1
|
Characterisation of Non-Carbapenemase-Producing Carbapenem-Resistant Klebsiella pneumoniae Based on Their Clinical and Molecular Profile in Malaysia. Antibiotics (Basel) 2022; 11:antibiotics11111670. [PMID: 36421313 PMCID: PMC9686620 DOI: 10.3390/antibiotics11111670] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/08/2022] [Accepted: 11/15/2022] [Indexed: 11/23/2022] Open
Abstract
Non-carbapenemase-producing carbapenem-resistant Klebsiella pneumoniae (NC-CRKP) confers carbapenem resistance through a combination of chromosomal mutations and acquired non-carbapenemase resistance mechanisms. In this study, we aimed to evaluate the clinical and molecular profiles of NC-CRKP isolated from patients in a tertiary teaching hospital in Malaysia from January 2013 to October 2019. During the study period, 54 NC-CRKP-infected/colonised patients’ isolates were obtained. Clinical parameters were assessed in 52 patients. The all-cause in-hospital mortality rate among NC-CRKP patients was 46.2% (24/52). Twenty-three (44.2%) patients were infected, while others were colonised. Based on the Charlson Comorbidity Index (CCI) score, 92.3% (48/52) of the infected/colonised patients had a score of ≥ 1. Resistance genes found among the 54 NC-CRKP isolates were blaTEM, blaSHV, blaCTX-M, blaOXA, and blaDHA. Porin loss was detected in 25/54 (46.3%) strains. None of the isolated strains conferred carbapenem resistance through the efflux pumps system. In conclusion, only 25/54 (46.3%) NC-CRKP conferred carbapenem resistance through a combination of porin loss and the acquisition of non-carbapenemase resistance mechanisms. The carbapenem resistance mechanisms for the remaining strains (53.7%) should be further investigated as rapid identification and distinction of the NC-CRKP mechanisms enable optimal treatment and infection control efforts.
Collapse
|
2
|
Xiong Y, Han Y, Zhao Z, Gao W, Ma Y, Jiang S, Wang M, Zhang Q, Zhou Y, Chen Y. Impact of Carbapenem Heteroresistance Among Multidrug-Resistant ESBL/AmpC-Producing Klebsiella pneumoniae Clinical Isolates on Antibiotic Treatment in Experimentally Infected Mice. Infect Drug Resist 2022; 14:5639-5650. [PMID: 34992390 PMCID: PMC8711563 DOI: 10.2147/idr.s340652] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/08/2021] [Indexed: 12/21/2022] Open
Abstract
Purpose Antibiotic resistance is a growing health crisis that is further complicated by treatment failures caused by bacteria that exhibit heterogeneous susceptibility to antibiotics. The aim of this study was to describe imipenem (IPM)-heteroresistant strains among multidrug-resistant (MDR) ESBL/AmpC-producing Klebsiella pneumoniae clinical isolates, investigate their molecular phenotypic characteristics, and elucidate the outcome of antibiotic treatment in mice infected with the heteroresistant isolates. Materials and Methods Antimicrobial susceptibility of K. pneumoniae isolates was determined by the disk diffusion and E-test methods. Heteroresistance to IPM was confirmed by population analysis profile (PAP) assays. PCR and sequencing were employed to detect MDR determinants. Molecular differences between the susceptible and resistant subpopulations were evaluated by sequencing and quantitative real-time reverse transcription PCR (qRT-PCR) analysis. The effect of the carbapenem-heteroresistant strains on antibiotic treatment was assessed using a mouse model of peritonitis with heteroresistant K. pneumoniae and subsequent treatment with IPM. Results In total, 37 MDR ESBL/AmpC-producing clinical isolates of K. pneumoniae were identified between September 2018 and December 2019. These strains were notably resistant to conventional antimicrobials other than carbapenems. Among the isolates, three strains exhibited heteroresistance to IPM and carried several ESBL and/or AmpC genes. Mice infected with a lethal dose of any of the three heteroresistant isolates were unable to survive in the presence of IPM treatment, as the percentage of the IPM-resistant subpopulation of each strain was increased in the peritoneum of these mice at 24 h after infection. The resistant subpopulation of the strains presented pulsed-field gel electrophoresis (PFGE) profiles that were identical to those of the susceptible subpopulation, but ompK36 porin showed a reduction in gene expression (0.09- to 0.50-fold) in the resistant subpopulation. Conclusion Carbapenem-heteroresistant strains were present among the MDR K. pneumoniae isolates producing ESBL/AmpC β-lactamases, and these heteroresistant strains failed IPM therapy in experimentally infected mice.
Collapse
Affiliation(s)
- Yilin Xiong
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University, Dalian, People's Republic of China
| | - Yuqiao Han
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University, Dalian, People's Republic of China
| | - Zinan Zhao
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University, Dalian, People's Republic of China
| | - Wenting Gao
- Institute of Genome Engineered Animal Models for Human Disease, Dalian Medical University, Dalian, People's Republic of China
| | - Yong Ma
- Institute of Genome Engineered Animal Models for Human Disease, Dalian Medical University, Dalian, People's Republic of China
| | - Shiyu Jiang
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University, Dalian, People's Republic of China
| | - Mengyao Wang
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University, Dalian, People's Republic of China
| | - Qingqing Zhang
- Laboratory of Pathogenic Biology, College of Basic Medical Sciences, Dalian Medical University, Dalian, People's Republic of China
| | - Yun Zhou
- Department of Clinical Nutrition, Second Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China
| | - Yang Chen
- Department of Biotechnology, College of Basic Medical Sciences, Dalian Medical University, Dalian, People's Republic of China
| |
Collapse
|
3
|
Khalifa SM, Abd El-Aziz AM, Hassan R, Abdelmegeed ES. β-lactam resistance associated with β-lactamase production and porin alteration in clinical isolates of E. coli and K. pneumoniae. PLoS One 2021; 16:e0251594. [PMID: 34014957 PMCID: PMC8136739 DOI: 10.1371/journal.pone.0251594] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 04/28/2021] [Indexed: 12/23/2022] Open
Abstract
β-lactam resistance represents a worldwide problem and a serious challenge for antimicrobial treatment. Hence this research was conducted to recognize several mechanisms mediating β-lactam resistance in E. coli and K. pneumoniae clinical isolates collected from Mansoura University hospitals, Egypt. A total of 80 isolates, 45 E. coli and 35 K. pneumoniae isolates, were collected and their antibiotic susceptibility was determined by the Disc diffusion method followed by phenotypic and genotypic detection of extended-spectrum β-lactamases (ESBLs), AmpC β-lactamase, carbapenemase enzymes. The outer membrane protein porins of all isolates were analyzed and their genes were examined using gene amplification and sequencing. Also, the resistance to complement-mediated serum killing was estimated. A significant percentage of isolates (93.8%) were multidrug resistance and showed an elevated resistance to β-lactam antibiotics. The presence of either ESBL or AmpC enzymes was high among isolates (83.75%). Also, 60% of the isolated strains were carbapenemase producers. The most frequently detected gene of ESBL among all tested isolates was blaCTX-M-15 (86.3%) followed by blaTEM-1 (81.3%) and blaSHV-1 (35%) while the Amp-C gene was present in 83.75%. For carbapenemase-producing isolates, blaNDM1 was the most common (60%) followed by blaVIM-1 (35%) and blaOXA-48 (13.8%). Besides, 73.3% and 40% of E. coli and K. pneumoniae isolates respectively were serum resistant. Outer membrane protein analysis showed that 93.3% of E. coli and 95.7% of K. pneumoniae isolates lost their porins or showed modified porins. Furthermore, sequence analysis of tested porin genes in some isolates revealed the presence of frameshift mutations that produced truncated proteins of smaller size. β-lactam resistance in K. pneumoniae and E. coli isolates in our hospitals is due to a combination of β-lactamase activity and porin loss/alteration. Hence more restrictions should be applied on β-lactams usage to decrease the emergence of resistant strains.
Collapse
Affiliation(s)
- Sara M. Khalifa
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Abeer M. Abd El-Aziz
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
- * E-mail: ,
| | - Ramadan Hassan
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Eman S. Abdelmegeed
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| |
Collapse
|
4
|
Bhagirath AY, Li Y, Patidar R, Yerex K, Ma X, Kumar A, Duan K. Two Component Regulatory Systems and Antibiotic Resistance in Gram-Negative Pathogens. Int J Mol Sci 2019; 20:E1781. [PMID: 30974906 PMCID: PMC6480566 DOI: 10.3390/ijms20071781] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 04/05/2019] [Accepted: 04/08/2019] [Indexed: 12/17/2022] Open
Abstract
Gram-negative pathogens such as Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa are the leading cause of nosocomial infections throughout the world. One commonality shared among these pathogens is their ubiquitous presence, robust host-colonization and most importantly, resistance to antibiotics. A significant number of two-component systems (TCSs) exist in these pathogens, which are involved in regulation of gene expression in response to environmental signals such as antibiotic exposure. While the development of antimicrobial resistance is a complex phenomenon, it has been shown that TCSs are involved in sensing antibiotics and regulating genes associated with antibiotic resistance. In this review, we aim to interpret current knowledge about the signaling mechanisms of TCSs in these three pathogenic bacteria. We further attempt to answer questions about the role of TCSs in antimicrobial resistance. We will also briefly discuss how specific two-component systems present in K. pneumoniae, A. baumannii, and P. aeruginosa may serve as potential therapeutic targets.
