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Zhao Z, Yang T, Xiang G, Zhang S, Cai Y, Zhong G, Pu J, Shen C, Zeng J, Chen C, Huang B. A novel small RNA PhaS contributes to polymyxin B-heteroresistance in carbapenem-resistant Klebsiella pneumoniae. Emerg Microbes Infect 2024; 13:2366354. [PMID: 38979571 PMCID: PMC11238654 DOI: 10.1080/22221751.2024.2366354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Accepted: 06/05/2024] [Indexed: 07/10/2024]
Abstract
In recent years, polymyxin has been used as a last-resort therapy for carbapenem-resistant bacterial infections. The emergence of heteroresistance (HR) to polymyxin hampers the efficacy of polymyxin treatment by amplifying resistant subpopulation. However, the mechanisms behind polymyxin HR remain unclear. Small noncoding RNAs (sRNAs) play an important role in regulating drug resistance. The purpose of this study was to investigate the effects and mechanisms of sRNA on polymyxin B (PB)-HR in carbapenem-resistant Klebsiella pneumoniae. In this study, a novel sRNA PhaS was identified by transcriptome sequencing. PhaS expression was elevated in the PB heteroresistant subpopulation. Overexpression and deletion of PhaS were constructed in three carbapenem-resistant K. pneumoniae strains. Population analysis profiling, growth curve, and time-killing curve analysis showed that PhaS enhanced PB-HR. In addition, we verified that PhaS directly targeted phoP through the green fluorescent protein reporter system. PhaS promoted the expression of phoP, thereby encouraging the expression of downstream genes pmrD and arnT. This upregulation of arnT promoted the 4-amino-4-deoxyL-arabinosaccharide (L-Ara4N) modification of lipid A in PhaS overexpressing strains, thus enhancing PB-HR. Further, within the promoter region of PhaS, specific PhoP recognition sites were identified. ONPG assays and RT-qPCR analysis confirmed that PhaS expression was positively modulated by PhoP and thus up-regulated by PB stimulation. To sum up, a novel sRNA enhancing PB-HR was identified and a positive feedback regulatory pathway of sRNA-PhoP/Q was demonstrated in the study. This helps to provide a more comprehensive and clear understanding of the underlying mechanisms behind polymyxin HR in carbapenem-resistant K. pneumoniae.
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Affiliation(s)
- Zhiwei Zhao
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Tingting Yang
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Guoxiu Xiang
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Shebin Zhang
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, State Key Laboratory of Traditional Chinese Medicine Syndrome, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
- Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
| | - Yimei Cai
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, State Key Laboratory of Traditional Chinese Medicine Syndrome, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
- Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
| | - Guosheng Zhong
- Department of Clinical Laboratory, The Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Jieying Pu
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, State Key Laboratory of Traditional Chinese Medicine Syndrome, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
- Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
- Guangdong Provincial Key Laboratory of Research on Emergency in TCM, Guangzhou, People’s Republic of China
| | - Cong Shen
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, State Key Laboratory of Traditional Chinese Medicine Syndrome, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
- Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
- Guangdong Provincial Key Laboratory of Research on Emergency in TCM, Guangzhou, People’s Republic of China
| | - Jianming Zeng
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, State Key Laboratory of Traditional Chinese Medicine Syndrome, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
- Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
- Guangdong Provincial Key Laboratory of Research on Emergency in TCM, Guangzhou, People’s Republic of China
| | - Cha Chen
- The Second Clinical Medical College, Guangzhou University of Chinese Medicine, State Key Laboratory of Traditional Chinese Medicine Syndrome, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
- Department of Clinical Laboratory, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, People’s Republic of China
| | - Bin Huang
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, People’s Republic of China
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Guitart-Matas J, Sánchez-Osuna M, Saez JL, de Frutos C, Giler-Baquerizo N, Tort-Miró C, Pich OQ, Migura-Garcia L. Deciphering resistance mechanisms to tigecycline and colistin in Salmonella enterica isolates from animal production. Int J Antimicrob Agents 2024; 64:107208. [PMID: 38763453 DOI: 10.1016/j.ijantimicag.2024.107208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 05/03/2024] [Accepted: 05/11/2024] [Indexed: 05/21/2024]
Affiliation(s)
- Judith Guitart-Matas
- Joint Research Unit IRTA-UAB in Animal Health, Animal Health Research Centre (CReSA), Autonomous University of Barcelona (UAB), Catalonia, Spain; Institute of Agrifood Research and Technology (IRTA), Animal Health Program (CReSA), WOAH Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe, Autonomous University of Barcelona (UAB), Catalonia, Spain.
| | - Miquel Sánchez-Osuna
- Laboratori de Recerca en Microbiologia i Malalties Infeccioses, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain; Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Jose Luis Saez
- Área de Programas Sanitarios y Zoonosis, S.G. de Sanidad e Higiene Animal y Trazabilidad, Ministerio de Agricultura, Pesca y Alimentación, Madrid, Spain
| | - Cristina de Frutos
- Laboratorio Central de Veterinaria (LCV Algete), Ministerio de Agricultura, Pesca y Alimentación, Madrid, Spain
| | - Noemí Giler-Baquerizo
- Joint Research Unit IRTA-UAB in Animal Health, Animal Health Research Centre (CReSA), Autonomous University of Barcelona (UAB), Catalonia, Spain; Institute of Agrifood Research and Technology (IRTA), Animal Health Program (CReSA), WOAH Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe, Autonomous University of Barcelona (UAB), Catalonia, Spain
| | - Carla Tort-Miró
- Joint Research Unit IRTA-UAB in Animal Health, Animal Health Research Centre (CReSA), Autonomous University of Barcelona (UAB), Catalonia, Spain; Institute of Agrifood Research and Technology (IRTA), Animal Health Program (CReSA), WOAH Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe, Autonomous University of Barcelona (UAB), Catalonia, Spain
| | - Oscar Q Pich
- Laboratori de Recerca en Microbiologia i Malalties Infeccioses, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain; Institut de Biotecnologia i Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Lourdes Migura-Garcia
- Joint Research Unit IRTA-UAB in Animal Health, Animal Health Research Centre (CReSA), Autonomous University of Barcelona (UAB), Catalonia, Spain; Institute of Agrifood Research and Technology (IRTA), Animal Health Program (CReSA), WOAH Collaborating Centre for the Research and Control of Emerging and Re-Emerging Swine Diseases in Europe, Autonomous University of Barcelona (UAB), Catalonia, Spain
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Alousi S, Saad J, Panossian B, Makhlouf R, Khoury CA, Rahy K, Thoumi S, Araj GF, Khnayzer R, Tokajian S. Genetic and structural basis of colistin resistance in Klebsiella pneumoniae: Unravelling the molecular mechanisms. J Glob Antimicrob Resist 2024; 38:256-264. [PMID: 39029657 DOI: 10.1016/j.jgar.2024.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Revised: 05/28/2024] [Accepted: 06/23/2024] [Indexed: 07/21/2024] Open
Abstract
OBJECTIVE Antimicrobial resistance (AMR), together with multidrug resistance (MDR), mainly among Gram-negative bacteria, has been on the rise. Colistin (polymyxin E) remains one of the primary available last resorts to treat infections caused by MDR bacteria during the rapid emergence of global resistance. As the exact mechanism of bacterial resistance to colistin remains undetermined, this study warranted elucidation of the underlying mechanisms of colistin resistance and heteroresistance among carbapenem-resistant Klebsiella pneumoniae isolates. METHODS Molecular analysis was carried out on the resistant isolates using a genome-wide characterisation approach, as well as MALDI-TOF mass spectrometry, to identify lipid A. RESULTS Among the 32 carbapenem-resistant K. pneumoniae isolates, several isolates showed resistance and intermediate resistance to colistin. The seven isolates with intermediate resistance exhibited the "skip-well" phenomenon, attributed to the presence of resistant subpopulations. The three isolates with full resistance to colistin showed ions using MALDI-TOF mass spectrometry at m/z of 1840 and 1824 representing bisphosphorylated and hexa-acylated lipid A, respectively, with or without hydroxylation at position C'-2 of the fatty acyl chain. Studying the genetic environment of mgrB locus revealed the presence of two insertion sequences that disrupted the mgrB locus in the three colistin-resistant isolates: IS1R and IS903B. CONCLUSIONS Our findings show that colistin resistance/heteroresistance was inducible with mutations in chromosomal regulatory networks controlling the lipid A moiety and insertion sequences disrupting the mgrB gene, leading to elevated minimum inhibitory concentration values and treatment failure. Different treatment strategies should be employed to avoid colistin heteroresistance-linked treatment failures, mainly through combination therapy using colistin with carbapenems, aminoglycosides, or tigecycline.
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Affiliation(s)
- Sahar Alousi
- Lebanese American University, Department of Natural Sciences, Byblos, Lebanon
| | - Jamal Saad
- Lebanese University, Department of Sciences, Beirut, Lebanon
| | - Balig Panossian
- Lebanese American University, Department of Natural Sciences, Byblos, Lebanon
| | - Rita Makhlouf
- Lebanese American University, Department of Natural Sciences, Byblos, Lebanon
| | - Charbel Al Khoury
- Lebanese American University, Department of Natural Sciences, Byblos, Lebanon
| | - Kelven Rahy
- Lebanese American University, School of Medicine, Byblos, Lebanon
| | - Sergio Thoumi
- Lebanese American University, Department of Computer Science and Mathematics, Beirut, Lebanon
| | - George F Araj
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - Rony Khnayzer
- Lebanese American University, Department of Natural Sciences, Byblos, Lebanon.
| | - Sima Tokajian
- Lebanese American University, Department of Natural Sciences, Byblos, Lebanon.
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Lin JC, Kristopher Siu LK, Chang FY, Wang CH. Mutations in the pmrB gene constitute the major mechanism underlying chromosomally encoded colistin resistance in clinical Escherichia coli. J Glob Antimicrob Resist 2024; 38:275-280. [PMID: 38996871 DOI: 10.1016/j.jgar.2024.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 06/06/2024] [Accepted: 06/19/2024] [Indexed: 07/14/2024] Open
Abstract
OBJECTIVES The mechanisms underlying chromosomally encoded colistin resistance in Escherichia coli remain insufficiently investigated. In this study, we investigated the contribution of various pmrB mutations from E. coli clinical isolates to colistin resistance. METHODS The resistance mechanisms in eight mcr-negative colistin-resistant E. coli isolates obtained from a nationwide surveillance program in Taiwan using recombinant DNA techniques and complementary experiments were investigated. The minimal inhibitory concentrations (MICs) of colistin in the recombinant strains were compared with those in the parental strains. The expression levels of pmrA and pmrK (which are part of the pmrCAB and pmrHFIJKLM operons associated with colistin resistance) were measured using reverse transcription-quantitative real-time polymerase chain reaction. RESULTS In the complementation experiments, various mutated pmrB alleles from the eight mcr-negative colistin-resistant E. coli strains were introduced into an ATCC25922 mutant with a PmrB deletion, which resulted in colistin resistance. The MIC levels of colistin in the most complemented strains were comparable to those of the parental colistin-resistant strains. Increased expression levels of pmrA and pmrK were consistently detected in most complemented strains. The impact for colistin resistance was confirmed for various novel amino acid substitutions, P94L, G19E, L194P, L98R and R27L in PmrB from the parental clinical strains. The detected amino acid substitutions are distributed in the different functional domains of PmrB. CONCLUSIONS Colistin resistance mediated by amino acid substitutions in PmrB is a major chromosomally encoded mechanism in E. coli of clinical origin.
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Affiliation(s)
- Jung-Chung Lin
- Division of Infectious Diseases and Tropical Medicine, Department of Internal, Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Leung-Kei Kristopher Siu
- Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Feng-Yee Chang
- Division of Infectious Diseases and Tropical Medicine, Department of Internal, Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Ching-Hsun Wang
- Division of Infectious Diseases and Tropical Medicine, Department of Internal, Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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Diani E, Bianco G, Gatti M, Gibellini D, Gaibani P. Colistin: Lights and Shadows of an Older Antibiotic. Molecules 2024; 29:2969. [PMID: 38998921 PMCID: PMC11243602 DOI: 10.3390/molecules29132969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2024] [Revised: 06/17/2024] [Accepted: 06/20/2024] [Indexed: 07/14/2024] Open
Abstract
The emergence of antimicrobial resistance represents a serious threat to public health and for infections due to multidrug-resistant (MDR) microorganisms, representing one of the most important causes of death worldwide. The renewal of old antimicrobials, such as colistin, has been proposed as a valuable therapeutic alternative to the emergence of the MDR microorganisms. Although colistin is well known to present several adverse toxic effects, its usage in clinical practice has been reconsidered due to its broad spectrum of activity against Gram-negative (GN) bacteria and its important role of "last resort" agent against MDR-GN. Despite the revolutionary perspective of treatment with this old antimicrobial molecule, many questions remain open regarding the emergence of novel phenotypic traits of resistance and the optimal usage of the colistin in clinical practice. In last years, several forward steps have been made in the understanding of the resistance determinants, clinical usage, and pharmacological dosage of this molecule; however, different points regarding the role of colistin in clinical practice and the optimal pharmacokinetic/pharmacodynamic targets are not yet well defined. In this review, we summarize the mode of action, the emerging resistance determinants, and its optimal administration in the treatment of infections that are difficult to treat due to MDR Gram-negative bacteria.
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Affiliation(s)
- Erica Diani
- Department of Diagnostic and Public Health, Microbiology Section, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | - Gabriele Bianco
- Department of Experimental Medicine, University of Salento, 73100 Lecce, Italy
| | - Milo Gatti
- Department of Medical and Surgical Sciences, Alma Mater Studiorum, University of Bologna, 40126 Bologna, Italy
| | - Davide Gibellini
- Department of Diagnostic and Public Health, Microbiology Section, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
| | - Paolo Gaibani
- Department of Diagnostic and Public Health, Microbiology Section, University of Verona, Strada Le Grazie 8, 37134 Verona, Italy
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Yang S, Wang H, Zhao D, Zhang S, Hu C. Polymyxins: recent advances and challenges. Front Pharmacol 2024; 15:1424765. [PMID: 38974043 PMCID: PMC11224486 DOI: 10.3389/fphar.2024.1424765] [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: 04/28/2024] [Accepted: 06/04/2024] [Indexed: 07/09/2024] Open
Abstract
Antibiotic resistance is a pressing global health challenge, and polymyxins have emerged as the last line of defense against multidrug-resistant Gram-negative (MDR-GRN) bacterial infections. Despite the longstanding utility of colistin, the complexities surrounding polymyxins in terms of resistance mechanisms and pharmacological properties warrant critical attention. This review consolidates current literature, focusing on polymyxins antibacterial mechanisms, resistance pathways, and innovative strategies to mitigate resistance. We are also investigating the pharmacokinetics of polymyxins to elucidate factors that influence their in vivo behavior. A comprehensive understanding of these aspects is pivotal for developing next-generation antimicrobials and optimizing therapeutic regimens. We underscore the urgent need for advancing research on polymyxins to ensure their continued efficacy against formidable bacterial challenges.
