Antibiotic resistance in Campylobacter jejuni and Campylobacter coli isolated from poultry in the South-East Queensland region.
OBJECTIVE
The aim of this study was to determine the antimicrobial resistance patterns of 125 Campylobacter jejuni and 27 Campylobacter coli isolates from 39 Queensland broiler farms.


METHODS
Two methods, a disc diffusion assay and an agar-based MIC assay, were used. The disc diffusion was performed and interpreted as previously described (Huysmans MB, Turnidge JD. Disc susceptibility testing for thermophilic campylobacters. Pathology 1997; 29: 209-16), whereas the MIC assay was performed according to CLSI (formerly NCCLS) methods and interpreted using DANMAP criteria.


RESULTS
In both assays, no C. jejuni or C. coli isolates were resistant to ciprofloxacin or chloramphenicol, no C. coli were resistant to nalidixic acid, and no C. jejuni were resistant to erythromycin. In the MIC assay, no C. jejuni isolate was resistant to nalidixic acid, whereas three isolates (2.4%) were resistant in the disc assay. The highest levels of resistance of the C. jejuni isolates were recorded for tetracycline (19.2% by MIC and 18.4% by disc) and ampicillin (19.2% by MIC and 17.6% by disc). The C. coli isolates gave very similar results (tetracycline resistance 14.8% by both MIC and disc; ampicillin resistance 7.4% by MIC and 14.8% by disc).


CONCLUSIONS
This work has shown that the majority of C. jejuni and C. coli isolates were susceptible to the six antibiotics tested by both disc diffusion and MIC methods. Disc diffusion represents a suitable alternative methodology to agar-based MIC methods for poultry Campylobacter isolates.
Miflin
Jeanette K
JK
Department of Primary Industries and Fisheries, Animal Research Institute, Yeerongpilly, Queensland 4105, Australia.
Templeton
Jillian M
JM
Blackall
P J
PJ
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017000:Campylobacter coli / Q000187:drug effects*; D016123:Campylobacter jejuni / Q000187:drug effects*; D002645:Chickens / Q000382:microbiology*; D052978:Disk Diffusion Antimicrobial Tests; D024881:Drug Resistance, Bacterial; D008826:Microbial Sensitivity Tests; D011793:Queensland; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000900:Anti-Bacterial Agents