1
|
Miranda CD, Concha C, Godoy FA, Lee MR. Aquatic Environments as Hotspots of Transferable Low-Level Quinolone Resistance and Their Potential Contribution to High-Level Quinolone Resistance. Antibiotics (Basel) 2022; 11:1487. [PMID: 36358142 PMCID: PMC9687057 DOI: 10.3390/antibiotics11111487] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 10/01/2022] [Accepted: 10/04/2022] [Indexed: 08/27/2023] Open
Abstract
The disposal of antibiotics in the aquatic environment favors the selection of bacteria exhibiting antibiotic resistance mechanisms. Quinolones are bactericidal antimicrobials extensively used in both human and animal medicine. Some of the quinolone-resistance mechanisms are encoded by different bacterial genes, whereas others are the result of mutations in the enzymes on which those antibiotics act. The worldwide occurrence of quinolone resistance genes in aquatic environments has been widely reported, particularly in areas impacted by urban discharges. The most commonly reported quinolone resistance gene, qnr, encodes for the Qnr proteins that protect DNA gyrase and topoisomerase IV from quinolone activity. It is important to note that low-level resistance usually constitutes the first step in the development of high-level resistance, because bacteria carrying these genes have an adaptive advantage compared to the highly susceptible bacterial population in environments with low concentrations of this antimicrobial group. In addition, these genes can act additively with chromosomal mutations in the sequences of the target proteins of quinolones leading to high-level quinolone resistance. The occurrence of qnr genes in aquatic environments is most probably caused by the release of bacteria carrying these genes through anthropogenic pollution and maintained by the selective activity of antimicrobial residues discharged into these environments. This increase in the levels of quinolone resistance has consequences both in clinical settings and the wider aquatic environment, where there is an increased exposure risk to the general population, representing a significant threat to the efficacy of quinolone-based human and animal therapies. In this review the potential role of aquatic environments as reservoirs of the qnr genes, their activity in reducing the susceptibility to various quinolones, and the possible ways these genes contribute to the acquisition and spread of high-level resistance to quinolones will be discussed.
Collapse
Affiliation(s)
- Claudio D. Miranda
- Laboratorio de Patobiología Acuática, Departamento de Acuicultura, Universidad Católica del Norte, Coquimbo 1780000, Chile
| | - Christopher Concha
- Laboratorio de Patobiología Acuática, Departamento de Acuicultura, Universidad Católica del Norte, Coquimbo 1780000, Chile
| | - Félix A. Godoy
- Centro i~mar, Universidad de Los Lagos, Puerto Montt 5480000, Chile
| | - Matthew R. Lee
- Centro i~mar, Universidad de Los Lagos, Puerto Montt 5480000, Chile
| |
Collapse
|
2
|
Genotypic Diversity of Ciprofloxacin Nonsusceptibility and Its Relationship with Minimum Inhibitory Concentrations in Nontyphoidal Salmonella Clinical Isolates in Taiwan. Antibiotics (Basel) 2021; 10:antibiotics10111383. [PMID: 34827321 PMCID: PMC8614936 DOI: 10.3390/antibiotics10111383] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/07/2021] [Accepted: 11/09/2021] [Indexed: 11/25/2022] Open
Abstract
This study analyzed the genetic diversity of ciprofloxacin (CIP) nonsusceptibility and the relationship between two major mechanisms and minimum inhibitory concentrations (MICs) of CIP in nontyphoidal Salmonella (NTS). Chromosomal mutations in quinolone resistance-determining regions (QRDRs) and plasmid-mediated quinolone resistance (PMQR) genes were searched from ResFinder, ARG-ANNOT, and PubMed for designing the sequencing regions in gyrA, gyrB, parC, and parE, and the 13 polymerase chain reactions for PMQR genes. We found that QRDR mutations were detected in gyrA (82.1%), parC (59.0%), and parE (20.5%) but not in gyrB among the 39 isolates. Five of the 13 PMQR genes were identified, including oqxA (28.2%), oqxB (28.2%), qnrS (18.0%), aac(6′)-Ib-cr (10.3%), and qnrB (5.1%), which correlated with the MICs of CIP within 0.25–2 μg/mL, and it was found that oxqAB contributed more than qnr genes to increase the MICs. All the isolates contained either QRDR mutations (53.8%), PMQR genes (15.4%), or both (30.8%). QRDR mutations (84.6%) were more commonly detected than PMQR genes (46.2%). QRDR mutation numbers were significantly associated with MICs (p < 0.001). Double mutations in gyrA and parC determined high CIP resistance (MICs ≥ 4 μg/mL). PMQR genes contributed to intermediate to low CIP resistance (MICs 0.25–2 μg/mL), thus providing insights into mechanisms underlying CIP resistance.
Collapse
|
3
|
Baquero F, Martínez JL, Novais Â, Rodríguez-Beltrán J, Martínez-García L, Coque TM, Galán JC. Allogenous Selection of Mutational Collateral Resistance: Old Drugs Select for New Resistance Within Antibiotic Families. Front Microbiol 2021; 12:757833. [PMID: 34745065 PMCID: PMC8569428 DOI: 10.3389/fmicb.2021.757833] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 10/05/2021] [Indexed: 11/22/2022] Open
Abstract
Allogeneous selection occurs when an antibiotic selects for resistance to more advanced members of the same family. The mechanisms of allogenous selection are (a) collateral expansion, when the antibiotic expands the gene and gene-containing bacterial populations favoring the emergence of other mutations, inactivating the more advanced antibiotics; (b) collateral selection, when the old antibiotic selects its own resistance but also resistance to more modern drugs; (c) collateral hyper-resistance, when resistance to the old antibiotic selects in higher degree for populations resistant to other antibiotics of the family than to itself; and (d) collateral evolution, when the simultaneous or sequential use of antibiotics of the same family selects for new mutational combinations with novel phenotypes in this family, generally with higher activity (higher inactivation of the antibiotic substrates) or broader spectrum (more antibiotics of the family are inactivated). Note that in some cases, collateral selection derives from collateral evolution. In this article, examples of allogenous selection are provided for the major families of antibiotics. Improvements in minimal inhibitory concentrations with the newest drugs do not necessarily exclude “old” antibiotics of the same family of retaining some selective power for resistance to the newest agents. If this were true, the use of older members of the same drug family would facilitate the emergence of mutational resistance to the younger drugs of the family, which is frequently based on previously established resistance traits. The extensive use of old drugs (particularly in low-income countries and in farming) might be significant for the emergence and selection of resistance to the novel members of the family, becoming a growing source of variation and selection of resistance to the whole family. In terms of future research, it could be advisable to focus antimicrobial drug discovery more on the identification of new targets and new (unique) classes of antimicrobial agents, than on the perpetual chemical exploitation of classic existing ones.
Collapse
Affiliation(s)
- Fernando Baquero
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - José L Martínez
- Department of Microbial Biotechnology, National Center for Biotechnology (CNB-CSIC), Madrid, Spain
| | - Ângela Novais
- UCIBIO - Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, REQUIMTE, Faculty of Pharmacy, University of Porto, Porto, Portugal.,Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Jerónimo Rodríguez-Beltrán
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Laura Martínez-García
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Teresa M Coque
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Juan Carlos Galán
- Department of Microbiology, Ramón y Cajal University Hospital, Ramón y Cajal Institute for Health Research (IRYCIS), Network Center for Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| |
Collapse
|
4
|
Kaspersen H, Sekse C, Zeyl Fiskebeck E, Slettemeås JS, Simm R, Norström M, Urdahl AM, Lagesen K. Dissemination of Quinolone-Resistant Escherichia coli in the Norwegian Broiler and Pig Production Chains and Possible Persistence in the Broiler Production Environment. Appl Environ Microbiol 2020; 86:e02769-19. [PMID: 31953334 PMCID: PMC7082582 DOI: 10.1128/aem.02769-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 12/20/2019] [Indexed: 11/20/2022] Open
Abstract
In Norway, the use of quinolones in livestock populations is very low, and prophylactic use is prohibited. Despite this, quinolone-resistant Escherichia coli (QREC) isolates are present at low levels in several animal species. The source of these QREC isolates is unknown. The aim of this study was to characterize and compare QREC isolates from different animal species to identify putative factors that may promote the occurrence of QREC. A total of 280 QREC isolates, from broilers, pigs, red foxes, and wild birds, were whole-genome sequenced and analyzed. Well-known chromosomal and plasmid-mediated resistance mechanisms were identified. In addition, mutations in marR, marA, and rpoB causing novel amino acid substitutions in their respective proteins were detected. Phylogenetic analyses were used to determine the relationships between the isolates. Quinolone resistance mechanism patterns appeared to follow sequence type groups. Similar QREC isolates with similar resistance mechanism patterns were detected from the samples, and further phylogenetic analysis indicated close evolutionary relationships between specific isolates from different sources. This suggests the dissemination of highly similar QREC isolates between animal species and also the persistence of QREC strains within the broiler production chain. This highlights the importance of both control measures at the top of the production chain as well as biosecurity measures to avoid the further dissemination and persistence of QREC in these environments.IMPORTANCE Since antimicrobial usage is low in Norwegian animal husbandry, Norway is an ideal country to study antimicrobial resistance in the absence of selective pressure from antimicrobial usage. In particular, the usage of quinolones is very low, which makes it possible to investigate the spread and development of quinolone resistance in natural environments. Comparison of quinolone-resistant E. coli (QREC) isolates from livestock and wild animals in light of this low quinolone usage provides new insights into the development and dissemination of QREC in both natural and production environments. With this information, preventive measures may be taken to prevent further dissemination within Norwegian livestock and between other animals, thus maintaining the favorable situation in Norway.
