Occurrence and antimicrobial resistance of 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 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% and 55.3% isolates found resistant against three or more classes of antimicrobials. Presence of mutations in 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 gene was present in 91.7% tetracycline resistant isolates and gene was detected in 97.9% of the ampicillin resistant isolates. The occurrence of antimicrobial resistant spp. in broiler chicken samples and slaughter house settings is a public health risk and calls for judicial use of antimicrobials.