Antibiotic-resistant and spp. associated with dairy cattle and farm environment having public health significance.

AIM

The present study was carried out to determine load of total bacteria, and spp. in dairy farm and its environmental components. In addition, the antibiogram profile of the isolated bacteria having public health impact was also determined along with identification of virulence and resistance genes by polymerase chain reaction (PCR) under a one-health approach.

MATERIALS AND METHODS

A total of 240 samples of six types (cow dung - 15, milk - 10, milkers' hand wash - 10, soil - 10 water - 5, and vegetables - 10) were collected from four dairy farms. For enumeration, the samples were cultured onto plate count agar, eosin methylene blue, and xylose-lysine deoxycholate agar and the isolation and identification of the and spp. were performed based on morphology, cultural, staining, and biochemical properties followed by PCR.The pathogenic strains of , and were also identified through PCR. The isolates were subjected to antimicrobial susceptibility test against 12 commonly used antibiotics by disk diffusion method. Detection of antibiotic resistance genes , and were performed by PCR.

RESULTS

The mean total bacterial count, and spp. count in the samples ranged from 4.54±0.05 to 8.65±0.06, 3.62±0.07 to 7.04±0.48, and 2.52±0.08 to 5.87±0.05 log colony-forming unit/g or ml, respectively. Out of 240 samples, 180 (75%) isolates of and 136 (56.67%) isolates of spp. were recovered through cultural and molecular tests. Among the 180 isolates, 47 (26.11%) were found positive for the presence of all the three virulent genes, of which was the most prevalent (13.33%). Only three isolates were identified as enterohemorrhagic . Antibiotic sensitivity test revealed that both and spp. were found highly resistant to azithromycin, tetracycline, erythromycin, oxytetracycline, and ertapenem and susceptible to gentamycin, ciprofloxacin, and imipenem. Among the four antibiotic resistance genes, the most observable was (80.51-84.74%) in and spp. and genes were the lowest one (22.06-25%).

CONCLUSION

Dairy farm and their environmental components carry antibiotic-resistant pathogenic and spp. that are potential threat for human health which requires a one-health approach to combat the threat.