scholarly journals Fluoroquinolone resistance mechanisms in an Escherichia coli isolate, HUE1, without quinolone resistance-determining region mutations

2013 ◽  
Vol 4 ◽  
Author(s):  
Toyotaka Sato ◽  
Shin-ichi Yokota ◽  
Ikuo Uchida ◽  
Torahiko Okubo ◽  
Msaru Usui ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Mechanisms ◽  
Quinolone Resistance ◽  
Fluoroquinolone Resistance ◽  
Coli Isolate

scholarly journals Contributions of individual mechanisms to fluoroquinolone resistance in 36 Escherichia coli strains isolated from humans and animals.

1996 ◽  
Vol 40 (10) ◽  
pp. 2380-2386 ◽  
Author(s):  
M J Everett ◽  
Y F Jin ◽  
V Ricci ◽  
L J Piddock
Keyword(s):  
Escherichia Coli ◽  
Dna Sequences ◽  
Quinolone Resistance ◽  
Fluoroquinolone Resistance ◽  
Polymorphism Analysis ◽  
Single Mutation ◽  
Wild Type ◽  
Single Strand Conformational Polymorphism ◽  
E Coli ◽  
High Level

Twenty-eight human isolates of Escherichia coli from Argentina and Spain and eight veterinary isolates received from the Ministry of Agriculture Fisheries and Foods in the United Kingdom required 2 to > 128 micrograms of ciprofloxacin per ml for inhibition. Fragments of gyrA and parC encompassing the quinolone resistance-determining region were amplified by PCR, and the DNA sequences of the fragments were determined. All isolates contained a mutation in gyrA of a serine at position 83 (Ser83) to an Leu, and 26 isolates also contained a mutation of Asp87 to one of four amino acids: Asn (n = 14), Tyr (n = 6), Gly (n = 5), or His (n = 1). Twenty-four isolates contained a single mutation in parC, either a Ser80 to Ile (n = 17) or Arg (n = 2) or a Glu84 to Lys (n = 3). The role of a mutation in gyrB was investigated by introducing wild-type gyrB (pBP548) into all isolates; for three transformants MICs of ciprofloxacin were reduced; however, sequencing of PCR-derived fragments containing the gyrB quinolone resistance-determining region revealed no changes. The analogous region of parE was analyzed in 34 of 36 isolates by single-strand conformational polymorphism analysis and sequencing; however, no amino acid substitutions were discovered. The outer membrane protein and lipopolysaccharide profiles of all isolates were compared with those of reference strains, and the concentration of ciprofloxacin accumulated (with or without 100 microM carbony cyanide m-chlorophenylhydrazone [CCCP] was determined. Twenty-two isolates accumulated significantly lower concentrations of ciprofloxacin than the wild-type E. coli isolate; nine isolates accumulated less then half the concentration. The addition of CCCP increased the concentration of ciprofloxacin accumulated, and in all but one isolate the percent increase was greater than that in the control strains. The data indicate that high-level fluoroquinolone resistance in E. coli involves the acquisition of mutations at multiple loci.

First characterization of fluoroquinolone resistance mechanisms in CTX-M-producing Escherichia coli from Mongolia

2016 ◽  
Vol 38 ◽  
pp. 79-81 ◽  
Author(s):  
Cheng-Yen Kao ◽  
Uuganbayar Udval ◽  
Hsiu-Mei Wu ◽  
Enkhbaatar Bolormaa ◽  
Jing-Jou Yan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Mechanisms ◽  
Fluoroquinolone Resistance

scholarly journals Comparative Analysis of Quinolone Resistance in Clinical Isolates ofKlebsiella pneumoniaeandEscherichia colifrom Chinese Children and Adults

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Ying Huang ◽  
James O. Ogutu ◽  
Jiarui Gu ◽  
Fengshu Ding ◽  
Yuhong You ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Environmental Issues ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Chinese Adults ◽  
Double Mutation ◽  
History Of ◽  
Ciprofloxacin Resistance ◽  
Resistance Rates

