resistant forms, using Li's method. At each step, new MICs were determined and subcultures were inoculated onto EMB and sheep blood agar (SBA). Colistin MICs of the subcultures were also determined using Mueller-Hinton agar (MHA) containing MB. Secondly, colistin-resistant clones from 31 multidrug-resistant AB clinical isolates were screened to investigate their susceptibilities to EMB agar.Results. In the first round, MICs of both strains had risen to 64 μg ml-1. Subpopulations with high colistin resistance were inhibited by MB and EMB agar, but could grow well on SBA. In MHA plates containing MB, the MICs decreased to 0.5 μg ml-1 for colistin-susceptible or moderately resistant clones. Additionally, clones with high colistin resistance showed atypical colony morphology on SBA. In the second round, 35 % of the clinical isolates, which had gained resistance to colistin, were inhibited by EMB agar.Conclusion. MB may have inhibitory effects against colistin-resistant AB. Secondly, using only EMB agar for subculturing may cause missing of colistin-resistant strains.
Collapse
Affiliation(s)
- Deniz Gazel
- Department of Medical Microbiology, Gaziantep University, Faculty of Medicine, Gaziantep, Turkey
| | - Müşerref Tatman Otkun
- Department of Medical Microbiology, Çanakkale Onsekiz Mart University, Faculty of Medicine, Çanakkale, Turkey
| | - Alper Akçalı
- Department of Medical Microbiology, Çanakkale Onsekiz Mart University, Faculty of Medicine, Çanakkale, Turkey
| |
Collapse
|
25
|
Masci D, Hind C, Islam MK, Toscani A, Clifford M, Coluccia A, Conforti I, Touitou M, Memdouh S, Wei X, La Regina G, Silvestri R, Sutton JM, Castagnolo D. Switching on the activity of 1,5-diaryl-pyrrole derivatives against drug-resistant ESKAPE bacteria: Structure-activity relationships and mode of action studies. Eur J Med Chem 2019; 178:500-514. [DOI: 10.1016/j.ejmech.2019.05.087] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 05/29/2019] [Accepted: 05/29/2019] [Indexed: 12/13/2022]
|
26
|
Leite GC, Stabler RA, Neves P, Perdigão Neto LV, Ruedas Martins RC, Rizek C, Rossi F, Levin AS, Costa SF. Genetic and virulence characterization of colistin-resistant and colistin-sensitive A. baumannii clinical isolates. Diagn Microbiol Infect Dis 2019; 95:99-101. [PMID: 31178071 DOI: 10.1016/j.diagmicrobio.2019.04.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 03/29/2019] [Accepted: 04/24/2019] [Indexed: 11/24/2022]
Abstract
Treatment of infections caused by A. baumannii is becoming a challenge due to the ability to develop multidrug-resistance, virulence, and high mortality. We described the colistin resistance and virulence genes present in sixA. baumannii clinical isolates using WGS, expression by qPCR, and virulence in the Galleria mellonella model. The colistin-resistant isolates were assigned as ST233 and the colistin-susceptible isolates as ST236 and ST407. The colistin-resistant isolates contained mutations within PmrA/PmrB, and the pmrA showed up-regulation in all of them. Only one colistin-resistant isolate indicating virulence in G. mellonella. This particular isolate belonged to a different clone, and it was the only isolate that presented non-synonymous mutations in pmrB. Colistinresistance in A. baumannii isolates seems to be caused by up-regulation of pmrA gene. Only one isolate appeared to be virulent in the G. mellonella model. This finding indicating low virulence in isolates belonging to emerging clones circulating in our hospital.
Collapse
Affiliation(s)
- Gleice Cristina Leite
- Department of Infectious Diseases, University of São Paulo, São Paulo, Brazil; Laboratory of Medical Investigation 54 (LIM-54), São Paulo, Brazil
| | | | - Patrícia Neves
- Department of Infectious Diseases, University of São Paulo, São Paulo, Brazil; Laboratory of Medical Investigation 54 (LIM-54), São Paulo, Brazil
| | - Lauro V Perdigão Neto
- Department of Infectious Diseases, University of São Paulo, São Paulo, Brazil; Laboratory of Medical Investigation 54 (LIM-54), São Paulo, Brazil
| | - Roberta C Ruedas Martins
- Department of Infectious Diseases, University of São Paulo, São Paulo, Brazil; Laboratory of Medical Investigation 54 (LIM-54), São Paulo, Brazil
| | - Camila Rizek
- Laboratory of Medical Investigation 54 (LIM-54), São Paulo, Brazil
| | - Flavia Rossi
- Laboratory of Microbiology, University of São Paulo, São Paulo, Brazil
| | - Anna S Levin
- Department of Infectious Diseases, University of São Paulo, São Paulo, Brazil; Laboratory of Medical Investigation 54 (LIM-54), São Paulo, Brazil; Institute of Tropical Medicine, University of São Paulo, São Paulo, Brazil
| | - Silvia Figueiredo Costa
- Department of Infectious Diseases, University of São Paulo, São Paulo, Brazil; Laboratory of Medical Investigation 54 (LIM-54), São Paulo, Brazil; Institute of Tropical Medicine, University of São Paulo, São Paulo, Brazil.
| |
Collapse
|
27
|
Bhagirath AY, Li Y, Patidar R, Yerex K, Ma X, Kumar A, Duan K. Two Component Regulatory Systems and Antibiotic Resistance in Gram-Negative Pathogens. Int J Mol Sci 2019; 20:E1781. [PMID: 30974906 PMCID: PMC6480566 DOI: 10.3390/ijms20071781] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 12/17/2022] Open
Abstract
Gram-negative pathogens such as Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa are the leading cause of nosocomial infections throughout the world. One commonality shared among these pathogens is their ubiquitous presence, robust host-colonization and most importantly, resistance to antibiotics. A significant number of two-component systems (TCSs) exist in these pathogens, which are involved in regulation of gene expression in response to environmental signals such as antibiotic exposure. While the development of antimicrobial resistance is a complex phenomenon, it has been shown that TCSs are involved in sensing antibiotics and regulating genes associated with antibiotic resistance. In this review, we aim to interpret current knowledge about the signaling mechanisms of TCSs in these three pathogenic bacteria. We further attempt to answer questions about the role of TCSs in antimicrobial resistance. We will also briefly discuss how specific two-component systems present in K. pneumoniae, A. baumannii, and P. aeruginosa may serve as potential therapeutic targets.
