酶底物法检测生活饮用水中大肠菌群的探讨

Discussion on Detection of Coliform in Water With Enzyme Substrate Technique

目的对酶底物法检测生活饮用水中大肠菌群的方法和结果进行探讨。方法用51孔和97孔定量盘共检测生活饮用水196份,其中出厂水112份,末梢水84份,检测项目为总大肠菌群、耐热大肠菌群、大肠埃希菌。结果 196份水样用51孔定量盘检测的合格率为33.7%,97孔定量盘检测的合格率为31.6%,对2种定量盘检测合格率进行χ2检验,差异无统计学意义;对51孔和97孔定量盘检测的总大肠菌群、耐热大肠菌群和大肠埃希菌合格率分别进行了χ2检验,差异无统计学意义;对51孔和97孔定量盘阳性结果 MPN值在1~200.5的总大肠菌群、耐热大肠菌群和大肠埃希菌进行配对t检验,差异有统计学意义;对大肠埃希菌在36.5℃和44.5℃2种温度下得到的MPN值进行配对t检验,差异无统计学意义。结论 51孔和97孔定量盘在对水活饮用水定性检测上没有差异,结果是等效的;97孔定量盘有更好的定量范围和灵敏度,适用于生活饮用水大肠菌群MPN法检测;酶底物法在36.5℃和44.5℃检测大肠埃希菌的结果没有差异。

Objective To discuss the enzyme substrate technique in detecting coliform in domestic drinking water.Methods A total of 196 water samples were detected with 51- hole and 97- hole quantitative plate,among which 112 were finished water sample and 84 were tap water smaple. The detection items included total coliform group,thermotoletant coliform bacteria and escherichia coli. Results The qualified rate of the 196 water samples was 33. 7% with 51-hole plate and was 31. 6% with 97-hole plate,with no statistical difference between the two methods. The aforementioned bacteria showed no statistical difference between 51- hole and 97- hole plate in terms of qualified rate and the MPN value within 1- 200 showed no statistical difference either. The MPN value of escherichia coli at 36. 5 ℃ and 44. 5 ℃ showed no statistical difference. Conclusion The results of 51-hole and 97-hole in qualitative detection of domestic water are equivalent. The 97-hole plate has better quantitative range and sensitivity,and suitable for detection of coliform with MPN method. With enzyme substrate technique,the results are no difference at 36. 5 ℃ and 44. 5 ℃ 。