Mutational Polymorphism in the Bacterial Topoisomerase Genes Driven by Treatment with Quinolones

Velhner, Maja; Stojanović, Dragica

doi:10.5772/35229

Cited by 5 publications

(4 citation statements)

References 110 publications

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“…The gene parC is a common second target for quinolones in Salmonella, and the Ser80→Arg mutation was previously detected in other Salmonella serotypes from France, China, Spain and Japan. However, in contrast to our findings, all these isolates were clinically resistant to CIP (Velhner and Stojanović, ). In CIP‐susceptible isolates exhibiting MICs of 0.25–0.5 μg/mL, mutations in the gyrB , parC and parE genes could not be detected.…”

Section: Resultscontrasting

confidence: 99%

Clonal Spread of Salmonella enterica Serovar Infantis in Serbia: Acquisition of Mutations in the Topoisomerase Genes gyrA and parC Leads to Increased Resistance to Fluoroquinolones

Velhner

Kozoderović

Grego

et al. 2013

Zoonoses and Public Health

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Quinolone-resistant Salmonella Infantis (n = 64) isolated from human stool samples, food and poultry during the years 2006-2011 were analysed for their resistance phenotypes, macrorestriction patterns and molecular mechanisms of decreased susceptibility to fluoroquinolones. Minimum inhibitory concentrations (MICs) of nalidixic acid (NAL) and ciprofloxacin (CIP) were determined by the agar dilution procedure, and the susceptibility to additional antimicrobial agents was determined by the disc diffusion method. To assess the influence of enhanced efflux activity, MICs were determined in the presence and absence of the inhibitor PAβN. The results of pulsed-field gel electrophoresis (PFGE) typing revealed that quinolone-resistant S. Infantis in Serbia had similar or indistinguishable PFGE profiles, suggesting a clonal spread. All S. Infantis showed combined resistance to NAL and tetracycline, whereas multiple drug resistance to three or more antibiotic classes was rare (2 isolates of human origin). The MICs ranged between 512 and 1024 μg/mL for NAL and 0.125-2 μg/mL for CIP. A single-point mutation in the gene gyrA leading to a Ser83→Tyr exchange was detected in all isolates, and a second exchange (Ser80→Arg) in the gene parC was only present in eight S. Infantis isolates exhibiting slightly higher MICs of CIP (2 μg/mL). The inhibitor PAβN decreased the MIC values of CIP by two dilution steps and of NAL by at minimum 3-6 dilution steps, indicating that enhanced efflux plays an important role in quinolone resistance in these isolates. The plasmid-mediated genes qnr, aac(6')-lb-cr and qepA were not detected by PCR assays.

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Section: Resultscontrasting

confidence: 99%

Clonal Spread of Salmonella enterica Serovar Infantis in Serbia: Acquisition of Mutations in the Topoisomerase Genes gyrA and parC Leads to Increased Resistance to Fluoroquinolones

Velhner

Kozoderović

Grego

et al. 2013

Zoonoses and Public Health

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“…In this study, mutations in the QRDR of gyrA were found either in codon 83 or 87, as reported from other countries [13]. The fact that different mutation types appeared during the 6-year period in different samples suggests that there was no clonal spread of NAL-resistant S. Enteritidis.…”

Section: Resultssupporting

confidence: 56%

Prevalence of quinolone resistance and mutations in the topoisomerase genes in Salmonella enterica serotype Enteritidis isolates from Serbia

Kozoderović

Velhner

Jelesić

et al. 2012

International Journal of Antimicrobial Agents

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“…Common mutations on the parC gene correspond to codons 78, 80 and 84 while the most frequent mutation on the gyrB and parE gene are at the codons 464 and 458 respectively. Concomitant mutations on the gyrA, gyrB, parC and parE genes in Salmonella spp, Escherichia coli (E. coli) and Campylobacter spp isolates from all around the globe have been summarized recently [9]. Particularly, double, triple and quadruplet FQ mutants in Salmonella are reported more frequently in isolates from developing countries.…”

Section: Chromosomally Mediated Resistance To Fl Uoroquinolonesmentioning

confidence: 99%

Mechanisms of Resistance to Quinolones and Epidemiological Significance of Salmonella spp.

Velhner

2016

Acta Veterinaria

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Bacteria develop resistance to antimicrobial agents by a number of different mechanisms. The resistance to (fl uoro)quinolones in Salmonella is of particular importance especially if therapy in humans is required. For decades there has been a signifi cant interest in studying the biology of Salmonella because these bacteria are among the leading causes of foodborne illnesses around the globe. To this date, two main mechanisms of quinolone resistance have been established: alteration in the targets for quinolones, decreased accumulation inside bacteria due to impermeability of the membrane and/or an over expression of the effl ux pump systems. Both of these mechanisms are chromosomally mediated. Furthermore, mobile elements have been described carrying the qnr gene which confers resistance to quinolones. The plasmid encoded QNR proteins belong to the pentapeptide repeat family of proteins. The plasmid mediated quinolone resistance (PMQR) is often associated with the resistance to beta lactam antibiotics. It was noticed that PMQR is backing up chromosomal mutations for quinolone resistance, hence becoming an important resistance mechanism worldwide. Even with our knowledge expanding over the years, it is not possible to predict how bacteria will respond in the future, if they are exposed to new external challenges. The possibility that they will fi nd a way to survive by introducing new mutations or by exchanging mobile genetic elements and subsequently developing resistance to survive in the environment should not be underestimated.

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Mutational Polymorphism in the Bacterial Topoisomerase Genes Driven by Treatment with Quinolones

Cited by 5 publications

References 110 publications

Clonal Spread of Salmonella enterica Serovar Infantis in Serbia: Acquisition of Mutations in the Topoisomerase Genes gyrA and parC Leads to Increased Resistance to Fluoroquinolones

Clonal Spread of Salmonella enterica Serovar Infantis in Serbia: Acquisition of Mutations in the Topoisomerase Genes gyrA and parC Leads to Increased Resistance to Fluoroquinolones

Prevalence of quinolone resistance and mutations in the topoisomerase genes in Salmonella enterica serotype Enteritidis isolates from Serbia

Mechanisms of Resistance to Quinolones and Epidemiological Significance of Salmonella spp.

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