饮用天然矿泉水中产气荚膜梭菌检测国标方法的改进

Improvement of Detection Method for Clostridium Perfringens in Drinking Natural Mineral Water of the National Standards

针对饮用天然矿泉水中产气荚膜梭菌(Clostridium perfringens)检测国家标准方法中,滤膜上的菌落在亚硫酸盐-多粘菌素-磺胺嘧啶琼脂经24 h厌氧环境培养后黑色产生不明显的问题,对检验方法进行改进。国标改进方法一:按GB/T 8538.4.55-2008进行过滤后增加一步骤,即用SPS培养基(约10 mL)倾注于培养皿的膜上,然后放置厌氧培养;国标改进方法二:按GB/T8538.4.55-2008进行过滤后将滤膜反贴于SPS培养基上,然后放置厌氧培养。对方法进行改进后,国标改进方法一和国标改进方法二滤膜上的菌落经24 h厌氧环境培养后均有明显的黑色产生。国标方法黑色菌落不明显,国标改进方法一和国标改进方法二产生的黑色菌落数与国标方法相比,具有显著性差异(P<0.01)。国标改进方法一不但有利于产气荚膜梭菌黑色的产生,而且容易挑取菌落做进一步试验。

The target colonies on the filtration membrane could not turn black obviously on sulfite - polymyxin - stdfadiazine agar after 24 h incubation in anaerobic conditions based on national standard method for the detection of Clostridium perfringens in drinking mineral water. To solve the above problem, the detection method was improved according to the methods of GB/T 8538.4.55-2008. After filteration, the SPS medium （10 mL） was poured on the membrane in the petri dish, and then placed in anaerobic conditions. Another improvement method was also based on the methods of GB/T 8538.4.55-2008. After filtration, the membrane was placed on the SPS culture medium at the reverse side, and then placed in anaerobic conditions. Using the two improved methods, the colonies of C. perfringens on the filtration membrane could turn black obviously after 24 h incubation in anaerobic conditions, Obvious difference was found in the number of black colonies using the two improved methods. The first improved method would make C.perfingens colonies turn black easily and obviously, and it also makes easy to pick colonies for further studies.