不同稀释液配制的菌悬液对染菌载体回收菌量和杀菌效果的影响

INFLUENCE OF BACTERIAL SUSPENSIONS PREPARED WITH DIFFERENT DILUENTS ON BACTERIAL COUNT RECOVERED FROM BACTERIAL CARRIER AND GERMICIDAL EFFICACY

目的观察不同稀释液配制的菌悬液滴染菌片,对载体回收菌量和杀菌效果的影响。方法采用载体定量法对胰蛋白胨生理盐水(TPS)和胰蛋白胨大豆肉汤(TSB)配制的菌悬液进行了检测。结果在菌悬液含菌量和载体滴染菌量一致的情况下,用TPS配制的菌悬液所制备的菌片,3组作用时间的菌量平均回收率为75.61%,脱落在浸泡液中菌数占染菌量的6.57%,并不随浸泡时间的延长而增加。用TSB配制的菌悬液所制备的菌片,3组作用时间的菌量平均回收率为14.95%,脱落在浸泡液中菌数占染菌量的2.90%,随着菌片浸泡时间的延长而增加。定量杀菌试验用含46.4 g/L过氧化氢复方消毒液浸泡作用5 min,对用TPS和TSB制备的菌悬液滴染的枯草杆菌黑色变种芽孢菌片杀灭对数值分别为1.26和1.88;作用10 min均达到完全杀灭。定性杀菌试验在同样条件下需要作用15 min,两组菌片全部无菌生长。结论用TSB配制菌悬液污染菌片,细菌回收率明显低于TPS组;在同样条件下,用过氧化氢对两组菌片细菌芽孢杀灭效果基本无差别。

Objective To observe the influence of bacterial carriers instilled with bacterial suspensions prepared with different diluents on bacterial count recovered from the carriers and germicidal efficacy. Methods Carrier quantitative method was used to exame the bacterial suspensions prepared with tryptone saline （TPS） and tryptone soybean broth （TSB）. Results With same bacterial content in bacterial suspension and same bacterial load of the carriers, the average bacterial count recovered from the bacterial carriers prepared with the bacterial suspensions prepared with TPS was 75.61% after exposure for 3 groups of time and the number of bacteria dropping in the immersion solution accounted for 6.57% of the bacteria load and did not increase with prolonging the immersion time. The average bacterial count recovered from the bacterial carriers prepared with the bacterial suspensions prepared with TSB was 14.95% after exposure for 3 groups of time and the number of bacteria dropping in the immersion solution accounted for 2.90% of the bacteria load and increased with prolonging the immersion time. In quantitative germicidal test, the killing logarithm values of spores of Bacillus subtilis var. niger in suspensions prepared with TPS and TSB added to the carriers were 1.26 and 1.88 respectively after immersion in the disinfection solution containing hydrogen peroxide 46.4 g/L for 5 min and immersion for 10 min could kill the spores completely. In qualitative germicidal test, under the same conditions, 15 min was required to achieve no bacteria growth on the 2 kinds of bacterial carriers. Conclusions The recovery rate of bacteria on the carriers instilled with the bacterial sus- pension prepared with TSB was lower than that prepared with TPS. Under the same conditions, the efficacy of hydrogen peroxide in killing bacterial spores on the 2 kinds of carriers was essentially not different.