Collapse
Affiliation(s)
| | | | | | | | - Roger Simm
- Institute of Oral Biology, Faculty of Dentistry, University of Oslo, Oslo, Norway
| | | | | | | |
Collapse
|
5
|
Nishikawa R, Murase T, Ozaki H. Plasmid-mediated quinolone resistance in Escherichia coli isolates from commercial broiler chickens and selection of fluoroquinolone-resistant mutants. Poult Sci 2020; 98:5900-5907. [PMID: 31198966 DOI: 10.3382/ps/pez337] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 05/29/2019] [Indexed: 11/20/2022] Open
Abstract
Plasmid-mediated quinolone resistance (PMQR) is a potential concern for animal husbandry and public health. Escherichia coli isolates from a total of 109 fecal samples collected from 6 commercial broiler farms between 2007 and 2011 were examined for PMQR genes, and transfer of these genes was tested by conjugation analysis to elucidate the prevalence and spread of PMQR in broiler chickens. Two isolates from 2 farms harbored the aac(6')-Ib-cr gene that was not detected in plasmids using Southern blot analysis of S1 nuclease-digested genomic DNA separated by pulsed-field gel electrophoresis. In these 2 isolates, nucleotide mutations in the gyrA and parC genes that result in amino acid substitutions were detected. Additionally, a total of 6 isolates originating from 6 chickens from the 2 farms were positive for the qnrS1 gene. In 2 of the 6 isolates, the qnrS1 gene was transferred to a recipient strain. Two transconjugants harboring the qnrS1 gene were cultured on media supplemented with successively higher concentrations of enrofloxacin (ERFX). After a 5-time subcultivation, the ERFX MICs reached 8 and 16 μg/mL, and no nucleotide mutations were detected in the gyrA, gyrB, parC, and parE genes. Our results suggest that the prevalence of PMQR was relatively low in broiler chickens and that exposure of bacteria carrying PMQR genes to the selective pressure of fluoroquinolones can result in resistance to fluoroquinolone, which is not caused by mutations in genes encoding topoisomerases.
Collapse
Affiliation(s)
- Ryo Nishikawa
- Laboratory of Veterinary Microbiology, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| | - Toshiyuki Murase
- Laboratory of Veterinary Microbiology, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.,The Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| | - Hiroichi Ozaki
- Laboratory of Veterinary Microbiology, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.,The Avian Zoonosis Research Center, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan
| |
Collapse
|
6
|
Abstract
While the description of resistance to quinolones is almost as old as these antimicrobial agents themselves, transferable mechanisms of quinolone resistance (TMQR) remained absent from the scenario for more than 36 years, appearing first as sporadic events and afterward as epidemics. In 1998, the first TMQR was soundly described, that is, QnrA. The presence of QnrA was almost anecdotal for years, but in the middle of the first decade of the 21st century, there was an explosion of TMQR descriptions, which definitively changed the epidemiology of quinolone resistance. Currently, 3 different clinically relevant mechanisms of quinolone resistance are encoded within mobile elements: (i) target protection, which is mediated by 7 different families of Qnr (QnrA, QnrB, QnrC, QnrD, QnrE, QnrS, and QnrVC), which overall account for more than 100 recognized alleles; (ii) antibiotic efflux, which is mediated by 2 main transferable efflux pumps (QepA and OqxAB), which together account for more than 30 alleles, and a series of other efflux pumps (e.g., QacBIII), which at present have been sporadically described; and (iii) antibiotic modification, which is mediated by the enzymes AAC(6')Ib-cr, from which different alleles have been claimed, as well as CrpP, a newly described phosphorylase.
Collapse
|
7
|
Li X, Zhang Y, Zhou X, Hu X, Zhou Y, Liu D, Maxwell A, Mi K. The plasmid-borne quinolone resistance protein QnrB, a novel DnaA-binding protein, increases the bacterial mutation rate by triggering DNA replication stress. Mol Microbiol 2019; 111:1529-1543. [PMID: 30838726 PMCID: PMC6617969 DOI: 10.1111/mmi.14235] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2019] [Indexed: 02/02/2023]
Abstract
Bacterial antibiotic resistance, a global health threat, is caused by plasmid transfer or genetic mutations. Quinolones are important antibiotics, partially because they are fully synthetic and resistance genes are unlikely to exist in nature; nonetheless, quinolone resistance proteins have been identified. The mechanism by which plasmid-borne quinolone resistance proteins promotes the selection of quinolone-resistant mutants is unclear. Here, we show that QnrB increases the bacterial mutation rate. Transcriptomic and genome sequencing analyses showed that QnrB promoted gene abundance near the origin of replication (oriC). In addition, the QnrB expression level correlated with the replication origin to terminus (oriC/ter) ratio, indicating QnrB-induced DNA replication stress. Our results also show that QnrB is a DnaA-binding protein that may act as an activator of DNA replication initiation. Interaction of QnrB with DnaA promoted the formation of the DnaA-oriC open complex, which leads to DNA replication over-initiation. Our data indicate that plasmid-borne QnrB increases bacterial mutation rates and that genetic changes can alleviate the fitness cost imposed by transmitted plasmids. Derivative mutations may impair antibiotic efficacy and threaten the value of antibiotic treatments. Enhanced understanding of how bacteria adapt to the antibiotic environment will lead to new therapeutic strategies for antibiotic-resistant infections.
Collapse
Affiliation(s)
- Xiaojing Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yujiao Zhang
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Xintong Zhou
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xinling Hu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yixuan Zhou
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Di Liu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 101408, China
| | - Anthony Maxwell
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Kaixia Mi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.,Savaid Medical School, University of Chinese Academy of Sciences, Beijing, 101408, China
| |
Collapse
|
8
|
van der Putten BCL, Remondini D, Pasquini G, Janes VA, Matamoros S, Schultsz C. Quantifying the contribution of four resistance mechanisms to ciprofloxacin MIC inEscherichia coli: a systematic review. J Antimicrob Chemother 2018; 74:298-310. [DOI: 10.1093/jac/dky417] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/16/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Boas C L van der Putten
- Amsterdam UMC, University of Amsterdam, Department of Global Health, Amsterdam Institute for Global Health and Development, Meibergdreef 9, Amsterdam, Netherlands
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Meibergdreef 9, Amsterdam, Netherlands
| | - Daniel Remondini
- Department of Physics and Astronomy (DIFA), University of Bologna, Viale Berti Pichat 6/2, Bologna, Bologna, Italy
| | - Giovanni Pasquini
- Department of Physics and Astronomy (DIFA), University of Bologna, Viale Berti Pichat 6/2, Bologna, Bologna, Italy
| | - Victoria A Janes
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Meibergdreef 9, Amsterdam, Netherlands
| | - Sébastien Matamoros
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Meibergdreef 9, Amsterdam, Netherlands
| | - Constance Schultsz
- Amsterdam UMC, University of Amsterdam, Department of Global Health, Amsterdam Institute for Global Health and Development, Meibergdreef 9, Amsterdam, Netherlands
- Amsterdam UMC, University of Amsterdam, Department of Medical Microbiology, Meibergdreef 9, Amsterdam, Netherlands
| |
Collapse
|
9
|
Ma G, Wu G, Li X, Wang H, Zhou M. Characterization of Ciprofloxacin Resistance in Laboratory-Derived Mutants of Vibrio parahaemolyticus with qnr Gene. Foodborne Pathog Dis 2018; 15:711-717. [PMID: 30074404 DOI: 10.1089/fpd.2018.2476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Ciprofloxacin, a broad-spectrum fluoroquinolone, is a bactericidal antibiotic targeting DNA gyrase and DNA topoisomerase IV encoded by the gyrA and parC genes. Resistance to fluoroquinolones requires the accumulation of multiple mutations including those that alter target genes and increase drug efflux. To examine the development of fluoroquinolones resistance in Vibrio parahaemolyticus, ciprofloxacin induction and selection was used to obtain several resistant V. parahaemolyticus mutants, which showed decreased susceptibilities to quinolones, and increased or decreased susceptibility to other structurally unrelated antibiotics. Quinolone resistance-determining region mutations were characterized, and it was found that gyrA mutations occurred in some of the high-level resistant mutants although qnr was present in both wild-type susceptible and resistant mutant strains. The mutants showed increased qnr expression and exposure to sub-inhibitory concentrations of ciprofloxacin caused a further increase in qnr expression independently of the SOS system. Two mutants demonstrated increased expression of the VmeCD-VpoC pump gene that promotes quinolone efflux. In addition, some of the high-level resistance mutants significantly decreased bacterial fitness. These data suggested that multiple genes contributed to the enhanced ciprofloxacin resistance appeared in V. parahaemolyticus and that acquisition of ciprofloxacin resistance impaired bacterial fitness.
Collapse
Affiliation(s)
- Gengqin Ma
- School of Food Science and Engineering, Wuhan Polytechnic University , Wuhan, China
| | - Gaosheng Wu
- School of Food Science and Engineering, Wuhan Polytechnic University , Wuhan, China
| | - Xiaofang Li
- School of Food Science and Engineering, Wuhan Polytechnic University , Wuhan, China
| | - Hongxun Wang
- School of Food Science and Engineering, Wuhan Polytechnic University , Wuhan, China
| | - Min Zhou
- School of Food Science and Engineering, Wuhan Polytechnic University , Wuhan, China
| |
Collapse
|
10
|
The genetic background of antibiotic resistance among clinical uropathogenic Escherichia coli strains. Mol Biol Rep 2018; 45:1055-1065. [PMID: 30008141 PMCID: PMC6156760 DOI: 10.1007/s11033-018-4254-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 07/10/2018] [Indexed: 01/07/2023]
Abstract
The spreading mechanisms of antibiotic resistance are related to many bacterial and environment factors. The overuse of antibiotics is leading to an unceasing emergence of new multidrug resistant strains. This problem also concerns uropathogenic Escherichia coli strains, which is the most common pathogen causing urinary tract infections. The aim of this study was the genetic analysis of antibiotic resistance in comparison to the phenotypic background of E. coli strains. The characterized collection of E. coli strains isolated 10 years ago from the urine samples of patients with urinary tract infections was used for antimicrobial susceptibility testing (the disc diffusion method) and analysis of antibiotic resistance genes (PCR reaction, sequencing). Additionally, the presence of ESBL strains was analyzed. Fourteen genes were associated with resistance to beta-lactams, aminoglycosides, sulfonamides and quinolones. The genetic analysis revealed that blaTEM-1 and sul2 were present in almost all of the studied strains. Other drug-resistance genes were very rare or non-existent. Otherwise, the phenotypic resistance to fluoroquinolones was well correlated with the genotypic background of the studied bacteria. The presence of particular genes and specific mutations indicate a high bacterial potential to multidrug resistance. On the other hand, it needs to be emphasized that the standard disk diffusion test for the routine antimicrobial susceptibility analysis is still the best way to estimate the current situation of bacterial drug-resistance.
