Abstract:Objective To study the contamination and molecular characteristics of Campylobacter isolated from chicken carcasses in Shunyi, Beijing, and provide scientific basis for the prevention and control of Campylobacter infection. Methods Sixty samples of chicken carcasses were collected from wholesale markets and retail stores. The Campylobacter was isolated by filtration method. Multilocus sequence typing (MLST) analysis were performed for all of the Campylobacter isolates and the minimum spanning tree was constructed based on the STs. Results The positive detection rate of Campylobacter in chicken carcasses was 75.0% (45/60) and the constituent ratios of C.jejuni and C.coli were 38.0% (19/50) and 62.0% (31/50), respectively. The positive ratio of Campylobacter were 86.0% (37/43) and 47.1% (8/17) in wholesale market and retail store, respectively, and there was significant difference between the positive ratio (χ2=9.877, P<0.05). The positive ratio of C.jejuni were 10.0% (2/20), 40.0% (8/20) and 45.0% (9/20) in May, June and July, respectively, and the positive ratio in May was significantly lower than both June and July (χ2=6.624, P<0.05). Thirteen STs were identified from the 19 C.jejuni isolates and 16 STs were identified from the 28 C.coli. The antibiotic resistance ratio for C.jejuni was tetracycline (100.0%,19/19), nalidixic acid (100.0%,19/19), ciprofloxacin (94.7%,18/19), florfenicol (57.9%,11/19) and gentamicin (36.8,7/19). The antibiotic resistance ratio for C.coli was nalidixic acid (100.0%,31/31), ciprofloxacin (100.0%,31/31), tetracycline (93.5%, 29/31), streptomycin (93.5%, 29/31) and gentamicin (83.9%,26/31). The multi-antibiotic resistance ratio of C.jejuni and C.coli were 68.4%(13/19) and 93.5%(29/31), respectively. Conclusion Campylobacter contamination rate in carcasses of retail chickens in Shunyi was relatively high. C.coli was the dominant Campylobacter isolated in the chicken carcasses. Contamination rate of Campylobacter in chicken carcasses in wholesale markets was more serious than retail stores.