A Study on the Occurrence, Pathogenicity, Antimicrobial Resistance and Biofilm Formation of Yersinia enterocolitica Associated with Pork and Pig Slaughterhouse Environments in Puducherry
Vishnu Priya
Department of Veterinary Public Health and Epidemiology, Rajiv Gandhi Institute of Veterinary Education and Research (RIVER), Puducherry – 605 009, India.
V. J. Ajay Kumar
Department of Veterinary Public Health and Epidemiology, Rajiv Gandhi Institute of Veterinary Education and Research (RIVER), Puducherry – 605 009, India.
V. Bhanu Rekha
Department of Veterinary Public Health and Epidemiology, Rajiv Gandhi Institute of Veterinary Education and Research (RIVER), Puducherry – 605 009, India.
A. Bhattacharya
Department of Veterinary Public Health and Epidemiology, Rajiv Gandhi Institute of Veterinary Education and Research (RIVER), Puducherry – 605 009, India.
S. Venkatesa Perumal
Department of Veterinary Biochemistry, Rajiv Gandhi Institute of Veterinary Education and Research (RIVER), Puducherry – 605 009, India.
R. Sivachandiran *
Department of Veterinary Public Health and Epidemiology, Veterinary College and Research Institute, Salem, Tamil Nadu – 636 112, India.
J. Devadharshini
Department of Veterinary Public Health and Epidemiology, Rajiv Gandhi Institute of Veterinary Education and Research (RIVER), Puducherry – 605 009, India.
*Author to whom correspondence should be addressed.
Abstract
Yersinia enterocolitica is an important foodborne zoonotic pathogen commonly associated with pigs and pork products. The present study investigated the occurrence, pathogenicity, antimicrobial susceptibility and biofilm-forming ability of Y. enterocolitica isolated from the pork production chain in Puducherry, India. A total of 250 samples comprising pork (n = 100), pig intestinal contents (n = 100) and slaughterhouse soil (n = 50) were analysed using cold enrichment followed by selective isolation on Yersinia Selective Agar. Presumptive isolates were confirmed by morphological and biochemical characterisation. Pathogenicity was evaluated by calcium dependency and Congo Red absorption tests and further confirmed by polymerase chain reaction targeting the ail gene. Antimicrobial susceptibility was determined by the Kirby–Bauer disc diffusion method, while biofilm formation was assessed using Congo Red Agar. Eleven (4.4%) Y. enterocolitica isolates were recovered, including seven from pork, two from pig intestinal contents and two from slaughterhouse soil. Nine (81.8%) isolates exhibited pathogenic phenotypes and were positive for the ail gene, demonstrating complete agreement between conventional and molecular methods. All nine phenotypically and molecularly confirmed pathogenic isolates were biofilm-positive, whereas the two non-pathogenic isolates were biofilm-negative. The antibiogram revealed that all isolates were resistant to ampicillin and amoxicillin–clavulanic acid, while all were susceptible to the other antimicrobials tested. The findings highlight pork and slaughterhouse environments as potential reservoirs of pathogenic Y. enterocolitica and emphasise the need for continuous surveillance, improved hygiene practices and prudent antimicrobial stewardship to minimise foodborne public health risks.
Keywords: Yersinia enterocolitica, pork, pig slaughterhouse, foodborne zoonosis, pathogenicity, ail gene, antimicrobial resistance, biofilm formation, food safety, Puducherry