食品及环境样品中肠球菌快速检验方法的 建立及优化

Development and optimization of rapid detection of Enterococcus spp. in retailed raw pork and environment samples

中文关键词:  肠球菌  生鲜猪肉  环境

英文关键词:Enterococci  raw pork  environment

中文摘要:

      目的 建立并优化食品及环境样品中肠球菌的快速检验方法。方法 用mEI培养基作为选择性培养基, 肠球菌tuf基因为靶基因设计引物, 建立食品及环境样品中肠球菌的快速检验方法。通过添加肠球菌和非肠球菌标准菌株, 验证方法的检测限、灵敏度及特异性, 并使用优化后的方法对北京市丰台区某大型生鲜猪肉集贸市场的地面、墙壁、污水和生鲜猪肉等样品中的肠球菌进行检验。结果 所建方法的检测限为1 CFU/100 cm2和1 CFU/25 g (mL), 且与10种非肠球菌无交叉反应; 地面涂抹、墙壁涂抹、污水和生鲜猪肉等样品中均检验出肠球菌, 检出率为100%。结论 建立了简便、快速、灵敏、特异的肠球菌检验方法; 集贸市场内部环境和生鲜猪肉存在肠球菌污染。应加强市售生鲜肉中肠球菌的监测, 并采取相应措施降低其污染水平。

英文摘要:

      Objective To develop and optimize a method for rapid detection of Enterococci in food and environment samples. Methods Using mEI as the selective culture-base, followed by Enterococcus spp. tuf gene-based genus-specific PCR assay, a rapid detection method was established for detection of Enterococci in retailed raw pork and environment samples. The limit of detection, sensitivity and specificity of the rapid detection method were tested and verified by adding standard strain Enterococcus faecalis ATCC 29212 and non-enterococcal standard strains into Enterococcus-free samples, respectively. The method was optimized and used to analyze floor swab samples, wall swab samples, sewage samples and retailed raw pork samples collected from a farm market in Fengtai district of Beijing. Results The limit of detection of the established method was 1 CFU/100 cm2 and 1 CFU/25 g (mL). The method showed no cross-reactivity in determination of 10 kinds of non-enterococcal standard strains. All samples collected from the farm market were positive for Enterococci, the positive detection rate was 100%. Conclusion A rapid, sensitive and specific detection method for Enterococci was developed. It was shown that internal environment of the farm market, as well as the raw pork were heavily contaminated by Enterococci. In consequence, action of monitoring Enterococci in raw meat should be strengthened and appropriate measures should be taken to reduce the contamination level.