Collapse
Affiliation(s)
- Anjali Y Bhagirath
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Yanqi Li
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Rakesh Patidar
- Department of Microbiology, Faculty of Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Katherine Yerex
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Xiaoxue Ma
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| | - Ayush Kumar
- Department of Microbiology, Faculty of Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada.
| | - Kangmin Duan
- Department of Oral Biology, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
- Department of Medical Microbiology & Infectious Diseases, Rady Faculty of Health Sciences, University of Manitoba, 780 Bannatyne Ave, Winnipeg, MB R3E 0J9, Canada.
| |
Collapse
|
5
|
Hamzaoui Z, Ocampo-Sosa A, Maamar E, Fernandez Martinez M, Ferjani S, Hammami S, Harbaoui S, Genel N, Arlet G, Saidani M, Slim A, Boutiba-Ben Boubaker I, Martinez-Martinez L. An Outbreak of NDM-1-ProducingKlebsiella pneumoniae, Associated with OmpK35 and OmpK36 Porin Loss in Tunisia. Microb Drug Resist 2018; 24:1137-1147. [DOI: 10.1089/mdr.2017.0165] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Affiliation(s)
- Zaineb Hamzaoui
- Faculty of Medicine of Tunis—LR99ES09 Research Laboratory of Antimicrobial Resistance, University of Tunis El Manar, Tunis, Tunisia
- Faculty of Sciences of Bizerte, University of Carthage, Tunis, Tunisia
| | - Alain Ocampo-Sosa
- Service of Microbiology, University Hospital Marqués de Valdecilla-IDIVAL, Santander, Spain
| | - Elaa Maamar
- Faculty of Medicine of Tunis—LR99ES09 Research Laboratory of Antimicrobial Resistance, University of Tunis El Manar, Tunis, Tunisia
| | | | - Sana Ferjani
- Faculty of Medicine of Tunis—LR99ES09 Research Laboratory of Antimicrobial Resistance, University of Tunis El Manar, Tunis, Tunisia
- Faculty of Sciences of Bizerte, University of Carthage, Tunis, Tunisia
| | - Samia Hammami
- Faculty of Medicine of Tunis—LR99ES09 Research Laboratory of Antimicrobial Resistance, University of Tunis El Manar, Tunis, Tunisia
- Faculty of Sciences of Bizerte, University of Carthage, Tunis, Tunisia
| | - Sarra Harbaoui
- Faculty of Medicine of Tunis—LR99ES09 Research Laboratory of Antimicrobial Resistance, University of Tunis El Manar, Tunis, Tunisia
| | - Nathalie Genel
- Department of Bacteriology, Medical School, University Pierre et Marie Curie, Paris, France
| | - Guillaume Arlet
- Department of Bacteriology, Medical School, University Pierre et Marie Curie, Paris, France
| | - Mabrouka Saidani
- Faculty of Medicine of Tunis—LR99ES09 Research Laboratory of Antimicrobial Resistance, University of Tunis El Manar, Tunis, Tunisia
- Laboratory of Microbiology, Charles Nicolle Hospital, Tunis, Tunisia
| | - Amine Slim
- Faculty of Medicine of Tunis—LR99ES09 Research Laboratory of Antimicrobial Resistance, University of Tunis El Manar, Tunis, Tunisia
- Laboratory of Microbiology, Charles Nicolle Hospital, Tunis, Tunisia
| | - Ilhem Boutiba-Ben Boubaker
- Faculty of Medicine of Tunis—LR99ES09 Research Laboratory of Antimicrobial Resistance, University of Tunis El Manar, Tunis, Tunisia
- Laboratory of Microbiology, Charles Nicolle Hospital, Tunis, Tunisia
| | - Luis Martinez-Martinez
- Service of Microbiology, University Hospital Marqués de Valdecilla-IDIVAL, Santander, Spain
- Department of Molecular Biology, School of Medicine, University of Cantabria, Santander, Spain
| |
Collapse
|
6
|
Akinbami OR, Olofinsae S, Ayeni FA. Prevalence of extended spectrum beta lactamase and plasmid mediated quinolone resistant genes in strains of Klebsiella pneumonia, Morganella morganii, Leclercia adecarboxylata and Citrobacter freundii isolated from poultry in South Western Nigeria. PeerJ 2018; 6:e5053. [PMID: 29942700 PMCID: PMC6016527 DOI: 10.7717/peerj.5053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 06/02/2018] [Indexed: 12/14/2022] Open
Abstract
A serious concern is arising on the coexistence of extended-spectrum beta-lactamase (ESBL) and plasmid mediated quinolone resistance (PMQR) producing bacteria in animal husbandry, which could be transferred to humans, especially in strains that may not be routinely screened for resistance. This study therefore tested the prevalence of ESBL and PMQR genes in selected bacteria isolated from poultry faeces. Faecal droppings of birds were collected from 11 farms in five states in South Western Nigeria. Bacteria were isolated from the samples on cefotaxime supplemented plates and identified with MALDI-TOF. The MIC was determined using VITEK system and resistance genes were detected with PCR. A total of 350 strains were isolated from different samples and selected strains were identified as 23 Klebsiella pneumonia, 12 Morganella morganii, seven Leclercia adecarboxylata and one Citrobacter freundii. All the species were resistant to gentamycin, trimethoprim/sulphamethaxole, tobramycin, piperacillin, cefotaxime and aztreonam (except Morganella morganii strains which were mostly susceptible to aztreonam). All the tested strains were susceptible to imipenem, meropenem and amikacin. All Leclercia adecarboxylata strains were resistant to ceftazidime, cefepime and fosfomycin while all Morganella morganii strains were resistant to fosfomycin, moxifloxacin and ciprofloxacin. All tested species were generally sensitive to ciprofloxacin except Morganella morganii strains which were resistant to ciprofloxacin. The resistance to ciprofloxacin, ceftazidime, cefepime, tigercylin, colistin and fosfomycin were 65%, 40%, 23%,, 7%, 33%, 48% respectively while the prevalence of SHV, TEM and CTX genes were 42%, 63%, 35% respectively. 9.3% of the isolates had the three ESBL genes, 2.33% had qnrA gene, 4.65% had qnr B gene while none had qnrS gene. The most prevalent PMQR gene is Oqxb (25.58%) while 6.98% had the qep gene. Klebsiella pneumoniae generally had both ESBL and PMQR genes. The high prevalence of extended spectrum beta-lactamase genes in the studied strains calls for caution in the use of beta lactam antibiotics in poultry feeds. This is the first report of the occurrence of extended spectrum beta-lactamase and plasmid mediated quinolone resistance genes in Morganella morganii and Leclercia adecarboxylata strains isolated from poultry faeces.
Collapse
Affiliation(s)
- Olajumoke R. Akinbami
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
| | - Samson Olofinsae
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
| | - Funmilola A. Ayeni
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Ibadan, Ibadan, Nigeria
| |
Collapse
|
7
|
Hamzaoui Z, Ocampo-Sosa A, Fernandez Martinez M, Landolsi S, Ferjani S, Maamar E, Saidani M, Slim A, Martinez-Martinez L, Boutiba-Ben Boubaker I. Role of association of OmpK35 and OmpK36 alteration and bla ESBL and/or bla AmpC genes in conferring carbapenem resistance among non-carbapenemase-producing Klebsiella pneumoniae. Int J Antimicrob Agents 2018; 52:898-905. [PMID: 29621592 DOI: 10.1016/j.ijantimicag.2018.03.020] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/01/2018] [Accepted: 03/28/2018] [Indexed: 12/16/2022]
Abstract
In Klebsiella pneumoniae, loss of the two major outer membrane porins (OMPs) OmpK35 and OmpK36 confers resistance to carbapenems in strains producing extended-spectrum β-lactamases (ESBLs) or plasmid-mediated AmpC-type β-lactamases. This study investigated mechanisms responsible for carbapenem resistance in non-carbapenemase-producing K. pneumoniae (NCPK). All carbapenem-resistant Enterobacteriaceae (CRE) at Charles Nicolle Hospital (Tunis, Tunisia) were collected over a 6-year period (2010-2015). Among the 334 CRE strains collected, 44 (13.2%) were NCPK. MIC ranges for ertapenem, imipenem and meropenem were 1 to >32 mg/L, 0.125-8 mg/L and 0.125-32 mg/L, respectively. All strains showed a multidrug-resistant (MDR) phenotype and were negative for carbapenemase activity. None of the carbapenemase genes searched for were found. ESBL production was confirmed in all isolates except one [CTX-M-15 (n = 39) and SHV-5 (n = 4)]. Three isolates produce DHA-1 (associated with CTX-M-15 in two strains). Molecular fingerprints grouped the 44 NCPK isolates into seven clusters. In seven representative strains of these clusters, SDS-PAGE results showed that four isolates lacked the OmpK35 porin, one isolate lacked OmpK36 and two isolates lacked both OmpK35 and OmpK36. Sequencing of the corresponding porin genes showed amino acid insertions and deletions leading to early termination of translation, point mutations in the promoter region, or insertion sequences disrupting the gene coding sequence. Loss or deficiency of OMPs, coupled with ESBL and/or AmpC production, plays an important role in conferring carbapenem resistance in K. pneumoniae. Dissemination of these MDR bacteria in our hospital may create serious therapeutic problems in the future.
Collapse
Affiliation(s)
- Zaineb Hamzaoui
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES09 Research Laboratory 'Antimicrobial resistance', 1007 Tunis, Tunisia; University of Carthage, Faculty of Sciences of Bizerte, Tunis, Tunisia.
| | - Alain Ocampo-Sosa
- Service of Microbiology, University Hospital Marqués de Valdecilla-IDIVAL, Santander 39008, Spain
| | - Marta Fernandez Martinez
- Service of Microbiology, University Hospital Marqués de Valdecilla-IDIVAL, Santander 39008, Spain
| | - Sarrah Landolsi
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES09 Research Laboratory 'Antimicrobial resistance', 1007 Tunis, Tunisia
| | - Sana Ferjani
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES09 Research Laboratory 'Antimicrobial resistance', 1007 Tunis, Tunisia; University of Carthage, Faculty of Sciences of Bizerte, Tunis, Tunisia
| | - Elaa Maamar
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES09 Research Laboratory 'Antimicrobial resistance', 1007 Tunis, Tunisia
| | - Mabrouka Saidani
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES09 Research Laboratory 'Antimicrobial resistance', 1007 Tunis, Tunisia; Charles Nicolle Hospital, Laboratory of Microbiology, 1006 Tunis, Tunisia
| | - Amine Slim
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES09 Research Laboratory 'Antimicrobial resistance', 1007 Tunis, Tunisia; Charles Nicolle Hospital, Laboratory of Microbiology, 1006 Tunis, Tunisia
| | - Luis Martinez-Martinez
- Clinical Unit of Microbiology, University Hospital Reina Sofía, Córdoba, Spain; Department of Microbiology, University of Córdoba, Córdoba, Spain; Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC), Córdoba, Spain
| | - Ilhem Boutiba-Ben Boubaker
- University of Tunis El Manar, Faculty of Medicine of Tunis, LR99ES09 Research Laboratory 'Antimicrobial resistance', 1007 Tunis, Tunisia; Charles Nicolle Hospital, Laboratory of Microbiology, 1006 Tunis, Tunisia
| |
Collapse
|
8
|
Prediction of Fluoroquinolone Susceptibility Directly from Whole-Genome Sequence Data by Using Liquid Chromatography-Tandem Mass Spectrometry To Identify Mutant Genotypes. Antimicrob Agents Chemother 2018; 62:AAC.01814-17. [PMID: 29263066 DOI: 10.1128/aac.01814-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/29/2017] [Indexed: 02/05/2023] Open
Abstract
Fluoroquinolone resistance in Gram-negative bacteria is multifactorial, involving target site mutations, reductions in fluoroquinolone entry due to reduced porin production, increased fluoroquinolone efflux, enzymes that modify fluoroquinolones, and Qnr, a DNA mimic that protects the drug target from fluoroquinolone binding. Here we report a comprehensive analysis, using transformation and in vitro mutant selection, of the relative importance of each of these mechanisms for fluoroquinolone nonsusceptibility using Klebsiella pneumoniae as a model system. Our improved biological understanding was then used to generate 47 rules that can predict fluoroquinolone susceptibility in K. pneumoniae clinical isolates. Key to the success of this predictive process was the use of liquid chromatography-tandem mass spectrometry to measure the abundance of proteins in extracts of cultured bacteria, identifying which sequence variants seen in the whole-genome sequence data were functionally important in the context of fluoroquinolone susceptibility.
Collapse
|
9
|
Pulzova L, Navratilova L, Comor L. Alterations in Outer Membrane Permeability Favor Drug-Resistant Phenotype ofKlebsiella pneumoniae. Microb Drug Resist 2017; 23:413-420. [DOI: 10.1089/mdr.2016.0017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Lucia Pulzova
- Laboratory of Biomedical Microbiology and Immunology, University of Veterinary Medicine and Pharmacy in Kosice, Kosice, Slovak Republic
| | - Lucie Navratilova
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic
- Laboratory of Growth Regulators, Institute of Experimental Botany AS CR, Palacky University, Olomouc, Czech Republic
| | - Lubos Comor
- Laboratory of Biomedical Microbiology and Immunology, University of Veterinary Medicine and Pharmacy in Kosice, Kosice, Slovak Republic
| |
Collapse
|
10
|
In vitro characterization and inhibition of the interaction between ciprofloxacin and berberine against multidrug-resistant Klebsiella pneumoniae. J Antibiot (Tokyo) 2016; 69:741-746. [PMID: 26932407 PMCID: PMC5399161 DOI: 10.1038/ja.2016.15] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 01/07/2016] [Accepted: 01/24/2016] [Indexed: 11/26/2022]
Abstract
Ciprofloxacin is a quinolone antibiotic used to treat Klebsiella pneumoniae infections in the clinic. Previous studies have demonstrated that berberine exhibits antibacterial activity and less acquired resistance related to efflux pumps. The multidrug efflux pump acrAB-tolC can be stimulated to expel as much toxic material as possible from the cells, but a detrimental effect can be produced owing to an overcrowded periplasm with excess expression products, which inhibits bacterial growth. In this study, the in vitro antibacterial activities of ciprofloxacin in combination with berberine were evaluated and compared with those of ciprofloxacin and berberine alone by evaluating the MIC, MBC and summation fractional IC against 20 clinical multidrug-resistant K. pneumoniae isolates, 1 quality control bacterium and 1 induced-resistance bacterium. Susceptibility tests showed that the MIC for the combination of berberine and ciprofloxacin was 1/2 that of the individual agents or less. Antimicrobial activities of 18.18% synergy and 77.27% additivity were found. Furthermore, synergism was verified through a time-kill assay, which suggested that the synergistic antibacterial effect of the two-drug combination may, to some extent, be related to the high expression of the acrAB-tolC and acrR multidrug efflux pumps. Indeed, the expression of these genes was increased >14-fold in the isolates affected by ciprofloxacin–berberine combination synergism.
Collapse
|
11
|
Searching for the Optimal Predictor of Ciprofloxacin Resistance in Klebsiella pneumoniae by Using In Vitro Dynamic Models. Antimicrob Agents Chemother 2015; 60:1208-15. [PMID: 26643328 DOI: 10.1128/aac.02334-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/23/2015] [Indexed: 12/20/2022] Open
Abstract
There is growing evidence of applicability of the hypothesis of the mutant selection window (MSW), i.e., the range between the MIC and the mutant prevention concentration (MPC), within which the enrichment of resistant mutants is most probable. However, it is not clear if MPC-based pharmacokinetic variables are preferable to the respective MIC-based variables as interstrain predictors of resistance. To examine the predictive power of the ratios of the area under the curve (AUC24) to the MPC and to the MIC, the selection of ciprofloxacin-resistant mutants of three Klebsiella pneumoniae strains with different MPC/MIC ratios was studied. Each organism was exposed to twice-daily ciprofloxacin for 3 days at AUC24/MIC ratios that provide peak antibiotic concentrations close to the MIC, between the MIC and the MPC, and above the MPC. Resistant K. pneumoniae mutants were intensively enriched at an AUC24/MIC ratio of 60 to 360 h (AUC24/MPC ratio from 2.5 to 15 h) but not at the lower or higher AUC24/MIC and AUC24/MPC ratios, in accordance with the MSW hypothesis. AUC24/MPC and AUC24/MIC relationships with areas under the time courses of ciprofloxacin-resistant K. pneumoniae (AUBCM) were bell shaped. These relationships predict highly variable "antimutant" AUC24/MPC ratios (20 to 290 h) compared to AUC24/MIC ratios (1,310 to 2,610 h). These findings suggest that the potential of the AUC24/MPC ratio as an interstrain predictor of K. pneumoniae resistance is lower than that of the AUC24/MIC ratio.
Collapse
|
12
|
Guillard T, Cholley P, Limelette A, Hocquet D, Matton L, Guyeux C, Lebreil AL, Bajolet O, Brasme L, Madoux J, Vernet-Garnier V, Barbe C, Bertrand X, de Champs On Behalf Of CarbaFrEst Group C. Fluoroquinolone Resistance Mechanisms and population structure of Enterobacter cloacae non-susceptible to Ertapenem in North-Eastern France. Front Microbiol 2015; 6:1186. [PMID: 26557115 PMCID: PMC4616961 DOI: 10.3389/fmicb.2015.01186] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/12/2015] [Indexed: 12/21/2022] Open
Abstract
Fluoroquinolone (FQ) agents are a potential resort to treat infection due to Enterobacteriaceae producing extended spectrum β-lactamase and susceptible to FQ. In a context of increase of non-susceptibility to carbapenems among Enterobacteriaceae, we characterized FQ resistance mechanisms in 75 Enterobacter cloacae isolates non-susceptible to ertapenem in North-Eastern France in 2012 and describe the population structure by pulsed field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Among them, 14.7% (12/75) carried a carbapenemase-encoding gene. Except one isolate producing VIM-1, the carbapenemase-producing isolates carried the well-known IncL/M pOXA48a plasmid. Most of the isolates (59/75) harbored at least a FQ-R determinant. qnr genes were predominant (40%, 30/75). The MLST study revealed that E. cloacae isolates’ clonality was wide [24 different sequence types (STs)]. The more widespread STs were ST74, ST101, ST110, ST114, and ST133. Carbapenem MICs were higher for E. cloacae ST74 than for other E. cloacae isolates. Plasmid-mediated quinolone resistance determinants were more often observed in E. cloacae ST74 isolates. These findings showed that (i) pOXA-48a is spreading in North-Eastern France, (ii) qnr is preponderant in E. cloacae, (iii) E. cloacae comprised a large amount of lineages spreading in North-Eastern France, and (iv) FQ as an alternative to β-lactams to treat ertapenem non-susceptible Enterobacteriaceae are compromised.
Collapse
Affiliation(s)
- Thomas Guillard
- Laboratoire de Bactériologie-Virologie-Hygiène, Hôpital Robert Debré, CHU Reims Reims, France ; Structure Fédérative de Recherche CAP-Santé, UFR Médecine, Université de Reims Champagne-Ardenne Reims, France
| | - Pascal Cholley
- Service d'Hygiène Hospitalière, CHRU Besançon Besançon, France ; UMR 6249 Chrono-environnement, Université de Franche-Comté Besançon, France
| | - Anne Limelette
- Laboratoire de Bactériologie-Virologie-Hygiène, Hôpital Robert Debré, CHU Reims Reims, France ; Structure Fédérative de Recherche CAP-Santé, UFR Médecine, Université de Reims Champagne-Ardenne Reims, France
| | - Didier Hocquet
- Service d'Hygiène Hospitalière, CHRU Besançon Besançon, France ; UMR 6249 Chrono-environnement, Université de Franche-Comté Besançon, France
| | - Lucie Matton
- Laboratoire de Bactériologie-Virologie-Hygiène, Hôpital Robert Debré, CHU Reims Reims, France ; Structure Fédérative de Recherche CAP-Santé, UFR Médecine, Université de Reims Champagne-Ardenne Reims, France
| | - Christophe Guyeux
- UMR 6174 CNRS, Département d'Informatique des Systèmes Complexes, Université de Franche-Comté Belfort, France
| | - Anne-Laure Lebreil
- Structure Fédérative de Recherche CAP-Santé, UFR Médecine, Université de Reims Champagne-Ardenne Reims, France
| | - Odile Bajolet
- Laboratoire de Bactériologie-Virologie-Hygiène, Hôpital Robert Debré, CHU Reims Reims, France ; Structure Fédérative de Recherche CAP-Santé, UFR Médecine, Université de Reims Champagne-Ardenne Reims, France
| | - Lucien Brasme
- Laboratoire de Bactériologie-Virologie-Hygiène, Hôpital Robert Debré, CHU Reims Reims, France ; Structure Fédérative de Recherche CAP-Santé, UFR Médecine, Université de Reims Champagne-Ardenne Reims, France
| | - Janick Madoux
- Laboratoire de Bactériologie-Virologie-Hygiène, Hôpital Robert Debré, CHU Reims Reims, France
| | - Véronique Vernet-Garnier
- Laboratoire de Bactériologie-Virologie-Hygiène, Hôpital Robert Debré, CHU Reims Reims, France ; Structure Fédérative de Recherche CAP-Santé, UFR Médecine, Université de Reims Champagne-Ardenne Reims, France
| | - Coralie Barbe
- Centre de Recherche et d'Investigation Clinique, Hôpital Robert Debré, CHU Reims Reims, France
| | - Xavier Bertrand
- Service d'Hygiène Hospitalière, CHRU Besançon Besançon, France ; UMR 6249 Chrono-environnement, Université de Franche-Comté Besançon, France
| | - Christophe de Champs On Behalf Of CarbaFrEst Group
- Laboratoire de Bactériologie-Virologie-Hygiène, Hôpital Robert Debré, CHU Reims Reims, France ; Structure Fédérative de Recherche CAP-Santé, UFR Médecine, Université de Reims Champagne-Ardenne Reims, France
| |
Collapse
|
13
|
Li XZ, Plésiat P, Nikaido H. The challenge of efflux-mediated antibiotic resistance in Gram-negative bacteria. Clin Microbiol Rev 2015; 28:337-418. [PMID: 25788514 PMCID: PMC4402952 DOI: 10.1128/cmr.00117-14] [Citation(s) in RCA: 939] [Impact Index Per Article: 104.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The global emergence of multidrug-resistant Gram-negative bacteria is a growing threat to antibiotic therapy. The chromosomally encoded drug efflux mechanisms that are ubiquitous in these bacteria greatly contribute to antibiotic resistance and present a major challenge for antibiotic development. Multidrug pumps, particularly those represented by the clinically relevant AcrAB-TolC and Mex pumps of the resistance-nodulation-division (RND) superfamily, not only mediate intrinsic and acquired multidrug resistance (MDR) but also are involved in other functions, including the bacterial stress response and pathogenicity. Additionally, efflux pumps interact synergistically with other resistance mechanisms (e.g., with the outer membrane permeability barrier) to increase resistance levels. Since the discovery of RND pumps in the early 1990s, remarkable scientific and technological advances have allowed for an in-depth understanding of the structural and biochemical basis, substrate profiles, molecular regulation, and inhibition of MDR pumps. However, the development of clinically useful efflux pump inhibitors and/or new antibiotics that can bypass pump effects continues to be a challenge. Plasmid-borne efflux pump genes (including those for RND pumps) have increasingly been identified. This article highlights the recent progress obtained for organisms of clinical significance, together with methodological considerations for the characterization of MDR pumps.
