Frequency of DNA gyrase and topoisomerase IV mutations and plasmid-mediated quinolone resistance genes among Escherichia coli and Klebsiella pneumoniae isolated from urinary tract infections in Azerbaijan, Iran.

Abstract

OBJECTIVES:

This study assessed genetic alterations in gyrA, gyrB, parC and parE and the prevalence of plasmid-mediated quinolone resistance (PMQR) genes among Escherichia coli and Klebsiella pneumoniae isolates from urinary tract infections (UTIs) in Azerbaijan, Iran.

METHODS:

A total of 205 clinical isolates of E. coli (n=177) and K. pneumoniae (n=28) were obtained from UTIs. Antimicrobial susceptibility was determined by disk diffusion and agar dilution assays. The presence of PMQR genes was determined by PCR, and sequencing of the gyrA, gyrB, parC and parE was performed.

RESULTS:

The rate of fluoroquinolone (FQ) resistance among the isolates was 77.1%. The Ser83Leu mutation in gyrA was observed in all 60 FQ-resistant isolates selected for direct sequencing. The second most common mutation in gyrA was Asp87Asn. Frequent mutations in parC were Ser80Ile and Glu84Val. Ser359Ala+Ser367Thr and Gly385Cys mutations in gyrB were identified in one isolate each of K. pneumoniae and E. coli, respectively. The parE gene had mutations at Ile529Leu, Ser458Ala and Leu416Phe. Overall, PMQR determinants were identified in 90% of E. coli and 100% of K. pneumoniae. The prevalence of PMQR genes was as follows: aac(6')-Ib-cr, 71.7%; oqxB, 51.7%; oqxA, 36.7%; qnrB, 28.3%; qnrS, 21.7%; qnrD, 16.7%; qepA, 5.0%; qnrA, 1.7%; and qnrC, 1.7%.

CONCLUSIONS:

FQ resistance rates were high. Mutations in DNA gyrase and topoisomerase IV and the prevalence of PMQR genes in E. coli and K. pneumoniae isolates were alarming. Moreover, the combination of these resistance mechanisms plays an important role in high-level FQ resistance.

• Authors: Robab Azargun, Mohammad Hossein Soroush Barhaghi, Hossein Samadi Kafil, Mahin Ahangar Oskouee, Vahid Sadeghi, Mohammad Yousef Memar, Reza Ghotaslou
• Journal: Journal of global antimicrobial resistance (J Glob Antimicrob Resist) Vol. 17 Pg. 39-43 (06 2019) ISSN: 2213-7173 [Electronic] Netherlands
• PMID: 30445211 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

Chemical References

• Anti-Bacterial Agents
• Bacterial Proteins
• Quinolones
• DNA Topoisomerase IV
• DNA Gyrase

Topics

• Adult
• Aged
• Anti-Bacterial Agents (pharmacology)
• Bacterial Proteins (genetics, metabolism)
• DNA Gyrase (genetics, metabolism)
• DNA Topoisomerase IV (genetics, metabolism)
• Drug Resistance, Bacterial
• Escherichia coli (drug effects, enzymology, genetics)
• Female
• Humans
• Iran
• Klebsiella pneumoniae (drug effects, enzymology, genetics)
• Male
• Microbial Sensitivity Tests
• Middle Aged
• Mutation
• Plasmids (genetics, metabolism)
• Quinolones (pharmacology)
• Urinary Tract Infections (microbiology)