Collapse
|
11
|
Vinué L, Hooper DC, Jacoby GA. Chromosomal mutations that accompany qnr in clinical isolates of Escherichia coli. Int J Antimicrob Agents 2018; 51:479-483. [PMID: 29360506 DOI: 10.1016/j.ijantimicag.2018.01.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/10/2018] [Accepted: 01/13/2018] [Indexed: 10/18/2022]
Abstract
We examined 13 qnr-positive and 14 qnr-negative clinical isolates of Escherichia coli for mutations previously seen in a qnr-containing laboratory strain exposed to supra minimum inhibitory concentrations (MICs) of ciprofloxacin. Among the qnr-positive strains, those with ciprofloxacin MICs of ≥ 2 µg/mL had at least one mutation in gyrA. Mutations in parC were present in strains with a ciprofloxacin MIC of ≥ 128 µg/mL. The 6 most ciprofloxacin-resistant strains contained additional plasmid-mediated quinolone resistance determinants. aac(6')-Ib-cr was found in 5 of the 6 strains. Eleven of the 13 strains had alterations in MarR, 9 in SoxR, and 5 had mutations in AcrR. All had elevated expression of at least one efflux pump gene, predominantly acrA (92% of the strains), followed by mdtE (54%) and ydhE (46%). Nine had functionally silent alterations in rfa, two had mutations in gmhB, and one of these also had a mutation in surA. An E. coli with ciprofloxacin MIC of 1024 µg/mL contained 4 different plasmid-mediated quinolone resistance determinants as well as gyrA, parC, parE and pump overexpression mutations. Nine of the 14 qnr-negative strains had mutations in topoisomerase genes with a ciprofloxacin MIC of 0.25 to 256 µg/mL. The three most resistant strains also had mutations in parE. Twelve had alterations in MarR, 10 in SoxR and 5 in AcrR. Ten of the 14 strains had elevated expression of efflux pumps with acrA (71.4%), followed by ydhE (50%) and mdtE (14.3%). A diversity of resistance mechanisms occurs in clinical isolates with and without qnr genes.
Collapse
Affiliation(s)
- Laura Vinué
- Massachusetts General Hospital, Boston, Massachusetts, USA.
| | - David C Hooper
- Massachusetts General Hospital, Boston, Massachusetts, USA
| | - George A Jacoby
- Lahey Hospital and Medical Center, Burlington, Massachusetts, USA
| |
Collapse
|
12
|
Tomova A, Ivanova L, Buschmann AH, Godfrey HP, Cabello FC. Plasmid-Mediated Quinolone Resistance (PMQR) Genes and Class 1 Integrons in Quinolone-Resistant Marine Bacteria and Clinical Isolates of Escherichia coli from an Aquacultural Area. MICROBIAL ECOLOGY 2018. [PMID: 28642992 DOI: 10.1007/s00248-017-1016-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Antimicrobial usage in aquaculture selects for antimicrobial-resistant microorganisms in the marine environment. The relevance of this selection to terrestrial animal and human health is unclear. Quinolone-resistance genes qnrA, qnrB, and qnrS were chromosomally located in four randomly chosen quinolone-resistant marine bacteria isolated from an aquacultural area with heavy quinolone usage. In quinolone-resistant uropathogenic clinical isolates of Escherichia coli from a coastal area bordering the same aquacultural region, qnrA was chromosomally located in two E. coli isolates, while qnrB and qnrS were located in small molecular weight plasmids in two other E. coli isolates. Three quinolone-resistant marine bacteria and three quinolone-resistant E. coli contained class 1 integrons but without physical association with PMQR genes. In both marine bacteria and uropathogenic E. coli, class 1 integrons had similar co-linear structures, identical gene cassettes, and similarities in their flanking regions. In a Marinobacter sp. marine isolate and in one E. coli clinical isolate, sequences immediately upstream of the qnrS gene were homologous to comparable sequences of numerous plasmid-located qnrS genes while downstream sequences were different. The observed commonality of quinolone resistance genes and integrons suggests that aquacultural use of antimicrobials might facilitate horizontal gene transfer between bacteria in diverse ecological locations.
Collapse
Affiliation(s)
- Alexandra Tomova
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY, USA
- Institute of Physiology, Faculty of Medicine, Comenius University in Bratislava, Bratislava, Slovakia
| | - Larisa Ivanova
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY, USA
| | | | - Henry P Godfrey
- Department of Pathology, New York Medical College, Valhalla, NY, USA
| | - Felipe C Cabello
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY, USA.
| |
Collapse
|
13
|
Wang J, Guo ZW, Zhi CP, Yang T, Zhao JJ, Chen XJ, Zeng L, Lv LC, Zeng ZL, Liu J. Impact of plasmid-borne oqxAB on the development of fluoroquinolone resistance and bacterial fitness in Escherichia coli. J Antimicrob Chemother 2017; 72:1293-1302. [DOI: 10.1093/jac/dkw576] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Accepted: 12/15/2016] [Indexed: 11/13/2022] Open
|
14
|
Albornoz E, Lucero C, Romero G, Quiroga MP, Rapoport M, Guerriero L, Andres P, Rodriguez C, Galas M, Centrón D, Corso A, Petroni A. Prevalence of Plasmid-Mediated Quinolone Resistance Genes in Clinical Enterobacteria from Argentina. Microb Drug Resist 2016; 23:177-187. [PMID: 27728774 DOI: 10.1089/mdr.2016.0033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This first nationwide study was conducted to analyze the prevalence of plasmid-mediated quinolone resistance (PMQR) genes in phenotypically unselected (consecutive) clinical enterobacteria. We studied 1,058 isolates that had been consecutively collected in 66 hospitals of the WHONET-Argentina Resistance Surveillance Network. Overall, 26% of isolates were nonsusceptible to at least one of the three quinolones tested (nalidixic acid, ciprofloxacin, and levofloxacin). The overall prevalence of PMQR genes was 8.1% (4.6% for aac(6')-Ib-cr; 3.9% for qnr genes; and 0.4% for oqxA and oqxB, which were not previously reported in enterobacteria other than Klebsiella spp. from Argentina). The PMQR prevalence was highly variable among the enterobacterial species or when the different genes were considered. The prevalent PMQR genes were located in class 1 integrons [qnrB2, qnrB10, and aac(6')-Ib-cr]; in the ColE1-type plasmid pPAB19-1 or Tn2012-like transposons (qnrB19); and in Tn6238 or bracketed by IS26 and blaOXA-1 [aac(6')-Ib-cr]. The mutations associated with quinolone resistance that were located in the quinolone resistance-determining region (QRDR mutations) of gyrA, parC, and gyrB were also investigated. The occurrence of QRDR mutations was significantly associated with the presence of PMQR genes: At least one QRDR mutation was present in 82% of the PMQR-harboring isolates but in only 23% of those without PMQR genes (p < 0.0001, Fisher's Test). To the best of our knowledge, this is the first report on the prevalence of PMQR genes in consecutive clinical enterobacteria where all the genes currently known have been screened.
Collapse
Affiliation(s)
- Ezequiel Albornoz
- 1 Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Celeste Lucero
- 1 Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Genara Romero
- 1 Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - María Paula Quiroga
- 2 Instituto de Investigaciones en Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET) , Ciudad Autónoma de Buenos Aires, Argentina
| | - Melina Rapoport
- 1 Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Leonor Guerriero
- 1 Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Patricia Andres
- 1 Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Cecilia Rodriguez
- 2 Instituto de Investigaciones en Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET) , Ciudad Autónoma de Buenos Aires, Argentina
| | - Marcelo Galas
- 3 Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Daniela Centrón
- 2 Instituto de Investigaciones en Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET) , Ciudad Autónoma de Buenos Aires, Argentina
| | - Alejandra Corso
- 1 Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| | - Alejandro Petroni
- 1 Servicio Antimicrobianos, Departamento de Bacteriología, Instituto Nacional de Enfermedades Infecciosas-ANLIS "Dr. Carlos G. Malbrán," Ciudad Autónoma de Buenos Aires, Argentina
| |
Collapse
|
15
|
Börjesson S, Guillard T, Landén A, Bengtsson B, Nilsson O. Introduction of quinolone resistant Escherichia coli to Swedish broiler population by imported breeding animals. Vet Microbiol 2016; 194:74-78. [DOI: 10.1016/j.vetmic.2015.11.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 10/29/2015] [Accepted: 11/08/2015] [Indexed: 01/04/2023]
|
16
|
Vinué L, Hooper DC. A simple technique for suppressor detection inEscherichia coli. FEMS Microbiol Lett 2016; 363:fnw228. [PMID: 27682418 PMCID: PMC7207127 DOI: 10.1093/femsle/fnw228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Revised: 09/02/2016] [Accepted: 09/27/2016] [Indexed: 11/13/2022] Open
Abstract
To study the viability of agyrA S83 stop mutation found in anEscherichia coli J53 ciprofloxacin-resistant strain (J53 CipR27), a pBR322 derivative was constructed with a TAG mutation in thebla gene knocking out ampicillin resistance. Ampicillin resistance was restored, suggesting that the strain contains tRNA suppressor activity able to suppress the UAG codongyrA and allow viability. The method was applied to 22 unique clinicalE. coli isolates, and all were found to have low-level suppressor activity. A simple cloning technique can be used to detect low to high levels of suppressor activity that could explain viability and widespread dissemination of resistance isolates.
Collapse
|
17
|
Plasmid-mediated quinolone resistance: Two decades on. Drug Resist Updat 2016; 29:13-29. [PMID: 27912841 DOI: 10.1016/j.drup.2016.09.001] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/03/2016] [Accepted: 08/29/2016] [Indexed: 11/21/2022]
Abstract
After two decades of the discovery of plasmid-mediated quinolone resistance (PMQR), three different mechanisms have been associated to this phenomenon: target protection (Qnr proteins, including several families with multiple alleles), active efflux pumps (mainly QepA and OqxAB pumps) and drug modification [AAC(6')-Ib-cr acetyltransferase]. PMQR genes are usually associated with mobile or transposable elements on plasmids, and, in the case of qnr genes, are often incorporated into sul1-type integrons. PMQR has been found in clinical and environmental isolates around the world and appears to be spreading. Although the three PMQR mechanisms alone cause only low-level resistance to quinolones, they can complement other mechanisms of chromosomal resistance to reach clinical resistance level and facilitate the selection of higher-level resistance, raising a threat to the treatment of infections by microorganisms that host these mechanisms.
