Antimicrobial susceptibilities of thermophilic Campylobacter from humans, swine, and chicken broilers.
The aim of this study was to evaluate the incidence and the distribution of antimicrobial resistance, and the presence of genetic determinants of resistance, in Campylobacter recovered from swine, poultry, and human populations in Quebec. Minimum inhibitory concentrations (MICs) of 10 antimicrobial agents were determined by the agar dilution technique. Polymerase chain reaction (PCR) was used to detect the tetO determinant, and mutations in gyrA were analyzed by sequencing and by mismatch amplification mutation assay (MAMA) PCR. Among C. coli isolates from pigs, the rates of resistance were high, at 59% for clindamycin, 61% for erythromycin, 67% for streptomycin, and 68% for tetracycline; isolates from chicken broilers were mainly resistant to streptomycin and tetracycline, with a rate of 50% for each; and 56% of the isolates from humans were resistant to tetracycline. The rates of resistance among C. jejuni isolates were low except for tetracycline (39% and 67% in humans and broilers, respectively). The tetO determinant was identified among both tetracycline-resistant and tetracycline-susceptible Campylobacter isolates from swine. Sequencing analysis showed that 64% and 100% of ciprofloxacin-resistant C. coli isolates from swine and humans, respectively, had the mutation Thr-86-->Ile, which is associated with quinolone resistance. The MAMA PCR gave identical results. Further analyses need to be done in order to detect other genetic determinants of tetracycline resistance.
Guévremont
Evelyne
E
Faculté de Médecine Vétérinaire, Université de Montréal, CP 5000, Saint-Hyacinthe, Québec J2S 7C6.
Nadeau
Eric
E
Sirois
Marc
M
Quessy
Sylvain
S
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002167:Campylobacter / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D002645:Chickens; D015169:Colony Count, Microbial / Q000662:veterinary; D004252:DNA Mutational Analysis / Q000662:veterinary; D004269:DNA, Bacterial / Q000032:analysis*; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000662:veterinary*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011792:Quebec / Q000453:epidemiology; D013552:Swine
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial