α-葡萄糖苷酶试验在克罗诺杆菌鉴定中的应用

Application of α-glucosidase test in the identification of Cronobacter spp.

中文关键词:  克罗诺杆菌  鉴定  α-葡萄糖苷酶试验  产黄色素试验

英文关键词:Cronobacter spp.  identification  α-glucosidase test  yellow pigment formation

中文摘要:

      目的 研究α-葡萄糖苷酶试验在克罗诺杆菌的快速准确鉴定中的应用。方法 对包括克罗诺杆菌在内的56株肠杆菌科细菌进行纯培养后, 将单个菌落的生理盐水混悬液, 加到α-葡萄糖苷酶检测试剂中, 于37 ℃水浴培养4 h后, 在405 nm波长处测量其吸光度值, 进行α-葡萄糖苷酶试验。同时将56株菌接种于TSA琼脂平板, 于25 ℃培养48 h后, 在自然光下观察菌落的黄色素。结果 40株克罗诺杆菌的α-葡萄糖苷酶试验均为阳性; 包括阴沟肠杆菌、大肠埃希氏菌、产气肠杆菌在内16株肠杆菌, α-葡萄糖苷酶试验均为阴性。在40株克罗诺杆菌中, 有37株菌产黄色素试验为阳性, 3株菌产黄色素试验为可疑; 其他16株肠杆菌, 产黄色素试验均为阴性。结论 与产黄色素试验相比, 用α-葡萄糖苷酶试验鉴定克罗诺杆菌, 结果更准确, 且检测时间短、客观性强。

英文摘要:

      Objective To study the application of α-glucosidase test in rapid and accurate identification of Cronobacter Spp. Methods After purely culturing 56 strains of Enterobacter including Cronobacter spp., a single colony of physiological saline suspension was added to the α-glucosidase detection reagent, and cultured in a water bath at 37 ℃ for 4 hours. The absorbance value was measured at a wavelength of 405 nm for the α-glucosidase test. At the same time, 56 strains were inoculated on TSA agar plates, and after incubation at 25 ℃ for 48 h, the yellow pigment of the colonies was observed under natural light. Results All 40 strains of Cronobacter spp. were positive for α-glucosidase test; 16 strains of Enterobacter, including Enterobacter cloacae, Escherichia coli and Enterobacter aerogenes were negative for α-glucosidase test. Among 40 strains of Cronobacter spp, 37 strains were positive for the yellow pigment test, 3 strains for the yellow pigment test were suspicious, and 16 strains of the Enterobacter were negative for the yellow pigment test. Conclusion Compared with the yellow pigment formation, the α-glucosidase test is more likely to obtain accurate results and takes less time to identify Cronobacter spp.