Fluoroquinolone resistance in Campylobacter species from man and animals: detection of mutations in topoisomerase genes.
Consecutive isolates of quinolone-resistant campylobacter isolated over a 5 year period (1990-1995) from the faeces of patients with enteritis in Plymouth, UK, were examined for the epidemiology of mutations in gyrA (n = 127). In addition, clinical isolates and poultry isolates from Germany, The Netherlands and other regions of the UK collected before 1995 were examined for mutations in the quinolone resistance-determining region of gyrA by single-stranded conformational polymorphism analysis and direct sequencing of a 270 bp fragment of PCR-generated DNA. The majority of isolates (173/208) carried a mutation at codon 86 in gyrA resulting in substitution of Ile for Thr; all of these were resistant to ciprofloxacin (MIC > or = 2 mg/L). One isolate of Campylobacter jejuni had a mutation at Asp-90, and another had a double mutation at Thr-86 and Pro-104. Only two resistant isolates showed no mutation in gyrA. A novel gyrA sequence was amplified from two Campylobacter lari and one C. jejuni, which exhibited a valine at codon 86. Only 8/192 isolates had changes in gyrB; all were shown to relate to silent mutations in gyrB and presumably reflect natural polymorphisms in the gene.
Piddock
Laura J V
LJ
Antimicrobial Agents Research Group, Department of Infection, The Medical School, University of Birmingham, Birmingham B15 2TT, UK. l.j.v.piddock@bham.ac.uk
Ricci
Vito
V
Pumbwe
Lilian
L
Everett
Martin J
MJ
Griggs
Deborah J
DJ
D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001483:Base Sequence; D002167:Campylobacter / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics*; D027081:DNA Gyrase / Q000235:genetics*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D024841:Fluoroquinolones; D005798:Genes, Bacterial / Q000235:genetics*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000706:statistics & numerical data; D008969:Molecular Sequence Data; D009154:Mutation; D018807:Polymorphism, Single-Stranded Conformational; D011200:Poultry / Q000382:microbiology; D012689:Sequence Homology, Nucleic Acid
D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D027081:DNA Gyrase