Collapse
Affiliation(s)
- Xian-Zhi Li
- Human Safety Division, Veterinary Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada
| | - Patrick Plésiat
- Laboratoire de Bactériologie, Faculté de Médecine-Pharmacie, Centre Hospitalier Régional Universitaire, Université de Franche-Comté, Besançon, France
| | - Hiroshi Nikaido
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
| |
Collapse
|
14
|
Shashwati N, Kiran T, Dhanvijay AG. Study of extended spectrum β-lactamase producing Enterobacteriaceae and antibiotic coresistance in a tertiary care teaching hospital. J Nat Sci Biol Med 2014; 5:30-5. [PMID: 24678193 PMCID: PMC3961948 DOI: 10.4103/0976-9668.127280] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Aims: To study the prevalence of extended spectrum β-lactamase (ESBL) producing Enterobacteriaceae and coresistance to other commonly used antibiotics from the Bhopal region of Central India. Settings and Design: A prospective study was conducted from September 2011 to August 2012 in Microbiology Department of our tertiary health care center. Materials and Methods: A total of 1044 Enterobacteriaceae isolates were recovered from various specimens. ESBL production was detected by using Clinical Laboratory Standard Institute (CLSI) that described the phenotypic confirmatory test along with routine antibiotic susceptibility testing. Statistical Analysis: Two-tailed Z-test. Results: Escherichia coli was the most common isolate (65.32%). ESBL production was confirmed in 504 (48.27%) isolates. The isolates of E. coli (50.14%) were the most common ESBL producers. Maximum ESBL isolates were obtained from urine samples (52.28%) and male patients (52.54%). Sensitivity to imipenem was 100% followed by piperacillin–tazobactam (89.28%), meropenem (87.5%), and amikacin (83.92%). Significant resistance was detected against trimethoprim–sulfomethoxazole, fluoroquinolones, and gentamicin. Conclusion: This is the only study conducted from Central India and shows high prevalence of ESBL production among Enterobacteriaceae. Imipenem seems to be more sensitive than meropenem. Piperacillin–tazobactam combination was found to be the best among the β-lactam–β-lactamase inhibitor combinations. Prevalence of ESBL producers were more in males than females.
Collapse
Affiliation(s)
- Nema Shashwati
- Department of Microbiology, L. N. Medical College and Research Centre, Bhopal, Madhya Pradesh, India
| | - Tripathi Kiran
- Department of Microbiology, L. N. Medical College and Research Centre, Bhopal, Madhya Pradesh, India
| | - A G Dhanvijay
- Department of Microbiology, L. N. Medical College and Research Centre, Bhopal, Madhya Pradesh, India
| |
Collapse
|
15
|
SATO T, YOKOTA SI, OKUBO T, ISHIHARA K, UENO H, MURAMATSU Y, FUJII N, TAMURA Y. Contribution of the AcrAB-TolC Efflux Pump to High-Level Fluoroquinolone Resistance in Escherichia coli Isolated from Dogs and Humans. J Vet Med Sci 2013; 75:407-14. [DOI: 10.1292/jvms.12-0186] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Toyotaka SATO
- Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, 582 Midorimachi, Bunkyoudai, Ebetsu, Hokkaido 069–8501, Japan
| | - Shin-ichi YOKOTA
- Department of Microbiology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060–8556, Hokkaido, Japan
| | - Torahiko OKUBO
- Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, 582 Midorimachi, Bunkyoudai, Ebetsu, Hokkaido 069–8501, Japan
| | - Kanako ISHIHARA
- Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, 582 Midorimachi, Bunkyoudai, Ebetsu, Hokkaido 069–8501, Japan
| | - Hiroshi UENO
- Laboratory of Zoonoses, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, 582 Midorimachi, Bunkyoudai, Ebetsu, Hokkaido 069–8501, Japan
| | - Yasukazu MURAMATSU
- Laboratory of Zoonoses, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, 582 Midorimachi, Bunkyoudai, Ebetsu, Hokkaido 069–8501, Japan
| | - Nobuhiro FUJII
- Department of Microbiology, Sapporo Medical University School of Medicine, South-1, West-17, Chuo-ku, Sapporo 060–8556, Hokkaido, Japan
| | - Yutaka TAMURA
- Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University, 582 Midorimachi, Bunkyoudai, Ebetsu, Hokkaido 069–8501, Japan
| |
Collapse
|
16
|
Fernández-Canigia L, Dowzicky MJ. Susceptibility of important Gram-negative pathogens to tigecycline and other antibiotics in Latin America between 2004 and 2010. Ann Clin Microbiol Antimicrob 2012; 11:29. [PMID: 23088592 PMCID: PMC3499165 DOI: 10.1186/1476-0711-11-29] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 09/29/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Tigecycline Evaluation and Surveillance Trial (T.E.S.T.) is a global surveillance study of antimicrobial susceptibility. This study reports data from Gram-negative isolates collected from centers in Latin America between 2004 and 2010. METHODS Consecutive bacterial isolates were tested at each center using broth microdilution methodology as described by the Clinical Laboratory Standards Institute (CLSI). Susceptibility was determined using the CLSI interpretive criteria. For tigecycline the US Federal Drug Administration (FDA) criteria were used. RESULTS A total of 16 232 isolates were analyzed. Susceptibility to imipenem, meropenem, and tigecycline was >95% against both non-extended-spectrum β-lactamase (ESBL) and ESBL producing Escherichia coli. Susceptibility to amikacin was also >95% for non-ESBL E. coli. 24.3% of E. coli were ESBL producers, ranging from 11.2% (58/519) in Colombia to 40.3% (31/77) in Honduras. Greater than 90% of non-ESBL Klebsiella pneumoniae were susceptible to tigecycline, carbapenems and amikacin. 35.3% of K. pneumoniae were ESBL producers, ranging from 17.2% (36/209) in Venezuela to 73.3% (55/75) in Honduras, with only imipenem and tigecycline maintaining >90% susceptibility. Greater than 90% of Klebsiella oxytoca, Enterobacter spp., and Serratia marcescens were susceptible to amikacin, carbapenems and tigecycline. The highest rates of susceptibility against Acinetobacter baumannii were seen for minocycline (89.4%) and imipenem (62.5%), while 95.8% of the A. baumannii isolates displayed an MIC≤2 μg/mL for tigecycline. CONCLUSIONS In this study carbapenems and tigecycline remain active against Enterobacteriaceae and A. baumannii; however, there is cause for concern with carbapenem non-susceptible isolates reported in all countries included in this study.
Collapse
Affiliation(s)
- Liliana Fernández-Canigia
- Laboratorio de Microbiología, Hospital Aleman, Pueyrredón 1640, PB, Ciudad Autónoma de Buenos Aires, Argentina.
| | | |
Collapse
|
17
|
Ruiz E, Ocampo-Sosa AA, Rezusta A, Revillo MJ, Román E, Torres C, Martínez-Martínez L. Acquisition of carbapenem resistance in multiresistant Klebsiella pneumoniae strains harbouring blaCTX-M-15, qnrS1 and aac(6')-Ib-cr genes. J Med Microbiol 2012; 61:672-677. [PMID: 22282462 DOI: 10.1099/jmm.0.038083-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Three closely related Klebsiella pneumoniae strains isolated from the same patient harboured bla(CTX-M-15), bla(OXA-1), bla(SHV-11), qnrS1, aac(6')-Ib-cr, oqxAB, aac(3)-II and aph(3')-Ia genes. Two of the isolates were recovered after treatment with meropenem and showed resistance to carbapenems. Sequencing of ompK35 and ompK36 porin genes of the carbapenem-resistant strains revealed the presence of premature stop codons in both, and OmpK35 and OmpK36 porins were not detected by SDS-PAGE. One carbepenem-resistant strain showed a high amount of LamB protein and did not express OmpK26 porin whereas the other strain expressed OmpK26 but not LamB. The lack of major porins apparently causes changes in the expression of other, specific, porins.
Collapse
Affiliation(s)
- Elena Ruiz
- Área Bioquímica y Biología Molecular, Univ. La Rioja, Logroño, Spain
| | - Alain A Ocampo-Sosa
- Service of Microbiology, Hosp. Univ. Marqués de Valdecilla-IFIMAV, Santander, Spain
| | | | | | - Elena Román
- Service of Microbiology, Hosp. Univ. Marqués de Valdecilla-IFIMAV, Santander, Spain
| | - Carmen Torres
- Área Bioquímica y Biología Molecular, Univ. La Rioja, Logroño, Spain
| | - Luis Martínez-Martínez
- Department of Molecular Biology, University of Cantabria, Santander, Spain.,Service of Microbiology, Hosp. Univ. Marqués de Valdecilla-IFIMAV, Santander, Spain
| |
Collapse
|
18
|
Shakib P, Ghafourian S, Zolfaghary MR, Hushmandfar R, Ranjbar R, Sadeghifard N. Prevalence of OmpK35 and OmpK36 porin expression in beta-lactamase and non-betalactamase- producing Klebsiella pneumoniae. Biologics 2011; 6:1-4. [PMID: 22291461 PMCID: PMC3266860 DOI: 10.2147/btt.s27582] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND The aims of this study were to confirm the presence of OmpK35 and OmpK36 in extended-spectrum beta-lactamase-producing and nonextended-spectrum beta-lactamase-producing Klebsiella pneumoniae and to determine the relationship between porin expression and resistance to third-generation cephalosporins. METHODS Fifty-two K. pneumoniae isolates were obtained and analyzed for extended-spectrum beta-lactamase and for OmpK35 and OmpK36. RESULTS Twenty-two (42.3%) isolates of K. pneumoniae were extended-spectrum beta-lactamase producers. The OmpK35 profile in K. pneumoniae producing extended-spectrum beta-lactamase showed the presence of porin protein in ceftazidime-sensitive K. pneumoniae (six isolates), and the OmpK36 profile in K. pneumoniae producing extended-spectrum beta-lactamase revealed isolates sensitive to cefotaxime (n = 8) and ceftriaxone (n = 6). All nonextended-spectrum beta-lactamase-producing K. pneumoniae showed the presence of OmpK35 and OmpK36 porin proteins. CONCLUSION The presence of OmpK35 is mostly related to ceftazidime susceptibility and less to cefotaxime and ceftriaxone susceptibility, while OmpK36 expression is seen more often in cefotaxime-sensitive isolates. OmpK35 and OmpK36 indicate nonextended-spectrum beta-lactamase producing strains, and their presence is important when selecting an antimicrobial agent.
