Antimicrobial resistance, virulence characteristics, and multilocus sequence typing of Campylobacter species from retail meat and milk products.

Aims: Campylobacter spp. are considered significant foodborne pathogens that pose a health threat worldwide to consumers. The study aimed to investigate the prevalence of Campylobacter spp. in meat and milk products and to evaluate antimicrobial resistance, virulence genes, biofilm formation, disinfectant susceptibility, and genetic relatedness by multilocus sequence typing (MLST).

Methods and results: Campylobacter spp. was detected in 20% of the 200 samples, including chicken meat, ground beef, homemade white cheese, and raw milk. Among them, 2% Campylobacter jejuni, 3.5% Campylobacter coli, and 14.5% other Campylobacter spp. were identified. Ampicillin and ciprofloxacin resistance were found to be 100%. All isolates were multidrug-resistant (MDR), and eight resistance patterns were found. The blaOXA-61 and tet(O) genes were detected in 100% of the C. coli and C. jejuni, respectively. The cmeB was present in all C. jejuni and 85.7% of the C. coli isolates. The virulence genes cdtA, cdtB, and cdtC were positive in all C. jejuni. All C. jejuni and C. coli isolates carried the cadF gene. The pldA, iamA, and ciaB genes varied from 25% to 100%. All isolates were biofilm producers. The minimal inhibitory concentrations of triclosan and cetyltrimethylammonium bromide (CTAB) to the isolates were 0.125-32 and 16-64 μg/ml, respectively. MLST identified nine sequence types (STs), including a novel ST (ST12345) from ground beef. All C. coli isolates were grouped into the ST-828 complex.

Conclusions: These results highlight that meat and milk products are potential sources for the transmission of MDR isolates and possibly pathogenic clonal types, posing a risk to human Campylobacter infection.