生活饮用水中粪肠球菌检验方法验证结果分析

Analysis of verification results by detection for Enterococci in drinking water

中文关键词:  生活饮用水  粪肠球菌  滤膜法  最近似值法

英文关键词:drinking water  Enterococcus faecalis  filter membrane method  maximum probable number method

中文摘要:

      目的 验证最近似值测定法、滤膜法检测生活饮用水中粪肠球菌的适用性。方法 参照SN/T 1933.1-2007《食品和水中肠球菌检验方法 第1部分: 平板计数法和最近似值测定法》、SN/T 1933.2-2007《食品和水中肠球菌检验方法 第2部分: 滤膜法》方法检测样品中粪肠球菌浓度, 对比不同培养基的检测效果。结果 最近似值测定法所用的肠球菌肉汤与叠氮化钠葡萄糖肉汤在结果计数上无明显差异P=0.331(P>0.05), 但肠球菌肉汤24 h就会产生明显变化, 而叠氮化钠葡萄糖肉汤48 h才产生混浊; 滤膜法中肠球菌琼脂和Pfizer琼脂不宜于计数, KF琼脂菌落生长缓慢, mEI琼脂与CATC琼脂表现优异, 在结果计数上5种培养基无明显差异P=0.957(P>0.05)。2种方法的检测结果均在接受范围之内。结论 2种方法均适用于生活饮用水(井水、末梢水)中粪肠球菌的检测, MPN法更推荐选择肠球菌肉汤培养, 滤膜法推荐使用CATC琼脂或mEI培养基作为选择性培养基。

英文摘要:

      Objective To verify the applicability of the maximum probable number method and filter membrane detection method in the detection of Enterococcus faecalis in drinking water. Methods According to the method of SN/T 1933.1-2007 Detection of Enterococci in food and water. Part 1: Method for plate count and maximum probable number method, SN/T 1933.2?2007 Detection of Enterococci in food and water—Part 2: Method for membrane filtration, the concentration of Enterococcus faecalis in the sample was detected, and the detection effect of different media was compared. Results There was no significant difference in colony count between Enterococcus broth and sodium azide glucose broth used in the recent likelihood determination method P=0.331 (P>0.05), but Enterococcus broth had a significant change in 24 h, while sodium azide glucose broth did not produce turbidity until 48 h. Enterococcus agar and Pfizer agar were not suitable for colony count in the filter method, colonies grew slowly on KF agar, but mEI agar and CATC agar performed well. There was no significant difference between the 5 media in the result of colony count P=0.957 (P>0.05). The test results of both methods were within the acceptable range. Conclusion Both methods are suitable for detecting the Enterococcus faecalis in drinking water (well water and peripheral water), Enterococcus broth culture is recommended for maximum probable number method, and CATC agar or mEI medium are chosen as the selective medium in the filter method.