Collapse
Affiliation(s)
- Anjali Y Bhagirath
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Yanqi Li
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Rakesh Patidar
- Department of Microbiology, Faculty of Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Katherine Yerex
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Xiaoxue Ma
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Ayush Kumar
- Department of Microbiology, Faculty of Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Kangmin Duan
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
- Department of Medical Microbiology & Infectious Diseases, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| |
Collapse
|
28
|
Investigation of Novel pmrB and eptA Mutations in Isogenic Acinetobacter baumannii Isolates Associated with Colistin Resistance and Increased Virulence In Vivo. Antimicrob Agents Chemother 2019; 63:AAC.01586-18. [PMID: 30617096 DOI: 10.1128/aac.01586-18] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 12/05/2018] [Indexed: 12/19/2022] Open
Abstract
Colistin resistance in Acinetobacter baumannii is of great concern and is a threat to human health. In this study, we investigate the mechanisms of colistin resistance in four isogenic pairs of A. baumannii isolates displaying an increase in colistin MICs. A mutation in pmrB was detected in each colistin-resistant isolate, three of which were novel (A28V, I232T, and ΔL9-G12). Increased expression of pmrC was shown by semi-quantitative reverse transcription-PCR (qRT-PCR) for three colistin-resistant isolates, and the addition of phosphoethanolamine (PEtN) to lipid A by PmrC was revealed by mass spectrometry. Interestingly, PEtN addition was also observed in some colistin-susceptible isolates, indicating that this resistance mechanism might be strain specific and that other factors could contribute to colistin resistance. Furthermore, the introduction of pmrAB carrying the short amino acid deletion ΔL9-G12 into a pmrAB knockout strain resulted in increased pmrC expression and lipid A modification, but colistin MICs remained unchanged, further supporting the strain specificity of this colistin resistance mechanism. Of note, a mutation in the pmrC homologue eptA and a point mutation in ISAba1 upstream of eptA were associated with colistin resistance and increased eptA expression, which is a hitherto undescribed resistance mechanism. Moreover, no cost of fitness was observed for colistin-resistant isolates, while the virulence of these isolates was increased in a Galleria mellonella infection model. Although the mutations in pmrB were associated with colistin resistance, PEtN addition appears not to be the sole factor leading to colistin resistance, indicating that the mechanism of colistin resistance is far more complex than previously suspected and is potentially strain specific.
Collapse
|
29
|
Espinal P, Pantel A, Rolo D, Marti S, López-Rojas R, Smani Y, Pachón J, Vila J, Lavigne JP. Relationship Between Different Resistance Mechanisms and Virulence in Acinetobacter baumannii. Microb Drug Resist 2019; 25:752-760. [PMID: 30632884 DOI: 10.1089/mdr.2018.0182] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aim: This study analyzed the virulence of several Acinetobacter baumannii strains expressing different resistance mechanisms using the Caenorhabditis elegans infection model. Results: Strains susceptible/resistant to carbapenems (presenting class D (OXA-23, OXA-24), class B metallo-β-lactamase (MBL) (NDM-1), penicillin binding protein (PBP) altered and decreased expression of Omp 33-36 kDa) and isogenic A. baumannii strains susceptible/resistant to colistin (presenting loss of lipopolysaccharide (LPS) and pmrA mutations) were included to evaluate the virulence using the C. elegans infection model. The nematode killing assay, bacterial ingestion in worms, and bacterial lawn avoidance assay were performed with the Fer-15 mutant line. A. baumannii strains generally presented low virulence, showing no difference between carbapenem-resistant strains (expressing class D, MBLs, or altered PBP) and their isogenic susceptible strains. In contrast, the absence of the Omp 33-36 kDa protein in the knockout was associated with a decrease of virulence, and a significant difference was observed between colistin-resistant mutants and their susceptible counterpart when the mechanism of resistance was associated with the loss of LPS but not with its modification. Conclusions: Resistance to carbapenems in A. baumannii associated with the production of OXA-type or NDM-type enzymes does not seem to affect their virulence in the C. elegans infection model. In contrast, the presence of Omp 33-36 kDa, and high level resistance to colistin related with the loss of LPS, might contribute with the virulence profile in A. baumannii.
Collapse
Affiliation(s)
- Paula Espinal
- 1 Barcelona Institute for Global Health (ISGlobal) Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,2 National Institute of Health and Medical Research, U1047, Montpellier University, Nîmes, France
| | - Alix Pantel
- 2 National Institute of Health and Medical Research, U1047, Montpellier University, Nîmes, France.,3 Department of Microbiology, University Hospital Nîmes, Nîmes, France
| | - Dora Rolo
- 1 Barcelona Institute for Global Health (ISGlobal) Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Sara Marti
- 4 Microbiology Department, Hospital Universitari Bellvitge, Barcelona, Spain.,5 Research Network for Respiratory Diseases (CIBERES), ISCIII, Madrid, Spain
| | - Rafael López-Rojas
- 6 Clinic Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville, IBiS, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Younes Smani
- 6 Clinic Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville, IBiS, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Jerónimo Pachón
- 6 Clinic Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville, IBiS, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Jordi Vila
- 1 Barcelona Institute for Global Health (ISGlobal) Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Jean-Philippe Lavigne
- 2 National Institute of Health and Medical Research, U1047, Montpellier University, Nîmes, France.,3 Department of Microbiology, University Hospital Nîmes, Nîmes, France
| |
Collapse
|
30
|
Giannakis S, Le TTM, Entenza JM, Pulgarin C. Solar photo-Fenton disinfection of 11 antibiotic-resistant bacteria (ARB) and elimination of representative AR genes. Evidence that antibiotic resistance does not imply resistance to oxidative treatment. WATER RESEARCH 2018; 143:334-345. [PMID: 29986243 DOI: 10.1016/j.watres.2018.06.062] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/24/2018] [Accepted: 06/26/2018] [Indexed: 06/08/2023]
Abstract
The emergence of antibiotic resistance represents a major threat to human health. In this work we investigated the elimination of antibiotic resistant bacteria (ARB) by solar light and solar photo-Fenton processes. As such, we have designed an experimental plan in which several bacterial strains (Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae) possessing different drug-susceptible and -resistant patterns and structures (Gram-positive and Gram-negative) were subjected to solar light and the photo-Fenton oxidative treatment in water. We showed that both solar light and solar photo-Fenton processes were effective in the elimination of ARB in water and that the time necessary for solar light disinfection and solar photo-Fenton disinfection were similar for antibiotic-susceptible and antibiotic-resistant strains (mostly 180-240 and 90-120 min, respectively). Moreover, the bacterial structure did not significantly affect the effectiveness of the treatment. Similar regrowth pattern was observed (compared to the susceptible strain) and no development of bacteria with higher drug-resistance values was found in waters after any treatment. Finally, both processes were effective to reduce AR genes (ARGs), although solar photo-Fenton was more rapid than solar light. In conclusion, the solar photo-Fenton process ensured effective disinfection of ARB and elimination of ARGs in water (or wastewater) and is a potential mean to ensure limitation of ARB and ARG spread in nature.
