Simultaneous Detection of Fluoroquinolone- and Macrolide-Resistant Campylobacter jejuni/Campylobacter coli in Retail Chicken Meat Using Multiplex-PCR

Campylobacter contamination in chicken meat, particularly with fluoroquinolone- and macrolide-resistant strains, is a significant public health concern. Therefore, developing an easy and rapid detection method for fluoroquinolone- and macrolide-resistant Campylobacter will improve food safety. In this study, we designed and evaluated a multiplex-Polymerase Chain Reaction (PCR) method for the simultaneous detection of fluoroquinolone- and macrolide-resistant Campylobacter jejuni and Campylobacter coli in chicken meat. Our multiplex-PCR-targeted mutations in the gyrA and rrl genes of Campylobacter species confer resistance to fluoroquinolones and macrolides, respectively. Overall, this method could detect Campylobacter contamination and identify C. jejuni and C. coli as well as their susceptibility to fluoroquinolone and macrolide. Spiking of chicken meat samples revealed that multiplex-PCR can detect at least 0.72 Colony-Forming Unit (CFU)/g C. jejuni/coli. Among 277 retail chicken meat samples, C. jejuni/coli were detected in 54 samples using multiplex-PCR, with isolation from 52 samples using microbial culture. The susceptibility of the isolates to fluoroquinolones and macrolides was determined using both the PCR and culture methods, and a comparison of these methods showed that the accuracy, specificity, and sensitivity were all above 95%. The culture method required approximately 8 days for Campylobacter isolation and antimicrobial susceptibility testing. Multiplex-PCR could determine the contamination with C. jejuni/coli and susceptibility to fluoroquinolones and macrolides within 2-3 days from the enrichment culture to final determination. These results indicate that the proposed multiplex-PCR enables rapid and simultaneous detection of fluoroquinolone- and macrolide-resistant C. jejuni/coli in chicken meat and its utility for monitoring their contamination in food.