Fluoroquinolone and metronidazole resistance of Campylobacter spp from broiler chickens and antimicrobial use on farms in Grenada, West Indies

One hundred twenty-five broiler chickens were sampled from five farms in Grenada, West Indies. A total of 375 samples from these chickens consisting of visceral and cloacal swabs were cultured for Campylobacter bacteria. Campylobacter spp. were detected in sixty-four percent of broilers (80 of 125 sampled) and 94 pure isolates were obtained. The most common species isolated were C. coli, 52% and C. jejuni, 47.9%. There was no difference among farms in number of isolates of Campylobacter spp. Seven antimicrobials were used to test for antimicrobial resistance profiles of Campylobacter isolates. Among all Campylobacter isolates the highest percent of antimicrobial resistance was observed for ciprofloxacin (47.9%), followed by metronidazole (34%) and tetracycline (16%) whereas the lowest percent of antimicrobial resistance was observed for ampicillin and erythromycin (5% each). Multiple resistance profiles (e” 2 antimicrobials) were seen in 34% of the isolates. The highest percent of isolates resistant to ciprofloxacin was observed on one of the farms where fluoroquinolones were used (12.2% of 49 isolates of C. coli and 24.4% of 45 isolates of C. jejuni). Similarly, the highest percent of isolates resistant to tetracycline (6.1% of 49 isolates of C. coli and 2.2% of 45 isolates of C. jejuni) was observed on a farm where tetracycline was used. The percent of Campylobacter isolates resistant to metronidazole (34%) was not correlated with farm use of this drug. The findings of this study support an association between farm use of tetracyclines and fluoroquinolones and antimicrobial resistance of Campylobacter isolates.