Collapse
Affiliation(s)
- Stefanos Giannakis
- School of Basic Sciences (SB), Institute of Chemical Science and Engineering (ISIC), Group of Advanced Oxidation Processes (GPAO), École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland.
| | - Truong-Thien Melvin Le
- School of Basic Sciences (SB), Institute of Chemical Science and Engineering (ISIC), Group of Advanced Oxidation Processes (GPAO), École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland
| | - Jose Manuel Entenza
- Faculty of Biology and Medicine, Department of Fundamental Microbiology, University of Lausanne (UNIL), Biophore Building, CH-1015, Lausanne, Switzerland
| | - Cesar Pulgarin
- School of Basic Sciences (SB), Institute of Chemical Science and Engineering (ISIC), Group of Advanced Oxidation Processes (GPAO), École Polytechnique Fédérale de Lausanne (EPFL), Station 6, CH-1015 Lausanne, Switzerland.
| |
Collapse
|
31
|
Colistin Heteroresistance and Involvement of the PmrAB Regulatory System in Acinetobacter baumannii. Antimicrob Agents Chemother 2018; 62:AAC.00788-18. [PMID: 29914966 DOI: 10.1128/aac.00788-18] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/14/2018] [Indexed: 02/08/2023] Open
Abstract
Multidrug-resistant Acinetobacter baumannii infection has recently emerged as a worldwide clinical problem, and colistin is increasingly being used as a last-resort therapy. Despite its favorable bacterial killing, resistance and heteroresistance (HR) to colistin have been described. The purpose of the present study was to investigate the role of the PmrAB regulatory pathway in laboratory-selected mutants representative of global epidemic strains. From three unrelated A. baumannii clinical strains (sequence types 2, 3, and 20), eight colistin-resistant mutants were selected. Half of the mutants showed HR to colistin according to the reference method (population analysis profiling), whereas the other half exhibited stable resistance. M12I mutation within pmrA and M308R, S144KLAGS, and P170L mutations for pmrB were associated with HR to colistin, while T235I, A226T, and P233S mutations within pmrB were associated with stable resistance. The transcript levels of the pmrCAB operon were upregulated in all the mutants. Compensatory mutations were explored for some mutants. A single mutant (T235I mutant) displayed a compensatory mutation through ISAba1 mobilization within the pmrB gene that was associated with the loss of colistin resistance. The mutant resistance phenotype associated with T235I was partially restored in a trans-complementation assay turning to HR. The level of colistin resistance was correlated with the level of expression of pmrC in the trans-complemented strains. This report shows the role of different mutations in the PmrAB regulatory pathway and warns of the development of colistin HR that could be present but not easily detected through routine testing.
Collapse
|
32
|
Distribution of biocide resistant genes and biocides susceptibility in multidrug-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii - A first report from the Kingdom of Saudi Arabia. J Infect Public Health 2018; 11:812-816. [PMID: 29907439 DOI: 10.1016/j.jiph.2018.05.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 05/21/2018] [Accepted: 05/28/2018] [Indexed: 11/24/2022] Open
Abstract
PURPOSES The aim of this study was to determine the frequency of biocide resistant genes, qacA, qacE and cepA in multidrug resistant (MDR) bacteria: Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii and to correlate the presence or absence of resistant genes with biocides susceptibility. MATERIALS AND METHODS The study included 44 MDR K. pneumoniae, P. aeruginosa and A. baumannii microorganisms. The bacteria were screened for the presence of biocide resistant genes by the polymerase chain reaction (PCR) method. The test organisms were isolated from various clinical specimens in the Qassim region, Saudi Arabia. The in vitro susceptibility tests of the three biocides (benzalkonium chloride, cetrimide and chlorhexidine gluconate) were studied against the test isolates by broth microdilution method following Clinical and Laboratory Standards Institute guidelines. RESULTS With the distribution of biocide resistant genes in K. pneumoniae, all 9 isolates (100%) possessed cepA; 4 (44.4%) and 1 (11.1%) isolate contained qacA and qacE genes respectively. Among 24 isolates of A. baumannii tested, cepA, qacA and qacE genes were found in 54.2%, 16.7% and 33.3% of isolates respectively. Among 11 P. aeruginosa isolates, 63.6% contained cepA gene, 18.2% contained qacE genes, and none of the isolates harboured qacA gene. There was no significant correlation between presence or absence of biocide resistant genes and high MIC values of the test isolates (p≥0.2). CONCLUSION Our observations imply that there was no significant correlation between presence or absence of biocide resistant genes and MICs observed in MDR K. pneumoniae, P. aeruginosa and A. baumannii. Further studies are required to find to confirm the trend of reduced susceptibility to biocides of problematic nosocomial pathogens.
Collapse
|
33
|
Lima WG, Alves MC, Cruz WS, Paiva MC. Chromosomally encoded and plasmid-mediated polymyxins resistance in Acinetobacter baumannii: a huge public health threat. Eur J Clin Microbiol Infect Dis 2018. [PMID: 29524060 DOI: 10.1007/s10096-018-3223-9] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen associated with nosocomial and community infections of great clinical relevance. Its ability to rapidly develop resistance to antimicrobials, especially carbapenems, has re-boosted the prescription and use of polymyxins. However, the emergence of strains resistant to these antimicrobials is becoming a critical issue in several regions of the world because very few of currently available antibiotics are effective in these cases. This review summarizes the most up-to-date knowledge about chromosomally encoded and plasmid-mediated polymyxins resistance in A. baumannii. Different mechanisms are employed by A. baumannii to overcome the antibacterial effects of polymyxins. Modification of the outer membrane through phosphoethanolamine addition, loss of lipopolysaccharide, symmetric rupture, metabolic changes affecting osmoprotective amino acids, and overexpression of efflux pumps are involved in this process. Several genetic elements modulate these mechanisms, but only three of them have been described so far in A. baumannii clinical isolates such as mutations in pmrCAB, lpxACD, and lpsB. Elucidation of genotypic profiles and resistance mechanisms are necessary for control and fight against resistance to polymyxins in A. baumannii, thereby protecting this class for future treatment.