Collapse
|
18
|
Hooper DC, Jacoby GA. Topoisomerase Inhibitors: Fluoroquinolone Mechanisms of Action and Resistance. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025320. [PMID: 27449972 DOI: 10.1101/cshperspect.a025320] [Citation(s) in RCA: 245] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Quinolone antimicrobials are widely used in clinical medicine and are the only current class of agents that directly inhibit bacterial DNA synthesis. Quinolones dually target DNA gyrase and topoisomerase IV binding to specific domains and conformations so as to block DNA strand passage catalysis and stabilize DNA-enzyme complexes that block the DNA replication apparatus and generate double breaks in DNA that underlie their bactericidal activity. Resistance has emerged with clinical use of these agents and is common in some bacterial pathogens. Mechanisms of resistance include mutational alterations in drug target affinity and efflux pump expression and acquisition of resistance-conferring genes. Resistance mutations in one or both of the two drug target enzymes are commonly in a localized domain of the GyrA and ParC subunits of gyrase and topoisomerase IV, respectively, and reduce drug binding to the enzyme-DNA complex. Other resistance mutations occur in regulatory genes that control the expression of native efflux pumps localized in the bacterial membrane(s). These pumps have broad substrate profiles that include other antimicrobials as well as quinolones. Mutations of both types can accumulate with selection pressure and produce highly resistant strains. Resistance genes acquired on plasmids confer low-level resistance that promotes the selection of mutational high-level resistance. Plasmid-encoded resistance is because of Qnr proteins that protect the target enzymes from quinolone action, a mutant aminoglycoside-modifying enzyme that also modifies certain quinolones, and mobile efflux pumps. Plasmids with these mechanisms often encode additional antimicrobial resistances and can transfer multidrug resistance that includes quinolones.
Collapse
Affiliation(s)
- David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - George A Jacoby
- Lahey Hospital and Medical Center, Burlington, Massachusetts 01805
| |
Collapse
|
19
|
Prevalence of quinolone resistance mechanisms in Enterobacteriaceae producing acquired AmpC β-lactamases and/or carbapenemases in Spain. Enferm Infecc Microbiol Clin 2016; 35:487-492. [PMID: 27345951 DOI: 10.1016/j.eimc.2016.05.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 05/19/2016] [Accepted: 05/23/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND Quinolone resistance in Enterobacteriaceae species has increased over the past few years, and is significantly associated to beta-lactam resistance. The aim of this study was to evaluate the prevalence of chromosomal- and plasmid-mediated quinolone resistance in acquired AmpC β-lactamase and/or carbapenemase-producing Enterobacteriaceae isolates. METHODS The presence of chromosomal- and plasmid-mediated quinolone resistance mechanisms [mutations in the quinolone resistance determining region (QRDR) of gyrA and parC and qnr, aac(6')-Ib-cr and qepA genes] was evaluated in 289 isolates of acquired AmpC β-lactamase- and/or carbapenemase-producing Enterobacteriaceae collected between February and July 2009 in 35 Spanish hospitals. RESULTS Plasmid mediated quinolone resistance (PMQR) genes were detected in 92 isolates (31.8%), qnr genes were detected in 83 isolates (28.7%), and the aac(6')-Ib-cr gene was detected in 20 isolates (7%). qnrB4 gene was the most prevalent qnr gene detected (20%), associated, in most cases, with DHA-1. Only 14.6% of isolates showed no mutations in gyrA or parC with a ciprofloxacin MIC of 0.5mg/L or higher, whereas PMQR genes were detected in 90% of such isolates. CONCLUSION qnrB4 gene was the most prevalent PMQR gene detected, and was significantly associated with acquired AmpC β-lactamase DHA-1. PMQR determinants in association with other chromosomal-mediated quinolone resistance mechanisms, different to mutations in gyrA and parC (increased energy-dependent efflux, altered lipopolysaccharide or porin loss), could lead to ciprofloxacin MIC values that exceed breakpoints established by the main international committees to define clinical antimicrobial susceptibility breakpoints.
Collapse
|
20
|
Abstract
Three mechanisms for plasmid-mediated quinolone resistance (PMQR) have been discovered since 1998. Plasmid genes qnrA, qnrB, qnrC, qnrD, qnrS, and qnrVC code for proteins of the pentapeptide repeat family that protects DNA gyrase and topoisomerase IV from quinolone inhibition. The qnr genes appear to have been acquired from chromosomal genes in aquatic bacteria, are usually associated with mobilizing or transposable elements on plasmids, and are often incorporated into sul1-type integrons. The second plasmid-mediated mechanism involves acetylation of quinolones with an appropriate amino nitrogen target by a variant of the common aminoglycoside acetyltransferase AAC(6')-Ib. The third mechanism is enhanced efflux produced by plasmid genes for pumps QepAB and OqxAB. PMQR has been found in clinical and environmental isolates around the world and appears to be spreading. The plasmid-mediated mechanisms provide only low-level resistance that by itself does not exceed the clinical breakpoint for susceptibility but nonetheless facilitates selection of higher-level resistance and makes infection by pathogens containing PMQR harder to treat.
Collapse
|
21
|
Mutations That Enhance the Ciprofloxacin Resistance of Escherichia coli with qnrA1. Antimicrob Agents Chemother 2015; 60:1537-45. [PMID: 26711751 DOI: 10.1128/aac.02167-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/13/2015] [Indexed: 01/20/2023] Open
Abstract
Plasmid-mediated qnr genes provide only a modest decrease in quinolone susceptibility but facilitate the selection of higher-level resistance. In Escherichia coli strain J53 without qnr, ciprofloxacin resistance often involves mutations in the GyrA subunit of DNA gyrase. Mutations in gyrA were absent, however, when 43 mutants with decreased ciprofloxacin susceptibility were selected from J53(pMG252) with qnrA1. Instead, in 13 mutants, individual and whole-genome sequencing identified mutations in marR and soxR associated with increased expression of marA and soxS and, through them, increased expression of the AcrAB pump, which effluxes quinolones. Nine mutants had increased expression of the MdtE efflux pump, and six demonstrated increased expression of the ydhE pump gene. Many efflux mutants also had increased resistance to novobiocin, another pump substrate, but other mutants were novobiocin hypersusceptible. Mutations in rfaD and rfaE in the pathway for inner core lipopolysaccharide (LPS) biosynthesis were identified in five such strains. Many of the pump and LPS mutants had decreased expression of OmpF, the major porin channel for ciprofloxacin entry. Three mutants had increased expression of qnrA that persisted when pMG252 from these strains was outcrossed. gyrA mutations were also rare when mutants with decreased ciprofloxacin susceptibility were selected from E. coli J53 with aac(6')-Ib-cr or qepA. We suggest that multiple genes conferring low-level resistance contribute to enhanced ciprofloxacin resistance selected from an E. coli strain carrying qnrA1, aac(6')-Ib-cr, or qepA because these determinants decrease the effective ciprofloxacin concentration and allow more common but lower-resistance mutations than those in gyrA to predominate.
Collapse
|
22
|
Thong KL, Ngoi ST, Chai LC, Teh CSJ. Quinolone Resistance Mechanisms Among Salmonella enterica in Malaysia. Microb Drug Resist 2015; 22:259-72. [PMID: 26683630 DOI: 10.1089/mdr.2015.0158] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The prevalence of quinolone-resistant Salmonella enterica is on the rise worldwide. Salmonella enterica is one of the major foodborne pathogens in Malaysia. Therefore, we aim to investigate the occurrence and mechanisms of quinolone resistance among Salmonella strains isolated in Malaysia. A total of 283 Salmonella strains isolated from food, humans, and animals were studied. The disk diffusion method was used to examine the quinolone susceptibility of the strains, and the minimum inhibitory concentration (MIC) values of nalidixic acid and ciprofloxacin were also determined. DNA sequencing of the quinolone resistance-determining regions (QRDRs) of gyrase and topoisomerase IV genes and the plasmid-borne qnr genes was performed. The transfer of the qnr gene was examined through transconjugation experiment. A total of 101 nalidixic acid-resistant Salmonella strains were identified. In general, all strains were highly resistant to nalidixic acid (average MICNAL, 170 μg/ml). Resistance to ciprofloxacin was observed in 30.7% of the strains (1 ≤ MICCIP ≤ 2 μg/ml). Majority of the strains contained missense mutations in the QRDR of gyrA (69.3%). Silent mutations were frequently detected in gyrB (75.2%), parC (27.7%), and parE (51.5%) within and beyond the QRDRs. Novel mutations were detected in parC and parE. The plasmid-borne qnrS1 variant was found in 36.6% of the strains, and two strains were found to be able to transfer the qnrS1 gene. Overall, mutations in gyrA and the presence of qnrS1 genes might have contributed to the high level of quinolone resistance among the strains. Our study provided a better understanding on the status of quinolone resistance among Salmonella strains circulating in Malaysia.