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Affiliation(s)
- Shan Yang
- Department of Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Hairui Wang
- Institute of Respiratory Health, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Dan Zhao
- Department of Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Shurong Zhang
- Department of Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Chenggong Hu
- Department of Critical Care Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
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Sarker S, Neeloy RM, Habib MB, Urmi UL, Al Asad M, Mosaddek ASM, Khan MRK, Nahar S, Godman B, Islam S. Mobile Colistin-Resistant Genes mcr-1, mcr-2, and mcr-3 Identified in Diarrheal Pathogens among Infants, Children, and Adults in Bangladesh: Implications for the Future. Antibiotics (Basel) 2024; 13:534. [PMID: 38927200 PMCID: PMC11200974 DOI: 10.3390/antibiotics13060534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/27/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
Colistin is a last-resort antimicrobial for treating multidrug-resistant Gram-negative bacteria. Phenotypic colistin resistance is highly associated with plasmid-mediated mobile colistin resistance (mcr) genes. mcr-bearing Enterobacteriaceae have been detected in many countries, with the emergence of colistin-resistant pathogens a global concern. This study assessed the distribution of mcr-1, mcr-2, mcr-3, mcr-4, and mcr-5 genes with phenotypic colistin resistance in isolates from diarrheal infants and children in Bangladesh. Bacteria were identified using the API-20E biochemical panel and 16s rDNA gene sequencing. Polymerase chain reactions detected mcr gene variants in the isolates. Their susceptibilities to colistin were determined by agar dilution and E-test by minimal inhibitory concentration (MIC) measurements. Over 31.6% (71/225) of isolates showed colistin resistance according to agar dilution assessment (MIC > 2 μg/mL). Overall, 15.5% of isolates carried mcr genes (7, mcr-1; 17, mcr-2; 13, and mcr-3, with co-occurrence occurring in two isolates). Clinical breakout MIC values (≥4 μg/mL) were associated with 91.3% of mcr-positive isolates. The mcr-positive pathogens included twenty Escherichia spp., five Shigella flexneri, five Citrobacter spp., two Klebsiella pneumoniae, and three Pseudomonas parafulva. The mcr-genes appeared to be significantly associated with phenotypic colistin resistance phenomena (p = 0.000), with 100% colistin-resistant isolates showing MDR phenomena. The age and sex of patients showed no significant association with detected mcr variants. Overall, mcr-associated colistin-resistant bacteria have emerged in Bangladesh, which warrants further research to determine their spread and instigate activities to reduce resistance.
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Affiliation(s)
- Shafiuzzaman Sarker
- Department of Microbiology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh; (S.S.); (R.M.N.); (M.B.H.); (U.L.U.); (M.A.A.); (S.N.)
| | - Reeashat Muhit Neeloy
- Department of Microbiology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh; (S.S.); (R.M.N.); (M.B.H.); (U.L.U.); (M.A.A.); (S.N.)
| | - Marnusa Binte Habib
- Department of Microbiology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh; (S.S.); (R.M.N.); (M.B.H.); (U.L.U.); (M.A.A.); (S.N.)
| | - Umme Laila Urmi
- Department of Microbiology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh; (S.S.); (R.M.N.); (M.B.H.); (U.L.U.); (M.A.A.); (S.N.)
- School of Optometry and Vision Science, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Mamun Al Asad
- Department of Microbiology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh; (S.S.); (R.M.N.); (M.B.H.); (U.L.U.); (M.A.A.); (S.N.)
| | | | | | - Shamsun Nahar
- Department of Microbiology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh; (S.S.); (R.M.N.); (M.B.H.); (U.L.U.); (M.A.A.); (S.N.)
| | - Brian Godman
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, UK;
- Division of Public Health Pharmacy and Management, School of Pharmacy, Sefako Makgatho Health Sciences University, Pretoria 0204, South Africa
| | - Salequl Islam
- Department of Microbiology, Jahangirnagar University, Savar, Dhaka 1342, Bangladesh; (S.S.); (R.M.N.); (M.B.H.); (U.L.U.); (M.A.A.); (S.N.)
- School of Optometry and Vision Science, UNSW Sydney, Sydney, NSW 2052, Australia
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Levin BR, Berryhill BA, Gil-Gil T, Manuel JA, Smith AP, Choby JE, Andersson DI, Weiss DS, Baquero F. Theoretical considerations and empirical predictions of the pharmaco- and population dynamics of heteroresistance. Proc Natl Acad Sci U S A 2024; 121:e2318600121. [PMID: 38588431 PMCID: PMC11032463 DOI: 10.1073/pnas.2318600121] [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: 10/24/2023] [Accepted: 02/28/2024] [Indexed: 04/10/2024] Open
Abstract
Antibiotics are considered one of the most important contributions to clinical medicine in the last century. Due to the use and overuse of these drugs, there have been increasing frequencies of infections with resistant pathogens. One form of resistance, heteroresistance, is particularly problematic; pathogens appear sensitive to a drug by common susceptibility tests. However, upon exposure to the antibiotic, resistance rapidly ascends, and treatment fails. To quantitatively explore the processes contributing to the emergence and ascent of resistance during treatment and the waning of resistance following cessation of treatment, we develop two distinct mathematical and computer-simulation models of heteroresistance. In our analysis of the properties of these models, we consider the factors that determine the response to antibiotic-mediated selection. In one model, heteroresistance is progressive, with each resistant state sequentially generating a higher resistance level. In the other model, heteroresistance is non-progressive, with a susceptible population directly generating populations with different resistance levels. The conditions where resistance will ascend in the progressive model are narrower than those of the non-progressive model. The rates of reversion from the resistant to the sensitive states are critically dependent on the transition rates and the fitness cost of resistance. Our results demonstrate that the standard test used to identify heteroresistance is insufficient. The predictions of our models are consistent with empirical results. Our results demand a reevaluation of the definition and criteria employed to identify heteroresistance. We recommend that the definition of heteroresistance should include a consideration of the rate of return to susceptibility.
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Affiliation(s)
- Bruce R. Levin
- Department of Biology, Emory University, Atlanta, GA30322
- Emory Antibiotic Resistance Center, Atlanta, GA30322
| | - Brandon A. Berryhill
- Department of Biology, Emory University, Atlanta, GA30322
- Program in Microbiology and Molecular Genetics, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, GA30322
| | - Teresa Gil-Gil
- Department of Biology, Emory University, Atlanta, GA30322
| | | | | | - Jacob E. Choby
- Emory Antibiotic Resistance Center, Atlanta, GA30322
- Emory Vaccine Center, Atlanta, GA30322
| | - Dan I. Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, UppsalaSE-75123, Sweden
| | - David S. Weiss
- Emory Antibiotic Resistance Center, Atlanta, GA30322
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA30322
- Georgia Emerging Infections Program, Georgia Department of Public Health, Atlanta, GA30322
| | - Fernando Baquero
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, and Centro de Investigación Biomédica en Red Epidemiología y Salud Pública, Madrid28034, Spain
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Wang CH, Siu LK, Chang FY, Tsai YK, Huang LY, Lin JC. Influence of PhoPQ and PmrAB two component system alternations on colistin resistance from non-mcr colistin resistant clinical E. Coli strains. BMC Microbiol 2024; 24:109. [PMID: 38565985 PMCID: PMC10986093 DOI: 10.1186/s12866-024-03259-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/14/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND The current understanding of acquired chromosomal colistin resistance mechanisms in Enterobacterales primarily involves the disruption of the upstream PmrAB and PhoPQ two-component system (TCS) control caused by mutations in the regulatory genes. Interestingly, previous studies have yielded conflicting results regarding the interaction of regulatory genes related to colistin resistance in Escherichia coli, specifically those surrounding PhoPQ and PmrAB TCS. RESULTS In our study, we focused on two clinical non-mcr colistin-resistant strains of E. coli, TSAREC02 and TSAREC03, to gain a better understanding of their resistance mechanisms. Upon analysis, we discovered that TSAREC02 had a deletion (Δ27-45) in MgrB, as well as substitutions (G206R, Y222H) in PmrB. On the other hand, TSAREC03 exhibited a long deletion (Δ84-224) in PhoP, along with substitutions (M1I, L14P, P178S, T235N) in PmrB. We employed recombinant DNA techniques to explore the interaction between the PhoPQ and PmrAB two-component systems (TCSs) and examine the impact of the mutated phoPQ and pmrB genes on the minimum inhibitory concentrations (MICs) of colistin. We observed significant changes in the expression of the pmrD gene, which encodes a connector protein regulated by the PhoPQ TCS, in the TSAREC02 wild-type (WT)-mgrB replacement mutant and the TSAREC03 WT-phoP replacement mutant, compared to their respective parental strains. However, the expressions of pmrB/pmrA, which reflect PmrAB TCS activity, and the colistin MICs remained unchanged. In contrast, the colistin MICs and pmrB/pmrA expression levels were significantly reduced in the pmrB deletion mutants from both TSAREC02 and TSAREC03, compared to their parental strains. Moreover, we were able to restore colistin resistance and the expressions of pmrB/pmrA by transforming a plasmid containing the parental mutated pmrB back into the TSAREC02 and TSAREC03 mutants, respectively. CONCLUSION While additional data from clinical E. coli isolates are necessary to validate whether our findings could be broadly applied to the E. coli population, our study illuminates distinct regulatory pathway interactions involving colistin resistance in E. coli compared to other species of Enterobacterales. The added information provided by our study contribute to a deeper understanding of the complex pathway interactions within Enterobacterales.
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Affiliation(s)
- Ching-Hsun Wang
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Section 2, Cheng-Kung Road, Neihu 114, Taipei, Taiwan
| | - L Kristopher Siu
- Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Feng-Yee Chang
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Section 2, Cheng-Kung Road, Neihu 114, Taipei, Taiwan
| | - Yu-Kuo Tsai
- Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Li-Yueh Huang
- Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli, Taiwan
| | - Jung-Chung Lin
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Section 2, Cheng-Kung Road, Neihu 114, Taipei, Taiwan.
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10
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Sánchez-León I, Pérez-Nadales E, Marín-Sanz JA, García-Martínez T, Martínez-Martínez L. Heteroresistance to colistin in wild-type Klebsiella pneumoniae isolates from clinical origin. Microbiol Spectr 2023; 11:e0223823. [PMID: 37962370 PMCID: PMC10714954 DOI: 10.1128/spectrum.02238-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 10/13/2023] [Indexed: 11/15/2023] Open
Abstract
IMPORTANCE Colistin is one of the last remaining therapeutic options for dealing with Enterobacteriaceae. Unfortunately, heteroresistance to colistin is also rapidly increasing. We described the prevalence of colistin heteroresistance in a variety of wild-type strains of Klebsiella pneumoniae and the evolution of these strains with colistin heteroresistance to a resistant phenotype after colistin exposure and withdrawal. Resistant mutants were characterized at the molecular level, and numerous mutations in genes related to lipopolysaccharide formation were observed. In colistin-treated patients, the evolution of K. pneumoniae heteroresistance to resistance phenotype could lead to higher rates of therapeutic failure.
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Affiliation(s)
- Irene Sánchez-León
- Maimonides Biomedical Research Institute of Cordoba, Cordoba, Spain
- Department of Agricultural Chemistry, Edaphology and Microbiology, University of Cordoba, Cordoba, Spain
| | - Elena Pérez-Nadales
- Maimonides Biomedical Research Institute of Cordoba, Cordoba, Spain
- Department of Agricultural Chemistry, Edaphology and Microbiology, University of Cordoba, Cordoba, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Juan Antonio Marín-Sanz
- Maimonides Biomedical Research Institute of Cordoba, Cordoba, Spain
- Department of Computer Sciences, University of Cordoba, Cordoba, Spain
| | - Teresa García-Martínez
- Department of Agricultural Chemistry, Edaphology and Microbiology, University of Cordoba, Cordoba, Spain
| | - Luis Martínez-Martínez
- Maimonides Biomedical Research Institute of Cordoba, Cordoba, Spain
- Department of Agricultural Chemistry, Edaphology and Microbiology, University of Cordoba, Cordoba, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- Clinical Unit of Microbiology, Reina Sofía University Hospital, Cordoba, Spain
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11
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Levin BR, Berryhill BA, Gil-Gil T, Manuel JA, Smith AP, Choby JE, Andersson DI, Weiss DS, Baquero F. Theoretical Considerations and Empirical Predictions of the Pharmaco- and Population Dynamics of Heteroresistance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.21.558832. [PMID: 37790545 PMCID: PMC10542493 DOI: 10.1101/2023.09.21.558832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Antibiotics are considered one of the most important contributions to clinical medicine in the last 100 years. Due to the use and overuse of these drugs, there have been increasing frequencies of infections with resistant pathogens. One form of resistance, heteroresistance, is particularly problematic; pathogens appear sensitive to a drug by common susceptibility tests. However, upon exposure to the antibiotic, resistance rapidly ascends, and treatment fails. To quantitatively explore the processes contributing to the emergence and ascent of resistance during treatment and the waning of resistance following cessation of treatment, we develop two distinct mathematical and computer-simulations models of heteroresistance. In our analysis of the properties of these models, we consider the factors that determine the response to antibiotic-mediated selection. In one model, heteroresistance is progressive, with each resistant state sequentially generating a higher resistance level. In the other model, heteroresistance is non-progressive, with a susceptible population directly generating populations with different resistance levels. The conditions where resistance will ascend in the progressive model are narrower than those of the non-progressive model. The rates of reversion from the resistant to the sensitive states are critically dependent on the transition rates and the fitness cost of resistance. Our results demonstrate that the standard test used to identify heteroresistance is insufficient. The predictions of our models are consistent with empirical results. Our results demand a reevaluation of the definition and criteria employed to identify heteroresistance. We recommend the definition of heteroresistance should include a consideration of the rate of return to susceptibility.
