试验平皿数对药品低水平微生物计数结果准确性的影响  

Effect of the Number of Test Plates on the Accuracy of Low Microbial Counting Results of Pharmaceutical Products

作　　者：王杠杠 王似锦[1] 马仕洪[1] WANG Ganggang;WANG Sijin;MA Shihong(National Institutes for Food and Drug Control,Beijing 100050)

机构地区：[1]中国食品药品检定研究院,北京100050

出　　处：《中国医药工业杂志》2025年第1期96-100,共5页Chinese Journal of Pharmaceuticals

基　　金：中国食品药品检定研究院中青年发展研究基金项目(2022A7)。

摘　　要：分别以浓度为0.85、1.15、3.08 cfu/mL的3组大肠埃希菌菌悬液为研究对象,每组各100个平皿进行菌落计数,作为数据基础模拟不同个数平皿合并计数后的计数结果,并分析不同情况下报告结果与真值之间的偏离程度。结果显示,3组数据均服从泊松分布;试验平皿数相同时,随着菌悬液浓度增加,平皿计数结果的RSD减小;同一份菌悬液,随试验平皿数增多,平皿计数结果的RSD减小,报告的结果范围缩窄。菌浓度越低,其RSD越大,误判的风险越高,增加试验平皿数有利于提高低生物负载水平供试液微生物计数结果的准确性。合并计数后菌落数不小于4 cfu、RSD≤50%时,菌落计数结果可对供试液的生物负载水平进行较为准确的估计。Three levels of concentration(0.85, 1.15, 3.08 cfu/mL) of Escherichia coli suspensions were used as objects, with 100 plates in each group for colony counting, which served as the data basis for simulating the data for different numbers of test plate combined with counting. The deviations between the reported results and the true values were analyzed under different conditions. Data of 3 groups followed Poisson distribution. For the same number of test plates,the RSD of plate counts decreased with the increasing of the concentration of bacterial suspension. For the same bacterial suspension, the RSD of plate counts and the range of reported results decreased with the increasing of the number of test plates. The lower concentration of bacterial suspension, the greater coefficient of dispersion, and the higher the risk of misjudgment. Increasing the number of test plates was beneficial to improve the accuracy of microbial count resulted in low bioburden test dilution. When the combined count of colonies was no less than 4 cfu and the RSD was no more than 50%,the colony count results could provide an accurate estimate of the bioburden of the sample solution.

关 键 词：平皿计数 泊松分布 微生物计数 微生物污染控制 

分 类 号：TQ460.7[化学工程—制药化工]