Collapse
Affiliation(s)
- Kwai Lin Thong
- 1 Microbiology Division, Faculty of Science, Institute of Biological Sciences, University of Malaya , Kuala Lumpur, Malaysia
| | - Soo Tein Ngoi
- 1 Microbiology Division, Faculty of Science, Institute of Biological Sciences, University of Malaya , Kuala Lumpur, Malaysia
| | - Lay Ching Chai
- 1 Microbiology Division, Faculty of Science, Institute of Biological Sciences, University of Malaya , Kuala Lumpur, Malaysia
| | - Cindy Shuan Ju Teh
- 2 Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur, Malaysia
| |
Collapse
|
23
|
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
|
24
|
Harada K, Sasaki A, Shimizu T. Effects of oral orbifloxacin on fecal coliforms in healthy cats: a pilot study. J Vet Med Sci 2015; 78:83-9. [PMID: 26311787 PMCID: PMC4751121 DOI: 10.1292/jvms.15-0407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The study objective was to determine the effect of oral orbifloxacin (ORB) on antimicrobial susceptibility and composition of fecal coliforms in cats. Nine cats were randomized to two groups administered a daily oral dose of 2.5 and 5.0 mg ORB/kg for 7 days and a control group (three cats per group). Coliforms were isolated from stool samples and were tested for susceptibilities to ORB and 5 other drugs. ORB concentration in feces was measured using high-performance liquid chromatography (HPLC). The coliforms were undetectable after 2 days of ORB administration, and their number increased in most cats after termination of the administration. Furthermore, only isolates of Escherichia coli were detected in all cats before administration, and those of Citrobacter freundii were detected after termination of the administration. E. coli isolates exhibited high ORB susceptibility [Minimum inhibitory concentration (MIC), ≤0.125 µg/ml] or relatively low susceptibility (MIC, 1-2 µg/ml) with a single gyrA mutation. C. freundii isolates largely exhibited intermediate ORB susceptibility (MIC, 4 µg/ml), in addition to resistance to ampicillin and cefazolin, and harbored qnrB, but not a gyrA mutation. HPLC revealed that the peaks of mean concentration were 61.3 and 141.0 µg/g in groups receiving 2.5 and 5.0 mg/kg, respectively. Our findings suggest that oral ORB may alter the total counts and composition of fecal coliform, but is unlikely to yield highly fluoroquinolone-resistant mutants of E. coli and C. freundii in cats, possibly because of the high drug concentration in feces.
Collapse
Affiliation(s)
- Kazuki Harada
- Department of Veterinary Internal Medicine, Tottori University, 4-101 Minami, Koyama-Cho, Tottori-Shi, Tottori 680-8553, Japan
| | | | | |
Collapse
|
25
|
Abstract
Quinolone antimicrobials are synthetic and widely used in clinical medicine. Resistance emerged with clinical use and became common in some bacterial pathogens. Mechanisms of resistance include two categories of mutation and acquisition of resistance-conferring genes. Resistance mutations in one or both of the two drug target enzymes, DNA gyrase and DNA topoisomerase IV, are commonly in a localized domain of the GyrA and ParE subunits of the respective enzymes and reduce drug binding to the enzyme-DNA complex. Other resistance mutations occur in regulatory genes that control the expression of native efflux pumps localized in the bacterial membrane(s). These pumps have broad substrate profiles that include quinolones as well as other antimicrobials, disinfectants, and dyes. Mutations of both types can accumulate with selection pressure and produce highly resistant strains. Resistance genes acquired on plasmids can confer low-level resistance that promotes the selection of mutational high-level resistance. Plasmid-encoded resistance is due to Qnr proteins that protect the target enzymes from quinolone action, one mutant aminoglycoside-modifying enzyme that also modifies certain quinolones, and mobile efflux pumps. Plasmids with these mechanisms often encode additional antimicrobial resistances and can transfer multidrug resistance that includes quinolones. Thus, the bacterial quinolone resistance armamentarium is large.
Collapse
Affiliation(s)
- David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - George A Jacoby
- Lahey Hospital and Medical Center, Burlington, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| |
Collapse
|
26
|
Goto K, Kawamura K, Arakawa Y. Contribution of QnrA, a Plasmid-Mediated Quinolone Resistance Peptide, to Survival of Escherichia coli Exposed to a Lethal Ciprofloxacin Concentration. Jpn J Infect Dis 2015; 68:196-202. [DOI: 10.7883/yoken.jjid.2014.153] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Kensuke Goto
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine
| | - Kumiko Kawamura
- Department of Pathophysiological Laboratory Science, Nagoya University Graduate School of Medicine
| | - Yoshichika Arakawa
- Department of Bacteriology, Nagoya University Graduate School of Medicine
| |
Collapse
|
27
|
A novel high-throughput cell-based assay aimed at identifying inhibitors of DNA metabolism in bacteria. Antimicrob Agents Chemother 2014; 58:7264-72. [PMID: 25246396 DOI: 10.1128/aac.03475-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Bacterial biosensor strains can be useful tools for the discovery and characterization of antibacterial compounds. A plasmid-based reporter vector containing a transcriptional fusion between the recA promoter and green fluorescence protein gene was introduced into an Escherichia coli ΔtolC strain to create a biosensor strain that selectively senses inhibitors of DNA metabolism via the SOS response. The strain was used to develop a high-throughput assay to identify new inhibitors of DNA metabolism. Screening of the AstraZeneca compound library with this strain identified known inhibitors of DNA metabolism, as well as novel chemotypes. The cellular target of one novel series was elucidated as DNA gyrase through genetic characterization of laboratory-generated resistant mutants followed by 50% inhibitory concentration measurements in a DNA gyrase activity assay. These studies validated the use of this antibiotic biosensor strain to identify novel selective inhibitors of DNA metabolism by high-throughput screening.
Collapse
|
28
|
Machuca J, Briales A, Labrador G, Díaz-de-Alba P, López-Rojas R, Docobo-Pérez F, Martínez-Martínez L, Rodríguez-Baño J, Pachón ME, Pascual A, Rodríguez-Martínez JM. Interplay between plasmid-mediated and chromosomal-mediated fluoroquinolone resistance and bacterial fitness in Escherichia coli. J Antimicrob Chemother 2014; 69:3203-15. [PMID: 25139837 DOI: 10.1093/jac/dku308] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
OBJECTIVES The aim of this study was to analyse the interplay among plasmid-mediated qnr genes, alone or in combination with multiple chromosomal-mediated fluoroquinolone (FQ) resistance determinants, susceptibility to FQs and bacterial fitness in an isogenic Escherichia coli collection. METHODS E. coli ATCC 25922 was used to modify or delete chromosomal genes. qnr genes were cloned into the pBK-CMV vector. The MICs of FQs were determined by microdilution. Mutant prevention concentration and frequency of mutants were evaluated. Bacterial fitness was analysed using ΔlacZ system competition assays using in vitro and in vivo models. RESULTS The relationships between the number of resistance mutations and bacterial fitness were complex. With specific combinations of resistance mechanisms the addition of a new resistance mutation was shown to improve bacterial fitness. qnrA1 caused a decrease in fitness (7%-21%) while qnrS1 caused an increase in fitness (9%-21%) when combined with chromosomal mutations. We identified susceptible triple mutants in which the acquisition of a fourth resistance mutation significantly increased fitness and at the same time reached the clinical resistance level (the acquisition of qnrS1 in a S83L + D87N + ΔmarR genetic background). A strong correlation with the production of reactive oxygen species, as well as changes in susceptibility, was observed following treatment with ciprofloxacin. CONCLUSIONS Our data indicate that there may be critical stages (depending on the genotype) in resistance development, including chromosomal- and plasmid-mediated mechanisms, at which some low-fitness mutants below the resistance breakpoint are able to evolve clinical resistance with just one or two mutations, and show increased fitness.
Collapse
Affiliation(s)
- Jesús Machuca
- Infectious Diseases and Clinical Microbiology Unit, University Hospital Virgen Macarena, Seville, Spain
| | - Alejandra Briales
- Department of Microbiology, University of Seville, Seville, Spain Spanish Network for Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain
| | - Gema Labrador
- Spanish Network for Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | | | - Rafael López-Rojas
- Spanish Network for Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Fernando Docobo-Pérez
- Infectious Diseases and Clinical Microbiology Unit, University Hospital Virgen Macarena, Seville, Spain Spanish Network for Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain
| | - Luis Martínez-Martínez
- Spanish Network for Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain University Hospital Marques de Valdecilla and Valdecilla Biomedical Research Institute (IDIVAL), Santander, Spain Department of Molecular Biology, University of Cantabria, Santander, Spain
| | - Jesús Rodríguez-Baño
- Infectious Diseases and Clinical Microbiology Unit, University Hospital Virgen Macarena, Seville, Spain Spanish Network for Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain Medicine Department, University of Seville, Seville, Spain
| | - Maria Eugenia Pachón
- Spanish Network for Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Alvaro Pascual
- Infectious Diseases and Clinical Microbiology Unit, University Hospital Virgen Macarena, Seville, Spain Department of Microbiology, University of Seville, Seville, Spain Spanish Network for Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain
| | - José-Manuel Rodríguez-Martínez
- Department of Microbiology, University of Seville, Seville, Spain Spanish Network for Research in Infectious Diseases (REIPI RD12/0015), Instituto de Salud Carlos III, Madrid, Spain
| |
Collapse
|
29
|
Wiedemann B, Heisig A, Heisig P. Uncomplicated Urinary Tract Infections and Antibiotic Resistance-Epidemiological and Mechanistic Aspects. Antibiotics (Basel) 2014; 3:341-52. [PMID: 27025749 PMCID: PMC4790371 DOI: 10.3390/antibiotics3030341] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/11/2014] [Accepted: 07/14/2014] [Indexed: 11/16/2022] Open
Abstract
Uncomplicated urinary tract infections are typically monobacterial and are predominantly caused by Escherichia coli. Although several effective treatment options are available, the rates of antibiotic resistance in urinary isolates of E. coli have increased during the last decade. Knowledge of the actual local rates of antibiotic resistant pathogens as well as the underlying mechanisms are important factors in addition to the geographical location and the health state of the patient for choosing the most effective antibiotic treatment. Recommended treatment options include trimethoprim alone or in combination with sulfamethoxazol, fluoroquinolones, β-lactams, fosfomycin-trometamol, and nitrofurantoin. Three basic mechanisms of resistance to all antibiotics are known, i.e., target alteration, reduced drug concentration and inactivation of the drug. These mechanisms—alone or in combination—contribute to resistance against the different antibiotic classes. With increasing prevalence, combinations of resistance mechanisms leading to multiple drug resistant (mdr) pathogens are being detected and have been associated with reduced fitness under in vitro situations. However, mdr clones among clinical isolates such as E. coli sequence type 131 (ST131) have successfully adapted in fitness and growth rate and are rapidly spreading as a worldwide predominating clone of extraintestinal pathogenic E. coli.
