2021-12-102021-12-102012-08-11Cengiz, M. vd. (2012). "Molecular characterisation of quinolone resistance in Escherichia coli from animals in Turkey". Veterinary Record, 171(6), 155-155.0042-49002042-7670https://doi.org/10.1136/vr.100719https://bvajournals.onlinelibrary.wiley.com/doi/full/10.1136/vr.100719http://hdl.handle.net/11452/23169The 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 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 mg/l to 256 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 mg/l), and there was a low prevalence of qnr genes among E coli isolated from animals.eninfo:eu-repo/semantics/closedAccessVeterinary sciencesFluoroquinolone-resistanceSalmonella-entericaKlebsiella-pneumoniaeQnr genesMechanismsEnterobacteriaceaePrevalenceStrainsDeterminantsGyraseAnimalsAnti-bacterial agentsCattleCattle diseasesDose-response relationship, drugDrug resistance, bacterialEscherichia coliEscherichia coli InfectionsMicrobial sensitivity testsMutationQuinolonesTurkeyArticle0003080022000202-s2.0-84865329442155155171622890400Veterinary sciencesQuinolones; Plasmids; EnterobacteriaceaeAntiinfective agentQuinolone derivativeAnimalAnimal diseaseAntibiotic resistanceArticleCattleCattle diseaseDose responseDrug effectEscherichia coliEscherichia coli infectionGeneticsMicrobiological examinationMicrobiologyMutationTurkey (republic)