Porcine carcasses as an underestimated source of antimicrobial resistant Campylobacter coli.

Introduction: Campylobacteriosis is the most common human foodborne bacterial infection worldwide and is caused by bacteria of the Camplylobacter genus. The main source of these bacteria is poultry, but other food-producing animals such as pigs are also responsible for human infections. An increasing number of strains with resistance to fluoroquinolones and other antimicrobials such as macrolides were recently noted. The aim of the study was to investigate Campylobacter contamination of porcine carcasses and determine the antimicrobial resistance of the obtained isolates.

Material and methods: A total of 534 swabs from carcasses of pigs slaughtered in Poland during 2019-2022 were tested for Campylobacter spp.

Results: Campylobacter was detected in 164 (30.7%) carcasses; among them 149 (90.8%) were classified as C. coli and the remaining 15 (9.2%) samples were C. jejuni-positive. Because a low number of C. jejuni isolates were identified, only the C. coli isolates were subjected to antimicrobial resistance analysis. The majority of these isolates were resistant to streptomycin (94.0%), ciprofloxacin (65.8%) and tetracycline (65.1%). A total of 94 (63.1%) strains displayed antimicrobial multiresistance patterns and were mainly resistant to fluoroquinolones, aminoglycosides and tetracyclines (74; 49.7% of the isolates tested).

Conclusion: The obtained results showed that pig carcasses may be contaminated with antimicrobial-resistant C. coli.