Collapse
Affiliation(s)
- Pegah Shakib
- Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam
- Department of Microbiology, Qom Branch, Islamic Azad University of Qom, Qom
| | - Sobhan Ghafourian
- Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam
| | | | | | - Reza Ranjbar
- Molecular Biology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | | |
Collapse
|
19
|
Aathithan S, French GL. Prevalence and role of efflux pump activity in ciprofloxacin resistance in clinical isolates of Klebsiella pneumoniae. Eur J Clin Microbiol Infect Dis 2011; 30:745-52. [DOI: 10.1007/s10096-010-1147-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 12/23/2010] [Indexed: 10/18/2022]
|
20
|
Rodríguez-Martínez JM, Velasco C, Pascual Á, Cano ME, Martínez-Martínez L, Martínez-Martínez L, Pascual Á. Plasmid-mediated quinolone resistance: an update. J Infect Chemother 2011; 17:149-82. [DOI: 10.1007/s10156-010-0120-2] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Indexed: 01/27/2023]
|
21
|
Structural and biochemical analysis of the pentapeptide repeat protein EfsQnr, a potent DNA gyrase inhibitor. Antimicrob Agents Chemother 2010; 55:110-7. [PMID: 20937785 DOI: 10.1128/aac.01158-10] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The chromosomally encoded Qnr homolog protein from Enterococcus faecalis (EfsQnr), when expressed, confers to its host a decreased susceptibility to quinolones and consists mainly of tandem repeats, which is consistent with belonging to the pentapeptide repeat family of proteins (PRPs). EfsQnr was cloned with an N-terminal 6× His tag and purified to homogeneity. EfsQnr partially protected DNA gyrase from fluoroquinolone inhibition at concentrations as low as 20 nM. EfsQnr inhibited the ATP-dependent supercoiling activity of DNA gyrase with a 50% inhibitory concentration (IC(50)) of 1.2 μM, while no significant inhibition of ATP-independent relaxation activity was observed. EfsQnr was cytotoxic when overexpressed in Escherichia coli, resulting in the clumping of cells and a loss of viability. The X-ray crystal structure of EfsQnr was determined to 1.6-Å resolution. EfsQnr exhibits the right-handed quadrilateral beta-helical fold typical of PRPs, with features more analogous to MfpA (mycobacterium fluoroquinolone resistance pentapeptide) than to the PRPs commonly found in cyanobacteria.
Collapse
|
22
|
Martínez-Martínez L, Calvo J. El problema creciente de la resistencia antibiótica en bacilos gramnegativos: situación actual. Enferm Infecc Microbiol Clin 2010; 28 Suppl 2:25-31. [DOI: 10.1016/s0213-005x(10)70027-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
23
|
Jetter M, Spaniol V, Troller R, Aebi C. Down-regulation of porin M35 in Moraxella catarrhalis by aminopenicillins and environmental factors and its potential contribution to the mechanism of resistance to aminopenicillins. J Antimicrob Chemother 2010; 65:2089-96. [PMID: 20801781 PMCID: PMC2941675 DOI: 10.1093/jac/dkq312] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Objectives The outer membrane protein M35 of Moraxella catarrhalis is an antigenically conserved porin. Knocking out M35 significantly increases the MICs of aminopenicillins. The aim of this study was to determine the biological mechanism of this potentially new antimicrobial resistance mechanism of M. catarrhalis and the behaviour of M35 in general stress situations. Methods PCR using m35-specific primers was used to detect the m35 gene in clinical isolates. The m35 mRNA expression of strains 300, O35E and 415 after exposure to amoxicillin and different stress conditions was measured by real-time PCR and normalized in relation to their 16S rRNA expression. The expression of M35 protein was analysed by SDS-PAGE and western blotting. Results Screening of 52 middle ear isolates resulted in positive PCR products for all tested strains. The analysis of m35 mRNA expression after amoxicillin treatment showed 24%–85% down-regulation compared with the respective amoxicillin-free controls in all three strains tested. Also, analysis of protein concentrations revealed lower M35 expression after growth with amoxicillin. Investigation of M35 during general stress responses showed down-regulation of the porin with growth at 26°C and 42°C, under hyperosmolar stress and under iron restriction. Conclusions The reduced expression of M35 after aminopenicillin exposure indicates a novel resistance mechanism against aminopenicillins in M. catarrhalis, which may be relevant in vivo. The differences in expression after different stress treatments demonstrate that M35 is involved in general stress responses.
Collapse
Affiliation(s)
- Marion Jetter
- Institute for Infectious Diseases, University of Bern, CH-3010 Bern, Switzerland
| | | | | | | |
Collapse
|
24
|
Klebsiella pneumoniae AcrAB efflux pump contributes to antimicrobial resistance and virulence. Antimicrob Agents Chemother 2009; 54:177-83. [PMID: 19858254 DOI: 10.1128/aac.00715-09] [Citation(s) in RCA: 281] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Respiratory infections caused by Klebsiella pneumoniae are characterized by high rates of mortality and morbidity. Management of these infections is often difficult, due to the high frequency of strains that are resistant to multiple antimicrobial agents. Multidrug efflux pumps play a major role as a mechanism of antimicrobial resistance in Gram-negative pathogens. In the present study, we investigated the role of the K. pneumoniae AcrRAB operon in antimicrobial resistance and virulence by using isogenic knockouts deficient in the AcrB component and the AcrR repressor, both derived from the virulent strain 52145R. We demonstrated that the AcrB knockout was more susceptible, not only to quinolones, but also to other antimicrobial agents, including beta-lactams, than the wild-type strain and the AcrR knockout. We further showed that the AcrB knockout was more susceptible to antimicrobial agents present in human bronchoalveolar lavage fluid and to human antimicrobial peptides than the wild-type strain and the AcrR knockout. Finally, the AcrB knockout exhibited a reduced capacity to cause pneumonia in a murine model, in contrast to the wild-type strain. The results of this study suggest that, in addition to contributing to the multidrug resistance phenotype, the AcrAB efflux pump may represent a novel virulence factor required for K. pneumoniae to resist innate immune defense mechanisms of the lung, thus facilitating the onset of pneumonia.
Collapse
|
25
|
Fàbrega A, Madurga S, Giralt E, Vila J. Mechanism of action of and resistance to quinolones. Microb Biotechnol 2009; 2:40-61. [PMID: 21261881 PMCID: PMC3815421 DOI: 10.1111/j.1751-7915.2008.00063.x] [Citation(s) in RCA: 257] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 08/20/2008] [Accepted: 08/24/2008] [Indexed: 01/11/2023] Open
Abstract
Fluoroquinolones are an important class of wide-spectrum antibacterial agents. The first quinolone described was nalidixic acid, which showed a narrow spectrum of activity. The evolution of quinolones to more potent molecules was based on changes at positions 1, 6, 7 and 8 of the chemical structure of nalidixic acid. Quinolones inhibit DNA gyrase and topoisomerase IV activities, two enzymes essential for bacteria viability. The acquisition of quinolone resistance is frequently related to (i) chromosomal mutations such as those in the genes encoding the A and B subunits of the protein targets (gyrA, gyrB, parC and parE), or mutations causing reduced drug accumulation, either by a decreased uptake or by an increased efflux, and (ii) quinolone resistance genes associated with plasmids have been also described, i.e. the qnr gene that encodes a pentapeptide, which blocks the action of quinolones on the DNA gyrase and topoisomerase IV; the aac(6')-Ib-cr gene that encodes an acetylase that modifies the amino group of the piperazin ring of the fluoroquinolones and efflux pump encoded by the qepA gene that decreases intracellular drug levels. These plasmid-mediated mechanisms of resistance confer low levels of resistance but provide a favourable background in which selection of additional chromosomally encoded quinolone resistance mechanisms can occur.
Collapse
Affiliation(s)
- Anna Fàbrega
- Department of Microbiology, Hospital Clinic, School of Medicine, University of Barcelona, Spain
| | - Sergi Madurga
- Institute for Research in Biomedicine, Barcelona, Spain
- Departments of Physical Chemistry & IQTCUB and
| | - Ernest Giralt
- Institute for Research in Biomedicine, Barcelona, Spain
- Organic Chemistry, University of Barcelona, Spain
| | - Jordi Vila
- Department of Microbiology, Hospital Clinic, School of Medicine, University of Barcelona, Spain
| |
Collapse
|
26
|
The porin and the permeating antibiotic: a selective diffusion barrier in Gram-negative bacteria. Nat Rev Microbiol 2008; 6:893-903. [PMID: 18997824 DOI: 10.1038/nrmicro1994] [Citation(s) in RCA: 607] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Gram-negative bacteria are responsible for a large proportion of antibiotic-resistant bacterial diseases. These bacteria have a complex cell envelope that comprises an outer membrane and an inner membrane that delimit the periplasm. The outer membrane contains various protein channels, called porins, which are involved in the influx of various compounds, including several classes of antibiotics. Bacterial adaptation to reduce influx through porins is an increasing problem worldwide that contributes, together with efflux systems, to the emergence and dissemination of antibiotic resistance. An exciting challenge is to decipher the genetic and molecular basis of membrane impermeability as a bacterial resistance mechanism. This Review outlines the bacterial response towards antibiotic stress on altered membrane permeability and discusses recent advances in molecular approaches that are improving our knowledge of the physico-chemical parameters that govern the translocation of antibiotics through porin channels.
Collapse
|
27
|
Rodríguez-Martínez J, Pichardo C, García I, Pachón-Ibañez M, Docobo-Pérez F, Pascual A, Pachón J, Martínez-Martínez L. Activity of ciprofloxacin and levofloxacin in experimental pneumonia caused by Klebsiella pneumoniae deficient in porins, expressing active efflux and producing QnrA1. Clin Microbiol Infect 2008; 14:691-7. [DOI: 10.1111/j.1469-0691.2008.02020.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
28
|
Alteration of GyrA amino acid required for ciprofloxacin resistance in Klebsiella pneumoniae isolates in China. Antimicrob Agents Chemother 2008; 52:2980-3. [PMID: 18505849 DOI: 10.1128/aac.00151-08] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Resistance to ciprofloxacin was detected in 111 (48.1%) isolates of Klebsiella pneumoniae from China. GyrA alterations were identified in the ciprofloxacin-resistant and ciprofloxacin-susceptible isolates. The results, including previously published data, indicate that the single substitution Ser83-->Ile and three types of double mutations at Ser83 and Asp87 were required for ciprofloxacin resistance (P < 0.05).
