Characteristics and antimicrobial resistance of Campylobacter isolated from pig and cattle carcasses in Poland

A total of 70 Campylobacter isolates recovered from 114 cattle and 177 pig carcasses at the slaughterhouse level were characterized by the presence of 7 putative virulence genes and antimicrobial susceptibility using the microbroth dilution method and minimal inhibitory concentration (MIC). The prevalence of Campylobacter was 14.9% and 29.9% in cattle and pig samples, respectively. The majority of cattle carcasses were contaminated with C. jejuni (64.7%), whereas pig carcasses were mainly positive for C. coli (77.4%). Most of the strain, irrespective of origin, possessed at least one pathogenic gene marker tested, mainly flaA and cadF genes responsible for motility and adherence to host epithelial cells, respectively. Several isolates also possessed the cdtA and cdtB genes responsible for the production of cytolethal distending toxin. Antibiotic profiling showed that campylobacters were most frequently resistant to quinolones (nalidixic acid and ciprofloxacin, total 57.1% of isolates) followed by streptomycin (52.9%, only C. coli strains) and tetracycline (51.4%). Resistance to erythromycin was demonstrated only in 4 C. coli strains of pig origin. None of the isolates, irrespective of origin, was resistant to gentamycim Multi-resistance patterns, defined as resistance to antimicrobials of at least two different classes, were observed among 65.4% of the isolates, mainly C. coli recovered from pig carcasses.