Collapse
Affiliation(s)
- William Gustavo Lima
- Laboratory of Medical Microbiology, Central-West Campus Dona Lindu, Federal University of São João del-Rei, Rua Sebastião Gonçalves Coelho, 400, Divinopolis, Minas Gerais, 35501-293, Brazil.
| | - Mara Cristina Alves
- Laboratory of Laboratorial Diagnostic and Clinical Microbiology, Central-West Campus Dona Lindu, Federal University of São João del-Rei, Divinopolis, MG, Brazil
| | - Waleska Stephanie Cruz
- Laboratory of Molecular and Celular Biology, Alto Paraopeba Campus, Federal University of São João del-Rei, Ouro Branco, MG, Brazil
| | - Magna Cristina Paiva
- Laboratory of Laboratorial Diagnostic and Clinical Microbiology, Central-West Campus Dona Lindu, Federal University of São João del-Rei, Divinopolis, MG, Brazil
| |
Collapse
|
34
|
Interplay between Colistin Resistance, Virulence and Fitness in Acinetobacter baumannii. Antibiotics (Basel) 2017; 6:antibiotics6040028. [PMID: 29160808 PMCID: PMC5745471 DOI: 10.3390/antibiotics6040028] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 11/14/2017] [Accepted: 11/20/2017] [Indexed: 12/22/2022] Open
Abstract
Acinetobacter baumannii is an important opportunistic nosocomial pathogen often resistant to multiple antibiotics classes. Colistin, an “old” antibiotic, is now considered a last-line treatment option for extremely resistant isolates. In the meantime, resistance to colistin has been reported in clinical A. baumannii strains. Colistin is a cationic peptide that disrupts the outer membrane (OM) of Gram-negative bacteria. Colistin resistance is primarily due to post-translational modification or loss of the lipopolysaccharide (LPS) molecules inserted into the outer leaflet of the OM. LPS modification prevents the binding of polymyxin to the bacterial surface and may lead to alterations in bacterial virulence. Antimicrobial pressure drives the evolution of antimicrobial resistance and resistance is often associated with a reduced bacterial fitness. Therefore, the alterations in LPS may induce changes in the fitness of A. baumannii. However, compensatory mutations in clinical A. baumannii may ameliorate the cost of resistance and may play an important role in the dissemination of colistin-resistant A. baumannii isolates. The focus of this review is to summarize the colistin resistance mechanisms, and understand their impact on the fitness and virulence of bacteria and on the dissemination of colistin-resistant A. baumannii strains.
Collapse
|
35
|
Jaidane N, Naas T, Mansour W, Radhia BB, Jerbi S, Boujaafar N, Bouallegue O, Bonnin RA. Genomic analysis of in vivo acquired resistance to colistin and rifampicin in Acinetobacter baumannii. Int J Antimicrob Agents 2017; 51:266-269. [PMID: 29127051 DOI: 10.1016/j.ijantimicag.2017.10.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 10/27/2017] [Accepted: 10/28/2017] [Indexed: 11/16/2022]
Abstract
Acinetobacter baumannii is an opportunistic pathogen in healthcare facilities responsible for nosocomial infections mostly in immunocompromised patients. Colistin resistance is increasingly reported worldwide in A. baumannii. Here we describe the in vivo selection of colistin and rifampicin resistance in carbapenem-resistant A. baumannii. Antimicrobial susceptibility testing, plasmid analysis and whole-genome sequencing (WGS) were performed to fully characterise the resistome of two clinical isolates (AbS1 and AbS2) selected during treatment. Clinical isolate AbS1 remained susceptible to colistin, rifampicin and tigecycline, whilst AbS2 was susceptible only to tigecycline. PCR analysis revealed the presence of a blaOXA-23-like carbapenemase gene. Kieser extraction revealed an ca. 74 kb plasmid harbouring blaOXA-23. WGS revealed genomes of 3.8 Mbp in size with a G + C content of 38.9%, and both belonged to ST281 according to the Oxford MLST scheme and ST641 according to the Institut Pasteur scheme. The resistome was also composed of naturally occurring β-lactamases, i.e. ADC-25 cephalosporinase and OXA-82 oxacillinase, aminoglycoside resistance genes [aac(3)-Ia, aadA1 and aph(3')-VIa (aphA6)], and mutations in DNA gyrases explaining fluoroquinolone resistance. Single nucleotide polymorphism analysis revealed that both isolates were identical except for a 30-nucleotide duplication within the pmrB gene and a point mutation in the rpoB gene resulting in colistin and rifampicin resistance, respectively. This study highlights the genomic plasticity of A. baumannii under antibiotic pressure. The 10-amino acid duplication in PmrB affects colistin susceptibility by regulating lipopolysaccharide modification through the PmrAB two-component system. These findings provide further information on the molecular mechanisms leading to colistin resistance in A. baumannii.
Collapse
Affiliation(s)
- Nadia Jaidane
- EA7361, Université Paris-Sud, Université Paris-Saclay, LabEx LERMIT, Bacteriology-Hygiene Unit, APHP, Hôpital Bicêtre, Le Kremlin-Bicêtre, France; UR 12 SP 37, Emerging Bacterial Resistance and Safety of Care, Department of Clinical Microbiology, University Hospital of Sahloul, Sousse, Tunisia; Faculté de pharmacie de Monastir, Université de Monastir, Monastir, Tunisia
| | - Thierry Naas
- EA7361, Université Paris-Sud, Université Paris-Saclay, LabEx LERMIT, Bacteriology-Hygiene Unit, APHP, Hôpital Bicêtre, Le Kremlin-Bicêtre, France; EERA 'Evolution and Ecology of Resistance to Antibiotics' Unit, Institut Pasteur, APHP, Université Paris-Sud, Paris, France; Associated French National Reference Center for Antibiotic Resistance 'Carbapenemase-producing Enterobacteriaceae', France
| | - Wejdene Mansour
- UR 12 SP 37, Emerging Bacterial Resistance and Safety of Care, Department of Clinical Microbiology, University Hospital of Sahloul, Sousse, Tunisia
| | - Bechir Ben Radhia
- Cardiovascular Surgery Unit at University Hospital of Sahloul, Sousse, Tunisia
| | - Sofiene Jerbi
- UR 12 SP 37, Emerging Bacterial Resistance and Safety of Care, Department of Clinical Microbiology, University Hospital of Sahloul, Sousse, Tunisia; Faculté de médecine de Sousse, Université de Sousse, Sousse, Tunisia
| | - Noureddine Boujaafar
- UR 12 SP 37, Emerging Bacterial Resistance and Safety of Care, Department of Clinical Microbiology, University Hospital of Sahloul, Sousse, Tunisia; Faculté de pharmacie de Monastir, Université de Monastir, Monastir, Tunisia
| | - Olfa Bouallegue
- UR 12 SP 37, Emerging Bacterial Resistance and Safety of Care, Department of Clinical Microbiology, University Hospital of Sahloul, Sousse, Tunisia; Faculté de médecine de Sousse, Université de Sousse, Sousse, Tunisia
| | - Rémy A Bonnin
- EA7361, Université Paris-Sud, Université Paris-Saclay, LabEx LERMIT, Bacteriology-Hygiene Unit, APHP, Hôpital Bicêtre, Le Kremlin-Bicêtre, France; EERA 'Evolution and Ecology of Resistance to Antibiotics' Unit, Institut Pasteur, APHP, Université Paris-Sud, Paris, France; Associated French National Reference Center for Antibiotic Resistance 'Carbapenemase-producing Enterobacteriaceae', France.