Collapse
|
29
|
Wang A, Yang Y, Lu Q, Wang Y, Chen Y, Deng L, Ding H, Deng Q, Wang L, Shen X. Occurrence of qnr-positive clinical isolates in Klebsiella pneumoniae producing ESBL or AmpC-type β-lactamase from five pediatric hospitals in China. FEMS Microbiol Lett 2008; 283:112-6. [DOI: 10.1111/j.1574-6968.2008.01163.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
30
|
Martínez-Martínez L. Extended-spectrum beta-lactamases and the permeability barrier. Clin Microbiol Infect 2008; 14 Suppl 1:82-9. [PMID: 18154531 DOI: 10.1111/j.1469-0691.2007.01860.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The outer membrane of Gram-negative bacteria represents a barrier for penetration of hydrophilic compounds. Loss of porins (water-filled protein channels) contributes to antimicrobial resistance, particularly when additional mechanisms of resistance are expressed. Many studies on the structure and regulation of porins in Escherichia coli K-12 are available, but there is little information concerning clinical isolates of this species. In Klebsiella pneumoniae, two major porins, OmpK35 and OmpK36, are produced, but many extended-spectrum beta-lactamase (ESBL)-producing K. pneumoniae isolates do not express OmpK35. Loss of both OmpK35 and OmpK36 in ESBL-producing K. pneumoniae causes resistance to cefoxitin, increased resistance to expanded-spectrum cephalosporins, and decreased susceptibility to carbapenems, particularly ertapenem. Porin loss also decreases the susceptibility to other non-beta-lactam compounds, such as fluoroquinolones, of ESBL-producing organisms.
Collapse
Affiliation(s)
- L Martínez-Martínez
- Service of Microbiology, University Hospital Marqués de Valdecilla, Santander, Spain.
| |
Collapse
|
31
|
Kim JY, Lautenbach E, Chu J, Goyal M, Nachamkin I, McGowan K, Coffin S, Zaoutis T. Fluoroquinolone resistance in pediatric bloodstream infections because of Escherichia coli and Klebsiella species. Am J Infect Control 2008; 36:70-3. [PMID: 18241740 DOI: 10.1016/j.ajic.2007.01.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2007] [Revised: 01/24/2007] [Accepted: 01/29/2007] [Indexed: 11/27/2022]
Abstract
In pediatric bloodstream infections with fluoroquinolone (FQ)-resistant Escherichia coli and Klebsielia species, we noted an association between FQ resistance and extended-spectrum beta-lactamase (ESBL) production (OR, 12; 95% CI: 2.28-83.8). A case control study revealed no significant risk factors (including prior antibiotic use) for FQ resistance among ESBL E coli and Klebsiella species (ESBL-EK).
Collapse
Affiliation(s)
- Jason Y Kim
- Division of Infectious Diseases, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Pérez-Vázquez M, Román F, García-Cobos S, Campos J. Fluoroquinolone resistance in Haemophilus influenzae is associated with hypermutability. Antimicrob Agents Chemother 2007; 51:1566-9. [PMID: 17283196 PMCID: PMC1855460 DOI: 10.1128/aac.01437-06] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Forty-three percent (12/28) of ciprofloxacin (CIP)-nonsusceptible respiratory isolates of Haemophilus influenzae were hypermutable, compared with 8.5% (3/35) in the CIP-susceptible control group (P=0.002). CIP-nonsusceptible mutants were obtained with hypermutable strains only; these mutants developed three resistance mechanisms in a step-by-step process: target modifications, loss of a porin protein, and increased efflux.
Collapse
Affiliation(s)
- María Pérez-Vázquez
- Antibiotic Laboratory, Bacteriology Service, Centro Nacional de Microbiología, Instituto de Salud Carlos III, 28220 Majadahonda, Madrid, Spain
| | | | | | | |
Collapse
|
33
|
Caccamo M, Perilli M, Celenza G, Bonfiglio G, Tempera G, Amicosante G. Occurrence of Extended Spectrumβ-Lactamases Among Isolates of Enterobacteriaceae from Urinary Tract Infections in Southern Italy. Microb Drug Resist 2006; 12:257-64. [PMID: 17227211 DOI: 10.1089/mdr.2006.12.257] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The present investigation was undertaken to assess the prevalence of extended-spectrum beta-lactamases (ESbetaLs) among urinary tract infection (UTI) isolates. During 4 months in 2004, a total of 650 Enterobacteriaceae strains from UTIs was collected by five clinical microbiology laboratories located in southern Italy and the beta-lactamase production was investigated. A total of 50 of the 650 isolates were double-disk positive and suspected of producing an ESbetaL; Escherichia coli (36.0%) and Klebsiella pneumoniae (32.0%) were the most common species among all ESbetaL producers. Characterization of ESbetaL determinants was carried out by the colony blot hybridization method, and polymerase chain reaction (PCR) and DNA sequencing in order to identify the presence of bla (TEM), bla (SHV), bla (PER), and bla (CTX-M) determinants. The ESbetaL variants found in this study were the following: TEM-15, TEM-24, TEM-52, TEM-134, SHV-12, CTX-M-1, CTX-M-3, CTX-M-15, and PER-1. As expected, the majority of the isolates were found to be susceptible to imipenem (94%), cefepime (54%) and piperacillin-tazobactam (54%). The results of this survey show the prevalence of ESbetaL enzymes among enterobacterial pathogens causing UTIs in southern Italy.
Collapse
Affiliation(s)
- Marisa Caccamo
- Dipartimento di Scienze Microbiologiche, Università di Catania, Catania, Italy
| | | | | | | | | | | |
Collapse
|
34
|
Doménech-Sánchez A, Benedí VJ, Martínez-Martínez L, Albertí S. Evaluation of differential gene expression in susceptible and resistant clinical isolates of Klebsiella pneumoniae by DNA microarray analysis. Clin Microbiol Infect 2006; 12:936-40. [PMID: 16882305 DOI: 10.1111/j.1469-0691..01470.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
DNA microarray technology was used to evaluate differential gene expression in a susceptible Klebsiella pneumoniae isolate and a resistant clinical derivative. Nineteen genes were up-regulated in the resistant isolate when compared with the susceptible isolate. An ABC transporter-related gene, ycjV, was strongly over-expressed, suggesting the existence of a novel active efflux mechanism. Approximately half of the up-regulated genes coded for ribosomal proteins, or proteins involved in tRNA metabolism. Among 33 downregulated genes, almost one-third were related to nitrogen metabolism. A possible role of fitness in the development of antimicrobial resistance is suggested.
Collapse
Affiliation(s)
- A Doménech-Sánchez
- Departamento de Biología and Institut Universitari d'Investigació en Ciències de la Salut, Universidad de las Islas Baleares, Palma de Mallorca, Spain
| | | | | | | |
Collapse
|
35
|
Campos MA, Morey P, Bengoechea JA. Quinolones sensitize gram-negative bacteria to antimicrobial peptides. Antimicrob Agents Chemother 2006; 50:2361-7. [PMID: 16801413 PMCID: PMC1489791 DOI: 10.1128/aac.01437-05] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The treatment of infections caused by bacteria resistant to the vast majority of antibiotics is a challenge worldwide. Antimicrobial peptides (APs) make up the front line of defense in those areas exposed to microorganisms, and there is intensive research to explore their use as new antibacterial agents. On the other hand, it is known that subinhibitory concentrations of antibiotics affect the expression of numerous bacterial traits. In this work we evaluated whether treatment of bacteria with subinhibitory concentrations of quinolones may alter the sensitivity to APs. A 1-h treatment of Klebsiella pneumoniae with 0.25 x the MIC of ciprofloxacin rendered bacteria more sensitive to polymyxins B and E, human neutrophil defensin 1, and beta-defensin 1. Levofloxacin and nalidixic acid at 0.25 x the MICs also increased the sensitivity of K. pneumoniae to polymyxin B, whereas gentamicin and ceftazidime at 0.25 x the MICs did not have such an effect. Ciprofloxacin also increased the sensitivities of K. pneumoniae ciprofloxacin-resistant strains to polymyxin B. Two other pathogens, Pseudomonas aeruginosa and Haemophilus influenzae, also became more sensitive to polymyxins B and E after treatment with 0.25 x the MIC of ciprofloxacin. Incubation with ciprofloxacin did not alter the expression of the K. pneumoniae loci involved in resistance to APs. A 1-N-phenyl-naphthylamine assay showed that ciprofloxacin and levofloxacin increased the permeabilities of the K. pneumoniae and P. aeruginosa outer membranes, while divalent cations antagonized this action. Finally, we demonstrated that ciprofloxacin and levofloxacin increased the binding of APs to the outer membrane by using dansylated polymyxin B.
Collapse
Affiliation(s)
- Miguel A Campos
- Unidad de Investigación, Hospital Universitario Son Dureta, and Institut Universitari d'Investigacions en Ciències de la Salut (IUNICS), Palma de Mallorca, Spain
| | | | | |
Collapse
|
36
|
Doménech-Sánchez A, Javier Benedí V, Martínez-Martínez L, Albertí S. Evaluation of differential gene expression in susceptible and resistant clinical isolates of Klebsiella pneumoniae by DNA microarray analysis. Clin Microbiol Infect 2006. [DOI: 10.1111/j.1469-0691.2006.01470.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
37
|
Rodríguez-Martínez JM, López L, García I, Pascual A. Characterization of a clinical isolate of Haemophilus influenzae with a high level of fluoroquinolone resistance. J Antimicrob Chemother 2006; 57:577-8. [PMID: 16431860 DOI: 10.1093/jac/dki488] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
38
|
Abstract
Extended-spectrum beta-lactamases (ESBLs) are a rapidly evolving group of beta-lactamases which share the ability to hydrolyze third-generation cephalosporins and aztreonam yet are inhibited by clavulanic acid. Typically, they derive from genes for TEM-1, TEM-2, or SHV-1 by mutations that alter the amino acid configuration around the active site of these beta-lactamases. This extends the spectrum of beta-lactam antibiotics susceptible to hydrolysis by these enzymes. An increasing number of ESBLs not of TEM or SHV lineage have recently been described. The presence of ESBLs carries tremendous clinical significance. The ESBLs are frequently plasmid encoded. Plasmids responsible for ESBL production frequently carry genes encoding resistance to other drug classes (for example, aminoglycosides). Therefore, antibiotic options in the treatment of ESBL-producing organisms are extremely limited. Carbapenems are the treatment of choice for serious infections due to ESBL-producing organisms, yet carbapenem-resistant isolates have recently been reported. ESBL-producing organisms may appear susceptible to some extended-spectrum cephalosporins. However, treatment with such antibiotics has been associated with high failure rates. There is substantial debate as to the optimal method to prevent this occurrence. It has been proposed that cephalosporin breakpoints for the Enterobacteriaceae should be altered so that the need for ESBL detection would be obviated. At present, however, organizations such as the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards) provide guidelines for the detection of ESBLs in klebsiellae and Escherichia coli. In common to all ESBL detection methods is the general principle that the activity of extended-spectrum cephalosporins against ESBL-producing organisms will be enhanced by the presence of clavulanic acid. ESBLs represent an impressive example of the ability of gram-negative bacteria to develop new antibiotic resistance mechanisms in the face of the introduction of new antimicrobial agents.
