Cole E C, Rutala W A, Samsa G P
University of North Carolina School of Medicine, Department of Medicine, Chapel Hill 27599.
J Assoc Off Anal Chem. 1988 Nov-Dec;71(6):1187-94.
An initial collaborative study of the AOAC use-dilution method (UDM), used for bactericidal disinfectant efficacy testing, demonstrated extreme variability of test results among the 18 laboratories testing identical hospital disinfectants. In an effort to improve the method, 32 changes were made by the UDM Task Force. These changes represented improvements in quality assurance practices and elimination of method variability; however, the basic framework of the method was retained. A second collaborative trial was conducted to determine if the interlaboratory variability of test results could be reduced to an acceptable level using the modified UDM. Twelve of the original 18 laboratories participated in the second study. Each laboratory processed 60 penicylinders (P) for each of the 6 randomly selected, federally registered disinfectants and 3 test organisms (Staphylococcus aureus, Salmonella choleraesuis, Pseudomonas aeruginosa). The number of positive penicylinders (greater than 1 positive P/60 replicates = failure) for the 6 products when P. aeruginosa was used as the challenge organism ranged 1-30, 0-36, 0-15, 0-5, 0-3, and 0-60 for the 3 quaternaries and 3 phenolics, respectively. The results of the variance components analysis for P. aeruginosa and the other 2 organisms showed that the variance components for laboratories were not significantly reduced for any organism in this study. Such interlaboratory variability of results questions the use of the original or the modified UDM for registration purposes.
一项对用于杀菌消毒剂功效测试的美国官方分析化学师协会（AOAC）使用稀释法（UDM）的初步合作研究表明，在对相同医院消毒剂进行测试的18个实验室中，测试结果存在极大差异。为改进该方法，UDM特别工作组进行了32项更改。这些更改体现了质量保证措施的改进以及方法变异性的消除；然而，该方法的基本框架得以保留。进行了第二项合作试验，以确定使用改进后的UDM能否将实验室间测试结果的变异性降低到可接受水平。最初的18个实验室中有12个参与了第二项研究。每个实验室针对6种随机选择的联邦注册消毒剂和3种测试微生物（金黄色葡萄球菌、猪霍乱沙门氏菌、铜绿假单胞菌），对60个青霉素瓶（P）进行处理。当使用铜绿假单胞菌作为挑战微生物时，6种产品的阳性青霉素瓶数量（大于1个阳性P/60次重复 = 失败），对于3种季铵盐类和3种酚类产品，分别为1 - 30、0 - 36、0 - 15、0 - 5、0 - 3和0 - 60。对铜绿假单胞菌和其他2种微生物的方差成分分析结果表明，在本研究中，任何微生物的实验室方差成分均未显著降低。这种实验室间结果的变异性使得原始或改进后的UDM用于注册目的受到质疑。