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Affiliation(s)
- Bruce R. Levin
- Department of Biology, Emory University; Atlanta, Georgia, 30322, USA
- Emory Antibiotic Resistance Center; Atlanta, Georgia, 30322, USA
| | - Brandon A. Berryhill
- Department of Biology, Emory University; Atlanta, Georgia, 30322, USA
- Program in Microbiology and Molecular Genetics, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University; Atlanta, GA, 30322, USA
| | - Teresa Gil-Gil
- Department of Biology, Emory University; Atlanta, Georgia, 30322, USA
| | - Joshua A. Manuel
- Department of Biology, Emory University; Atlanta, Georgia, 30322, USA
| | - Andrew P. Smith
- Department of Biology, Emory University; Atlanta, Georgia, 30322, USA
| | - Jacob E. Choby
- Emory Antibiotic Resistance Center; Atlanta, Georgia, 30322, USA
- Emory Vaccine Center; Atlanta, Georgia, 30322, USA
| | - Dan I. Andersson
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, SE-75123, Sweden
| | - David S. Weiss
- Emory Antibiotic Resistance Center; Atlanta, Georgia, 30322, USA
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine; Atlanta, GA, 30322, USA
- Georgia Emerging Infections Program, Georgia Department of Public Health; Atlanta, GA, 30322, USA
| | - Fernando Baquero
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal, Instituto Ramón y Cajal de Investigación Sanitaria, and Centro de Investigación Médica en Red, Epidemiología y Salud Pública (CIBERESP) Madrid, Spain
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12
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Muñoz-Escudero D, Breazeale SD, Lee M, Guan Z, Raetz CRH, Sousa MC. Structure and Function of ArnD. A Deformylase Essential for Lipid A Modification with 4-Amino-4-deoxy-l-arabinose and Polymyxin Resistance. Biochemistry 2023; 62:2970-2981. [PMID: 37782650 PMCID: PMC10914315 DOI: 10.1021/acs.biochem.3c00293] [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] [Indexed: 10/04/2023]
Abstract
Covalent modification of lipid A with 4-deoxy-4-amino-l-arabinose (Ara4N) mediates resistance to cationic antimicrobial peptides and polymyxin antibiotics in Gram-negative bacteria. The proteins required for Ara4N biosynthesis are encoded in the pmrE and arnBCADTEF loci, with ArnT ultimately transferring the amino sugar from undecaprenyl-phospho-4-deoxy-4-amino-l-arabinose (C55P-Ara4N) to lipid A. However, Ara4N is N-formylated prior to its transfer to undecaprenyl-phosphate by ArnC, requiring a deformylase activity downstream in the pathway to generate the final C55P-Ara4N donor. Here, we show that deletion of the arnD gene in an Escherichia coli mutant that constitutively expresses the arnBCADTEF operon leads to accumulation of the formylated ArnC product undecaprenyl-phospho-4-deoxy-4-formamido-l-arabinose (C55P-Ara4FN), suggesting that ArnD is the downstream deformylase. Purification of Salmonella typhimurium ArnD (stArnD) shows that it is membrane-associated. We present the crystal structure of stArnD revealing a NodB homology domain structure characteristic of the metal-dependent carbohydrate esterase family 4 (CE4). However, ArnD displays several distinct features: a 44 amino acid insertion, a C-terminal extension in the NodB fold, and sequence divergence in the five motifs that define the CE4 family, suggesting that ArnD represents a new family of carbohydrate esterases. The insertion is responsible for membrane association as its deletion results in a soluble ArnD variant. The active site retains a metal coordination H-H-D triad, and in the presence of Co2+ or Mn2+, purified stArnD efficiently deformylates C55P-Ara4FN confirming its role in Ara4N biosynthesis. Mutations D9N and H233Y completely inactivate stArnD implicating these two residues in a metal-assisted acid-base catalytic mechanism.
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Affiliation(s)
- Daniel Muñoz-Escudero
- Department of Molecular Cellular and Developmental Biology, University of Colorado Boulder, Boulder, CO 80309
| | - Steven D. Breazeale
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710
| | - Myeongseon Lee
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309
| | - Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC 27710
| | | | - Marcelo C. Sousa
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309
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13
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Riquelme MP, Martinez RW, Brito B, García P, Legarraga P, Wozniak A. Chromosome-Mediated Colistin Resistance in Clinical Isolates of Klebsiella pneumoniae and Escherichia coli: Mutation Analysis in the Light of Genetic Background. Infect Drug Resist 2023; 16:6451-6462. [PMID: 37789836 PMCID: PMC10544214 DOI: 10.2147/idr.s427398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 08/10/2023] [Indexed: 10/05/2023] Open
Abstract
Purpose Colistin resistance mechanisms involving mutations in chromosomal genes associated with LPS modification are not completely understood. Mutations in genes coding for the MgrB regulator frequently account for colistin resistance in Klebsiella pneumoniae, whereas mutations in genes coding for PhoPQ and PmrAB are frequent in E. coli. Our aim was to perform a genetic analysis of chromosomal mutations in colistin-resistant (MIC ≥4 µg/mL) clinical isolates of K. pneumoniae (n = 8) and E. coli (n = 7) of different STs. Methods Isolates were obtained in a 3-year period in a university hospital in Santiago, Chile. Susceptibility to colistin, aminoglycosides, cephalosporins, carbapenems and ciprofloxacin was determined through broth microdilution. Whole genome sequencing was performed for all isolates and chromosomal gene sequences were compared with sequences of colistin-susceptible isolates of the same sequence types. Results None of the isolates carried mcr genes. Most of the isolates were susceptible to all the antibiotics analyzed. E. coli isolates were ST69, ST127, ST59, ST131 and ST14, and K. pneumoniae isolates were ST454, ST45, ST6293, ST380 and ST25. All the isolates had mutations in chromosomal genes analyzed. K. pneumoniae had mutations mainly in mgrB gene, whereas E. coli had mutations in pmrA, pmrB and pmrE genes. Most of the amino acid changes in LPS-modifying enzymes of colistin-resistant isolates were found in colistin-susceptible isolates of the same and/or different ST. Eleven of them were found only in colistin-resistant isolates. Conclusion Colistin resistance mechanisms depend on genetic background, and are due to chromosomal mutations, which implies a lower risk of transmission than plasmid-mediated genes. Colistin resistance is not associated with multidrug-resistance, nor to high-risk sequence types.
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Affiliation(s)
- María Paz Riquelme
- Department of Clinical Laboratories - School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Rodrigo W Martinez
- Genomics & Resistant Microbes Group (Germ) - Instituto de Ciencias e Innovación en Medicina (ICIM); School of Medicine-Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
- Millennium Nucleus for Collaborative Research on Bacterial Resistance (MICROB-R), SantiagoChile
| | - Bárbara Brito
- Australian Institute for Microbiology & Infection - Faculty of Science, University of Technology Sydney, Sydney, Australia
| | - Patricia García
- Department of Clinical Laboratories - School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Nucleus for Collaborative Research on Bacterial Resistance (MICROB-R), SantiagoChile
- Clinical Laboratories Network, Red de Salud UC-CHRISTUS, Santiago, Chile
| | - Paulette Legarraga
- Department of Clinical Laboratories - School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Clinical Laboratories Network, Red de Salud UC-CHRISTUS, Santiago, Chile
| | - Aniela Wozniak
- Department of Clinical Laboratories - School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
- Millennium Nucleus for Collaborative Research on Bacterial Resistance (MICROB-R), SantiagoChile
- Clinical Laboratories Network, Red de Salud UC-CHRISTUS, Santiago, Chile
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14
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AL-Muzahmi M, Rizvi M, AL-Quraini M, AL-Muharrmi Z, AL-Jabri Z. Comparative Genomic Analysis Reveals the Emergence of ST-231 and ST-395 Klebsiella pneumoniae Strains Associated with the High Transmissibility of blaKPC Plasmids. Microorganisms 2023; 11:2411. [PMID: 37894068 PMCID: PMC10608898 DOI: 10.3390/microorganisms11102411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 09/21/2023] [Accepted: 09/23/2023] [Indexed: 10/29/2023] Open
Abstract
Conjugative transposons in Gram-negative bacteria have a significant role in the dissemination of antibiotic-resistance-conferring genes between bacteria. This study aims to genomically characterize plasmids and conjugative transposons carrying integrons in clinical isolates of Klebsiella pneumoniae. The genetic composition of conjugative transposons and phenotypic assessment of 50 multidrug-resistant K. pneumoniae isolates from a tertiary-care hospital (SQUH), Muscat, Oman, were investigated. Horizontal transferability was investigated by filter mating conjugation experiments. Whole-genome sequencing (WGS) was performed to determine the sequence type (ST), acquired resistome, and plasmidome of integron-carrying strains. Class 1 integrons were detected in 96% of isolates and, among integron-positive isolates, 18 stains contained variable regions. Horizontal transferability by conjugation confirmed the successful transfer of integrons between cells and WGS confirmed their presence in conjugative plasmids. Dihydrofolate reductase (dfrA14) was the most prevalent (34.8%) gene cassette in class 1 integrons. MLST analysis detected predominantly ST-231 and ST-395. BlaOXA-232 and blaCTX-M-15 were the most frequently detected carbapenemases and beta-lactamases in the sequenced isolates. This study highlighted the high transmissibility of MDR-conferring conjugative plasmids in clinical isolates of K. pneumoniae. Therefore, the wise use of antibiotics and the adherence to effective infection control measures are necessary to limit the further dissemination of multidrug-resistant bacteria.
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Affiliation(s)
| | - Meher Rizvi
- Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat 123, Oman;
| | - Munawr AL-Quraini
- Microbiology and Immunology Diagnostic Laboratory, Department of Microbiology and Immunology, Sultan Qaboos University Hospital, Muscat 123, Oman; (M.A.-Q.); (Z.A.-M.)
| | - Zakariya AL-Muharrmi
- Microbiology and Immunology Diagnostic Laboratory, Department of Microbiology and Immunology, Sultan Qaboos University Hospital, Muscat 123, Oman; (M.A.-Q.); (Z.A.-M.)
| | - Zaaima AL-Jabri
- Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat 123, Oman;
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15
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Weng Y, Wang T, Huang B, Yu H, Jia W, Shan B, Qu F, Tang Y, Chen L, Du H. Multicenter Study of Colistin Heteroresistance in Carbapenem-Resistant Klebsiella pneumoniae Strains in China. Microbiol Spectr 2023; 11:e0221822. [PMID: 37428093 PMCID: PMC10434274 DOI: 10.1128/spectrum.02218-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 06/23/2023] [Indexed: 07/11/2023] Open
Abstract
Colistin has been considered a last-line option for the treatment of infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP). Heterogeneous resistance to colistin leads to unexplained clinical colistin treatment failure for CRKP. Our study aimed to investigate the extent of colistin heteroresistance among CRKP strains in China. A total of 455 colistin-susceptible strains, collected from six tertiary care hospitals in China, were characterized. The overall rate of colistin heteroresistance was 6.2%, as determined by the population analysis profiles (PAPs). Genomic analysis revealed that 60.7% of the colistin-heteroresistant isolates belonged to the epidemic sequence type 11 (ST11) clone. Single-nucleotide polymorphisms (SNPs) suggested that 6 ST5216 strains shared the same origin. Each of the subpopulations had a ≥8-fold decrease in colistin MIC in the presence of carbonyl cyanide m-chlorophenylhydrazone (CCCP), which indicated that heteroresistance could be suppressed by an efflux pump inhibitor. In addition, our results suggested that the PhoPQ pathway plays an important role in the mechanisms of heteroresistance. IMPORTANCE The problem of CRKP has raised alarms concerning global health. Our study enriches the epidemiological study of colistin heteroresistance among CRKP strains in China, where the prevalence of this phenomenon was previously unknown. Importantly, colistin-heteroresistant strains may cause the failure of clinical treatment with colistin, even if the clinical laboratory reports that the strains are sensitive. The commonly used broth microdilution method is unable to detect this special phenomenon. Additionally, our results indicate that efflux pumps play a major role in colistin heteroresistance, and inhibitors can effectively reverse it. Our study is the first to provide a detailed analysis of the prevalence of colistin heteroresistance in China, as well as an analysis of the genetic mechanisms of this phenomenon.
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Affiliation(s)
- Yuesong Weng
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
- Department of Clinical Laboratory, The Affiliated Peoples' Hospital of Ningbo University, Ningbo, Zhejiang, China
- Department of Laboratory Medicine, Ningbo First Hospital, Ningbo, Zhejiang, China
| | - Tao Wang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
- Center of Clinical Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
| | - Bin Huang
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Hua Yu
- Sichuan Academy of Medical Science and Sichuan Provincial People’s Hospital, Chengdu, Sichuan, China
| | - Wei Jia
- Center of Medical Laboratory, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Bin Shan
- Department of Laboratory Medicine, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Fen Qu
- Laboratory Medicine Center, Aviation General Hospital, Beijing, China
| | - Yiwei Tang
- Department of Medical Affairs, Danaher Diagnostic Platform/Cepheid (China), New York, New York, USA
| | - Liang Chen
- Hackensack Meridian Health Center for Discovery and Innovation, Nutley, New Jersey, USA
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, New Jersey, USA
| | - Hong Du
- Department of Clinical Laboratory, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
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16
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Mitchell ME, Gatzeva-Topalova PZ, Bargmann AD, Sammakia T, Sousa MC. Targeting the Conformational Change in ArnA Dehydrogenase for Selective Inhibition of Polymyxin Resistance. Biochemistry 2023; 62:2216-2227. [PMID: 37410993 PMCID: PMC10914316 DOI: 10.1021/acs.biochem.3c00227] [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] [Indexed: 07/08/2023]
Abstract
Polymyxins are important last resort antibiotics for the treatment of infections caused by multidrug-resistant Gram-negative pathogens. However, pathogens have acquired resistance to polymyxins through a pathway that modifies lipid A with 4-amino-4-deoxy-l-arabinose (Ara4N). Inhibition of this pathway is, therefore, a desirable strategy to combat polymyxin resistance. The first pathway-specific reaction is an NAD+-dependent oxidative decarboxylation of UDP-glucuronic acid (UDP-GlcA) catalyzed by the dehydrogenase domain of ArnA (ArnA_DH). We present the crystal structure of Salmonella enterica serovar typhimurium ArnA in complex with UDP-GlcA showing that binding of the sugar nucleotide is sufficient to trigger a conformational change conserved in bacterial ArnA_DHs but absent in its human homologs, as confirmed by structure and sequence analysis. Ligand binding assays show that the conformational change is essential for NAD+ binding and catalysis. Enzyme activity and binding assays show that (i) UDP-GlcA analogs lacking the 6' carboxylic acid bind the enzyme but fail to trigger the conformational change, resulting in poor inhibition, and (ii) the uridine monophosphate moiety of the substrate provides most of the ligand binding energy. Mutation of asparagine 492 to alanine (N492A) disrupts the ability of ArnA_DH to undergo the conformational change while retaining substrate binding, suggesting that N492 is involved in sensing the 6' carboxylate in the substrate. These results identify the UDP-GlcA-induced conformational change in ArnA_DH as an essential mechanistic step in bacterial enzymes, providing a platform for selective inhibition.
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Affiliation(s)
- Megan E. Mitchell
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309
| | | | - Austin D. Bargmann
- Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309
| | - Tarek Sammakia
- Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309
| | - Marcelo C. Sousa
- Department of Biochemistry, University of Colorado Boulder, Boulder, CO 80309
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17
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Li L, Ma J, Cheng P, Li M, Yu Z, Song X, Yu Z, Sun H, Zhang W, Wang Z. Roles of two-component regulatory systems in Klebsiella pneumoniae: Regulation of virulence, antibiotic resistance, and stress responses. Microbiol Res 2023; 272:127374. [PMID: 37031567 DOI: 10.1016/j.micres.2023.127374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 04/04/2023] [Accepted: 04/04/2023] [Indexed: 04/09/2023]
Abstract
Klebsiella pneumoniae is an opportunistic pathogen belonging to the Enterobacteriaceae family, which is the leading cause of nosocomial infections. The emergence of hypervirulent and multi-drug resistant K. pneumoniae is a serious health threat. In the process of infection, K. pneumoniae needs to adapt to different environmental conditions, and the two-component regulatory system (TCS) composed of a sensor histidine kinase and response regulator is an important bacterial regulatory system in response to external stimuli. Understanding how K. pneumoniae perceives and responds to complex environmental stimuli provides insights into TCS regulation mechanisms and new targets for drug design. In this review, we analyzed the TCS composition and summarized the regulation mechanisms of TCSs, focusing on the regulation of genes involved in virulence, antibiotic resistance, and stress response. Collectively, these studies demonstrated that several TCSs play important roles in the regulation of virulence, antibiotic resistance and stress responses of K. pneumoniae. A single two-component regulatory system can participate in the regulation of several stress responses, and one stress response process may include several TCSs, forming a complex regulatory network. However, the function and regulation mechanism of some TCSs require further study. Hence, future research endeavors are required to enhance the understanding of TCS regulatory mechanisms and networks in K. pneumoniae, which is essential for the design of novel drugs targeting TCSs.