The objective of this study was to compare quinolone resistance andgyrAmutations in clinical isolates ofKlebsiella pneumoniaeandEscherichia colifrom Chinese adults who used quinolone in the preceding month and children without any known history of quinolone administration. The antimicrobial susceptibilities of 61 isolates from children and 79 isolates from adults were determined. The mutations in the quinolone resistance-determining regions ingyrAgene were detected by PCR and DNA sequencing. Fluoroquinolone resistance and types ofgyrAmutations in isolates from children and adults were compared and statistically analyzed. No significant differences were detected in the resistance rates of ciprofloxacin and levofloxacin between children and adults among isolates of the two species (allP>0.05). The double mutation Ser83→Leu + Asp87→Asn in the ciprofloxacin-resistant isolates occurred in 73.7% isolates from the children and 67.9% from the adults, respectively (P=0.5444). Children with no known history of quinolone administration were found to carry fluoroquinolone-resistantEnterobacteriaceaeisolates. The occurrence of ciprofloxacin resistance and the major types ofgyrAmutations in the isolates from the children were similar to those from adults. The results indicate that precautions should be taken on environmental issues resulting from widespread transmission of quinolone resistance.

scholarly journals Contribution of Different Mechanisms to Ciprofloxacin Resistance in Salmonella spp.

2021 ◽  
Vol 12 ◽  
Author(s):  
Man-Xia Chang ◽  
Jin-Fei Zhang ◽  
Yin-Huan Sun ◽  
Rong-Sheng Li ◽  
Xiao-Ling Lin ◽  
...  
Keyword(s):  
Resistance Mechanisms ◽  
Quinolone Resistance ◽  
Gene Location ◽  
Fluoroquinolone Resistance ◽  
Salmonella Spp ◽  
Resistance Development ◽  
Bacterial Fitness ◽  
Ciprofloxacin Resistance ◽  
Gyra Mutation ◽  
Chromosomal Mutations

Development of fluoroquinolone resistance can involve several mechanisms that include chromosomal mutations in genes (gyrAB and parCE) encoding the target bacterial topoisomerase enzymes, increased expression of the AcrAB-TolC efflux system, and acquisition of transmissible quinolone-resistance genes. In this study, 176 Salmonella isolates from animals with a broad range of ciprofloxacin MICs were collected to analyze the contribution of these different mechanisms to different phenotypes. All isolates were classified according to their ciprofloxacin susceptibility pattern into five groups as follows: highly resistant (HR), resistant (R), intermediate (I), reduced susceptibility (RS), and susceptible (S). We found that the ParC T57S substitution was common in strains exhibiting lowest MICs of ciprofloxacin while increased MICs depended on the type of GyrA mutation. The ParC T57S substitution appeared to incur little cost to bacterial fitness on its own. The presence of PMQR genes represented an route for resistance development in the absence of target-site mutations. Switching of the plasmid-mediated quinolone resistance (PMQR) gene location from a plasmid to the chromosome was observed and resulted in decreased ciprofloxacin susceptibility; this also correlated with increased fitness and a stable resistance phenotype. The overexpression of AcrAB-TolC played an important role in isolates with small decreases in susceptibility and expression was upregulated by MarA more often than by RamA. This study increases our understanding of the relative importance of several resistance mechanisms in the development of fluoroquinolone resistance in Salmonella from the food chain.

scholarly journals Genomic Sequences of Uropathogenic Escherichia coli Strains with Various Fluoroquinolone Resistance Profiles

2020 ◽  
Vol 9 (38) ◽  
Author(s):  
Kayo Okumura ◽  
Masako Kaido ◽  
Eiki Yamasaki ◽  
Yasumasa Akai ◽  
Hisao Kurazono ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Mechanisms ◽  
Uropathogenic Escherichia Coli ◽  
Fluoroquinolone Resistance ◽  
Whole Genome ◽  
Drug Resistant ◽  
Valuable Resource ◽  
Sequencing Data ◽  
Content Type ◽  
Tract Infections

ABSTRACT The emergence of drug-resistant uropathogenic Escherichia coli (UPEC) has hampered antibiotic therapy for urinary tract infections. To elucidate the resistance mechanisms of UPEC, we performed whole-genome sequencing of eight UPEC strains with different fluoroquinolone resistance levels. Here, we report our sequencing data, providing a valuable resource for understanding such mechanisms.

