Occurrence and antimicrobial resistance of Campylobacter isolates from broiler chicken and slaughter house environment in India.

Campylobacteriosis is among the most frequently reported foodborne zoonoses. A total of 848 samples were screened for Campylobacter spp. and occurrence was found to be 8.7%, 2.3% and 1.65% in broiler cecum samples, chicken meat samples and slaughter house environment swabs, respectively. High level of antimicrobial resistance was found against tetracycline (64.1%), doxycycline (54.4%), ampicillin (46.6%), nalidixic acid (42.7%), kanamycin (35.9%), and ciprofloxacin (33.33%). Resistance to co-amoxiclav (19.4%) and erythromycin (21.4%) was less common. The MAR index of the isolates was in the range of 0.11-0.78. Multi-drug resistance was observed in 54.4% of the isolates, with 53.2% C. jejuni and 55.3% C. coli isolates found resistant against three or more classes of antimicrobials. Presence of mutations in gyrA and 23S rRNA genes was investigated, which revealed that all the fluoroquinolone resistant isolates possessed Thr-86-Ile point mutation, whereas only 68% of erythromycin resistant isolates had A2075G mutation. The tetO gene was present in 91.7% tetracycline resistant isolates and blaOXA-61 gene was detected in 97.9% of the ampicillin resistant isolates. The occurrence of antimicrobial resistant Campylobacter spp. in broiler chicken samples and slaughter house settings is a public health risk and calls for judicial use of antimicrobials.