Isolation and molecular identification of Campylobacter jejuni and Campylobacter coli from poultry in Karnataka, India

Campylobacteriosis stands out as one of the extensively characterized bacterial foodborne infections globally, primarily linked to the consumption of poultry meat and related products. This disease is predominantly caused by Campylobacter jejuni. The current research aimed to isolate and characterize C. jejuni and C. coli from poultry sources. A total of 158 poultry samples, comprising 86 cloacal swabs from both commercial and backyard poultry farms and 72 intestinal samples from retail meat shops, were collected. All samples underwent pre-enrichment followed by selective isolation of Campylobacters using mCCDA and Columbia blood agar. A total of 75 (47.47%) Campylobacter isolates were obtained and subsequently confirmed by PCR. Initially, a genus-specific PCR targeting the 16S rRNA gene was employed, followed by species-level identification through the amplification of the lpxA gene. This confirmed 52 isolates as C. jejuni and seven as C. coli, while 16 isolates remained unidentified campylobacter species. The prevalence of C. jejuni was higher at 76% compared to C. coli at 9.33%. To assess pathogenic potential, virulence genes such as cad-F and flaA were amplified through PCR for the 52 C. jejuni isolates. All C. jejuni isolates revealed the cad-F gene, and 29 isolates showed the flaA gene, indicating the pathogenicity of C. jejuni. The study revealed a higher prevalence of C. jejuni in poultry, indicating a potential public health hazard due to this emerging foodborne pathogen in the region. Contamination of chicken carcasses may occur during slaughtering processes. PCR-based detection of Campylobacters proved to be more sensitive and rapid compared to culturing.