Collapse
Affiliation(s)
| | - Anke Heisig
- Pharmaceutical Biology and Microbiology, Institute of Biochemistry and Molecular Biology, University of Hamburg, Bundesstrasse 45, 20146 Hamburg, Germany.
| | - Peter Heisig
- Pharmaceutical Biology and Microbiology, Institute of Biochemistry and Molecular Biology, University of Hamburg, Bundesstrasse 45, 20146 Hamburg, Germany.
| |
Collapse
|
30
|
Guillard T, Grillon A, de Champs C, Cartier C, Madoux J, Berçot B, Lebreil AL, Lozniewski A, Riahi J, Vernet-Garnier V, Cambau E. Mobile insertion cassette elements found in small non-transmissible plasmids in Proteeae may explain qnrD mobilization. PLoS One 2014; 9:e87801. [PMID: 24504382 PMCID: PMC3913671 DOI: 10.1371/journal.pone.0087801] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 12/30/2013] [Indexed: 01/01/2023] Open
Abstract
qnrD is a plasmid mediated quinolone resistance gene from unknown origin, recently described in Enterobacteriaceae. It encodes a pentapeptide repeat protein 36-60% different from the other Qnr (A, B, C, S and VC). Since most qnrD-positive strains were described as strains belonging to Proteus or Providencia genera, we hypothesized that qnrD originated in Proteeae before disseminating to other enterobacterial species. We screened 317 strains of Proteeae for qnrD and its genetic support by PCR. For all the seven qnrD-positive strains (4 Proteus mirabilis, 1 Proteus vulgaris and 2 Providencia rettgeri) the gene was carried onto a small non-transmissible plasmid, contrarily to other qnr genes that are usually carried onto large multi-resistant plasmids. Nucleotide sequences of the qnrD-bearing plasmids were 96% identical. Plasmids contained 3 ORFs apart from qnrD and belonged to an undescribed incompatibility group. Only one plasmid, in P. vulgaris, was slightly different with a 1,568-bp insertion between qnrD and its promoter, leading to absence of quinolone resistance. We sought for similar plasmids in 15 reference strains of Proteeae, but which were tested negative for qnrD, and found a 48% identical plasmid (pVERM) in Providencia vermicola. In order to explain how qnrD could have been inserted into such native plasmid, we sought for gene mobilization structures. qnrD was found to be located within a mobile insertion cassette (mic) element which sequences are similar to one mic also found in pVERM. Our conclusions are that (i) the small non-transmissible qnrD-plasmids described here may result from the recombination between an as-yet-unknown progenitor of qnrD and pVERM, (ii) these plasmids are maintained in Proteeae being a qnrD reservoir (iii) the mic element may explain qnrD mobilization from non-transmissible plasmids to mobilizable or conjugative plasmids from other Enterobacteriaceae, (iv) they can recombined with larger multiresistant plasmids conjugated in Proteeae.
Collapse
Affiliation(s)
- Thomas Guillard
- EA 4687, UFR Médecine SFR CAP-Santé Université de Reims Champagne-Ardenne, Reims, France ; EA3964, PRES Sorbonne Paris Cité Université Paris Diderot-Paris 7, Paris, France ; Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France
| | - Antoine Grillon
- Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France
| | - Christophe de Champs
- EA 4687, UFR Médecine SFR CAP-Santé Université de Reims Champagne-Ardenne, Reims, France ; Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France
| | - Céline Cartier
- Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France
| | - Janick Madoux
- Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France
| | - Béatrice Berçot
- EA3964, PRES Sorbonne Paris Cité Université Paris Diderot-Paris 7, Paris, France ; Laboratoire de Bactériologie, AP-HP Groupe Hospitalier Lariboisière - Saint Louis, Paris, France
| | - Anne-Laure Lebreil
- EA 4687, UFR Médecine SFR CAP-Santé Université de Reims Champagne-Ardenne, Reims, France
| | - Alain Lozniewski
- Laboratoire de Bactériologie, CHU Nancy - Hôpital Central, Nancy, France
| | - Jacques Riahi
- Laboratoire de Bactériologie, AP-HP Groupe Hospitalier Lariboisière - Saint Louis, Paris, France
| | - Véronique Vernet-Garnier
- EA 4687, UFR Médecine SFR CAP-Santé Université de Reims Champagne-Ardenne, Reims, France ; Laboratoire de Bactériologie-Virologie-Hygiène, CHU Reims - Hôpital Robert Debré, Reims, France
| | - Emmanuelle Cambau
- EA3964, PRES Sorbonne Paris Cité Université Paris Diderot-Paris 7, Paris, France ; Laboratoire de Bactériologie, AP-HP Groupe Hospitalier Lariboisière - Saint Louis, Paris, France
| |
Collapse
|
31
|
Yang T, Zeng Z, Rao L, Chen X, He D, Lv L, Wang J, Zeng L, Feng M, Liu JH. The association between occurrence of plasmid-mediated quinolone resistance and ciprofloxacin resistance in Escherichia coli isolates of different origins. Vet Microbiol 2014; 170:89-96. [PMID: 24553411 DOI: 10.1016/j.vetmic.2014.01.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 01/23/2014] [Accepted: 01/24/2014] [Indexed: 10/25/2022]
Abstract
This study was performed to determine the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants and characterize the ciprofloxacin resistance in Escherichia coli isolated from different sources in China. PMQR determinants were detected by PCR amplification and sequencing in 2297 E. coli isolates randomly collected from animals, food and humans during 2004 to 2011. MICs of ciprofloxacin were determined by agar dilution method. Of the 2297 E. coli isolates, 43.6% harbored at least one PMQR gene. The most common PMQR gene was oqxAB (29.3%), followed by qnr (13.6%), aac(6')-Ib-cr (11.6%), and qepA (3.3%). 12.0% isolates carried two or more PMQR genes. The prevalence of PMQR genes in food animal isolates increased over time, from 38.7% in 2004 to 69.8% in 2011. The prevalence of PMQR/ciprofloxacin resistance among isolates from pig, chicken, duck, companion animals, animal food and human volunteers were 65.2%/69.6%, 42.4%/60.0%, 59.4%/65.0%, 28.6%/57.5%, 29.3%/25.6%, and 14.0/8.7%, respectively. Most isolates carrying qnr along showed susceptible to ciprofloxacin, and only 21.6% the isolates exhibited resistance to ciprofloxacin, which was significantly lower than those carrying other PMQR genes (65.2-89.9%) and those that do not (43.1%) (p<0.01). In conclusion, high frequency of ciprofloxacin resistance and PMQR genes was observed among E. coli isolates of different origins in China, with oqxAB being the most frequent. qnr-positive E. coli isolates have relatively low ciprofloxacin resistance rate compared with other PMQR determinants-carrying isolates and PMQR-negative isolates.
Collapse
Affiliation(s)
- Tong Yang
- College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China
| | - Zhenling Zeng
- College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China
| | - Lili Rao
- College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China
| | - Xiaojie Chen
- College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China
| | - Dandan He
- College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China
| | - Luchao Lv
- College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China
| | - Jing Wang
- College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China
| | - Li Zeng
- College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China
| | - Minsha Feng
- College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China
| | - Jian-Hua Liu
- College of Veterinary Medicine, National and Regional Joint Engineering Laboratory for Medicament of Zoonosis Prevention and Control, South China Agricultural University, Guangzhou, People's Republic of China.
| |
Collapse
|
32
|
Martínez-Martínez L, Eliecer Cano M, Manuel Rodríguez-Martínez J, Calvo J, Pascual Á. Plasmid-mediated quinolone resistance. Expert Rev Anti Infect Ther 2014; 6:685-711. [DOI: 10.1586/14787210.6.5.685] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
33
|
Sato T, Yokota SI, Uchida I, Okubo T, Usui M, Kusumoto M, Akiba M, Fujii N, Tamura Y. Fluoroquinolone resistance mechanisms in an Escherichia coli isolate, HUE1, without quinolone resistance-determining region mutations. Front Microbiol 2013; 4:125. [PMID: 23745120 PMCID: PMC3662882 DOI: 10.3389/fmicb.2013.00125] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2013] [Accepted: 05/02/2013] [Indexed: 12/30/2022] Open
Abstract
Fluoroquinolone resistance can cause major clinical problems. Here, we investigated fluoroquinolone resistance mechanisms in a clinical Escherichia coli isolate, HUE1, which had no mutations quinolone resistance-determining regions (QRDRs) of DNA gyrase and topoisomerase IV. HUE1 demonstrated MICs that exceeded the breakpoints for ciprofloxacin, levofloxacin, and norfloxacin. HUE1 harbored oqxAB and qnrS1 on distinct plasmids. In addition, it exhibited lower intracellular ciprofloxacin concentrations and higher mRNA expression levels of efflux pumps and their global activators than did reference strains. The genes encoding AcrR (local AcrAB repressor) and MarR (MarA repressor) were disrupted by insertion of the transposon IS3-IS629 and a frameshift mutation, respectively. A series of mutants derived from HUE1 were obtained by plasmid curing and gene knockout using homologous recombination. Compared to the MICs of the parent strain HUE1, the fluoroquinolone MICs of these mutants indicated that qnrS1, oqxAB, acrAB, acrF, acrD, mdtK, mdfA, and tolC contributed to the reduced susceptibility to fluoroquinolone in HUE1. Therefore, fluoroquinolone resistance in HUE1 is caused by concomitant acquisition of QnrS1 and OqxAB and overexpression of AcrAB–TolC and other chromosome-encoded efflux pumps. Thus, we have demonstrated that QRDR mutations are not absolutely necessary for acquiring fluoroquinolone resistance in E. coli.
Collapse
Affiliation(s)
- Toyotaka Sato
- Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University Ebetsu, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Cengiz M, Sahinturk P, Sonal S, Buyukcangaz E, Sen A, Arslan E. In vitro bactericidal activity of enrofloxacin against gyrA mutant and qnr-containing Escherichia coli isolates from animals. Vet Rec 2013; 172:474. [PMID: 23605176 DOI: 10.1136/vr.101331] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The objective of this work was to investigate the bactericidal activity of enrofloxacin against gyrA mutant and qnr-containing Escherichia coli isolates from animals. The minimum inhibitory concentrations (MICs) of gyrA mutant and qnr-containing E coli isolates ranged from 1 µg/ml to 32 µg/ml for enrofloxacin. Time-kill experiments were performed using selected E coli isolates. For the time-kill experiments, the colony counts were determined by plating each diluted sample onto plate count agar and an integrated pharmacokinetic/pharmacodynamics area measure (log ratio area) was applied to the colony-forming units (cfu) data. In general, enrofloxacin exhibited bactericidal activity against all the gyrA mutant E coli isolates at all concentrations greater than four times the MIC. However, the bactericidal activity of enrofloxacin for all the qnr-containing E coli isolates was less dependent on concentration. The results of the present study indicated that the genetic mechanism of resistance might account for the different bactericidal activities of enrofloxacin observed for the gyrA mutant and the qnr-containing E coli isolates. Therefore, in addition to MIC assays, genetic mechanism-based pharmacodynamic models should be used to provide accurate predictions of the effects of drugs on resistant bacteria.