| |
Collapse
|
36
|
Clinical and Pathophysiological Overview of Acinetobacter Infections: a Century of Challenges. Clin Microbiol Rev 2017; 30:409-447. [PMID: 27974412 DOI: 10.1128/cmr.00058-16] [Citation(s) in RCA: 642] [Impact Index Per Article: 91.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Acinetobacter is a complex genus, and historically, there has been confusion about the existence of multiple species. The species commonly cause nosocomial infections, predominantly aspiration pneumonia and catheter-associated bacteremia, but can also cause soft tissue and urinary tract infections. Community-acquired infections by Acinetobacter spp. are increasingly reported. Transmission of Acinetobacter and subsequent disease is facilitated by the organism's environmental tenacity, resistance to desiccation, and evasion of host immunity. The virulence properties demonstrated by Acinetobacter spp. primarily stem from evasion of rapid clearance by the innate immune system, effectively enabling high bacterial density that triggers lipopolysaccharide (LPS)-Toll-like receptor 4 (TLR4)-mediated sepsis. Capsular polysaccharide is a critical virulence factor that enables immune evasion, while LPS triggers septic shock. However, the primary driver of clinical outcome is antibiotic resistance. Administration of initially effective therapy is key to improving survival, reducing 30-day mortality threefold. Regrettably, due to the high frequency of this organism having an extreme drug resistance (XDR) phenotype, early initiation of effective therapy is a major clinical challenge. Given its high rate of antibiotic resistance and abysmal outcomes (up to 70% mortality rate from infections caused by XDR strains in some case series), new preventative and therapeutic options for Acinetobacter spp. are desperately needed.
Collapse
|
37
|
Kaye KS, Pogue JM, Tran TB, Nation RL, Li J. Agents of Last Resort: Polymyxin Resistance. Infect Dis Clin North Am 2017; 30:391-414. [PMID: 27208765 DOI: 10.1016/j.idc.2016.02.005] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Polymyxin resistance is a major public health threat, as the polymyxins represent "last-line" therapeutics for Gram-negative pathogens resistant to essentially all other antibiotics. Improved understanding of mechanisms of, and risk factors for, polymyxin resistance, as well as infection prevention and stewardship strategies, together with optimization of dosing of polymyxins including in combination regimens, can help to limit the emergence and dissemination of polymyxin resistance.
Collapse
Affiliation(s)
- Keith S Kaye
- Division of Infectious Diseases, Department of Medicine, Detroit Medical Center, Wayne State University, 3990 John R, Detroit, MI 48201, USA.
| | - Jason M Pogue
- Department of Pharmacy Services, Sinai-Grace Hospital, Detroit Medical Center, Wayne State University School of Medicine, Detroit, MI, USA
| | - Thien B Tran
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia
| | - Jian Li
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia
| |
Collapse
|
38
|
Wand ME, Bock LJ, Sutton JM. Retention of virulence following colistin adaptation in Klebsiella pneumoniae is strain-dependent rather than associated with specific mutations. J Med Microbiol 2017; 66:959-964. [PMID: 28741998 DOI: 10.1099/jmm.0.000530] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
This study aimed to understand the impact on virulence and fitness of mutations in specific genes found after adaptation of Klebsiella pneumoniae to colistin. Isolates with an increase in their inhibitory concentration (MIC) to colistin of 32- to >128-fold were shown to have mutations in mgrB, phoPQ and pmrAB, all known regulators of pathways affecting membrane lipid content. When these strains were used in studies in Galleria mellonella there was no clear correlation between mutations in specific genes per se and loss of virulence. Strains which showed sequence duplication in the HAMP-domain of PmrB showed reduced virulence but strains with point mutations in pmrAB showed no decrease in virulence. Similarly, specific mutations in mgrB in individual strains showed either loss of virulence or no effect/increased virulence. This study suggests that the impact on virulence may be independent of the colistin resistance mechanism and reflects differences in individual strain backgrounds.
Collapse
Affiliation(s)
- Matthew E Wand
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
| | - Lucy J Bock
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
| | - J Mark Sutton
- Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire, SP4 0JG, UK
| |
Collapse
|
39
|
Zhang Y, Liao K, Gao H, Wang Q, Wang X, Li H, Wang R, Wang H. Decreased Fitness and Virulence in ST10 Escherichia coli Harboring blaNDM-5 and mcr-1 against a ST4981 Strain with blaNDM-5. Front Cell Infect Microbiol 2017. [PMID: 28642846 PMCID: PMC5463033 DOI: 10.3389/fcimb.2017.00242] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Although coexistence of blaNDM-5 and mcr-1 in Escherichia coli has been reported, little is known about the fitness and virulence of such strains. Three carbapenem-resistant Escherichia coli (GZ1, GZ2, and GZ3) successively isolated from one patient in 2015 were investigated for microbiological fitness and virulence. GZ1 and GZ2 were also resistant to colistin. To verify the association between plasmids and fitness, growth kinetics of the transconjugants were performed. We also analyzed genomic sequences of GZ2 and GZ3 using PacBio sequencing. GZ1 and GZ2 (ST10) co-harbored blaNDM-5 and mcr-1, while GZ3 (ST4981) carried only blaNDM-5. GZ3 demonstrated significantly more rapid growth (P < 0.001) and overgrew GZ2 with a competitive index of 1.0157 (4 h) and 2.5207 (24 h). Increased resistance to serum killing and mice mortality was also identified in GZ3. While GZ2 had four plasmids (IncI2, IncX3, IncHI2, IncFII), GZ3 possessed one plasmid (IncFII). The genetic contexts of blaNDM-5 in GZ2 and GZ3 were identical but inserted into different backbones, IncX3 (102,512 bp) and IncFII (91,451 bp), respectively. The growth was not statistically different between the transconjugants with mcr-1 or blaNDM-5 plasmid and recipient (P = 0.6238). Whole genome sequence analysis revealed that 28 virulence genes were specific to GZ3, potentially contributing to increased virulence of GZ3. Decreased fitness and virulence in a mcr-1 and blaNDM-5 co-harboring ST10 E. coli was found alongside a ST4981 strain with only blaNDM-5. Acquisition of mcr-1 or blaNDM-5 plasmid did not lead to considerable fitness costs, indicating the potential for dissemination of mcr-1 and blaNDM-5 in Enterobacteriaceae.