Collapse
Affiliation(s)
- David L Paterson
- Infectious Disease Division, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
| | | |
Collapse
|
39
|
Pagès JM, Masi M, Barbe J. Inhibitors of efflux pumps in Gram-negative bacteria. Trends Mol Med 2005; 11:382-9. [PMID: 15996519 DOI: 10.1016/j.molmed.2005.06.006] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Revised: 05/23/2005] [Accepted: 06/20/2005] [Indexed: 11/16/2022]
Abstract
In Gram-negative bacteria, efflux complexes, consisting of an inner-membrane pump, a periplasmic adaptor protein and outer-membrane channel, provide an efficient means for the export of structurally unrelated drugs, causing the multidrug-resistance phenotype. Resistance due to this antibiotic efflux is an increasing problem worldwide. A new molecular challenge is to combat this transport by searching for new molecules to block efflux and thus restore drug susceptibility to resistant clinical strains. Recent data shed new light on the structure and activity of the archetypal efflux pumps AcrAB-TolC and MexAB-OprM. Here, we describe recent insights into the molecular mechanisms of bacterial efflux pumps and their inhibitors. Current progress for the clinical use of efflux-pump inhibitors and new strategies to combat the drug-efflux mechanisms will be discussed.
Collapse
Affiliation(s)
- Jean-Marie Pagès
- EA2197, IFR48, Faculté de Médecine, Université de la Méditerranée, 13385-Marseille, France.
| | | | | |
Collapse
|
40
|
Abstract
Bacterial resistance to quinolones/fluoroquinolones has emerged rapidly and such resistance has traditionally been attributed to the chromosomally mediated mechanisms that alter the quinolone targets (i.e. DNA gyrase and topoisomerase IV) and/or overproduce multidrug resistance efflux pumps. However, the discovery of the plasmid-borne quinolone resistance determinant, named qnr, has substantially broadened our horizon on the molecular mechanisms of quinolone resistance. Several recent reports of Qnr or its homologues encoded by transferable plasmids in Gram-negative bacteria isolated worldwide highlight the significance of the emerging plasmid-mediated mechanism(s). This also alerts us to the potential rapid dissemination of quinolone resistance determinants. Qnr belongs to the pentapeptide repeat family and protects DNA gyrase from the action of quinolone agents including the newer fluoroquinolones. This protection interplays with chromosomal mechanisms to raise significantly the resistance levels. The qnr-bearing strains generate quinolone-resistant mutants at a much higher frequency than those qnr-free strains. Furthermore, the qnr-plasmids are integron-associated and carry multiple resistance determinants providing resistance to several classes of antimicrobials including beta-lactams and aminoglycosides. The high quinolone resistance rates in Escherichia coli are used to address issues of quinolone resistance, and possible strategies for minimising quinolone resistance are discussed.
Collapse
Affiliation(s)
- Xian-Zhi Li
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA.
| |
Collapse
|
41
|
Skopková-Zarnayová M, Siebor E, Rovná D, Bujdáková H, Neuwirth C. Outer membrane protein profiles of clonally related Klebsiella pneumoniae isolates that differ in cefoxitin resistance. FEMS Microbiol Lett 2005; 243:197-203. [PMID: 15668019 DOI: 10.1016/j.femsle.2004.12.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2004] [Revised: 10/13/2004] [Accepted: 12/07/2004] [Indexed: 11/19/2022] Open
Abstract
Eleven genotypically related Klebsiella pneumoniae isolates were obtained from 11 patients. All isolates were resistant to third-generation cephalosporins due to the production of SHV-2a extended-spectrum beta-lactamase. Comparison of the outer membrane protein profiles revealed one isolate that lacked porins. This porin-deficient isolate was also resistant to cefoxitin (MIC 128 microg ml(-1)) and moxalactam (MIC 64 microg ml(-1)) and had elevated MIC of meropenem (2 microg ml(-1)) when compared to porin-expressing isolates (2-8, 4 and <0.06-0.125 microg ml(-1), respectively). Higher MICs, associated with loss of porins in outer membrane, were also observed for cefotaxime (4-8-fold), cefepime (>2-16-fold), ciprofloxacin (4-16-fold), imipenem and aztreonam (2-16-fold), but there was no significant difference among MICs of ceftazidime. The porin-deficient mutant was probably selected in vivo during ofloxacin therapy.
Collapse
Affiliation(s)
- Martina Skopková-Zarnayová
- Department of Microbiology and Virology, Comenius University, Mlynska dolina B-2, 845 15 Bratislava, Slovakia.
| | | | | | | | | |
Collapse
|
42
|
Pichardo C, del Carmen Conejo M, Bernabéu-Wittel M, Pascual A, Jiménez-Mejías ME, de Cueto M, Pachón-Ibáñez ME, García I, Pachón J, Martínez-Martínez L. Activity of cefepime and carbapenems in experimental pneumonia caused by porin-deficient Klebsiella pneumoniae producing FOX-5 beta-lactamase. Clin Microbiol Infect 2005; 11:31-8. [PMID: 15649301 DOI: 10.1111/j.1469-0691.2004.01018.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The in-vivo activities of cefepime, imipenem and meropenem against the porin-deficient strain Klebsiella pneumoniae C2 and its derivative K. pneumoniae C2(pMG252) coding for the AmpC-type beta-lactamase FOX-5 were determined. Bactericidal activities were determined with the kill-curve method. A pneumonia model in guinea-pigs was developed, and Cmax, t(1/2) and DeltaT/MIC were calculated for the three agents tested. Animals were treated for 72 h with sterile saline (control group) or with cefepime, imipenem or meropenem (240 mg/kg/day, intramuscularly, three times daily). Bacterial counts in lungs (log10 CFU/g tissue) were determined by serial dilution. MICs (mg/L) of cefepime, imipenem and meropenem against K. pneumoniae C2/K. pneumoniae C2(pMG252), determined by macrodilution, were: 0.5/4, 0.5/0.5 and 0.25/0.5, respectively. Bacterial counts in the lungs of animals infected with K. pneumoniae C2 and treated with antimicrobial agents were always lower than in the control group (cefepime, 4.4 +/- 0.5; imipenem, 4.6 +/- 0.4; meropenem, 4.7 +/- 0.5; control group, 5.6 +/- 0.8; p <0.01). No significant differences were observed among the groups receiving therapy (p >0.05). Bacterial lung clearance was higher in treated animals than in control animals following infection with K. pneumoniae C2(pMG252) (cefepime, 4.5 +/- 0.4; imipenem, 4.0 +/- 0.3; meropenem, 4.6 +/- 0.4; control group, 6.1 +/- 0.6; p <0.01), with imipenem producing better clearance than either cefepime or meropenem (p <0.05). Thus, in the guinea-pig pneumonia model, cefepime, imipenem and meropenem were each effective against the porin-deficient K. pneumoniae strain C2 and its derivative expressing the plasmid-mediated AmpC type beta-lactamase FOX-5.
Collapse
Affiliation(s)
- C Pichardo
- Service of Infectious Diseases, Hospitales Universitarios Virgen del Rocío, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Miró E, Vergés C, García I, Mirelis B, Navarro F, Coll P, Prats G, Martínez-Martínez L. [Resistance to quinolones and beta-lactams in Salmonella enterica due to mutations in topoisomerase-encoding genes, altered cell permeability and expression of an active efflux system]. Enferm Infecc Microbiol Clin 2005; 22:204-11. [PMID: 15056435 DOI: 10.1016/s0213-005x(04)73067-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The mechanisms of resistance to fluoroquinolones and beta-lactams were studied in isolates of Salmonella enterica resistant to both antimicrobial groups, isolated over time from two patients treated with fluoroquinolones. METHODS The clonal relationships among the various strains was established by serotyping and pulsed-field gel electrophoresis. MICs for beta-lactams, quinolones, chloramphenicol and tetracycline were determined. Presence of beta-lactamases was ruled out by a colorimetric assay. Quinolone resistance-determining regions of the gyrA, gyrB, parC, and parE genes were sequenced, and the relevance of the mutations in these regions was evaluated by complementation assays. Outer membrane protein profiles, the effect of phenylalanyl-arginyl-naphthylamide (PAN, 20 mg/l) on the MICs of several quinolones, and norfloxacin accumulation in the absence and in the presence of a metabolic inhibitor were also determined. RESULTS The following mutations were found: gyrA (Asp87 --> Gly; Ser83 --> Phe; Asp87 --> Lys), gyrB (Ser463 --> Phe) and parC (Glu84 --> Gly). Altered outer membrane protein profiles, including decreased expression of a porin equivalent to OmpF from Escherichia coli was observed. Active efflux of norfloxacin was proved in both a clinical isolate and a mutant obtained in vitro. In the presence of PAN, nalidixic acid MICs decreased 4-32 times (except in one strain), pefloxacin MICs decreased 4-16 times for 5 out of 9 evaluated strains, and MICs of both norfloxacin and ciprofloxacin did not change or changed within a single dilution step. CONCLUSIONS Quinolone-resistance is the consequence of a combination of mutations in topoisomerase-encoding genes, altered permeability and active efflux. Altered permeability and active efflux would also contribute to decreased susceptibility to beta-lactams.
Collapse
Affiliation(s)
- Elisenda Miró
- Servicio de Microbiología, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Ghisalberti D, Masi M, Pagès JM, Chevalier J. Chloramphenicol and expression of multidrug efflux pump in Enterobacter aerogenes. Biochem Biophys Res Commun 2005; 328:1113-8. [PMID: 15707992 DOI: 10.1016/j.bbrc.2005.01.069] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Indexed: 10/25/2022]
Abstract
Chloramphenicol has been reported to act as an inducer of the multidrug resistance in Escherichia coli. A resistant variant able to grow on plates containing 64 microg/ml chloramphenicol was obtained from the Enterobacter aerogenes ATCC 13048-type strain. Chloramphenicol resistance was due to an active efflux of this antibiotic and it was associated with resistance to fluoroquinolones and tetracycline, but not to aminoglycoside or beta-lactam antibiotics. MDR in the chloramphenicol-resistant variant is linked to the overexpression of the major AcrAB-TolC efflux system. This overexpression seems unrelated to the global Mar and the local AcrR regulatory pathways.
