Metronidazole Resistance of Campylobacter Jejuni and Campylobacter Coli from Different Animal Species

Abstract

In this study, we aimed to screen animal isolates of Campylobacter jejuni/Campylobacter coli for resistance to metronidazole and compared the resistance of selected groups of isolates. A total of 240 C. jejuni/C. coli isolates isolated from chickens, cattle, sheep and dogs were tested by an agar dilution technique to determine the Minimum Inhibitory Concentration (MIC) of metronidazole. The frequency of resistance in 133 avian, 32 bovine, 48 ovine and 27 canine isolates were 91.7%, 18.75%, 16.7% and 18.5%, respectively. Of 170 C. jejuni and 70 C. coli isolates tested, 52.9% and 72.85% were resistant to metronidazole, respectively. MIC (mcg/ml) ranges of metronidazole for animal isolates were as follows: chicken, 2->64; cattle, 0.25-32; sheep, 0.12-16 and dog, 0.25-32. MIC50/MIC90 values of metronidazole for animal isolates were as follows: chicken 16/64 (mcg/ml), cattle 2/8 (mcg/ml), sheep 1/8 (mcg/ml) and dog 2/8 (mcg/ml). We observed a wide range of sensitivity to metronidazole among campylobacters and frequency of resistance differed in relation to the origin of the isolate. Although it was not clear why the resistant isolates were common in chickens, a host-phenotype relationship for metronidazole resistance was demonstrated.