Collapse
Affiliation(s)
- Yawei Zhang
- Department of Clinical Laboratory, Peking University People's HospitalBeijing, China
| | - Kang Liao
- Department of Clinical Laboratory, First Affiliated Hospital of Sun Yat-sen UniversityGuangzhou, China
| | - Hua Gao
- Department of Clinical Laboratory, Peking University People's HospitalBeijing, China
| | - Qi Wang
- Department of Clinical Laboratory, Peking University People's HospitalBeijing, China
| | - Xiaojuan Wang
- Department of Clinical Laboratory, Peking University People's HospitalBeijing, China
| | - Henan Li
- Department of Clinical Laboratory, Peking University People's HospitalBeijing, China
| | - Ruobing Wang
- Department of Clinical Laboratory, Peking University People's HospitalBeijing, China
| | - Hui Wang
- Department of Clinical Laboratory, Peking University People's HospitalBeijing, China
| |
Collapse
|
40
|
Geisinger E, Isberg RR. Interplay Between Antibiotic Resistance and Virulence During Disease Promoted by Multidrug-Resistant Bacteria. J Infect Dis 2017; 215:S9-S17. [PMID: 28375515 DOI: 10.1093/infdis/jiw402] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Diseases caused by antibiotic-resistant bacteria in hospitals are the outcome of complex relationships between several dynamic factors, including bacterial pathogenicity, the fitness costs of resistance in the human host, and selective forces resulting from interventions such as antibiotic therapy. The emergence and fate of mutations that drive antibiotic resistance are governed by these interactions. In this review, we will examine how different forms of antibiotic resistance modulate bacterial fitness and virulence potential, thus influencing the ability of pathogens to evolve in the context of nosocomial infections. We will focus on 3 important multidrug-resistant pathogens that are notoriously problematic in hospitals: Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus. An understanding of how antibiotic resistance mutations shape the pathobiology of multidrug-resistant infections has the potential to drive novel strategies that can control the development and spread of drug resistance.
Collapse
Affiliation(s)
- Edward Geisinger
- Howard Hughes Medical Institute, and.,Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts
| | - Ralph R Isberg
- Howard Hughes Medical Institute, and.,Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts
| |
Collapse
|
41
|
Turner D, Wand ME, Briers Y, Lavigne R, Sutton JM, Reynolds DM. Characterisation and genome sequence of the lytic Acinetobacter baumannii bacteriophage vB_AbaS_Loki. PLoS One 2017; 12:e0172303. [PMID: 28207864 PMCID: PMC5313236 DOI: 10.1371/journal.pone.0172303] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 02/02/2017] [Indexed: 01/17/2023] Open
Abstract
Acinetobacter baumannii has emerged as an important nosocomial pathogen in healthcare and community settings. While over 100 of Acinetobacter phages have been described in the literature, relatively few have been sequenced. This work describes the characterisation and genome annotation of a new lytic Acinetobacter siphovirus, vB_AbaS_Loki, isolated from activated sewage sludge. Sequencing revealed that Loki encapsulates a 41,308 bp genome, encoding 51 predicted open reading frames. Loki is most closely related to Acinetobacter phage IME_AB3 and more distantly related to Burkholderia phage KL1, Paracoccus phage vB_PmaS_IMEP1 and Pseudomonas phages vB_Pae_Kakheti25, vB_PaeS_SCH_Ab26 and PA73. Loki is characterised by a narrow host range, among the 40 Acinetobacter isolates tested, productive infection was only observed for the propagating host, A. baumannii ATCC 17978. Plaque formation was found to be dependent upon the presence of Ca2+ ions and adsorption to host cells was abolished upon incubation with a mutant of ATCC 17978 encoding a premature stop codon in lpxA. The complete genome sequence of vB_AbaS_Loki was deposited in the European Nucleotide Archive (ENA) under the accession number LN890663.
Collapse
Affiliation(s)
- Dann Turner
- Centre for Research in Biosciences, Department of Applied Sciences, Faculty of Health and Applied Sciences, University of the West of England, Coldharbour Lane, Bristol, United Kingdom
| | - Matthew E. Wand
- National Infections Service, Public Health England, Porton Down, Salisbury, Wiltshire, United Kingdom
| | - Yves Briers
- Laboratory of Applied Biotechnology, Department of Applied Biosciences, Ghent University, Ghent, Belgium
- Laboratory of Gene Technology, Biosystems Department, KU Leuven, Heverlee, Belgium
| | - Rob Lavigne
- Laboratory of Gene Technology, Biosystems Department, KU Leuven, Heverlee, Belgium
| | - J. Mark Sutton
- National Infections Service, Public Health England, Porton Down, Salisbury, Wiltshire, United Kingdom
| | - Darren M. Reynolds
- Centre for Research in Biosciences, Department of Applied Sciences, Faculty of Health and Applied Sciences, University of the West of England, Coldharbour Lane, Bristol, United Kingdom
| |
Collapse
|
42
|
Diversity of polymyxin resistance mechanisms among Acinetobacter baumannii clinical isolates. Diagn Microbiol Infect Dis 2017; 87:37-44. [DOI: 10.1016/j.diagmicrobio.2016.10.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/26/2016] [Accepted: 10/03/2016] [Indexed: 02/01/2023]
|
43
|
Mu X, Wang N, Li X, Shi K, Zhou Z, Yu Y, Hua X. The Effect of Colistin Resistance-Associated Mutations on the Fitness of Acinetobacter baumannii. Front Microbiol 2016; 7:1715. [PMID: 27847502 PMCID: PMC5088200 DOI: 10.3389/fmicb.2016.01715] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 10/13/2016] [Indexed: 01/27/2023] Open
Abstract
Acinetobacter baumannii had emerged as an important nosocomial and opportunistic pathogen worldwide. To assess the evolution of colistin resistance in A. baumannii and its effect on bacterial fitness, we exposed five independent colonies of A. baumannii ATCC 17978 to increasing concentrations of colistin in agar (4/5) and liquid media (1/5). Stable resistant isolates were analyzed using whole genome sequencing. All strains were colistin resistant after exposure to colistin. In addition to the previously reported lpxCAD and pmrAB mutations, we identified four novel putative colistin resistance genes: A1S_1983. hepA. A1S_3026, and rsfS. Lipopolysaccharide (LPS) loss mutants exhibited higher fitness costs than those of the pmrB mutant in nutrient-rich medium. The colistin-resistant mutants had a higher inhibition ratio in the serum growth experiment than that of the wild type strain in 100% serum. Minimum inhibitory concentration (MIC) results showed that the LPS-deficient but not the pmrB mutant had an altered antibiotic resistance profile. The compensatory mutations partially or completely rescued the LPS-deficient’s fitness, suggesting that compensatory mutations play an important role in the emergence and spread of colistin resistance in A. baumannii.
Collapse
Affiliation(s)
- Xinli Mu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University Hangzhou, China
| | - Nanfei Wang
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University Hangzhou, China
| | - Xi Li
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University Hangzhou, China
| | - Keren Shi
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University Hangzhou, China
| | - Zhihui Zhou
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University Hangzhou, China
| | - Yunsong Yu
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang UniversityHangzhou, China; State Key Laboratory for Diagnosis and Treatment of Infectious Disease, First Affiliated Hospital, College of Medicine, Zhejiang UniversityHangzhou, China
| | - Xiaoting Hua
- Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University Hangzhou, China
| |
Collapse
|
44
|
Faksri K, Tan JH, Disratthakit A, Xia E, Prammananan T, Suriyaphol P, Khor CC, Teo YY, Ong RTH, Chaiprasert A. Whole-Genome Sequencing Analysis of Serially Isolated Multi-Drug and Extensively Drug Resistant Mycobacterium tuberculosis from Thai Patients. PLoS One 2016; 11:e0160992. [PMID: 27518818 PMCID: PMC4982626 DOI: 10.1371/journal.pone.0160992] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 07/28/2016] [Indexed: 01/08/2023] Open
Abstract
Multi-drug and extensively drug-resistant tuberculosis (MDR and XDR-TB) are problems that threaten public health worldwide. Only some genetic markers associated with drug-resistant TB are known. Whole-genome sequencing (WGS) is a promising tool for distinguishing between re-infection and persistent infection in isolates taken at different times from a single patient, but has not yet been applied in MDR and XDR-TB. We aim to detect genetic markers associated with drug resistance and distinguish between reinfection and persistent infection from MDR and XDR-TB patients based on WGS analysis. Samples of Mycobacterium tuberculosis (n = 7), serially isolated from 2 MDR cases and 1 XDR-TB case, were retrieved from Siriraj Hospital, Bangkok. The WGS analysis used an Illumina Miseq sequencer. In cases of persistent infection, MDR-TB isolates differed at an average of 2 SNPs across the span of 2–9 months whereas in the case of reinfection, isolates differed at 61 SNPs across 2 years. Known genetic markers associated with resistance were detected from strains susceptible to streptomycin (2/7 isolates), p-aminosalicylic acid (3/7 isolates) and fluoroquinolone drugs. Among fluoroquinolone drugs, ofloxacin had the highest phenotype-genotype concordance (6/7 isolates), whereas gatifloxcain had the lowest (3/7 isolates). A putative candidate SNP in Rv2477c associated with kanamycin and amikacin resistance was suggested for further validation. WGS provided comprehensive results regarding molecular epidemiology, distinguishing between persistent infection and reinfection in M/XDR-TB and potentially can be used for detection of novel mutations associated with drug resistance.
Collapse
Affiliation(s)
- Kiatichai Faksri
- Department of Microbiology Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
- Research and Diagnostic Center for Emerging Infectious Diseases (RCEID), Khon Kaen University, Khon Kaen, Thailand
- * E-mail: (KF); (AC)
| | - Jun Hao Tan
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Areeya Disratthakit
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Eryu Xia
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore
| | - Therdsak Prammananan
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Ministry of Science and Technology, Pathum Thani, Thailand
| | - Prapat Suriyaphol
- Bioinformatics and Data Management for Research Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | - Yik-Ying Teo
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore
- Genome Institute of Singapore, Singapore
- Department of Statistics and Applied Probability, National University of Singapore, Singapore
- Life Sciences Institute, National University of Singapore, Singapore
| | - Rick Twee-Hee Ong
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Angkana Chaiprasert
- Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- * E-mail: (KF); (AC)
| |
Collapse
|
45
|
Baron S, Hadjadj L, Rolain JM, Olaitan AO. Molecular mechanisms of polymyxin resistance: knowns and unknowns. Int J Antimicrob Agents 2016; 48:583-591. [PMID: 27524102 DOI: 10.1016/j.ijantimicag.2016.06.023] [Citation(s) in RCA: 288] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/14/2016] [Accepted: 06/23/2016] [Indexed: 12/19/2022]
Abstract
Colistin, also referred to as polymyxin E, is an effective antibiotic against most multidrug-resistant Gram-negative bacteria and is currently used as a last-line drug for treating severe bacterial infections. Colistin resistance has increased gradually for the last few years, and knowledge of its multifaceted mechanisms is expanding. This includes the newly discovered plasmid-mediated colistin resistance gene mcr-1, which has been detected in over 20 countries within 3 months of its first report. We previously reported all of the known mechanisms of polymyxin resistance in our first review in 2014, but an update seems necessary in 2016, considering the significant recent discoveries that have been made in this domain. This review provides an update about what is already known, what is new, and some unresolved questions with respect to colistin resistance.
Collapse
Affiliation(s)
- Sophie Baron
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France
| | - Linda Hadjadj
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France
| | - Jean-Marc Rolain
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France.
| | - Abiola Olumuyiwa Olaitan
- Unité de recherche sur les maladies infectieuses et tropicales émergentes (URMITE), CNRS-IRD UMR 6236, Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille Université, Marseille, France.
| |
Collapse
|
46
|
The induction and identification of novel Colistin resistance mutations in Acinetobacter baumannii and their implications. Sci Rep 2016; 6:28291. [PMID: 27329501 PMCID: PMC4916428 DOI: 10.1038/srep28291] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 06/01/2016] [Indexed: 01/25/2023] Open
Abstract
Acinetobacter baumannii is a significant cause of opportunistic hospital acquired infection and has been identified as an important emerging infection due to its high levels of antimicrobial resistance. Multidrug resistant A. baumannii has risen rapidly in Vietnam, where colistin is becoming the drug of last resort for many infections. In this study we generated spontaneous colistin resistant progeny (up to >256 μg/μl) from four colistin susceptible Vietnamese isolates and one susceptible reference strain (MIC <1.5 μg/μl). Whole genome sequencing was used to identify single nucleotide mutations that could be attributed to the reduced colistin susceptibility. We identified six lpxACD and three pmrB mutations, the majority of which were novel. In addition, we identified further mutations in six A. baumannii genes (vacJ, pldA, ttg2C, pheS and conserved hypothetical protein) that we hypothesise have a role in reduced colistin susceptibility. This study has identified additional mutations that may be associated with colistin resistance through novel resistance mechanisms. Our work further demonstrates how rapidly A. baumannii can generate resistance to a last resort antimicrobial and highlights the need for improved surveillance to identified A. baumannii with an extensive drug resistance profile.