Collapse
Affiliation(s)
- Didier Ghisalberti
- Enveloppe Bactérienne, Perméabilité et Antibiotiques, EA2197, IFR48, Faculté de Médecine, Université de la Méditerranée, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France
| | | | | | | |
Collapse
|
45
|
Horcajada JP, Fariñas MDC. Implicaciones de las resistencias bacterianas en las infecciones urinarias adquiridas en la comunidad. Enferm Infecc Microbiol Clin 2005; 23:1-3. [PMID: 15701324 DOI: 10.1157/13070400] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
46
|
Tavío MM, Vila J, Perilli M, Casañas LT, Maciá L, Amicosante G, Jiménez de Anta MT. Enhanced active efflux, repression of porin synthesis and development of Mar phenotype by diazepam in two enterobacteria strains. J Med Microbiol 2004; 53:1119-1122. [PMID: 15496390 DOI: 10.1099/jmm.0.45613-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The aim of this work was to determine whether diazepam could induce the multiple antibiotic resistance (Mar) phenotype in Klebsiella pneumoniae and Escherichia coli strains. The Mar phenotype is characterized by decreased susceptibility to multiple antibiotics due to the loss of porins and/or increased expression of active efflux systems. The effect of subinhibitory concentrations of diazepam on the susceptibility of different antimicrobial agents, outer-membrane protein expression and norfloxacin intracellular accumulation was studied. The results revealed that diazepam concentrations equal or twice adult dosage induced the same Mar phenotype as two well known E. coli marRAB inducers, sodium salicylate and sodium benzoate. Susceptibility to norfloxacin in a K. pneumoniae clinical isolate and E. coli strain Ag100 decreased due to enhanced active efflux and loss of porin expression. A decreased susceptibility to chloramphenicol, tetracycline, nalidixic acid and β-lactam antibiotics was also observed. In conclusion, like sodium salicylate or sodium benzoate, diazepam may induce the Mar phenotype.
Collapse
Affiliation(s)
- María M Tavío
- Microbiology, Department of Clinical Sciences, School of Medicine, University of Las Palmas de G. C., Dr. Pasteur, 35080 Las Palmas, Spain 2Department of Microbiology, Hospital Clinic, IDIBAPS, School of Medicine, University of Barcelona, Villarroel, 170, 08036 Barcelona, Spain 3Department of Science and Biomedical Technology, School of Medicine, University of L'Aquila, L'Aquila, Italy
| | - Jordi Vila
- Microbiology, Department of Clinical Sciences, School of Medicine, University of Las Palmas de G. C., Dr. Pasteur, 35080 Las Palmas, Spain 2Department of Microbiology, Hospital Clinic, IDIBAPS, School of Medicine, University of Barcelona, Villarroel, 170, 08036 Barcelona, Spain 3Department of Science and Biomedical Technology, School of Medicine, University of L'Aquila, L'Aquila, Italy
| | - Mariagrazia Perilli
- Microbiology, Department of Clinical Sciences, School of Medicine, University of Las Palmas de G. C., Dr. Pasteur, 35080 Las Palmas, Spain 2Department of Microbiology, Hospital Clinic, IDIBAPS, School of Medicine, University of Barcelona, Villarroel, 170, 08036 Barcelona, Spain 3Department of Science and Biomedical Technology, School of Medicine, University of L'Aquila, L'Aquila, Italy
| | - Lucía T Casañas
- Microbiology, Department of Clinical Sciences, School of Medicine, University of Las Palmas de G. C., Dr. Pasteur, 35080 Las Palmas, Spain 2Department of Microbiology, Hospital Clinic, IDIBAPS, School of Medicine, University of Barcelona, Villarroel, 170, 08036 Barcelona, Spain 3Department of Science and Biomedical Technology, School of Medicine, University of L'Aquila, L'Aquila, Italy
| | - Laura Maciá
- Microbiology, Department of Clinical Sciences, School of Medicine, University of Las Palmas de G. C., Dr. Pasteur, 35080 Las Palmas, Spain 2Department of Microbiology, Hospital Clinic, IDIBAPS, School of Medicine, University of Barcelona, Villarroel, 170, 08036 Barcelona, Spain 3Department of Science and Biomedical Technology, School of Medicine, University of L'Aquila, L'Aquila, Italy
| | - Gianfranco Amicosante
- Microbiology, Department of Clinical Sciences, School of Medicine, University of Las Palmas de G. C., Dr. Pasteur, 35080 Las Palmas, Spain 2Department of Microbiology, Hospital Clinic, IDIBAPS, School of Medicine, University of Barcelona, Villarroel, 170, 08036 Barcelona, Spain 3Department of Science and Biomedical Technology, School of Medicine, University of L'Aquila, L'Aquila, Italy
| | - María T Jiménez de Anta
- Microbiology, Department of Clinical Sciences, School of Medicine, University of Las Palmas de G. C., Dr. Pasteur, 35080 Las Palmas, Spain 2Department of Microbiology, Hospital Clinic, IDIBAPS, School of Medicine, University of Barcelona, Villarroel, 170, 08036 Barcelona, Spain 3Department of Science and Biomedical Technology, School of Medicine, University of L'Aquila, L'Aquila, Italy
| |
Collapse
|
47
|
Hasdemir UO, Chevalier J, Nordmann P, Pagès JM. Detection and prevalence of active drug efflux mechanism in various multidrug-resistant Klebsiella pneumoniae strains from Turkey. J Clin Microbiol 2004; 42:2701-6. [PMID: 15184455 PMCID: PMC427859 DOI: 10.1128/jcm.42.6.2701-2706.2004] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The prevalence of active drug efflux pump and porin alterations was investigated in Turkish nosocomial strains of Klebsiella pneumoniae exhibiting a multidrug-resistant phenotype. MICs of various antibiotics, including quinolones, chloramphenicol, tetracycline, and beta-lactams, for those strains were determined either with or without the efflux pump inhibitor phenylalanine arginine beta-naphthylamide (PAbetaN). Thirty-nine percent of the strains exhibited a PAbetaN-modulated resistance for quinolones, chloramphenicol, and tetracycline. In these strains, a significant increase of chloramphenicol accumulation was gained in the presence of the efflux pump inhibitor PAbetaN or with the energy uncoupler carbonyl cyanide m-chlorophenylhydrazone. Moreover, high-level expression of the membrane fusion protein AcrA, which was immunodetected in most of those isolates, suggests that the AcrAB/TolC efflux machinery contributed to their antibiotic resistance. Studies of K. pneumoniae porins indicated that the majority of the strains, including extended-spectrum beta-lactamase producers and efflux-positive ones, presented an alteration in their sorbitol-sensitive porin (OmpK35) expression. This is the first report showing the prominent role of active drug efflux in the antibiotic resistance of nosocomial K. pneumoniae strains from Turkey.
Collapse
Affiliation(s)
- Ufuk Over Hasdemir
- Department of Microbiology, School of Medicine, Marmara University, Istanbul, Turkey
| | | | | | | |
Collapse
|
48
|
Chevalier J, Bredin J, Mahamoud A, Malléa M, Barbe J, Pagès JM. Inhibitors of antibiotic efflux in resistant Enterobacter aerogenes and Klebsiella pneumoniae strains. Antimicrob Agents Chemother 2004; 48:1043-6. [PMID: 14982806 PMCID: PMC353160 DOI: 10.1128/aac.48.3.1043-1046.2004] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Enterobacter aerogenes and Klebsiella pneumoniae, efflux provides efficient extrusion of antibiotics and contributes to the multidrug resistance phenotype. One of the alkoxyquinoline derivatives studied here, 2,8-dimethyl-4-(2'-pyrrolidinoethyl)-oxyquinoline, restores noticeable drug susceptibility to resistant clinical strains. Analyses of energy-dependent chloramphenicol efflux indicate that this compound inhibits the efflux pump mechanism and improves the activity of structurally unrelated antibiotics on multidrug-resistant E. aerogenes and K. pneumoniae isolates.
Collapse
Affiliation(s)
- Jacqueline Chevalier
- EA2197, Faculté de Médecine, Université de la Méditerranée, 13385 Marseille Cedex 05, France
| | | | | | | | | | | |
Collapse
|
49
|
Rodríguez-Baño J, Navarro MD, Romero L, Martínez-Martínez L, Muniain MA, Perea EJ, Pérez-Cano R, Pascual A. Epidemiology and clinical features of infections caused by extended-spectrum beta-lactamase-producing Escherichia coli in nonhospitalized patients. J Clin Microbiol 2004; 42:1089-94. [PMID: 15004058 PMCID: PMC356843 DOI: 10.1128/jcm.42.3.1089-1094.2004] [Citation(s) in RCA: 311] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Infections due to extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBLEC) in nonhospitalized patients seem to be emerging in different countries. Their incidence, epidemiology, and clinical impact in the community have not been studied. We describe the epidemiology and clinical features of infections caused by ESBLEC in nonhospitalized patients in Spain and the results of a case-control study performed to investigate the risk factors associated with the acquisition of these organisms. The clonal relatedness of the organisms was assessed by repetitive extragenic palindromic sequence PCR. The ESBLs and the genes encoding the ESBLs were initially characterized by isoelectric focusing and PCR, respectively. Forty-nine patients (76% with urinary tract infections, 22% with asymptomatic bacteriuria, and 2% with acute cholangitis) were included. Six patients were bacteremic. Diabetes mellitus (odds ratio, 5.5; 95% confidence interval, 1.6 to 18.7), previous fluoroquinolone use (odds ratio, 7.6; 95% confidence interval, 1.9 to 30.1), recurrent urinary tract infections (odds ratio, 4.5; 95% confidence interval, 1.3 to 15.1), a previous hospital admission (odds ratio, 18.2; 95% confidence interval, 5.3 to 61.1), and older age in male patients (odds ratio per year, 1.03; 95% confidence interval, 1.03 to 1.05) were identified as risk factors by multivariate analysis. The ESBLEC isolates were not clonally related. The ESBLs were characterized as members of the CTX-M-9 group, the SHV group, and the TEM group in 64, 18, and 18% of the isolates, respectively. ESBLEC is an emergent cause of urinary tract infections in nonhospitalized patients. There was no evidence of horizontal transmission of ESBLEC strains. Avoidance of fluoroquinolone use in high-risk patients should be considered whenever possible in order to avoid the selection of these organisms.
Collapse
Affiliation(s)
- Jesús Rodríguez-Baño
- Sección de Enfermedades Infecciosas, Servicio de Medicina Interna, Hospital Universitario Virgen Macarena, Seville, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
Multiresistance in Gram-negative pathogens, particularly Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter spp. and the Enterobacteriaceae, is a significant problem in medicine today. While multiple mechanisms often contribute to multiresistance, a broadly distributed family of three-component multidrug efflux systems is an increasingly recognised determinant of both intrinsic and acquired multiresistance in these organisms. Homologues of these efflux systems are also readily identifiable in the genome sequences of a wide range of Gram-negative organisms, pathogens and non-pathogens alike, where they probably promote efflux-mediated resistance to multiple antimicrobials. Significantly, these systems often accommodate biocides, raising the spectre of biocide-mediated selection of multiresistance in Gram-negative pathogens. While there is some debate as to the natural function of these efflux systems, only some of which are inducible by their antimicrobial substrates, their contribution to resistance in a variety of pathogens nonetheless makes them reasonable targets for therapeutic intervention. Indeed, given the incredible chemical diversity of substrates accommodated by these efflux systems, it is likely that many novel or yet to be discovered antimicrobials will themselves be efflux substrates and, as such, efflux inhibitors may become an important component of Gram-negative antimicrobial therapy.
Collapse
Affiliation(s)
- K Poole
- Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, Canada K7L 3N6.
| |
Collapse
|