Molecular characterisation of quinolone resistance in Escherichia coli from animals in Turkey.
The aim of this study were to detect the gyrA, parC and marR mutations and qnr genes (qnrA, qnrB and qnrS) in 120 strains of Escherichia coli isolated from animals. European Committee on Antimicrobial Susceptibility Testing and Clinical Laboratory Standards Institute disc diffusion and minimum inhibitory concentration (MIC) tests, respectively, were used to determine fluoroquinolone (FQ) resistance, and molecular methods were used to detect the mutations and the genes. E coli isolates with an MIC of ≥8&emsp14;mg/l had mutation at Ser-80 in parC in addition to mutations at Ser-83, Asp-87 or both in gyrA. The nucleotide change was detected in marR (Ser-3 → Asn, Ala-53 → Glu, Gly-103 → Ser, Tyr-137 → His). Only four E coli isolates (3.3 per cent) contained qnrA and qnrS, and qnrB was not detected. Two E coli isolates from healthy calves also contained qnrA and qnrS. The MICs of enrofloxacin and danofloxacin for qnr-containing E coli isolates ranged from 32&emsp14;mg/l to 256&emsp14;mg/l. The results of this study indicated that the FQ-resistant E coli isolates presented an alteration in gyrA (Ser-83 → Leu, Asp-87 → Asn) and parC (Ser-80 → Ile) with high MICs (8-256&emsp14;mg/l), and there was a low prevalence of qnr genes among E coli isolated from animals.
Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Uludag University, 16059, Nilufer, Bursa, Turkey. cengizm@uludag.edu.tr
M
M
Cengiz
E
E
Buyukcangaz
E
E
Arslan
B
B
Mat
P
P
Sahinturk
S
S
Sonal
H
H
Gocmen
A
A
Sen
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D002418:Cattle Diseases / Q000188:drug therapy / Q000382:microbiology; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics*; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary; D008826:Microbial Sensitivity Tests / Q000662:veterinary*; D009154:Mutation; D015363:Quinolones / Q000494:pharmacology*; D014421:Turkey
D000900:Anti-Bacterial Agents; D015363:Quinolones