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18
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Sánchez-León I, García-Martínez T, Diene SM, Pérez-Nadales E, Martínez-Martínez L, Rolain JM. Heteroresistance to Colistin in Clinical Isolates of Klebsiella pneumoniae Producing OXA-48. Antibiotics (Basel) 2023; 12:1111. [PMID: 37508209 PMCID: PMC10375995 DOI: 10.3390/antibiotics12071111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/21/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
Heteroresistance to colistin can be defined as the presence of resistant subpopulations in an isolate that is susceptible to this antibiotic. Colistin resistance in Gram-negative bacteria is more frequently related to chromosomal mutations and insertions. This work aimed to study heteroresistance in nine clinical isolates of Klebsiella pneumoniae producing OXA-48 and to describe genomic changes in mutants with acquired resistance in vitro. Antimicrobial susceptibility was determined by broth microdilution (BMD) and heteroresistance by population analysis profiling (PAP). The proteins related to colistin resistance were analyzed for the presence of mutations. Additionally, PCR of the mgrB gene was performed to identify the presence of insertions. In the nine parental isolates, the PAP method showed colistin heteroresistance of colonies growing on plates with concentrations of up to 64 mg/L, corresponding to stable mutant subpopulations. The MICs of some mutants from the PAP plate containing 4×MIC of colistin had absolute values of ≤2 mg/L that were higher than the parental MICs and were defined as persistent variants. PCR of the mgrB gene identified an insertion sequence that inactivated the gene in 21 mutants. Other substitutions in the investigated mutants were found in PhoP, PhoQ, PmrB, PmrC, CrrA and CrrB proteins. Colistin heteroresistance in K. pneumoniae isolates was attributed mainly to insertions in the mgrB gene and point mutations in colistin resistance proteins. The results of this study will improve understanding regarding the mechanisms of colistin resistance in mutants of K. pneumoniae producing OXA-48.
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Affiliation(s)
- Irene Sánchez-León
- Maimonides Biomedical Research Institute of Cordoba, 14004 Cordoba, Spain
- Department of Agricultural Chemistry, Edaphology and Microbiology, Agrifood Campus of International Excellence CeiA3, University of Cordoba, 14014 Cordoba, Spain
| | - Teresa García-Martínez
- Department of Agricultural Chemistry, Edaphology and Microbiology, Agrifood Campus of International Excellence CeiA3, University of Cordoba, 14014 Cordoba, Spain
| | - Seydina M Diene
- Microbes Evolution Phylogeny and Infections (MEPHI), IRD, APHM, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-University, 13005 Marseille, France
| | - Elena Pérez-Nadales
- Maimonides Biomedical Research Institute of Cordoba, 14004 Cordoba, Spain
- Department of Agricultural Chemistry, Edaphology and Microbiology, Agrifood Campus of International Excellence CeiA3, University of Cordoba, 14014 Cordoba, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Luis Martínez-Martínez
- Maimonides Biomedical Research Institute of Cordoba, 14004 Cordoba, Spain
- Department of Agricultural Chemistry, Edaphology and Microbiology, Agrifood Campus of International Excellence CeiA3, University of Cordoba, 14014 Cordoba, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Clinical Unit of Microbiology, Reina Sofía University Hospital, 14004 Cordoba, Spain
| | - Jean-Marc Rolain
- Microbes Evolution Phylogeny and Infections (MEPHI), IRD, APHM, IHU Méditerranée Infection, Faculté de Médecine et de Pharmacie, Aix-Marseille-University, 13005 Marseille, France
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19
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Li Y, Li D, Liang Y, Cui J, He K, He D, Liu J, Hu G, Yuan L. Characterization of a Tigecycline-Resistant and blaCTX-M-Bearing Klebsiella pneumoniae Strain from a Peacock in a Chinese Zoo. Appl Environ Microbiol 2023; 89:e0176422. [PMID: 36809063 PMCID: PMC10057878 DOI: 10.1128/aem.01764-22] [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: 10/13/2022] [Accepted: 01/20/2023] [Indexed: 02/23/2023] Open
Abstract
In Chinese zoos, there are usually specially designed bird parks, similar to petting zoos, that allow children and adults to interact with diverse birds. However, such behaviors present a risk for the transmission of zoonotic pathogens. Recently, we isolated eight strains of Klebsiella pneumoniae and identified two blaCTX-M-positive strains from 110 birds, including parrots, peacocks, and ostriches, using anal or nasal swabs in a bird park of a zoo in China. There, K. pneumoniae LYS105A was obtained from a diseased peacock with chronic respiratory diseases by a nasal swab, which harbored the blaCTX-M-3 gene and exhibited resistance to amoxicillin, cefotaxime, gentamicin, oxytetracycline, doxycycline, tigecycline, florfenicol, and enrofloxacin. According to an analysis by whole-genome sequencing, K. pneumoniae LYS105A belongs to serotype ST859 (sequence type 859)-K19 (capsular serotype 19) and contains two plasmids, of which pLYS105A-2 can be transferred by electrotransformation and harbors numerous resistance genes such as blaCTX-M-3, aac(6')-Ib-cr5, and qnrB91. The above-mentioned genes are located in a novel mobile composite transposon, Tn7131, which makes horizontal transfer more flexible. Although no known genes were identified in the chromosome, a significant increase in SoxS upregulated the expression levels of phoPQ, acrEF-tolC, and oqxAB, which contributed to strain LYS105A acquiring resistance to tigecycline (MIC = 4 mg/L) and intermediate resistance to colistin (MIC = 2 mg/L). Altogether, our findings show that bird parks in zoos may act as important vehicles for the spread of multidrug-resistant bacteria from birds to humans and vice versa. IMPORTANCE A multidrug-resistant ST859-K19 K. pneumoniae strain, LYS105A, was obtained from a diseased peacock in a Chinese zoo. In addition, multiple resistance genes such as blaCTX-M-3, aac(6')-Ib-cr5, and qnrB91 were located in a novel composite transposon, Tn7131, of a mobile plasmid, implying that most of the resistance genes in strain LYS105A can be moved easily via horizontal gene transfer. Meanwhile, an increase in SoxS can further positively regulate the expression of phoPQ, acrEF-tolC, and oqxAB, which is the key factor for strain LYS105A to develop resistance to tigecycline and colistin. Taken together, these findings enrich our understanding of the horizontal cross-species spread of drug resistance genes, which will help us curb the development of bacterial resistance.
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Affiliation(s)
- Yinshu Li
- College of Animal Medicine, Henan Agricultural University, Zhengzhou, China
| | | | - Yulei Liang
- College of Animal Medicine, Henan Agricultural University, Zhengzhou, China
| | - Junling Cui
- College of Animal Medicine, Henan Agricultural University, Zhengzhou, China
| | - Kun He
- College of Animal Medicine, Henan Agricultural University, Zhengzhou, China
| | - Dandan He
- College of Animal Medicine, Henan Agricultural University, Zhengzhou, China
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Jianhua Liu
- College of Animal Medicine, Henan Agricultural University, Zhengzhou, China
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Gongzheng Hu
- College of Animal Medicine, Henan Agricultural University, Zhengzhou, China
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Li Yuan
- College of Animal Medicine, Henan Agricultural University, Zhengzhou, China
- International Joint Research Center of National Animal Immunology, College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
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20
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Identification of mcr-1 Genes and Characterization of Resistance Mechanisms to Colistin in Escherichia coli Isolates from Colombian Hospitals. Antibiotics (Basel) 2023; 12:antibiotics12030488. [PMID: 36978355 PMCID: PMC10044228 DOI: 10.3390/antibiotics12030488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/22/2023] [Accepted: 02/25/2023] [Indexed: 03/05/2023] Open
Abstract
We report the presence of the mcr-1 gene among 880 Escherichia coli clinical isolates collected in 13 hospitals from 12 Colombian cities between 2016 and 2019. Seven (0.8%) isolates were colistin resistant (MIC ≥ 4 µg/mL). These colistin-resistant isolates were screened for the presence of the mcr-1 gene; five carried the gene. These five isolates were subjected to whole genome sequencing (WGS) to identify additional resistomes and their ST. In addition, antimicrobial susceptibility testing revealed that all E. coli isolates carrying mcr-1 were susceptible to third generation-cephalosporin and carbapenems, except one, which carried an extended-spectrum β-lactamase (CTX-M-55), along with the fosfomycin resistance encoding gene, fosA. WGS indicated that these isolates belonged to four distinct sequence types (ST58, ST46, ST393, and a newly described ST14315) and to phylogroups B1, A, and D. In this geographic region, the spread of mcr-1 in E. coli is low and has not been inserted into high-risk clones such as ST131, which has been present in the country longer.
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21
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Xiao C, Li X, Huang L, Cao H, Han L, Ni Y, Xia H, Yang Z. Prevalence and molecular characteristics of polymyxin-resistant Enterobacterales in a Chinese tertiary teaching hospital. Front Cell Infect Microbiol 2023; 13:1118122. [PMID: 37143741 PMCID: PMC10151768 DOI: 10.3389/fcimb.2023.1118122] [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: 12/07/2022] [Accepted: 03/29/2023] [Indexed: 05/06/2023] Open
Abstract
Introduction Polymyxin-resistant Enterobacterales poses a significant threat to public health globally, but its prevalence and genomic diversity within a sole hospital is less well known. In this study, the prevalence of polymyxin-resistant Enterobacterales in a Chinese teaching hospital was investigated with deciphering of their genetic determinants of drug resistance. Methods Polymyxin-resistant Enterobacterales isolates identified by matrix-assisted laser desorption were collected in Ruijin Hospital from May to December in 2021. Both the VITEK 2 Compact and broth dilution methods were used to determine polymyxin B (PMB) susceptibility. Polymyxin-resistant isolates were further characterized by molecular typing using PCR, multi-locus sequence typing, and sequencing of the whole genome. Results Of the 1,216 isolates collected, 32 (2.6%) across 12 wards were polymyxin-resistant (minimum inhibitory concentration (MIC) range, PMB 4-256 mg/ml, and colistin 4 ≥ 16 mg/ ml). A total of 28 (87.5%) of the polymyxin-resistant isolates had reduced susceptibility to imipenem and meropenem (MIC ≥ 16 mg/ml). Of the 32 patients, 15 patients received PMB treatment and 20 survived before discharge. The phylogenetic tree of these isolates showed they belonged to different clones and had multiple origins. The polymyxin-resistant Klebsiella pneumoniae isolates belonged to ST-11 (85.72%), ST-15 (10.71%), and ST-65 (3.57%), and the polymyxin-resistant Escherichia coli belonged to four different sequence types, namely, ST-69 (25.00%), ST-38 (25.00%), ST-648 (25.00%), and ST-1193 (25.00%). In addition, six mgrB specific mutations (snp_ALT c.323T>C and amino acid change p.Val8Ala) were identified in 15.6% (5/32) of the isolates. mcr-1, a plasmid-mediated polymyxin-resistant gene, was found in three isolates, and non-synonymous mutations including T157P, A246T, G53V, and I44L were also observed. Discussion In our study, a low prevalence of polymyxin-resistant Enterobacterales was observed, but these isolates were also identified as multidrug resistant. Therefore, efficient infection control measures should be implemented to prevent the further spread of resistance to last-line polymyxin therapy.
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Affiliation(s)
- Chenlu Xiao
- Department of Laboratory Medicine, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Clinical Microbiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xuming Li
- Department of Scientific Affairs, Hugobiotech Co., Ltd., Beijing, China
| | - Lianjiang Huang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Xiamen Medical College, Xiamen, China
| | - Huiluo Cao
- Department of Microbiology, The University of Hongkong, Hong Kong, Hong Kong SAR, China
| | - Lizhong Han
- Department of Laboratory Medicine, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Department of Clinical Microbiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yuxing Ni
- Department of Infection Control, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Han Xia
- Department of Scientific Affairs, Hugobiotech Co., Ltd., Beijing, China
| | - Zhitao Yang
- Department of Emergency, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
- *Correspondence: Zhitao Yang,
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22
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Chen X, Sun Z, Xu X, Jiang J, Su J. Genomic characterization of colistin resistance in Klebsiella spp. under the pressure of colistin. J Med Microbiol 2023; 72. [PMID: 36748641 DOI: 10.1099/jmm.0.001647] [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: 01/12/2023] Open
Abstract
Introduction. Carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a serious threat to global public health. Colistin is regarded as the last-resort antibiotic for CRKP infections, but colistin resistance among CRKP is increasingly being reported, making clinical treatment for CRKP infections more difficult.Hypothesis/Gap Statement. The molecular mechanisms of colistin resistance in Klebsiella spp. under the pressure of colistin have not been fully investigated.Aim. We aimed to investigate the phenotypic and genetic variation in two colistin-susceptible Klebsiella spp. strains under selective pressure of colistin.Methodology. One hundred microlitres of overnight cultures of the CRKP clinical strain CRKP12-130 and of ATCC 700603 was spread on five Mueller-Hinton Agar (MHA) plates with colistin concentrations of 2, 4, 8, 16 and 32 µg ml-1, and growth of colonies was observed for five consecutive days. Colonies collected from plates were passaged daily for 10 days on MHA plates without colistin and susceptibility testing of colistin was performed by broth microdilution. Thirty-four colistin-resistant strains randomly selected were submitted to whole genome sequencing (WGS). Transcriptional levels of genes involved in colistin resistance (mgrB, phoP, phoQ, pmrA, pmrB, pmrD, pmrE and pmrK) were measured by quantitative real-time PCR.Results. A total of 114 and 119 colistin-resistant colonies were obtained from CRKP12-130 and ATCC 700603 in this study, among which 16 and 18 colonies were submitted to WGS, respectively. Among these 34 sequenced isolates, mutation in phoQ (13/16, 81.25 %) was the main genetic factor mediating colistin resistance in strains from CRKP12-130, while for strains from ATCC 700603, mutation associated with mgrB (8/18, 44.44 %) was found to be the commonest. Mutation of mgrB led to a significant increase in the MIC for colistin (from 64 to >128 µg ml-1), and a novel mutation C28R in mgrB was first reported in this study.Conclusion. Colistin-resistant Klebsiella spp. could be easily selected under pressure of different concentrations of colistin. Mutations of mgrB, phoP, phoQ and pmrB genes were the main mechanisms leading to chromosomally mediated colistin resistance in Klebsiella spp.