Collapse
|
47
|
Synergy between Colistin and the Signal Peptidase Inhibitor MD3 Is Dependent on the Mechanism of Colistin Resistance in Acinetobacter baumannii. Antimicrob Agents Chemother 2016; 60:4375-9. [PMID: 27139471 DOI: 10.1128/aac.00510-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 04/24/2016] [Indexed: 02/08/2023] Open
Abstract
Synergy between colistin and the signal peptidase inhibitor MD3 was tested against isogenic mutants and clinical pairs of Acinetobacter baumannii isolates. Checkerboard assays and growth curves showed synergy against both colistin-susceptible strains (fractional inhibitory concentration index [FICindex] = 0.13 to 0.24) and colistin-resistant strains with mutations in pmrB and phosphoethanolamine modification of lipid A (FICindex = 0.14 to 0.25) but not against colistin-resistant Δlpx strains with loss of lipopolysaccharide (FICindex = 0.75 to 1). A colistin/MD3 combination would need to be targeted to strains with specific colistin resistance mechanisms.
Collapse
|
48
|
Multiple Genetic Mutations Associated with Polymyxin Resistance in Acinetobacter baumannii. Antimicrob Agents Chemother 2015; 59:7899-902. [PMID: 26438500 DOI: 10.1128/aac.01884-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 09/30/2015] [Indexed: 11/20/2022] Open
Abstract
We studied polymyxin B resistance in 10 pairs of clinical Acinetobacter baumannii isolates, two of which had developed polymyxin B resistance in vivo. All polymyxin B-resistant isolates had lower growth rates than and substitution mutations in the lpx or pmrB gene compared to their parent isolates. There were significant differences in terms of antibiotic susceptibility and genetic determinants of resistance in A. baumannii isolates that had developed polymyxin B resistance in vivo compared to isolates that had developed polymyxin B resistance in vitro.
Collapse
|
49
|
Kilianski A, Nuzzo JB, Modjarrad K. Gain-of-Function Research and the Relevance to Clinical Practice. J Infect Dis 2015; 213:1364-9. [PMID: 26416657 PMCID: PMC7107371 DOI: 10.1093/infdis/jiv473] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 09/02/2015] [Indexed: 11/13/2022] Open
Abstract
The ongoing moratorium on gain-of-function (GOF) research with highly pathogenic avian influenza virus, severe acute respiratory syndrome coronavirus, and Middle East respiratory syndrome coronavirus has drawn attention to the current debate on these research practices and the potential benefits and risks they present. While much of the discussion has been steered by members of the microbiology and policy communities, additional input from medical practitioners will be highly valuable toward developing a broadly inclusive policy that considers the relative value and harm of GOF research. This review attempts to serve as a primer on the topic for the clinical community by providing a historical context for GOF research, summarizing concerns about its risks, and surveying the medical products that it has yielded.
Collapse
Affiliation(s)
- Andy Kilianski
- BioDefense Branch, Biosciences Division, Edgewood Chemical Biological Center, Aberdeen Proving Ground
| | - Jennifer B Nuzzo
- University of Pittsburgh Medical Center-Center for Health Security, Baltimore
| | - Kayvon Modjarrad
- US Military HIV Research Program, Walter Reed Army Institute for Research, Silver Spring, Maryland
| |
Collapse
|
50
|
Benthall G, Touzel RE, Hind CK, Titball RW, Sutton JM, Thomas RJ, Wand ME. Evaluation of antibiotic efficacy against infections caused by planktonic or biofilm cultures of Pseudomonas aeruginosa and Klebsiella pneumoniae in Galleria mellonella. Int J Antimicrob Agents 2015; 46:538-45. [PMID: 26364845 DOI: 10.1016/j.ijantimicag.2015.07.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 05/19/2015] [Accepted: 07/08/2015] [Indexed: 10/23/2022]
Abstract
The lack of novel antibiotics for more than a decade has placed increased pressure on existing therapies to combat the emergence of multidrug-resistant (MDR) bacterial pathogens. This study evaluated the Galleria mellonella insect model in determining the efficacy of available antibiotics against planktonic and biofilm infections of MDR Pseudomonas aeruginosa and Klebsiella pneumoniae strains in comparison with in vitro minimum inhibitory concentration (MIC) determination. In general, in vitro analysis agreed with the G. mellonella studies, and susceptibility in Galleria identified different drug resistance mechanisms. However, the carbapenems tested appeared to perform better in vivo than in vitro, with meropenem and imipenem able to clear K. pneumoniae and P. aeruginosa infections with strains that had bla(NDM-1) and bla(VIM) carbapenemases. This study also established an implant model in G. mellonella to allow testing of antibiotic efficacy against biofilm-derived infections. A reduction in antibiotic efficacy of amikacin against K. pneumoniae and P. aeruginosa biofilms was observed compared with a planktonic infection. Ciprofloxacin was found to be less effective at clearing a P. aeruginosa biofilm infection compared with a planktonic infection, but no statistical difference was seen between K. pneumoniae biofilm and planktonic infections treated with this antibiotic (P>0.05). This study provides important information regarding the suitability of Galleria as a model for antibiotic efficacy testing both against planktonic and biofilm-derived MDR infections.
Collapse
Affiliation(s)
- Gabriel Benthall
- Public Health England, Microbiology Services Division, Porton Down, Salisbury, Wiltshire SP4 0JG, UK; College of Life and Environmental Sciences, University of Exeter, Exeter, Devon EX4 4QD, UK
| | - Rebecca E Touzel
- Public Health England, Microbiology Services Division, Porton Down, Salisbury, Wiltshire SP4 0JG, UK
| | - Charlotte K Hind
- Public Health England, Microbiology Services Division, Porton Down, Salisbury, Wiltshire SP4 0JG, UK
| | - Richard W Titball
- College of Life and Environmental Sciences, University of Exeter, Exeter, Devon EX4 4QD, UK
| | - J Mark Sutton
- Public Health England, Microbiology Services Division, Porton Down, Salisbury, Wiltshire SP4 0JG, UK
| | - Rachael J Thomas
- College of Life and Environmental Sciences, University of Exeter, Exeter, Devon EX4 4QD, UK
| | - Matthew E Wand
- Public Health England, Microbiology Services Division, Porton Down, Salisbury, Wiltshire SP4 0JG, UK.
| |
Collapse
|