银川市市售食品中单增李斯特菌污染状况分析研究

Analysis of Contamination Status of Listeria monocytogenes from Retail Food in Yinchuan

[目的]了解银川市市售食品中单增李斯特菌的污染状况及其血清型和耐药性特点。[方法]以宁夏银川市售各类生鲜食品为原料,菌株的分离鉴定按照GB4789.30-2010《单核细胞增生李斯特氏菌检验》和国家食源性疾病监测网监测方案进行;血清型检验按照血清凝集试验进行;药物敏感性试验按照K-B纸片扩散法进行。[结果]720份食品中检出单增李斯特菌45株,总检出率为6.25%,分属5个血清型,主要为1/2a型。污染率最高的是生鸡肉(8.33%)。耐药性研究表明单增李斯特菌对多粘菌素的耐受最严重,耐药率为77.78%,此外还耐受头孢噻肟、四环素、呋喃妥因、青霉素、红霉素和头孢噻吩,且出现多重耐药。[结论]银川市食品中存在不同程度的单增李斯特菌污染,生肉中单增李斯特菌检出率较高,应加强监测工作。同时存在致病性较强的血清型,呈多重耐药性趋势。

[ Objective] To know the contamination condition of L. monocytogenes from retail foods in Yinehuan and investigate the serotype and the susceptibility. [ Method] With Ningxia, Yinchuan retail fresh food as raw material, national standards method （GB4789.30-2010） and national foodborne disease surveillance network monitoring program were used to isolation and identification from collected samples for L. monocytogenes. All isolates were serotyped using commercially available antisera for subtyping. Drug sensitivity tests were conducted in accord- ance with K-B disk diffusion method. [ Result] 45 L. monocytogenes were detected from 720 samples, the total detection rate was 6.25%. Among all isolates there were 5 serotypes, and serotype 1/2a was dominant. The detection rate of raw chicken meat products was the highest （8.33%）. Resistance to antimicrobial agents was most frequently observed for polymyxin （77.78%） and to some extent resistance to cefo- taxime, tetracycline, nitrofurantoin, penicillin, erythromycin and cefalotin and showed multiple character. [ Conclusion ] The investigated food in Yinehuan had been contaminated by L. monocytogenes in different degrees. The raw meat should be focus on supervision and monitoring work due to serious pollution of L. monocytogenes. There were the pathogenic stronger serotypes, and isolates belonged to multiple antibiotics resistance.