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Affiliation(s)
- Xin Chen
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, PR China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, PR China
| | - Zhewei Sun
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, PR China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, PR China
| | - Xiaogang Xu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, PR China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, PR China.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, PR China
| | - Jianping Jiang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, PR China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, PR China
| | - Jiachun Su
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, PR China.,Key Laboratory of Clinical Pharmacology of Antibiotics, National Health and Family Planning Commission, Shanghai, PR China
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23
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Prevalence of Mutated Colistin-Resistant Klebsiella pneumoniae: A Systematic Review and Meta-Analysis. Trop Med Infect Dis 2022; 7:tropicalmed7120414. [PMID: 36548669 PMCID: PMC9782491 DOI: 10.3390/tropicalmed7120414] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/21/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022] Open
Abstract
The emergence of genetic mutations in chromosomal genes and the transmissible plasmid-mediated colistin resistance gene may have helped in the spread of colistin resistance among various Klebsiella pneumoniae (K. pneumoniae) isolates and other different bacteria. In this study, the prevalence of mutated colistin-resistant K. pneumoniae isolates was studied globally using a systematic review and meta-analysis approach. A systematic search was conducted in databases including PubMed, ScienceDirect, Scopus and Google Scholar. The pooled prevalence of mutated colistin resistance in K. pneumoniae isolates was analyzed using Comprehensive Meta-Analysis Software (CMA). A total of 50 articles were included in this study. The pooled prevalence of mutated colistin resistance in K. pneumoniae was estimated at 75.4% (95% CI = 67.2−82.1) at high heterogeneity (I2 = 81.742%, p-value < 0.001). Meanwhile, the results of the subgroup analysis demonstrated the highest prevalence in Saudi Arabia with 97.9% (95% CI = 74.1−99.9%) and Egypt, with 4.5% (95% CI = 0.6−26.1%), had the lowest. The majority of mutations could be observed in the mgrB gene (88%), pmrB gene (54%) and phoQ gene (44%). The current study showed a high prevalence of the mutation of colistin resistance genes in K. pneumoniae. Therefore, it is recommended that regular monitoring be performed to control the spread of colistin resistance.
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24
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Zeczycki TN, Milton ME, Jung D, Thompson RJ, Jaimes FE, Hondros AD, Palethorpe S, Melander C, Cavanagh J. 2-Aminoimidazole Analogs Target PhoP Altering DNA Binding Activity and Affect Outer Membrane Stability in Gram-Negative Bacteria. Biochemistry 2022; 61:2948-2960. [DOI: 10.1021/acs.biochem.2c00560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Tonya N. Zeczycki
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina27834, United States
| | - Morgan E. Milton
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina27834, United States
| | - David Jung
- Agile Sciences Inc., 617 Hutton Street, Raleigh, North Carolina27606, United States
| | - Richele J. Thompson
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina27834, United States
| | - Felicia E. Jaimes
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina27834, United States
| | - Alexander D. Hondros
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina27834, United States
| | - Samantha Palethorpe
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina27834, United States
| | - Christian Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana46556, United States
| | - John Cavanagh
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina27834, United States
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25
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Peng L, Peng C, Fu S, Qiu Y. Adsorption-desorption and degradation of colistin in soils under aerobic conditions. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 243:113989. [PMID: 35994905 DOI: 10.1016/j.ecoenv.2022.113989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 03/11/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
Colistin has broad-spectrum activity against Gram-negative bacteria and has been considered as the last-resort treatment for multiantibiotic-resistant Gram-negative bacteria infections in human. And it is also world widely utilized as a veterinary medicine for the promotion of growth, prevention and control of diseases in livestock and poultry. Extensive use of colistin in husbandry results in the introduction of large amounts of colistin to the surrounding environment via animals' urine and feces, potentially inducing the prevalence of colistin resistance bacteria and the impact of the ecological environment. The study investigated the adsorption, desorption and degradation of colistin in soils using high sensitivity UPLC-MS/MS assays. An MS based assay was established to directly determine colistin in the soil. It was observed that the moderate adsorption affinity of colistin to the three soils with adsorption strength (1/n) ranging from 0.6897 to 1.3333. Colistin exhibited the highest adsorption affinity to the sandy loam, followed by the sand and loam. Despite of different characteristics of three soils, the adsorption capacity of the three soils was comparable. The adsorption of colistin to the three types of soils analyzed was irreversible. The degradation experiments showed that the degradation of colistin in the sandy loam was relatively slow with a degradation half-life in a range of 13.2-29.7 days when colistin was applied to the sandy loam at a level of 10 ~ 40 µg/g. The degradation of colistin occurred in the mixture of the sandy loam and feces recovered from the colistin treated broiler as well. 25% of colistin remained in the mixture under environmental conditions after 14 days. Composting the sandy loam by directly covering the soil surface with colistin treated broilers' feces resulted in the introduction of colistin to the sandy loam. Colistin was observed in both the topsoil from the contact surface and sandy loam samples collected 20 cm below the contact surface. The understanding of adsorption-desorption behaviors, degradation and mobility of colistin in soils might offer insights into the potential impact of colistin on the emergence and prevalence of resistant bacteria and the ecological environment.
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Affiliation(s)
- Lijuan Peng
- School of Food Science and Engineering, Wuhan Polytechnic University, n ChangQing Garden, Hankou, Wuhan 430023, PR China.
| | - Chun Peng
- School of Animal Science, Wuhan Polytechnic University, ChangQing Garden, Hankou, Wuhan 430023, PR China.
| | - Shulin Fu
- School of Animal Science, Wuhan Polytechnic University, ChangQing Garden, Hankou, Wuhan 430023, PR China.
| | - Yinsheng Qiu
- School of Animal Science, Wuhan Polytechnic University, ChangQing Garden, Hankou, Wuhan 430023, PR China.
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26
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Chen X, Li P, Sun Z, Xu X, Jiang J, Su J. Insertion sequence mediating mrgB disruption is the major mechanism of polymyxin resistance in carbapenem-resistant Klebsiella pneumoniae isolates from China. J Glob Antimicrob Resist 2022; 30:357-362. [PMID: 35817263 DOI: 10.1016/j.jgar.2022.07.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 06/11/2022] [Accepted: 07/01/2022] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVES Infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) pose a huge health challenge worldwide. The aim of this study was to evaluate the incidence of polymyxin resistance in clinical CRKP isolates in China and to characterize the molecular mechanisms underlying these polymyxin-resistant CRKP (PR-CRKP) isolates. METHODS A total of 493 CRKP clinical isolates from patients were collected from six tertiary-care hospitals in China during 2017-2018. Minimum inhibitory concentrations of polymyxin B and colistin were determined using the broth microdilution method. PR-CRKP isolates were identified and subjected to whole-genome sequencing. Quantitative real-time PCR and structural modelling analysis were also performed. RESULTS We observed a 2.2% (11/493) polymyxin resistance rate in this multicentre cohort. Polymyxin B MICs ranged from 4 to 64 μg/mL and colistin MICs ranged from 8 to 128 μg/mL in 11 PR-CRKP isolates. Key genetic variations identified in PR-CRKP isolates involved eight disruptions (seven insertional inactivation by an insertion sequence [IS] element, one frameshift deletion) in mgrB, and three missense mutations in pmrA, pmrB, and phoP. ISKpn26 was the predominant IS (4/7), and three of these occurred in nucleotide position 74 in the mgrB gene. In addition, we reported a novel mutation S62R in pmrB that may confer polymyxin resistance in K. pneumoniae. CONCLUSIONS Our findings highlight the multifaceted molecular mechanisms of polymyxin resistance in CRKP.
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Affiliation(s)
- Xin Chen
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Pei Li
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhewei Sun
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Xiaogang Xu
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China
| | - Jianping Jiang
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.
| | - Jiachun Su
- Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, China.
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27
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Characterization of Carbapenemase-Producing Klebsiella pneumoniae Isolates from Two Romanian Hospitals Co-Presenting Resistance and Heteroresistance to Colistin. Antibiotics (Basel) 2022; 11:antibiotics11091171. [PMID: 36139950 PMCID: PMC9495256 DOI: 10.3390/antibiotics11091171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 08/12/2022] [Accepted: 08/29/2022] [Indexed: 11/16/2022] Open
Abstract
Klebsiella pneumoniae is a notorious human pathogen involved in healthcare-associated infections. The worldwide expansion of infections induced by colistin-resistant and carbapenemase-producing Enterobacterales (CPE) isolates has been increasingly reported. This study aims to analyze the phenotypic and molecular profiles of 10 colistin-resistant (CR) isolates and 2 pairs of colistin-heteroresistant (ChR) (parental and the corresponding resistant mutants) isolates of K. pneumoniae CPE sourced from two hospitals. The phenotypes of strains in the selected collection had been previously characterized. Antimicrobial susceptibility testing was performed using a Vitek 2 Compact system (BioMérieux SA, Marcy l’Etoile, France), the disc diffusion method, and broth microdilution (BMD) for colistin. Whole-genome sequencing (WGS) did not uncover evidence of any mobile colistin resistance (mcr) genes, although the mgrB gene of seven isolates appeared to be disrupted by insertion sequences (ISKpn25 or ISKpn26). Possible deleterious missense mutations were found in phoP (L4F), phoQ (Q426L, L26Q, L224Q, Q317K), pmrB (R256G, P95L, T157P, V352E), and crrB (P151S) genes. The identified isolates belonged to the following clonal lineages: ST101 (n = 6), ST147 (n = 5), ST258 (n = 2), and ST307 (n = 1). All strains harbored IncF plasmids. OXA-48 producers carried IncL and IncR plasmids, while one blaNDM-1 genome was found to harbor IncC plasmids. Ceftazidime–avibactam remains a therapeutic option for KPC-2 and OXA-48 producers. Resistance to meropenem–vaborbactam has emerged in some blakPC-2-carrying isolates. Our study demonstrates that the results of WGS can provide essential evidence for the surveillance of antimicrobial resistance.
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28
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Hassen B, Hammami S, Hassen A, Abbassi MS. Molecular mechanisms and clonal lineages of colistin-resistant bacteria across the African continent: A scoping review. Lett Appl Microbiol 2022; 75:1390-1422. [PMID: 36000241 DOI: 10.1111/lam.13818] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 07/11/2022] [Accepted: 08/16/2022] [Indexed: 11/28/2022]
Abstract
Colistin (also known as Polymyxin E), a polymyxin antibiotic discovered in the late 1940s, has recently reemerged as a last-line treatment option for multidrug-resistant infections. However, in recent years, colistin-resistant pathogenic bacteria have been increasingly reported worldwide. Accordingly, the presented review was undertaken to identify, integrate and synthesize current information regarding the detection and transmission of colistin-resistant bacteria across the African continent, in addition to elucidating their molecular mechanisms of resistance. PubMed, Google Scholar, and Science Direct were employed for study identification, screening and extraction. Overall, based on the developed literature review protocol and associated inclusion/exclusion criteria, 80 studies published between 2000 and 2021 were included comprising varying bacterial species and hosts. Numerous mechanisms of colistin resistance were reported, including chromosomal mutation(s) and transferable plasmid-mediated colistin resistance (encoded by mcr genes). Perhaps unexpectedly, mcr-variants have exhibited rapid emergence and spread across most African regions. The genetic variant mcr-1 is predominant in humans, animals, and the natural environment, and is primarily carried by IncHI2- type plasmid. The highest numbers of studies reporting the dissemination of colistin-resistant Gram-negative bacteria were conducted in the North African region.
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Affiliation(s)
- B Hassen
- University of Tunis El Manar, Laboratory of Bacteriological Research, Institute of Veterinary Research of Tunisia, 20 street Jebel Lakhdhar, Bab Saadoun, Tunis, 1006, Tunisia
| | - S Hammami
- University of Manouba, IRESA, School of Veterinary Medicine of Sidi-Thabet, Ariana, Tunis, Tunisia
| | - A Hassen
- Laboratoire de Traitement et de Valorisation des rejets hydriques, Centre des Recherches et des Technologies des Eaux (CERTE), Technopole Borj-Cédria, BP, 273, 8020, Soliman, Tunisia
| | - M S Abbassi
- University of Tunis El Manar, Laboratory of Bacteriological Research, Institute of Veterinary Research of Tunisia, 20 street Jebel Lakhdhar, Bab Saadoun, Tunis, 1006, Tunisia.,University of Tunis El Manar, Faculty de Medicine of Tunis, Laboratory of antibiotic resistance LR99ES09, Tunis, Tunisia
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Zhang K, Liu L, Yan M, Chen C, Li X, Tian J, Luo C, Wang X, Wang M. Reduced porin expression with EnvZ-OmpR, PhoPQ, BaeSR two-component system down-regulation in carbapenem resistance of Klebsiella Pneumoniae based on proteomic analysis. Microb Pathog 2022; 170:105686. [PMID: 35917986 DOI: 10.1016/j.micpath.2022.105686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 07/15/2022] [Accepted: 07/17/2022] [Indexed: 11/30/2022]
Abstract
Carbapenem-resistant Klebsiella pneumoniae (CRKP) has proven to be an urgent threat to human health. Proteomics (TMT/LC-MS/MS) and bioinformatics approaches were employed to explore the potential mechanisms underlying carbapenem resistance. Proteomic profiling of CRKP and susceptible KP (sKP) isolates revealed the involvement of outer membrane, beta-lactam resistance pathway, and two-component systems (TCSs) in carbapenem resistance. 27 CRKP strains and 27 susceptible Klebsiella pneumoniae strains were isolated from inpatients at the Second Xiangya Hospital, China to verify the mechanisms. Modified carbapenem inactivation method (mCIM) and PCR of common carbapenem resistance genes confirmed that 77.8% (21/27) of CRKP isolates were carbapenemase-producing. Porin decrease in CRKP isolates was found by SDS-PAGE and mRNA levels of major porins (OmpK35 and OmpK36). RT-qPCR detection of two-component systems (envZ, ompR, phoP, phoQ, baeS and baeR) revealed down-regulation of EnvZ-OmpR, PhoPQ, BaeSR TCSs. Expression of the TCSs, except ompR, were closely correlated with OMPs with the R-value >0.7. Together, this study reaffirmed the significance of the β-lactam resistance pathway in CRKP based on proteomic analysis. OmpK35/36 porin reduction and the controversial downregulation of EnvZ-OmpR, PhoPQ, and BaeSR TCSs were confirmed in carbapenem resistance of Klebsiella pneumoniae.
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Affiliation(s)
- Kan Zhang
- Department of Laboratory Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Lei Liu
- Department of Laboratory Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Min Yan
- Department of Laboratory Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Chunmei Chen
- Department of Laboratory Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Xianping Li
- Department of Laboratory Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Jingjing Tian
- Department of Laboratory Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Can Luo
- Department of Laboratory Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Xiaofan Wang
- Department of Laboratory Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
| | - Min Wang
- Department of Laboratory Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China.
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High prevalence of mgrB-mediated colistin resistance among carbapenem-resistant Klebsiella pneumoniae is associated with biofilm formation, and can be overcome by colistin-EDTA combination therapy. Sci Rep 2022; 12:12939. [PMID: 35902639 PMCID: PMC9334626 DOI: 10.1038/s41598-022-17083-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 07/20/2022] [Indexed: 12/02/2022] Open
Abstract
The global prevalence of colistin-resistant Klebsiella pneumoniae (ColRkp) facilitated by chromosomal and plasmid-mediated Ara4N or PEtN-remodeled LPS alterations has steadily increased with increased colistin usage for treating carbapenem-resistant K. pneumoniae (CRkp). Our study demonstrated the rising trend of ColRkp showing extensively and pandrug-resistant characteristics among CRkp, with a prevalence of 28.5%, which was mediated by chromosomal mgrB, pmrB, or phoQ mutations (91.5%), and plasmid-mediated mcr-1.1, mcr-8.1, mcr-8.2 alone or in conjunction with R256G PmrB (8.5%). Several genetic alterations in mgrB (85.1%) with increased expressions of Ara4N-related phoPQ and pmrK were critical for establishing colistin resistance in our isolates. In this study, we discovered the significant associations between extensively drug-resistant bacteria (XDR) and pandrug-resistant bacteria (PDR) ColRkp in terms of moderate, weak or no biofilm-producing abilities, and altered expressions of virulence factors. These ColRkp would therefore be very challenging to treat, emphasizing for innovative therapy to combat these infections. Regardless of the underlying colistin-resistant mechanisms, colistin-EDTA combination therapy in this study produced potent synergistic effects in both in vitro and in vivo murine bacteremia, with no ColRkp regrowth and improved animal survival, implying the significance of colistin-EDTA combination therapy as systemic therapy for unlocking colistin resistance in ColRkp-associated bacteremia.
