对生孢梭菌CFU计数培养基的验证试验

Verifying the Efficacy of CFU Counting Culture Medium for Clostridium sporogenes

目的:对新研制的生孢梭菌 CFU 计数培养基的 CFU 计数效果的可重复性进行验证。方法:将生孢子梭状芽孢杆菌(简称生孢梭菌)复苏、增菌培养,培养物与标准比浊管比浊至相同浊度,然后10倍系列稀释至1×10^(-6),作为工作菌液。将工作菌液采用浇注法接种生孢梭菌 CFU 计数培养基,分别置厌氧条件及有氧条件35℃培养;将工作菌液采用涂抹法接种于营养琼脂培养基和厌氧菌琼脂培养基,置厌氧条件35℃培养,用未接种的培养基做空白对照。分别于18,24,48,72 h 进行 CFU·mL^(-1)计数、观察菌落形态。用同一工作菌液重复上述实验5次,分别计算不同培养基 CFU·mL^(-1)的平均值。将以上试验重复2次。结果:生孢梭菌 CFU 计数培养基的 CFU 计数结果明显优于营养琼脂培养基和厌氧琼脂培养基(P<0.01);厌氧条件培养明显优于有氧条件培养(P<0.01)。生孢梭菌以浇注法接种于 CFU 计数培养基,置厌氧条件35℃培养18 h,CFU·mL^(-1)计数最多,可能最接近最大活菌数,且菌落形态良好。结论:新研制的生孢梭菌 CFU 计数培养基可以认为是目前最适于生孢梭菌 CFU 计数的培养基,可以推荐作为生孢梭菌 CFU 计数培养基使用。

Objective ： To verify the repeatability of the CFU （ Colony Forming Units） counting efficacy of the new developed CFU counting culture medium for Clostridium sporogenes, nethod： Resurged and enriched the strain of Clostridium sporogenes,diluted the culture with 0.9% sterilized NaCl solution to a concentration against the stand- ard opacity, and then carried out 10 -fold serial dilutions to the dilution of 1 × 10^-6, now the working bacterial suspension was already prepared. Inoculated the above working bacterial suspension into the CFU counting culture medium for Clostridium sporogenes with pouring method, and incubated them under anaerobic condition and aerobic condition separately at 35℃ ;Inoculated the above working bacterial suspension into the nutrient agar medium and anaerobic bacterium agar medium with daubing method and incubated them under anaerobic condition at 35 ℃, and used the culture medium without inoculated as control. Counted CFU · mL^-1 and observed the colony configuration at 18,24,48,72 h. Repeated the test with the above same working bacterial suspension for 5 times, and calculate the mean of CFU · mL^- 1 of different media separately. Repeat the above test for 2 times. Results ： The CFU counting efficacy of CFU counting culture medium for Clostridium sporogenes was apparently better than those of nutrient agar medium and anaerobic bacterial agar medium（ P 〈 0.01 ）. And culture under anaerobic condition is apparently bet- ter than that under aerobic condition（P 〈 0.01 ）. When inoculated Clostridium sporogenes with pouring method into the CFU counting culture medium for Clostridium sporogenes for 18 h at 35℃ under anaerobic condition, CFU count was maximal and maybe the proximal amount of the living bacteria, and colony configuration was good. Conclusions：In the present, the new developed medium may be the most appropriate medium for Clostridium sporogenes to count CFU. And the culture medium can be recommended for CFU counting of Clostridium sporogenes.