Collapse
Affiliation(s)
- M Cengiz
- Laboratory of Molecular Pharmacology, Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Uludag University, Nilufer, Bursa 16059, Turkey.
| | | | | | | | | | | |
Collapse
|
35
|
Mechanisms accounting for fluoroquinolone multidrug resistance Escherichia coli isolated from companion animals. Vet Microbiol 2012; 161:159-68. [DOI: 10.1016/j.vetmic.2012.07.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2012] [Revised: 07/08/2012] [Accepted: 07/12/2012] [Indexed: 11/22/2022]
|
36
|
Zhang Y, Yang J, Ye L, Luo Y, Wang W, Zhou W, Cui Z, Han L. Characterization of Clinical Multidrug-ResistantEscherichia coliandKlebsiella pneumoniaeIsolates, 2007–2009, China. Microb Drug Resist 2012; 18:465-70. [PMID: 22548669 DOI: 10.1089/mdr.2012.0016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Youjiang Zhang
- Department of Microbiology, Chinese PLA General Hospital, Beijing, China
| | - Jiyong Yang
- Department of Microbiology, Chinese PLA General Hospital, Beijing, China
| | - Liyan Ye
- Department of Microbiology, Chinese PLA General Hospital, Beijing, China
| | - Yanping Luo
- Department of Microbiology, Chinese PLA General Hospital, Beijing, China
| | - Weiwei Wang
- Center for Hospital Infection Control, Chinese PLA Institute for Disease Control & Prevention, Beijing, China
| | - Wei Zhou
- Laboratory of Synthetic Biology and Microbial Genomics, Beijing Institute of Biotechnology, Beijing, China
| | - Zhigang Cui
- State Key Laboratory for Infectious Disease Prevention and Control, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Li Han
- Center for Hospital Infection Control, Chinese PLA Institute for Disease Control & Prevention, Beijing, China
| |
Collapse
|
37
|
Transferable mechanisms of quinolone resistance. Int J Antimicrob Agents 2012; 40:196-203. [DOI: 10.1016/j.ijantimicag.2012.02.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 02/20/2012] [Accepted: 02/21/2012] [Indexed: 11/20/2022]
|
38
|
Krishnan S, Balasubramanian D, Raju BA, Lakshmi BS. Use of a naturally occurring codon bias for identifying topoisomerase mutations in ciprofloxacin resistant <i>Escherichia coli</i> using PCR and future prospects with other bacterial genera: A pilot study. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/abc.2012.24045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
39
|
Michon A, Allou N, Chau F, Podglajen I, Fantin B, Cambau E. Plasmidic qnrA3 enhances Escherichia coli fitness in absence of antibiotic exposure. PLoS One 2011; 6:e24552. [PMID: 21915350 PMCID: PMC3168526 DOI: 10.1371/journal.pone.0024552] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 08/12/2011] [Indexed: 01/12/2023] Open
Abstract
The widespread presence of plasmid-mediated quinolone resistance determinants, particularly qnr genes, has become a current issue. By protecting DNA-gyrase from quinolones, Qnr proteins confer a low level quinolone resistance that is not sufficient to explain their emergence. Since Qnr proteins were hypothesized to act as DNA-binding protein regulators, qnr genes could have emerged by providing a selective advantage other than antibiotic resistance. We investigated host fitness of Escherichia coli isogenic strains after acquisition of the qnrA3 gene, inserted either alone onto a small plasmid (pBR322), or harbored on a large conjugative native plasmid, pHe96(qnrA3) found in a clinical isolate. The isogenic strains were derived from the susceptible E. coli CFT073, a virulent B2 group strain known to infect bladder and kidneys in a mouse model of pyelonephritis. In vitro experiments included growth analysis by automatic spectrophotometry and flow cytometry, and competitions with CFU enumeration. In vivo experiments included infection with each strain and pairwise competitions in absence of antimicrobial exposure. As controls for our experiments we used mutations known to reduce fitness (rpsL K42N mutation) or to enhance fitness (tetA deletion in pBR322). E. coli CFT073 transformed with pBRAM(PBR322-qnrA3) had significantly higher maximal OD than E. coli CFT073 transformed with pBR322 or pBR322ΔtetA, and in vivo competitions were more often won by the qnrA3 carrying strain (24 victories vs. 9 loss among 42 competitions, p = 0.001). In contrast, when pHe96(qnrA3) was introduced by conjugation in E. coli CFT073, it exerted a fitness cost shown by an impaired growth observed in vitro and in vivo and a majority of lost competitions (33/35, p<0.0001). In conclusion, qnrA3 acquisition enhanced bacterial fitness, which may explain qnr emergence and suggests a regulation role of qnr. However, fitness was reduced when qnrA3 was inserted onto multidrug-resistant plasmids and this can slow down its dissemination without antibiotic exposure.
Collapse
Affiliation(s)
| | | | | | | | - Bruno Fantin
- EA 3964, University Paris Diderot, Paris, France
- Medecine Interne Hôpital Beaujon, APHP, Clichy, France
| | - Emmanuelle Cambau
- EA 3964, University Paris Diderot, Paris, France
- Bacteriologie, Groupe Hospitalier Saint Louis-Lariboisière-Fernand Widal, APHP, Paris, France
- * E-mail:
| |
Collapse
|
40
|
Rapid detection of qnr and qepA plasmid-mediated quinolone resistance genes using real-time PCR. Diagn Microbiol Infect Dis 2011; 70:253-9. [DOI: 10.1016/j.diagmicrobio.2011.01.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Revised: 12/31/2010] [Accepted: 01/11/2011] [Indexed: 11/21/2022]
|
41
|
Yang J, Luo Y, Cui S, Wang W, Han L. Diverse phenotypic and genotypic characterization among clinical Klebsiella pneumoniae and Escherichia coli isolates carrying plasmid-mediated quinolone resistance determinants. Microb Drug Resist 2011; 17:363-7. [PMID: 21563956 DOI: 10.1089/mdr.2011.0034] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
A total of 59 and 74 nonduplicate plasmid-mediated quinolone resistance (PMQR) genes-carrying Klebsiella pneumoniae and Escherichia coli isolates were collected. All strains were assayed for fluoroquinolone susceptibility and the prevalence of quinolone resistance-determining regions (QRDRs) mutation. The association between PMQR determinants and common β-lactamase genes was also analyzed. Genetic relatedness of the isolates was analyzed by pulsed-field gel electrophoresis (PFGE). The PMQR genes-carrying K. pneumoniae and E. coli isolates exhibited high fluoroquinolone resistance rates, indicating that PMQR determinants play an essential role in the development of fluoroquinolone resistance. Remarkably, most qnr-carrying strains had only a single or no QRDR mutation in GyrA or ParC, and most exhibited decreased ciprofloxacin (CIP) susceptibility or low-level CIP resistance. However, 71.4% and 98.4% of qnr-negative K. pneumoniae and E. coli contained double QRDR mutations, and most presented high-level CIP resistance. Additionally, K. pneumoniae presented a lower CIP resistance rate than E. coli (59.3% vs. 91.9%) and low carriage of double QRDR mutations (38.9% vs. 89.9%). Also, most (88.1%) K. pneumoniae examined in this study carried qnr and only 14.9% of E. coli were qnr positive. Thus, the high fluoroquinolone susceptibility of K. pneumoniae isolates is primarily due to fewer QRDR substitutions as a result of high prevalence of qnr alleles in the host. Our findings support the hypothesis that chromosomal resistance mutations could be affected by the presence of Qnr, in other words, Qnr may protect the QRDR domains in the gyrase and topoisomerase IV from mutations under the inhibition of fluoroquinolones. Another remarkable finding was that the PMQR genes-carrying K. pneumoniae exhibited much higher proportions of extended-spectrum β-lactamases (ESBLs)-positive phenotype than E. coli (73.5% vs. 59.5%). This is due to not only the high prevalence of SHV-type ESBL-conferring enzymes in K. pneumoniae but also the interference of DHA-producing K. pneumoniae as a result of the strong association between qnrB and bla(DHA).
Collapse
Affiliation(s)
- Jiyong Yang
- Department of Microbiology, Chinese PLA General Hospital, Beijing, China
| | | | | | | | | |
Collapse
|
42
|
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]
|
43
|
Prevalence and dissemination of oqxAB in Escherichia coli isolates from animals, farmworkers, and the environment. Antimicrob Agents Chemother 2010; 54:4219-24. [PMID: 20696876 DOI: 10.1128/aac.00139-10] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
OqxAB has recently been identified as one of the mechanisms of plasmid-mediated quinolone resistance (PMQR). Compared to what is observed for other PMQR determinants, there is a paucity of data with regard to the prevalence and epidemiology of OqxAB and its contribution to resistance to different antimicrobials. In this study, the prevalence and dissemination of oqxAB and other PMQR genes in Escherichia coli isolates from animals, farmworkers, and the environment in 2002 in China were investigated. Of the 172 E. coli isolates, 39.0% carried oqxA, while only 4.1%, 2.9%, and 0.6% carried qnr (1 qnrB6 isolate, 5 qnrS1 isolates, and 1 qnrD isolate), qepA, and aac(6')-Ib-cr, respectively. Among the 33 isolates from farmworkers, 10 (30.3%) were positive for oqxA. oqxAB was associated with IS26 and was carried on the 43- to 115-kb IncF transferable plasmid. Transconjugants carrying oqxAB showed 4- to 16-fold increases in the MICs of quinolones, 16- to 64-fold increases in the MICs of quinoxalines, 8- to 32-fold increases in the MICs of chloramphenicol and trimethoprim-sulfamethoxazole, and 4- to 8-fold increases in the MICs of florfenicol compared to the levels for the recipient. The pulsed-field gel electrophoresis (PFGE) analysis showed that the high levels of prevalence and dissemination of oqxAB in E. coli in animal farms were primarily due to the transmission of plasmids carrying oqxAB, although clonal transmission between human and swine E. coli isolates was observed. It is concluded that oqxAB was widespread in animal farms in China, which may be due to the overuse of quinoxalines in animals. This study warrants the prudent use of quinoxalines in food animals.