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31
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Conceição-Neto OC, da Costa BS, Pontes LDS, Silveira MC, Justo-da-Silva LH, de Oliveira Santos IC, Teixeira CBT, Tavares e Oliveira TR, Hermes FS, Galvão TC, Antunes LCM, Rocha-de-Souza CM, Carvalho-Assef APD. Polymyxin Resistance in Clinical Isolates of K. pneumoniae in Brazil: Update on Molecular Mechanisms, Clonal Dissemination and Relationship With KPC-Producing Strains. Front Cell Infect Microbiol 2022; 12:898125. [PMID: 35909953 PMCID: PMC9334684 DOI: 10.3389/fcimb.2022.898125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 06/24/2022] [Indexed: 11/14/2022] Open
Abstract
In Brazil, the production of KPC-type carbapenemases in Enterobacteriales is endemic, leading to widespread use of polymyxins. In the present study, 502 Klebsiella pneumoniae isolates were evaluated for resistance to polymyxins, their genetic determinants and clonality, in addition to the presence of carbapenem resistance genes and evaluation of antimicrobial resistance. Resistance to colistin (polymyxin E) was evaluated through initial selection on EMB agar containing 4% colistin sulfate, followed by Minimal Inhibitory Concentration (MIC) determination by broth microdilution. The susceptibility to 17 antimicrobials was assessed by disk diffusion. The presence of blaKPC, blaNDM and blaOXA-48-like carbapenemases was investigated by phenotypic methods and conventional PCR. Molecular typing was performed by PFGE and MLST. Allelic variants of the mcr gene were screened by PCR and chromosomal mutations in the pmrA, pmrB, phoP, phoQ and mgrB genes were investigated by sequencing. Our work showed a colistin resistance frequency of 29.5% (n = 148/502) in K. pneumoniae isolates. Colistin MICs from 4 to >128 µg/mL were identified (MIC50 = 64 µg/mL; MIC90 >128 µg/mL). All isolates were considered MDR, with the lowest resistance rates observed for amikacin (34.4%), and 19.6% of the isolates were resistant to all tested antimicrobials. The blaKPC gene was identified in 77% of the isolates, in consonance with the high rate of resistance to polymyxins related to its use as a therapeutic alternative. Through XbaI-PFGE, 51 pulsotypes were identified. MLST showed 21 STs, with ST437, ST258 and ST11 (CC11) being the most prevalent, and two new STs were determined: ST4868 and ST4869. The mcr-1 gene was identified in 3 K. pneumoniae isolates. Missense mutations in chromosomal genes were identified, as well as insertion sequences in mgrB. Furthermore, the identification of chromosomal mutations in K. pneumoniae isolates belonging from CC11 ensures its success as a high-risk epidemic clone in Brazil and worldwide.
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Affiliation(s)
- Orlando C. Conceição-Neto
- Laboratório de Pesquisa em Infecção Hospitalar (LAPIH), Instituto Oswaldo Cruz - Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
- Faculdade de Medicina, Universidade Estácio de Sá (UNESA), Rio de Janeiro, Brazil
| | - Bianca Santos da Costa
- Laboratório de Pesquisa em Infecção Hospitalar (LAPIH), Instituto Oswaldo Cruz - Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Leilane da Silva Pontes
- Laboratório de Pesquisa em Infecção Hospitalar (LAPIH), Instituto Oswaldo Cruz - Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Melise Chaves Silveira
- Laboratório de Pesquisa em Infecção Hospitalar (LAPIH), Instituto Oswaldo Cruz - Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | | | - Ivson Cassiano de Oliveira Santos
- Laboratório de Pesquisa em Infecção Hospitalar (LAPIH), Instituto Oswaldo Cruz - Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Camila Bastos Tavares Teixeira
- Laboratório de Pesquisa em Infecção Hospitalar (LAPIH), Instituto Oswaldo Cruz - Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Thamirys Rachel Tavares e Oliveira
- Laboratório de Pesquisa em Infecção Hospitalar (LAPIH), Instituto Oswaldo Cruz - Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Fernanda Stephens Hermes
- Laboratório de Genômica Funcional e Bioinformática (LAGFB), Instituto Oswaldo Cruz-FIOCRUZ, Rio de Janeiro, Brazil
| | - Teca Calcagno Galvão
- Laboratório de Genômica Funcional e Bioinformática (LAGFB), Instituto Oswaldo Cruz-FIOCRUZ, Rio de Janeiro, Brazil
| | - L. Caetano M. Antunes
- Laboratório de Pesquisa em Infecção Hospitalar (LAPIH), Instituto Oswaldo Cruz - Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Cláudio Marcos Rocha-de-Souza
- Laboratório de Pesquisa em Infecção Hospitalar (LAPIH), Instituto Oswaldo Cruz - Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Ana P. D. Carvalho-Assef
- Laboratório de Pesquisa em Infecção Hospitalar (LAPIH), Instituto Oswaldo Cruz - Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
- *Correspondence: Ana P. D. Carvalho-Assef,
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Denissen J, Reyneke B, Waso-Reyneke M, Havenga B, Barnard T, Khan S, Khan W. Prevalence of ESKAPE pathogens in the environment: Antibiotic resistance status, community-acquired infection and risk to human health. Int J Hyg Environ Health 2022; 244:114006. [PMID: 35841823 DOI: 10.1016/j.ijheh.2022.114006] [Citation(s) in RCA: 76] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/30/2022] [Accepted: 06/30/2022] [Indexed: 01/10/2023]
Abstract
The ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens are characterised by increased levels of resistance towards multiple classes of first line and last-resort antibiotics. Although these pathogens are frequently isolated from clinical environments and are implicated in a variety of life-threatening, hospital-associated infections; antibiotic resistant ESKAPE strains have been isolated from environmental reservoirs such as surface water, wastewater, food, and soil. Literature on the persistence and subsequent health risks posed by the ESKAPE isolates in extra-hospital settings is however, limited and the current review aims to elucidate the primary reservoirs of these pathogens in the environment, their antibiotic resistance profiles, and the link to community-acquired infections. Additionally, information on the current state of research regarding health-risk assessments linked to exposure of the ESKAPE pathogens in the natural environment, is outlined.
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Affiliation(s)
- Julia Denissen
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Brandon Reyneke
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Monique Waso-Reyneke
- Faculty of Health Sciences, University of Johannesburg, PO Box 17011, Doornfontein, 2028, South Africa
| | - Benjamin Havenga
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa
| | - Tobias Barnard
- Water and Health Research Centre, University of Johannesburg, PO Box 17011, Doornfontein, 7305, South Africa
| | - Sehaam Khan
- Faculty of Health Sciences, University of Johannesburg, PO Box 17011, Doornfontein, 2028, South Africa
| | - Wesaal Khan
- Department of Microbiology, Faculty of Science, Stellenbosch University, Private Bag X1, Stellenbosch, 7602, South Africa.
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Xiao C, Zhu Y, Yang Z, Shi D, Ni Y, Hua L, Li J. Prevalence and Molecular Characteristics of Polymyxin-Resistant Pseudomonas aeruginosa in a Chinese Tertiary Teaching Hospital. Antibiotics (Basel) 2022; 11:antibiotics11060799. [PMID: 35740205 PMCID: PMC9219935 DOI: 10.3390/antibiotics11060799] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 06/09/2022] [Accepted: 06/13/2022] [Indexed: 12/01/2022] Open
Abstract
Polymyxin-resistant Pseudomonas aeruginosa is a major threat to public health globally. We investigated the prevalence of polymyxin-resistant P. aeruginosa in a Chinese teaching hospital and determined the genetic and drug-resistant phenotypes of the resistant isolates. P. aeruginosa isolates identified by MALDI-TOF MS were collected across a 3-month period in Ruijin Hospital. Antimicrobial susceptibility was determined by a Vitek-2 Compact system with broth dilution used to determine polymyxin B (PMB) susceptibility. Polymyxin-resistant isolates were further characterized by molecular typing using PCR, multi-locus sequence typing (MLST) and whole-genome sequencing. Phylogenetic relationships were analyzed using single nucleotide polymorphism (SNP) from the whole-genome sequencing. Of 362 P. aeruginosa isolates collected, 8 (2.2%) isolates from separate patients across six wards were polymyxin-resistant (MIC range, PMB 4–16 μg/mL and colistin 4–≥16 μg/mL). Four patients received PMB treatments (intravenous, aerosolized and/or topical) and all patients survived to discharge. All polymyxin-resistant isolates were genetically related and were assigned to five different clades (Isolate 150 and Isolate 211 being the same ST823 type). Genetic variations V51I, Y345H, G68S and R155H in pmrB and L71R in pmrA were identified, which might confer polymyxin resistance in these isolates. Six of the polymyxin-resistant isolates showed reduced susceptibility to imipenem and meropenem (MIC range ≥ 16 μg/mL), while two of the eight isolates were resistant to ceftazidime. We revealed a low prevalence of polymyxin-resistant P. aeruginosa in a Chinese teaching hospital with most polymyxin-resistant isolates being multidrug-resistant. Therefore, effective infection control measures are urgently needed to prevent further spread of resistance to the last-line polymyxins.
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Affiliation(s)
- Chenlu Xiao
- Department of Laboratory Medicine, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China;
- Department of Clinical Microbiology, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yan Zhu
- Monash Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Melbourne 3800, Australia;
| | - Zhitao Yang
- Department of Emergency, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China;
| | - Dake Shi
- Department of Infection Control, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; (D.S.); (Y.N.)
| | - Yuxing Ni
- Department of Infection Control, Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China; (D.S.); (Y.N.)
| | - Li Hua
- School of Public Health, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- Correspondence: (L.H.); (J.L.)
| | - Jian Li
- Monash Biomedicine Discovery Institute, Infection Program and Department of Microbiology, Monash University, Melbourne 3800, Australia;
- Correspondence: (L.H.); (J.L.)
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34
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Elias R, Spadar A, Phelan J, Melo-Cristino J, Lito L, Pinto M, Gonçalves L, Campino S, Clark TG, Duarte A, Perdigão J. A phylogenomic approach for the analysis of colistin resistance associated genes in Klebsiella pneumoniae, its mutational diversity and implications for phenotypic resistance. Int J Antimicrob Agents 2022; 59:106581. [DOI: 10.1016/j.ijantimicag.2022.106581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 02/17/2022] [Accepted: 03/27/2022] [Indexed: 11/05/2022]
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The Role of Colistin in the Era of New β-Lactam/β-Lactamase Inhibitor Combinations. Antibiotics (Basel) 2022; 11:antibiotics11020277. [PMID: 35203879 PMCID: PMC8868358 DOI: 10.3390/antibiotics11020277] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/17/2022] [Accepted: 02/17/2022] [Indexed: 02/06/2023] Open
Abstract
With the current crisis related to the emergence of carbapenem-resistant Gram-negative bacteria (CR-GNB), classical treatment approaches with so-called “old-fashion antibiotics” are generally unsatisfactory. Newly approved β-lactam/β-lactamase inhibitors (BLBLIs) should be considered as the first-line treatment options for carbapenem-resistant Enterobacterales (CRE) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) infections. However, colistin can be prescribed for uncomplicated lower urinary tract infections caused by CR-GNB by relying on its pharmacokinetic and pharmacodynamic properties. Similarly, colistin can still be regarded as an alternative therapy for infections caused by carbapenem-resistant Acinetobacter baumannii (CRAB) until new and effective agents are approved. Using colistin in combination regimens (i.e., including at least two in vitro active agents) can be considered in CRAB infections, and CRE infections with high risk of mortality. In conclusion, new BLBLIs have largely replaced colistin for the treatment of CR-GNB infections. Nevertheless, colistin may be needed for the treatment of CRAB infections and in the setting where the new BLBLIs are currently unavailable. In addition, with the advent of rapid diagnostic methods and novel antimicrobials, the application of personalized medicine has gained significant importance in the treatment of CRE infections.
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Liu X, Wu Y, Zhu Y, Jia P, Li X, Jia X, Yu W, Cui Y, Yang R, Xia W, Xu Y, Yang Q. Emergence of colistin-resistant hypervirulent Klebsiella pneumoniae (CoR-HvKp) in China. Emerg Microbes Infect 2022; 11:648-661. [PMID: 35086435 PMCID: PMC8896207 DOI: 10.1080/22221751.2022.2036078] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Colistin is regarded as a last-resort agent to combat infections caused by multidrug-resistant (MDR) Gram-negative bacteria, especially carbapenem-resistant isolates. In recent years, reports of colistin-resistant Klebsiella pneumoniae (CoRKp) are increasing. However, the molecular mechanism and relevance of colistin resistance and virulence remain unclear. Fourteen CoRKp strains were retrospectively screened from 1884 clinical K. pneumoniae isolates during 2017–2018 in China. Six CoRKp strains belonging to ST11 were MDR strains. Plasmid-mediated mobile colistin-resistance genes had a low prevalence in CoRKp. Our results revealed that up-regulated expression of two-component systems, especially phoPQ, contributed more to colistin resistance. mgrB mutation was the most common molecular mechanism of colistin resistance, caused by either nonsense mutations or insertion sequences, which drove the overexpression of phoPQ system. This study also identified three novel point mutations in pmrAB system, in which D313N mutation in pmrB was proved to increase the MIC to colistin by 16-fold. In addition, 6 out of 14 CoRKP strains independently carried hypervirulence genes. All six strains showed medium-to-high virulence phenotype compared with NTUH-K2044 strain in mice intraperitoneal challenge models. We found that 4 strains were biofilm strong producers and transcriptome analysis revealed that three of them significantly up-regulated expression of type III fimbrial shaft gene mrkA. In conclusion, our result revealed the emergence of colistin-resistant and hypervirulent MDR K. pneumoniae, which is a noticeable superbug and could cause a severe challenge to public health.
