Mutations in gyrA gene of quinolone-resistant Salmonella serotypes isolated from humans and animals

Abstract

The quinolone resistance-determining regions (QRDRs) of the gyrA genes of quinolone-resistant clinical and veterinary salmonella isolates were sequenced. Substitutions analogous to a substitution of a Ser to a Phe at position 83 (Ser83-->Phe) and Asp87-->Gly or Tyr in Escherichia coli were found, as was a single novel mutation outside of the QRDR resulting in Ala119-->Glu. The data suggest that gyrA mutations are associated with quinolone resistance in veterinary and clinical salmonella isolates and that the limits of the QRDR may require revision.

Quinolone resistance in the food chain

“…Changes in GyrB are rarely found in Salmonella but Tyr420 → Cys and Arg437 → Leu may be found. Changes in ParE have been observed most rarely and may be Glu453 → Gly, His461 → Tyr, Ala498 → Thr, Val512 → Gly and Ser518 → Cys [37][38][39][40][41][42].…”

Antimicrobial resistance of Salmonella isolated from food animals: A review

“…Bacterial resistance to quinolones or fluoroquinolones is usually accomplished by interference with bacterial DNA metabolism mediated by mutations in bacterial DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE) genes, as well as by active efflux (Eaves et al, 2004;Griggs, Gensberg, & Piddock, 1996;Piddock, 2002;Piddock, Ricci, McLaren, & Griggs, 1998). These mutations prevent antimicrobial agents from binding to their topoisomerase targets and carrying out their antimicrobial activity (Heisig, 1993).…”

Detection of novel gyrA mutations in nalidixic acid-resistant isolates of Salmonella enterica from patients with diarrhoea

“…PCR amplification of the segment of the gyrA gene encoding the QRDR region of GyrA was performed using previously described specific primers [10]. Owing to the absence of CIP-resistant (CIP R ) isolates, only substitutions in QRDR of GyrA were considered as the most relevant [1].…”