Collapse
|
44
|
Gibson JS, Cobbold RN, Heisig P, Sidjabat HE, Kyaw-Tanner MT, Trott DJ. Identification of Qnr and AAC(6′)-1b-cr plasmid-mediated fluoroquinolone resistance determinants in multidrug-resistant Enterobacter spp. isolated from extraintestinal infections in companion animals. Vet Microbiol 2010; 143:329-36. [DOI: 10.1016/j.vetmic.2009.11.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 11/19/2009] [Accepted: 11/24/2009] [Indexed: 11/16/2022]
|
45
|
Richter SN, Frasson I, Bergo C, Manganelli R, Cavallaro A, Palù G. Characterisation of qnr plasmid-mediated quinolone resistance in Enterobacteriaceae from Italy: association of the qnrB19 allele with the integron element ISCR1 in Escherichia coli. Int J Antimicrob Agents 2010; 35:578-83. [PMID: 20356715 DOI: 10.1016/j.ijantimicag.2010.02.015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 02/03/2010] [Accepted: 02/10/2010] [Indexed: 11/30/2022]
Abstract
The spread of plasmid-mediated quinolone resistance determinants (qnr-like determinants) was evaluated in a collection of 232 ciprofloxacin-resistant or extended-spectrum beta-lactamase (ESBL)-producing enterobacterial isolates recovered between November 2007 and May 2008 at Padua University Hospital, Italy. qnr genes were mainly found in Klebsiella pneumoniae (68%) and to a lesser extent in Escherichia coli (5.1%). Among the qnrA1, qnrS1 and qnrB19 alleles found, the latter was by far the most frequent. Genetic environment analysis revealed that one qnrB19 gene in E. coli was embedded in an ISCR1 complex class 1 integron. All other qnrB19 genes were flanked by an ISEcp1C region as part of the Tn2012 transposon. qnrA1- and qnrS1-containing strains were not clonally related. Both topoisomerase II mutations and ESBL (mainly SHV-12, TEM-1 and TEM-150 types) were present in most of the qnr-positive strains. qnrB19 is extremely frequent in K. pneumoniae isolates from Italy. In addition, association of qnrB19 with the ISCR1 mobile element in E. coli suggests a broad distribution of this resistance gene in the near future.
Collapse
Affiliation(s)
- Sara N Richter
- Department of Histology, Microbiology and Medical Biotechnologies, University of Padua, via Gabelli 63, 35121 Padua, Italy.
| | | | | | | | | | | |
Collapse
|
46
|
Abstract
Although plasmid-mediated quinolone resistance (PMQR) was thought not to exist before its discovery in 1998, the past decade has seen an explosion of research characterizing this phenomenon. The best-described form of PMQR is determined by the qnr group of genes. These genes, likely originating in aquatic organisms, code for pentapeptide repeat proteins. These proteins reduce susceptibility to quinolones by protecting the complex of DNA and DNA gyrase or topoisomerase IV enzymes from the inhibitory effect of quinolones. Two additional PMQR mechanisms were recently described. aac(6')-Ib-cr encodes a variant aminoglycoside acetyltransferase with two amino acid alterations allowing it to inactivate ciprofloxacin through the acetylation of its piperazinyl substituent. oqxAB and qepA encode efflux pumps that extrude quinolones. All of these genes determine relatively small increases in the MICs of quinolones, but these changes are sufficient to facilitate the selection of mutants with higher levels of resistance. The contribution of these genes to the emergence of quinolone resistance is being actively investigated. Several factors suggest their importance in this process, including their increasing ubiquity, their association with other resistance elements, and their emergence simultaneous with the expansion of clinical quinolone resistance. Of concern, these genes are not yet being taken into account in resistance screening by clinical microbiology laboratories.
Collapse
|
47
|
Impact of low-level resistance to fluoroquinolones due to qnrA1 and qnrS1 genes or a gyrA mutation on ciprofloxacin bactericidal activity in a murine model of Escherichia coli urinary tract infection. Antimicrob Agents Chemother 2009; 53:4292-7. [PMID: 19635960 DOI: 10.1128/aac.01664-08] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We investigated the impact of low-level resistance to fluoroquinolones on the bactericidal activity of ciprofloxacin in a murine model of urinary tract infection. The susceptible Escherichia coli strain CFT073 (ciprofloxacin MIC [CIP MIC] of 0.008 microg/ml) was compared to its transconjugants harboring qnrA1 or qnrS1 and to an S83L gyrA mutant. The three derivatives showed similar low-level resistance to fluoroquinolones (CIP MICs, 0.25 to 0.5 microg/ml). Bactericidal activity measured in vitro after 1, 3, and 6 h of exposure to 0.5 microg/ml of ciprofloxacin was significantly lower for the derivative strains (P < 0.01). In the murine model of urinary tract infection (at least 45 mice inoculated per strain), mice were treated with a ciprofloxacin regimen of 2.5 mg/kg, given subcutaneously twice daily for 2 days. In mice infected with the susceptible strain, ciprofloxacin significantly decreased viable bacterial counts (log10 CFU/g of tissue) in the bladder (4.2 +/- 0.5 versus 5.5 +/- 1.3; P = 0.001) and in the kidney (3.6 +/- 0.8 versus 5.0 +/- 1.1; P = 0.003) compared with those of untreated mice. In contrast, no significant decrease in viable bacterial counts was observed with any of the three derivative strains. The area under the concentration-time curve from 0 to 24 h/MIC and the maximum concentration of drug in serum/MIC ratios measured in plasma were indeed equal to 827 and 147, respectively, for the parental strain, and only 12.4 to 24.8 and 2.2 to 4.4, respectively, for the derivative strains. In conclusion, low-level resistance to fluoroquinolones conferred by a qnr gene is associated with decreased bactericidal activity of ciprofloxacin, similar to that obtained with a gyrA mutation.
Collapse
|
48
|
Mechanisms of resistance in nontyphoidal Salmonella enterica strains exhibiting a nonclassical quinolone resistance phenotype. Antimicrob Agents Chemother 2009; 53:3832-6. [PMID: 19596880 DOI: 10.1128/aac.00121-09] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nontyphoidal Salmonella enterica strains with a nonclassical quinolone resistance phenotype were isolated from patients returning from Thailand or Malaysia to Finland. A total of 10 isolates of seven serovars were studied in detail, all of which had reduced susceptibility (MIC > or = 0.125 microg/ml) to ciprofloxacin but were either susceptible or showed only low-level resistance (MIC < or = 32 microg/ml) to nalidixic acid. Phenotypic characterization included susceptibility testing by the agar dilution method and investigation of efflux activity. Genotypic characterization included the screening of mutations in the quinolone resistance-determining regions (QRDR) of gyrA, gyrB, parC, and parE by PCR and denaturing high-pressure liquid chromatography and the amplification of plasmid-mediated quinolone resistance (PMQR) genes qnrA, qnrB, qnrS, qnrD, aac(6')-Ib-cr, and qepA by PCR. PMQR was confirmed by plasmid analysis, Southern hybridization, and plasmid transfer. No mutations in the QRDRs of gyrA, gyrB, parC, or parE were detected with the exception of a Thr57-Ser substitution within ParC seen in all but the S. enterica serovar Typhimurium strains. The qnrA and qnrS genes were the only PMQR determinants detected. Plasmids carrying qnr alleles were transferable in vitro, and the resistance phenotype was reproducible in Escherichia coli DH5alpha transformants. These data demonstrate the emergence of a highly mobile qnr genotype that, in the absence of mutation within topoisomerase genes, confers the nontypical quinolone resistance phenotype in S. enterica isolates. The qnr resistance mechanism enables bacteria to survive elevated quinolone concentrations, and therefore, strains carrying qnr alleles may be able to expand during fluoroquinolone treatment. This is of concern since nonclassical quinolone resistance is plasmid mediated and therefore mobilizable.
Collapse
|
49
|
Guillard T, Cavallo JD, Cambau E, Duval V, Bajolet O, Brasme L, de Champs C, Vernet-Garnier V. [Real-time PCR for fast detection of plasmid-mediated qnr genes in extended spectrum beta-lactamase producing Enterobacteriaceae]. ACTA ACUST UNITED AC 2009; 58:430-3. [PMID: 19375248 DOI: 10.1016/j.patbio.2009.03.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Accepted: 03/06/2009] [Indexed: 10/20/2022]
Abstract
AIM OF THE STUDY To develop a fast and reliable real time PCR technique for detecting plasmid-mediated quinolone resistance genes qnrA, qnrB and qnrS. METHODS A real-time PCR assay using SYBR Green I and Roche LightCycler(®) was developed to detect qnr genes. Detection of qnr genes was based on comparison of melting temperature differences with a positive control of each qnr genes. This assay was performed to study 138 isolates collected from diagnostic and screening samples in the Champagne-Ardenne region in 2004 (France). RESULTS In optimized conditions, the three positive controls tested alone and with isolates confirmed the specificity of the PCR primers. Each PCR assay was able to test 30 strains in 60min for 1 qnr gene. Out of 138 isolates screened, 3.6 % isolates were positive for a qnrA1, 1.5 % for qnrS1 and no qnrB-like gene. Prevalence of qnr determinants was 5 % and reached 9.5 % in clinical isolates. CONCLUSION Real-time PCR is a fast and reliable technique for screening of qnr-positive strains. This study shows a relatively high prevalence of qnr determinants (5 %) among ESBL-producing Enterobacteriaceae.
Collapse
Affiliation(s)
- T Guillard
- Laboratoire de bactériologie-virologie-hygiène, CHU Robert-Debré, rue du Général-Koenig, 51092 Reims cedex, France.
| | | | | | | | | | | | | | | |
Collapse
|