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Affiliation(s)
- Xiaoyu Liu
- Medical Technology Academy, Beihua University, Jilin, Jilin Province, China; Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Beijing, China; Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yarong Wu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Ying Zhu
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Peiyao Jia
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Xue Li
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Department of Clinical Laboratory, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Xinmiao Jia
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Medical Research Center, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Central Research Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Wei Yu
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yujun Cui
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Ruifu Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Wei Xia
- Medical Technology Academy, Beihua University, Jilin, Jilin Province, China; Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Beijing, China; Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yingchun Xu
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qiwen Yang
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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Prevalence of polymyxin resistance through the food chain, the global crisis. J Antibiot (Tokyo) 2022; 75:185-198. [PMID: 35079146 DOI: 10.1038/s41429-022-00502-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 09/30/2021] [Accepted: 10/10/2021] [Indexed: 12/24/2022]
Abstract
Antimicrobial resistance is one of the vital challenges facing global health today. Multi-drug resistant (MDR) infections are often treated with the narrow-spectrum drugs, colistin (polymyxin E) or polymyxin B, which are last-resort antibiotics for human therapeutics that are effective against Gram-negative bacteria. Unfortunately, resistance to these polymyxins has occurred because of selective pressure caused by the inappropriate use of those antibiotics, especially in farming. The mechanisms of resistance to polymyxins are mediated through intrinsic, mutational, or genetic alteration in chromosomal genes. The mechanism includes the regulatory network controlling chemical modifications of lipid A moiety of lipopolysaccharide, reducing the negative charge of lipid A and its affinity for polymyxins. Additionally, the unique mobile colistin/polymyxin B resistance (mcr) gene reported in Enterobacteriales is responsible for the horizontal dissemination of resistance to polymyxins via the food chain. There is now an urgent need to increase surveillance for detecting resistance to polymyxins. Therefore, this review presents an overview of presently available scientific literature on the mechanism of resistance to polymyxins, with their associated gene variants, evaluation methods, resistance transmission through the food chain via food bacteria, and related risk factors. We further focus on the significant implications of polymyxins usage in India and future views for food safety to preserve polymyxin activity.
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Colistin exposure enhances expression of eptB in colistin-resistant Escherichia coli co-harboring mcr-1. Sci Rep 2022; 12:1348. [PMID: 35079093 PMCID: PMC8789769 DOI: 10.1038/s41598-022-05435-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 01/12/2022] [Indexed: 01/20/2023] Open
Abstract
Colistin resistance has increased due to the increasing and inappropriate use of this antibiotic. The mechanism involves modification of lipid A with phosphoethanolamine (PEtN) and/or 4-amino-4deoxy-l-arabinose (L-Ara4N). EptA and eptB catalyze the transfer of phosphoethanolamine to lipid A. In this study, gene network was constructed to find the associated genes related to colistin resistance, and further in vitro validation by transcriptional analysis was performed. In silico studies showed that eptB gene is a highly interconnected node in colistin resistance gene network. To ascertain these findings twelve colistin-resistant clinical isolates of Escherichia coli were selected in which five were harboring the plasmid-mediated mcr-1. Screening for colistin resistance was performed by broth microdilution (BMD) method and Rapid polymyxin NP test. PCR confirmed the presence of the eptA and eptB genes in all isolates and five isolates were harboring mcr-1. Transcriptional expression in five isolates harboring mcr-1, showed an enhanced expression of eptB when exposed under sub-inhibitory colistin stress. The present study for the first time highlighted genetic interplay between mcr-1 and eptA and eptB under colistin exposure.
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Zhang F, Li Q, Bai J, Ding M, Yan X, Wang G, Zhu B, Zhou Y. Heteroresistance to Amikacin in Carbapenem-Resistant Klebsiella pneumoniae Strains. Front Microbiol 2022; 12:682239. [PMID: 35035381 PMCID: PMC8753984 DOI: 10.3389/fmicb.2021.682239] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Heteroresistance can lead to treatment failure and is difficult to detect by the methods currently employed by clinical laboratories. The aim of this study was to investigate the prevalence of the amikacin-heteroresistant Klebsiella pneumoniae strains and explore potential amikacin heteroresistance mechanism through whole-genome sequencing (WGS) and quantitative reverse-transcription PCR (qRT-PCR). In this study, 13 isolates (8.39%) were considered as amikacin-heteroresistant K. pneumoniae strains among a total of 155 K. pneumoniae strains. The majority of the heterogeneous phenotypes (11/13, 84.61%) was unstable and the minimal inhibitory concentrations (MICs) fully or partially reverted back to the level of susceptibility of the parental isolate. The frequency of heteroresistant subpopulation ranged from 2.94×10-7 to 5.59×10-6. Whole-genome sequencing and single-nucleotide variants (SNVs) analysis showed that there were different nucleotide and resultant amino acid alterations among an amikacin-heteroresistant strain S38 and the resistant subpopulation S38L in several genes. Quantitative reverse-transcription PCR analysis revealed that the increased expression of aminoglycoside resistance genes detected in amikacin-heteroresistant K. pneumoniae strains might be associated with amikacin heteroresistance. The findings raise concerns for the emergence of amikacin-heteroresistant K. pneumoniae strains and the use of amikacin as therapy for the treatment of multidrug-resistant K. pneumoniae strains.
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Affiliation(s)
- Feiyang Zhang
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Qin Li
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Jiawei Bai
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Manlin Ding
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Xiangjin Yan
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Guangxi Wang
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
| | - Baoli Zhu
- Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yingshun Zhou
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, China
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Silva KED, Rossato L, Leite AF, Simionatto S. Overview of polymyxin resistance in Enterobacteriaceae. Rev Soc Bras Med Trop 2022; 55:e0349. [PMID: 35239902 PMCID: PMC8909443 DOI: 10.1590/0037-8682-0349-2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/12/2021] [Indexed: 11/21/2022] Open
Abstract
Polymyxin antibiotics are disfavored owing to their potential clinical toxicity, especially nephrotoxicity. However, the dry antibiotic development pipeline, together with the increasing global prevalence of infections caused by multidrug-resistant (MDR) gram-negative bacteria, have renewed clinical interest in these polypeptide antibiotics. This review highlights the current information regarding the mechanisms of resistance to polymyxins and their molecular epidemiology. Knowledge of the resistance mechanisms and epidemiology of these pathogens is critical for the development of novel antibacterial agents and rapid treatment choices.
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Stojowska-Swędrzyńska K, Łupkowska A, Kuczyńska-Wiśnik D, Laskowska E. Antibiotic Heteroresistance in Klebsiella pneumoniae. Int J Mol Sci 2021; 23:449. [PMID: 35008891 PMCID: PMC8745652 DOI: 10.3390/ijms23010449] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 12/28/2021] [Accepted: 12/29/2021] [Indexed: 12/12/2022] Open
Abstract
Klebsiella pneumoniae is one of the most common pathogens responsible for infections, including pneumonia, urinary tract infections, and bacteremias. The increasing prevalence of multidrug-resistant K. pneumoniae was recognized in 2017 by the World Health Organization as a critical public health threat. Heteroresistance, defined as the presence of a subpopulation of cells with a higher MIC than the dominant population, is a frequent phenotype in many pathogens. Numerous reports on heteroresistant K. pneumoniae isolates have been published in the last few years. Heteroresistance is difficult to detect and study due to its phenotypic and genetic instability. Recent findings provide strong evidence that heteroresistance may be associated with an increased risk of recurrent infections and antibiotic treatment failure. This review focuses on antibiotic heteroresistance mechanisms in K. pneumoniae and potential therapeutic strategies against antibiotic heteroresistant isolates.
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Affiliation(s)
| | | | | | - Ewa Laskowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland; (K.S.-S.); (A.Ł.); (D.K.-W.)
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Viehweger A, Blumenscheit C, Lippmann N, Wyres KL, Brandt C, Hans JB, Hölzer M, Irber L, Gatermann S, Lübbert C, Pletz MW, Holt KE, König B. Context-aware genomic surveillance reveals hidden transmission of a carbapenemase-producing Klebsiella pneumoniae. Microb Genom 2021; 7:000741. [PMID: 34913861 PMCID: PMC8767333 DOI: 10.1099/mgen.0.000741] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Genomic surveillance can inform effective public health responses to pathogen outbreaks. However, integration of non-local data is rarely done. We investigate two large hospital outbreaks of a carbapenemase-carrying Klebsiella pneumoniae strain in Germany and show the value of contextual data. By screening about 10 000 genomes, over 400 000 metagenomes and two culture collections using in silico and in vitro methods, we identify a total of 415 closely related genomes reported in 28 studies. We identify the relationship between the two outbreaks through time-dated phylogeny, including their respective origin. One of the outbreaks presents extensive hidden transmission, with descendant isolates only identified in other studies. We then leverage the genome collection from this meta-analysis to identify genes under positive selection. We thereby identify an inner membrane transporter (ynjC) with a putative role in colistin resistance. Contextual data from other sources can thus enhance local genomic surveillance at multiple levels and should be integrated by default when available.
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Affiliation(s)
- Adrian Viehweger
- Institute of Medical Microbiology and Virology, University Hospital Leipzig, Leipzig, Germany
- *Correspondence: Adrian Viehweger,
| | | | - Norman Lippmann
- Institute of Medical Microbiology and Virology, University Hospital Leipzig, Leipzig, Germany
| | - Kelly L. Wyres
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Australia
| | - Christian Brandt
- Institute for Infectious Diseases and Infection Control, Jena University Hospital, Jena, Germany
| | - Jörg B. Hans
- National Reference Center for multidrug-resistant Gram-negative bacteria, Department for Medical Microbiology, Ruhr-University Bochum, Bochum, Germany
| | - Martin Hölzer
- Methodology and Research Infrastructure, MF1 Bioinformatics, Robert Koch Institute, Berlin, Germany
| | - Luiz Irber
- Department of Population Health and Reproduction, University of California, Davis, Davis, California, USA
| | - Sören Gatermann
- National Reference Center for multidrug-resistant Gram-negative bacteria, Department for Medical Microbiology, Ruhr-University Bochum, Bochum, Germany
| | - Christoph Lübbert
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine II, University Hospital Leipzig, Leipzig, Germany
| | - Mathias W. Pletz
- Institute for Infectious Diseases and Infection Control, Jena University Hospital, Jena, Germany
| | - Kathryn E. Holt
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Australia
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Brigitte König
- Institute of Medical Microbiology and Virology, University Hospital Leipzig, Leipzig, Germany
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Elias R, Melo-Cristino J, Lito L, Pinto M, Gonçalves L, Campino S, Clark TG, Duarte A, Perdigão J. Klebsiella pneumoniae and Colistin Susceptibility Testing: Performance Evaluation for Broth Microdilution, Agar Dilution and Minimum Inhibitory Concentration Test Strips and Impact of the "Skipped Well" Phenomenon. Diagnostics (Basel) 2021; 11:2352. [PMID: 34943590 PMCID: PMC8700027 DOI: 10.3390/diagnostics11122352] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 11/16/2022] Open
Abstract
The emergence of multidrug resistant Gram-negative pathogens, particularly carbapenemase producers, has forced clinicians to use last line antibiotics, such as colistin. Since colistin susceptibility testing presents several challenges, this study aimed at evaluating the performance of two alternative susceptibility methods for Klebsiella pneumoniae, namely, agar dilution (AD) and MIC test strips (MTS). These approaches were compared with the reference method, broth microdilution (BMD), and provide a quantitative description for the "skipped well" (SW) phenomenon. Colistin susceptibility was evaluated by BMD and AD in parallel and triplicate, using 141 K. pneumoniae clinical isolates while MTS performance was evaluated only for a subset (n = 121). Minimum inhibitory concentration analysis revealed that a substantial part (n = 26/141; 18.4%) of the initial isolates was deemed undetermined by BMD due to the following: discordance between replicates (1.4%); presence of multiple SWs (7.8%); and the combination of both events (9.2%). Both AD and MTS revealed a high number of false-susceptible strains ("very major errors"), 37.5% and 68.8%, respectively. However, AD agreement indices were reasonably high (EA = 71.3% and CA = 94.8%). For MTS these indices were lower, in particular EA (EA = 41.7% and CA = 89.6), but the approach enabled the detection of distinct sub-populations for four isolates. In conclusion, this study provides the most comprehensive study on the performance of AD and MTS for colistin susceptibility testing in K. pneumoniae, highlighting its limitations, and stressing the importance of sample size and composition. Further, this study highlights the impact of the SW phenomenon associated with the BMD method for K. pneumoniae.
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Affiliation(s)
- Rita Elias
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal;
| | - José Melo-Cristino
- Laboratório de Microbiologia, Serviço de Patologia Clínica, Centro Hospitalar Universitário Lisboa Norte, 1649-049 Lisboa, Portugal; (J.M.-C.); (L.L.)
- Instituto de Microbiologia, Faculdade de Medicina, Universidade de Lisboa, 1640-028 Lisboa, Portugal
| | - Luís Lito
- Laboratório de Microbiologia, Serviço de Patologia Clínica, Centro Hospitalar Universitário Lisboa Norte, 1649-049 Lisboa, Portugal; (J.M.-C.); (L.L.)
| | - Margarida Pinto
- Laboratório de Microbiologia, Serviço de Patologia Clínica, Centro Hospitalar Universitário Lisboa Central, 1169-050 Lisboa, Portugal;
| | - Luísa Gonçalves
- Serviço de Patologia Clínica, Hospital SAMS, 1849-019 Lisboa, Portugal;
| | - Susana Campino
- London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK; (S.C.); (T.G.C.)
| | - Taane G. Clark
- London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK; (S.C.); (T.G.C.)
| | - Aida Duarte
- Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal
- Centro de Investigação Interdisciplinar Egas Moniz, Instituto Universitário Egas Moniz, Quinta da Granja, 2829-511 Monte da Caparica, Portugal
| | - João Perdigão
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, 1649-003 Lisboa, Portugal;
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Melander RJ, Mattingly AE, Melander C. Phenotypic screening of compound libraries as a platform for the identification of antibiotic adjuvants: Identification of colistin adjuvants from a natural product library. Methods Enzymol 2021; 665:153-176. [PMID: 35379433 PMCID: PMC10942738 DOI: 10.1016/bs.mie.2021.11.005] [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] [Indexed: 11/21/2022]
Abstract
The identification of antibiotic adjuvants, small molecules that potentiate the activity of conventional antibiotics, provides an orthogonal approach to the development of new antibiotics in the fight against drug resistant bacterial infections. Methods to identify novel adjuvants could potentially aid efforts to overcome the increasing prevalence of resistance and stave off the onset of a "post-antibiotic era." Phenotypic whole cell screens allow for the identification of hits with the necessary properties to access their biomolecular target, and may also facilitate the discovery of novel adjuvant targets. A phenotypic screening platform is outlined, in which a natural product library was explored for activity with antibiotics from several mechanistically distinct classes against clinically important bacterial species. General approaches to delineating the mechanism of action of hit compounds identified from phenotypic screens are described, followed by specific approaches to uncovering the mechanism of action of the colistin adjuvants identified from the natural product screen.
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Affiliation(s)
- Roberta J Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Anne E Mattingly
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Christian Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.
