Analysis of ciprofloxacin-resistant Salmonella strains from swine, chicken, and their carcasses in Taiwan and detection of parC resistance mutations by a mismatch amplification mutation assay PCR.
One hundred thirty-three Salmonella strains isolated from the viscera of swine, chicken, and carcasses of swine and chicken in Taiwan from 2004 to 2006 were identified to serotype level and analyzed for their susceptibility to ciprofloxacin. In total, 76 (57%) strains of the Salmonella isolates exhibited high-level resistance to ciprofloxacin, having MICs ranging from 16 to 64 microg/ml. DNA sequence analysis revealed that mutations in the quinolone resistance-determining regions of gyrA (Ser83Phe, Asp87Gly or Asp87Asn), parC (Ser80Arg, or Ser80Ile or Glu84Lys), and parE (Ser458Pro) genes were associated with the Salmonella strains that demonstrated resistance to ciprofloxacin. A mismatch amplification mutation assay (MAMA)-PCR was developed to identify mutations in parC at codons 80 and 84. Specific PCR products were only recovered from ciprofloxacin-resistant Salmonella strains but not from the susceptible strains. MAMA-PCR targeting the mutations in parC correlated with what DNA sequencing revealed. In conclusion, monitoring ciprofloxacin-resistant Salmonella from animal sources should be performed on a regular basis. MAMA-PCR targeting parC could provide a fast method for those laboratories interested in quickly characterizing the resistance profile and with little access to DNA sequencing facilities.
Lin
Cheng-Chung
CC
Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan.
Chen
Ter-Hsin
TH
Wang
Yu-Chih
YC
Chang
Chao-Chin
CC
Hsuan
Shih-Ling
SL
Chang
Yi-Chih
YC
Yeh
Kuang-Sheng
KS
D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001483:Base Sequence; D002645:Chickens / Q000382:microbiology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D003062:Codon; D015169:Colony Count, Microbial; D027081:DNA Gyrase / Q000235:genetics; D027101:DNA Topoisomerase IV / Q000235:genetics*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005784:Gene Amplification; D008826:Microbial Sensitivity Tests; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000379:methods; D012475:Salmonella / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification; D012481:Salmonella Infections, Animal / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013552:Swine / Q000382:microbiology*; D013624:Taiwan / Q000453:epidemiology
D000890:Anti-Infective Agents; D003062:Codon; D002939:Ciprofloxacin; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase