The Enterotoxin Production and Antimicrobial Resistance of Campylobacter Strains Originating from Slaughter Animals

Pathogens. 2022 Sep 30;11(10):1131. doi: 10.3390/pathogens11101131.


The pathogenicity of animal-origin Campylobacter strains, including antimicrobial resistance and enterotoxigenicity, was determined in this study. Overall, 149 Campylobacter isolates originating from cattle, swine and poultry were tested. The antimicrobial resistance profiles were examined by the diffusion disk method. The dominant resistance pattern was CIP_TET. The resistance rates for ciprofloxacin among swine, cattle and poultry isolates were 84%, 51% and 66%, respectively; for tetracycline, they were 82%, 57.1% and 76%, respectively. None of the obtained isolates was resistant to all four antimicrobials tested. The ability to produce enterotoxins was assessed by the use of a suckling mouse bioassay, with intestinal fluid accumulation as a positive result, and by CHO assay, with the elongation of cells as a positive result. The ability to produce enterotoxins was significantly higher among cattle isolates (61.2% and 71.4% positive isolates, respectively, in the bioassay and the CHO assay) than among swine (16% and 32% positive isolates, respectively) or poultry isolates (14% and 22% positive isolates, respectively). A strong positive correlation between in vitro and in vivo enterotoxicity tests was demonstrated.

Keywords: CHO assay; Campylobacter; antimicrobial resistance; enterotoxicity; suckling mouse assay.

Grants and funding

This project was financially supported by the Minister of Education and Science under the program entitled “Regional lnitiative of Excellence” for the years 2019–2023, Project no. 010/RID/2018/19, amount of funding 12.000.000 PLN.