Prevalence, drug resistance spectrum and virulence gene analysis of Campylobacter jejuni in broiler farms in central Shanxi, China

This study collected 324 chicken cloacal swabs from 6 broiler farms in 4 different areas in Shanxi Province, China (i.e., Lvliang, Taiyuan, Jinzhong, and Yangquan), and analyzed the antimicrobial resistance and virulence-associated genes of the isolates to investigate the prevalence, drug resistance, and virulence gene data of Campylobacter jejuni in broilers. The population structure of C. jejuni and genetic evolutionary relationships among isolates from broiler farms in different regions were studied by using multilocus sequence typing. A total of 35 C. jejuni isolates with an infection rate of 10.8% (35/324) were obtained. The isolates were most resistant to ampicillin (85.7%) and were most sensitive to erythromycin (14.3%). Isolates with multidrug resistance accounted for 88.6% of the total isolates. In this experiment, 15 distinct sequence types were identified and included 9 new unique sequence types. cadF was present in all isolates, and ciaB had the lowest prevalence (51.4%). C. jejuni collected from broiler farms in central Shanxi had varied infection rates, and their overall positive rate was lower than of C. jejuni collected from other regions of the country. The isolates had high resistance to quinolones and β-lactams, and multidrug resistance was prevalent. The isolates were genotypically diverse and carried 5 virulence-associated genes at high rates. Therefore, the importance of source contamination control in broiler farms is emphasized and may have considerable effects on human and animal health.