北京市顺义区零售鸡胴体中弯曲菌分布与分子特征研究

Contamination and molecular characteristics of Campylobacter spp. isolated from chicken carcasses in Shunyi, Beijing

目的研究北京市顺义区鸡胴体中弯曲菌分布和分子特征,为顺义区弯曲菌防控提供科学依据。方法采集批发市场和零售店鸡胴体60份,采用滤膜法分离培养弯曲菌,对分离菌株进行多位点序列分型分析并构建最小生成树。结果鸡胴体中弯曲菌检出率为75.0%(45/60),空肠弯曲菌与结肠弯曲菌占比分别为38.0%(19/50)和62.0%(31/50)。批发市场和零售店弯曲菌检出率分别为86.0%(37/43)和47.1%(8/17),差异有统计学意义(χ2=9.877,P<0.05);5~7月空肠弯曲菌检出率分别为10.0%(2/20)、40.0%(8/20)和45.0%(9/20),差异有统计学意义(χ2=6.624,P<0.05)。19株空肠弯曲菌共分为13个ST型;28株结肠弯曲菌共分为16个ST型。空肠弯曲菌耐药率前五位由高至低依次为四环素(100.0%,19/19)、萘啶酸(100.0%,19/19)、环丙沙星(94.7%,18/19)、氟苯尼考(57.9%,11/19)、庆大霉素(36.8%,7/19);结肠弯曲菌耐药率前五位由高至低依次为萘啶酸(100.0%,31/31)、环丙沙星(100.0%,31/31)、四环素(93.5%,29/31)、链霉素(93.5%,29/31)、庆大霉素(83.9%,26/31)。空肠弯曲菌和结肠弯曲菌多重耐药率分别为68.4%(13/19)和93.5%(29/31)。结论北京市顺义区市场零售鸡胴体中弯曲菌污染水平较高,结肠弯曲菌为污染的优势菌种。批发市场鸡胴体污染弯曲菌的情况比零售店严重。

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.