消毒剂杀灭淋球菌的试验方法研究

淋球菌对营养要求特殊,普通培养基上生长较慢。为科学评价化学消毒剂对淋球菌的杀灭效果,采用平板浸润接种法对不同培养基进行比较,以评价杀菌效果的差异。结果,淋球菌在普通营养琼脂和酵母浸膏琼脂上生长的菌落均小于2 mm;在酵母浸膏血琼脂和巧克力琼脂上生长的菌落为2~3 mm,计数回收率高出26%。而平板涂布法的回收菌数低于平板浸润法,其标准差大于平板浸润法。进行悬液定量杀菌试验时,采用酵母浸膏血平板浸润接种方法。观察临床分离的淋球菌和标准菌株对化学消毒剂的抗力,选择抗力较高的标准菌株作有机干扰物试验。用大白兔作为淋球菌感染部位和感染量的试验动物。结果表明,用酵母浸膏血琼脂替代巧克力琼脂培养淋球菌无统计学差异,淋球菌用平板浸润法接种比平板涂布法好。临床分离菌株对化学消毒剂的抗力略低于标准菌株。在30 g/L牛血清白蛋白的存在下,达到消毒要求的消毒剂浓度是PBS菌悬液的消毒剂浓度的5~6倍。淋球菌可通过皮肤、角膜感染大白兔的泌尿系统,可感染角膜菌量为80 cfu。故建议在30 g/L牛血清白蛋白的条件下,淋球菌经消毒剂处理后,下降5个对数值,作为消毒合格标准较可靠。

STUDY ON METHOD OF TEST FOR KILLING GONOCOCCUS BY DISINFECTANTS

Gonococcus(Neisseria gonorrhoeae) requires special nutrition and grows slowly in ordinary culture medium.In order to evaluate scientifically the efficacy of chemical disinfectants in killing gonococcus, plate infiltration inoculation method was used to compare different culture media for evaluating difference of germicidal efficacy.Results: The colonies of gonococcus growing on ordinary nutrient agar and yeast extract agar were smaller than 2 mm,while those growing on yeast extract blood agar and chocolate agar were 2～3 mm and the recovery rate was 26% higher.The bacteria count recovered using plate smearing method was lower than that using plate infiltration method and the standard deviation was greater than that using plate infiltration method.For suspension quantitative germicidal test,yeast extract blood plate infiltration inoculation method was used.For observing the resistance of clinically isolated gonococcus and the standard bacterial strain to chemical disinfectants,standard strain with relatively high resistance was selected to carry out organic interfering substance test.White rabbits were used as the animal for testing gonococcal infection site and infecting dose.The results indicated that there was no statistical difference when yeast extract blood agar was used instead of chocolate agar for culturing gonococcus.Inoculation of gonococcus using plate infiltration method was better than that using plate smearing method.The resistance of clinically isolated strain to chemical disinfectants was slightly lower than that of standard strain.The disinfectant concentration fulfilling the disinfection requirement in presence of 30 g/Lbovine serum albumin was 5～6-folds the disinfectant concentration for disinfecting PBS bacterial suspension.Gonococcus could infect the urinary system of rabbit through skin and cornea and the number of bacteria for infecting cornea was 80 cfu.Therefore,it is recommended that in presence of 30 g/L bovine serum albumin,it is relatively reliable to use reduction of gonococcus by 5 logarithm value after disinfectant treatment as the eligible standard of disinfection.