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Valcourt C, Buyck JM, Grégoire N, Couet W, Marchand S, Tewes F. Lipid Nanoparticles Loaded with Farnesol or Geraniol to Enhance the Susceptibility of E. coli MCR-1 to Colistin. Pharmaceutics 2021; 13:pharmaceutics13111849. [PMID: 34834268 PMCID: PMC8625850 DOI: 10.3390/pharmaceutics13111849] [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: 09/17/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 11/24/2022] Open
Abstract
Resistance to colistin, one of the antibiotics of last resort against multidrug-resistant Gram-negative bacteria, is increasingly reported. Notably, MCR plasmids discovered in 2015 have now been reported worldwide in humans. To keep this antibiotic of last resort efficient, a way to tackle this mechanism seems essential. Terpene alcohols such as farnesol have been shown to improve the efficacy of some antibiotics. However, their high lipophilicity makes them difficult to use. This problem can be solved by encapsulating them in water-dispersible lipid nanoparticles (LNPs). The aim of this study was to discover, using checkerboard tests and time-kill curve experiments, an association between colistin and farnesol or geraniol loaded in LNPs, which would improve the efficacy of colistin against E. coli and, in particular, MCR-1 transconjugants. Then, the effect of the combination on E. coli inner membrane permeabilisation was evaluated using propidium iodide (PI) uptake and compared to human red blood cells plasma membrane permeabilisation. Both terpene alcohols were able to restore the susceptibility of E. coli J53 MCR-1 to colistin with the same efficacy (Emax = 16, i.e., colistin MIC was decreased from 8 to 0.5 mg/L). However, with an EC50 of 2.69 mg/L, farnesol was more potent than geraniol (EC50 = 39.49 mg/L). Time-kill studies showed a bactericidal effect on MCR-1 transconjugant 6 h after incubation, with no regrowth up to 30 h in the presence of 1 mg/L colistin (1/8 MIC) and 60 mg/L or 200 mg/L farnesol or geraniol, respectively. Colistin alone was more potent in increasing PI uptake rate in the susceptible strain (EC50 = 0.86 ± 0.08 mg/L) than in the MCR-1 one (EC50 = 7.38 ± 0.85 mg/L). Against the MCR-1 strain, farnesol-loaded LNP at 60 mg/L enhanced the colistin-induced inner membrane permeabilization effect up to 5-fold and also increased its potency as shown by the decrease in its EC50 from 7.38 ± 0.85 mg/L to 2.69 ± 0.25 mg/L. Importantly, no hemolysis was observed for LNPs loaded with farnesol or geraniol, alone or in combination with colistin, at the concentrations showing the maximum decrease in colistin MICs. The results presented here indicate that farnesol-loaded LNPs should be studied as combination therapy with colistin to prevent the development of resistance to this antibiotic of last resort.
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Affiliation(s)
- Chantal Valcourt
- INSERM U1070 “Pharmacology of Anti-Infective Agents”, 1 rue Georges Bonnet, Pôle Biologie Santé, 86022 Poitiers, France; (C.V.); (J.M.B.); (N.G.); (W.C.); (S.M.)
| | - Julien M. Buyck
- INSERM U1070 “Pharmacology of Anti-Infective Agents”, 1 rue Georges Bonnet, Pôle Biologie Santé, 86022 Poitiers, France; (C.V.); (J.M.B.); (N.G.); (W.C.); (S.M.)
- UFR Médecine-Pharmacie Université de Poitiers, 6 rue de la Milétrie, TSA 51115, 86073 Poitiers, France
| | - Nicolas Grégoire
- INSERM U1070 “Pharmacology of Anti-Infective Agents”, 1 rue Georges Bonnet, Pôle Biologie Santé, 86022 Poitiers, France; (C.V.); (J.M.B.); (N.G.); (W.C.); (S.M.)
- UFR Médecine-Pharmacie Université de Poitiers, 6 rue de la Milétrie, TSA 51115, 86073 Poitiers, France
- Laboratoire de Toxicologie-Pharmacocinétique, CHU de Poitiers, 2 rue de la Miletrie, 86021 Poitiers, France
| | - William Couet
- INSERM U1070 “Pharmacology of Anti-Infective Agents”, 1 rue Georges Bonnet, Pôle Biologie Santé, 86022 Poitiers, France; (C.V.); (J.M.B.); (N.G.); (W.C.); (S.M.)
- UFR Médecine-Pharmacie Université de Poitiers, 6 rue de la Milétrie, TSA 51115, 86073 Poitiers, France
- Laboratoire de Toxicologie-Pharmacocinétique, CHU de Poitiers, 2 rue de la Miletrie, 86021 Poitiers, France
| | - Sandrine Marchand
- INSERM U1070 “Pharmacology of Anti-Infective Agents”, 1 rue Georges Bonnet, Pôle Biologie Santé, 86022 Poitiers, France; (C.V.); (J.M.B.); (N.G.); (W.C.); (S.M.)
- UFR Médecine-Pharmacie Université de Poitiers, 6 rue de la Milétrie, TSA 51115, 86073 Poitiers, France
- Laboratoire de Toxicologie-Pharmacocinétique, CHU de Poitiers, 2 rue de la Miletrie, 86021 Poitiers, France
| | - Frédéric Tewes
- INSERM U1070 “Pharmacology of Anti-Infective Agents”, 1 rue Georges Bonnet, Pôle Biologie Santé, 86022 Poitiers, France; (C.V.); (J.M.B.); (N.G.); (W.C.); (S.M.)
- UFR Médecine-Pharmacie Université de Poitiers, 6 rue de la Milétrie, TSA 51115, 86073 Poitiers, France
- Correspondence:
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Binsker U, Käsbohrer A, Hammerl JA. Global colistin use: A review of the emergence of resistant Enterobacterales and the impact on their genetic basis. FEMS Microbiol Rev 2021; 46:6382128. [PMID: 34612488 PMCID: PMC8829026 DOI: 10.1093/femsre/fuab049] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 10/04/2021] [Indexed: 02/06/2023] Open
Abstract
The dramatic global rise of MDR and XDR Enterobacterales in human medicine forced clinicians to the reintroduction of colistin as last-resort drug. Meanwhile, colistin is used in the veterinary medicine since its discovery, leading to a steadily increasing prevalence of resistant isolates in the livestock and meat-based food sector. Consequently, transmission of resistant isolates from animals to humans, acquisition via food and exposure to colistin in the clinic are reasons for the increased prevalence of colistin-resistant Enterobacterales in humans in the last decades. Initially, resistance mechanisms were caused by mutations in chromosomal genes. However, since the discovery in 2015, the focus has shifted exclusively to mobile colistin resistances (mcr). This review will advance the understanding of chromosomal-mediated resistance mechanisms in Enterobacterales. We provide an overview about genes involved in colistin resistance and the current global situation of colistin-resistant Enterobacterales. A comparison of the global colistin use in veterinary and human medicine highlights the effort to reduce colistin sales in veterinary medicine under the One Health approach. In contrast, it uncovers the alarming rise in colistin consumption in human medicine due to the emergence of MDR Enterobacterales, which might be an important driver for the increasing emergence of chromosome-mediated colistin resistance.
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Affiliation(s)
- Ulrike Binsker
- Department Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Annemarie Käsbohrer
- Department Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany.,Department for Farm Animals and Veterinary Public Health, Institute of Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Jens A Hammerl
- Department Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
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Elizabeth R, Wangkheimayum J, Singha KM, Chanda DD, Bhattacharjee A. Subinhibitory concentration stress of colistin enhanced PhoPQ expression in Escherichia coli harboring mcr-1. J Basic Microbiol 2021; 61:1029-1034. [PMID: 34510495 DOI: 10.1002/jobm.202100355] [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] [Received: 07/23/2021] [Revised: 08/17/2021] [Accepted: 08/28/2021] [Indexed: 12/17/2022]
Abstract
The increased and inappropriate use of colistin led to the emergence of its resistance among Gram-negative bacterial isolates and the most common mechanism of colistin resistance in Gram-negative bacteria is the modification of the lipopolysaccharide mediated by two-component regulatory systems, PhoPQ and PmrAB. The aim of the present study was to investigate the transcriptional expression of the PhoPQ system against colistin stress in clinical isolates of Escherichia coli with colistin-resistant phenotype. Six colistin-resistant E. coli isolates were obtained from Silchar Medical College and Hospital, Silchar that were of clinical origin and received for routine culture and sensitivity testing. Screening for colistin resistance was done by broth microdilution method and further screened for the presence of the different types of plasmid-mediated colistin resistance mcr genes namely, mcr-1 to mcr-10 by polymerase chain reaction (PCR). The screened positive isolates were subjected to PCR assay targeting phoP and phoQ genes and their expression was measured by quantitative real-time PCR. The results of this study revealed that two E. coli isolates (TS2 and TS4) were found to carry the mcr-1 gene. PhoP and PhoQ gene amplification was observed in all the isolates. Transcriptional analysis showed that the isolates harboring the mcr-1 gene showed an enhanced level of expression in the PhoP, PhoQ genes in the presence of a subinhibitory concentration of colistin whereas no significant expression was observed for the isolates which were devoid of the mcr gene. This study demonstrates the involvement of mcr-1 in the PhoPQ system in clinical isolates of colistin-resistant E. coli which will help in designing a molecular marker for detecting colistin-resistant E. coli and contribute to the assessment of resistance burden and infection control strategy.
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Affiliation(s)
| | | | - K Melson Singha
- Department of Microbiology, Silchar Medical College and Hospital, Silchar, Assam, India
| | - Debadatta D Chanda
- Department of Microbiology, Silchar Medical College and Hospital, Silchar, Assam, India
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Gogry FA, Siddiqui MT, Sultan I, Haq QMR. Current Update on Intrinsic and Acquired Colistin Resistance Mechanisms in Bacteria. Front Med (Lausanne) 2021; 8:677720. [PMID: 34476235 PMCID: PMC8406936 DOI: 10.3389/fmed.2021.677720] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 07/09/2021] [Indexed: 01/07/2023] Open
Abstract
Colistin regained global interest as a consequence of the rising prevalence of multidrug-resistant Gram-negative Enterobacteriaceae. In parallel, colistin-resistant bacteria emerged in response to the unregulated use of this antibiotic. However, some Gram-negative species are intrinsically resistant to colistin activity, such as Neisseria meningitides, Burkholderia species, and Proteus mirabilis. Most identified colistin resistance usually involves modulation of lipid A that decreases or removes early charge-based interaction with colistin through up-regulation of multistep capsular polysaccharide expression. The membrane modifications occur by the addition of cationic phosphoethanolamine (pEtN) or 4-amino-l-arabinose on lipid A that results in decrease in the negative charge on the bacterial surface. Therefore, electrostatic interaction between polycationic colistin and lipopolysaccharide (LPS) is halted. It has been reported that these modifications on the bacterial surface occur due to overexpression of chromosomally mediated two-component system genes (PmrAB and PhoPQ) and mutation in lipid A biosynthesis genes that result in loss of the ability to produce lipid A and consequently LPS chain, thereafter recently identified variants of plasmid-borne genes (mcr-1 to mcr-10). It was hypothesized that mcr genes derived from intrinsically resistant environmental bacteria that carried chromosomal pmrC gene, a part of the pmrCAB operon, code three proteins viz. pEtN response regulator PmrA, sensor kinase protein PmrAB, and phosphotransferase PmrC. These plasmid-borne mcr genes become a serious concern as they assist in the dissemination of colistin resistance to other pathogenic bacteria. This review presents the progress of multiple strategies of colistin resistance mechanisms in bacteria, mainly focusing on surface changes of the outer membrane LPS structure and other resistance genetic determinants. New handier and versatile methods have been discussed for rapid detection of colistin resistance determinants and the latest approaches to revert colistin resistance that include the use of new drugs, drug combinations and inhibitors. Indeed, more investigations are required to identify the exact role of different colistin resistance determinants that will aid in developing new less toxic and potent drugs to treat bacterial infections. Therefore, colistin resistance should be considered a severe medical issue requiring multisectoral research with proper surveillance and suitable monitoring systems to report the dissemination rate of these resistant genes.
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Affiliation(s)
| | | | - Insha Sultan
- Department of Biosciences, Jamia Millia Islamia, New Delhi, India
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Zhang F, Ding M, Yan X, Bai J, Li Q, Zhang B, Liang Q, Liang S, Wang G, Zhou Y. Carbapenem-resistant K. pneumoniae exhibiting clinically undetected amikacin and meropenem heteroresistance leads to treatment failure in a murine model of infection. Microb Pathog 2021; 160:105162. [PMID: 34461245 DOI: 10.1016/j.micpath.2021.105162] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/06/2021] [Accepted: 08/26/2021] [Indexed: 11/17/2022]
Abstract
Heteroresistance is a poorly understood mechanism of resistance which refers to a phenomenon where there are different subpopulations of seemingly isogenic bacteria which exhibit a range of susceptibilities to a particular antibiotic. In the current study, we identified a multidrug-resistant, carbapenemase-positive K. pneumoniae strain SWMUF35 which was classified as susceptible to amikacin and resistant to meropenem by clinical diagnostics yet harbored different subpopulations of phenotypically resistant cells, and has the ability to form biofilm. Population analysis profile (PAP) indicated that SWMUF35 showed heteroresistance towards amikacin and meropenem which was considered as co-heteroresistant K. pneumoniae strain. In vitro experiments such as dual PAP, dual Times-killing assays and checkerboard assay showed that antibiotic combination therapy (amikacin combined with meropenem) can effectively combat SWMUF35. Importantly, using an in vivo mouse model of peritonitis, we found that amikacin or meropenem monotherapy was unable to rescue mice infected with SWMUF35. Antibiotic combination therapy could be a rational strategy to use clinically approved antibiotics when monotherapy would fail. Furthermore, our data warn that antibiotic susceptibility testing results may be unreliable due to undetected heteroresistance which can lead to treatment failure and the detection of this phenotype is a prerequisite for a proper choice of antibiotic to support a successful treatment outcome.
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Affiliation(s)
- Feiyang Zhang
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Manlin Ding
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Xiangjin Yan
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Jiawei Bai
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Qin Li
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Biying Zhang
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Qinghua Liang
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Shuang Liang
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Guangxi Wang
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, Sichuan, 646000, China
| | - Yingshun Zhou
- Department of Pathogen Biology, School of Basic Medicine, Public Center of Experimental Technology of Pathogen Biology Technology Platform, Southwest Medical University, Luzhou, Sichuan, 646000, China.
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A new mutation in mgrb mediating polymyxin resistance in Klebsiella variicola. Int J Antimicrob Agents 2021; 58:106424. [PMID: 34419577 DOI: 10.1016/j.ijantimicag.2021.106424] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 08/06/2021] [Accepted: 08/15/2021] [Indexed: 11/21/2022]
Abstract
Polymyxin resistance is a public health concern - present in humans, animals and the environment - caused by chromosomal-encoding or plasmid-encoding mechanisms. Chromosomal alterations in MgrB are frequently detected in Klebsiella spp., but not yet reported and characterised in Klebsiella variicola (K. variicola). This study performed microbiological and genomic characterisation of three polymyxin-resistant K. variicola isolates (M14, M15 and M50) recovered from the microbiota of migratory birds in Brazil. The isolates were submitted to SpeI-PFGE, broth microdilution and whole genome sequencing using Illumina MiSeq for analysis of genetic relatedness, sequence typing and detection of antimicrobial-resistance genes. K. variicola isolates belonged to two clones, and susceptibility tests showed resistance only for polymyxins. Sequences of chromosomal two-component systems (PmrAB, PhoPQ, RstAB, CrrAB) and MgrB were evaluated by blastN and blastP against a polymyxin-susceptible K. variicola (A58243), and mutations with biological effect were checked by the PROVEAN tool. K. variicola isolates belonged to two clones, and susceptibility tests showed resistance for polymyxins. In M14 and M15, phoQ deleterious mutations (D90N, I122S and G385S) were identified, while an mgrB variant containing a single deletion (C deletion on position 93) leading to the production of a non-functional protein was detected in M50. mgrB complementation studies showed restoration of polymyxin susceptibility (64 to ≤ 0.25 mg/L) as a wild-type mgrB was inserted into the mgrB-deficient M50. This study confirmed the role of a non-functional mgrB variant in conferring polymyxin resistance, stressing the role of this regulator in K. variicola and drawing attention to novel polymyxin resistance mechanisms emerging in wildlife.
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