Fluoroquinolone resistance mechanisms in multidrug-resistant Escherichia coli isolated from extraintestinal infections in dogs

2010 ◽  
Vol 146 (1-2) ◽  
pp. 161-166 ◽  
Author(s):  
Justine S. Gibson ◽  
Rowland N. Cobbold ◽  
Myat T. Kyaw-Tanner ◽  
Peter Heisig ◽  
Darren J. Trott
Keyword(s):  
Escherichia Coli ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Fluoroquinolone Resistance

scholarly journals Intensity and Mechanisms of Fluoroquinolone Resistance within theH30 andH30Rx Subclones of Escherichia coli Sequence Type 131 Compared with Other Fluoroquinolone-Resistant E. coli

2015 ◽  
Vol 59 (8) ◽  
pp. 4471-4480 ◽  
Author(s):  
James R. Johnson ◽  
Brian Johnston ◽  
Michael A. Kuskowski ◽  
Evgeni V. Sokurenko ◽  
Veronika Tchesnokova
Keyword(s):  
Escherichia Coli ◽  
Efflux Pump ◽  
Resistance Mechanisms ◽  
Sequence Type ◽  
Fluoroquinolone Resistance ◽  
Solvent Tolerance ◽  
Organic Solvent Tolerance ◽  
Content Type ◽  
E Coli ◽  
Pump Activity

ABSTRACTThe recent expansion of theH30 subclone ofEscherichia colisequence type 131 (ST131) and its CTX-M-15-associatedH30Rx subset remains unexplained. Although ST131H30 typically exhibits fluoroquinolone resistance, so do multiple otherE. colilineages that have not expanded similarly. To determine whetherH30 isolates have more intense fluoroquinolone resistance than other fluoroquinolone-resistantE. coliisolates and to identify possible mechanisms, we determined the MICs for four fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin, and norfloxacin) among 89 well-characterized, genetically diverse fluoroquinolone-resistantE. coliisolates (48 non-H30 and 41H30 [23H30Rx and 18H30 non-Rx]). We compared the MICs with theH30 andH30Rx status, the presence/number of nonsynonymous mutations ingyrA,parC, andparE, the presence ofaac(6′)-1b-cr(an aminoglycoside/fluoroquinolone agent-modifying enzyme), and the efflux pump activity (measured as organic solvent tolerance [OST]). Among 1,518 recentE. coliclinical isolates, ST131H30 predominated clonally, both overall and among the fluoroquinolone-resistant isolates. Among the 89 study isolates, compared with non-H30 isolates,H30 isolates exhibited categorically higher MICs for all four fluoroquinolone agents, higher absolute ciprofloxacin and norfloxacin MICs, more nonsynonymous mutations ingyrA,parC, andparE(specificallygyrAD87N,parCE84V, andparEI529L), and a numerically higher prevalence of (H30Rx-associated)aac(6′)-1b-crbut lower OST scores. All putative resistance mechanisms were significantly associated with the MICs [foraac(6′)-1b-cr: ciprofloxacin and norfloxacin only].parCD87N corresponded with ST131H30 andparEI529L with ST131 generally. Thus, more intense fluoroquinolone resistance may provide ST131H30, especiallyH30Rx [ifaac(6′)-1b-crpositive], with subtle fitness advantages over other fluoroquinolone-resistantE. colistrains. This urges both parsimonious fluoroquinolone use and a search for other fitness-enhancing traits within ST131H30.

scholarly journals Plasmid-Mediated Quinolone Resistance Pump QepA2 in an Escherichia coli Isolate from France

2008 ◽  
Vol 52 (10) ◽  
pp. 3801-3804 ◽  
Author(s):  
Vincent Cattoir ◽  
Laurent Poirel ◽  
Patrice Nordmann
Keyword(s):  
Escherichia Coli ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Coli Isolate ◽  
Mobilizable Plasmid ◽  
Extended Spectrum

ABSTRACT One hundred twenty-one extended-spectrum β-lactamse-producing enterobacterial clinical isolates were screened for the qepA gene. A single CTX-M-15-positive Escherichia coli isolate (0.8%) that produced the putative pump QepA2 was identified. This qepA2 gene was located onto a 90-kb mobilizable plasmid that conferred reduced susceptibility to hydrophilic fluoroquinolones.

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