Campylobacter in backyard poultry: hidden risks and public health implications

Although risk factors associated with Campylobacter infection in poultry have been recognised, a notable gap exists associated with this infection in backyard poultry.

Birds were examined by taking 315 cloacal swabs in six small, backyard poultry flocks of ducks, geese and ornamental chickens to determine the occurrence, genetic diversity and antimicrobial susceptibility of Campylobacter spp. Genomic diversity was assessed by sequencing the short variable region of the flaA gene and by virulence gene profiling. Antimicrobial susceptibility was analysed by the minimal inhibitory concentration method with the agar dilution technique.

The prevalence of Campylobacter was 5.1%, with positive findings limited to ducks and ornamental chickens. A total of 16 isolates were recovered, comprising 14 of C. jejuni and 2 of C. coli. Duck isolates showed higher genetic diversity (Simpson's diversity index (SDI) = 1.000), but ornamental chicken isolates were also not homogeneous (SDI = 0.911). The most frequently detected virulence determinants were flaA (100.0%), ciaB (75.0%), cadF (62.5%) and cdtC (62.5%). Antimicrobial resistance was most frequently to ciprofloxacin (93.8%), and to tetracycline (43.8%) and erythromycin (43.8%) in many instances, while multidrug resistance was found in 18.8% of isolates.

The results will contribute to a more comprehensive understanding of the ecology and transmission dynamics of Campylobacter under the One Health framework.