Gregory A W, Schaalje G B, Smart J D, Robison R A
Department of Microbiology, Brigham Young University, Provo, Utah 84602-5133, USA.
Infect Control Hosp Epidemiol. 1999 May;20(5):324-30. doi: 10.1086/501625.
To assess the mycobactericidal efficacy of an agent relatively new to disinfection, ortho-phthalaldehyde (OPA) and to compare the resistances of three Mycobacterium species. Mycobacterium bovis (strain BCG) was compared with Mycobacterium chelonae and Mycobacterium terrae to investigate the feasibility of using either of the latter two species in tuberculocidal testing. M. chelonae (a rapid grower) and M. terrae (an intermediate grower) both grow faster and are less virulent than M. bovis (a slow grower).
The quantitative suspension protocol specified by the Environmental Protection Agency (EPA), the Tuberculocidal Activity Test Method (EPA test), was used throughout this study. Standard suspensions of all three species were prepared in a similar manner. Two suspensions of M. bovis, created in different laboratories, were used. These were tested against two concentrations of alkaline glutaraldehyde to provide reference data. Two concentrations of OPA were evaluated against all mycobacterial test suspensions. Four replicates of each organism-disinfectant combination were performed.
Results were assessed by analysis of variance. M. terrae was significantly more resistant to 0.05% OPA than either M. bovis or M. chelonae. At 0.21% OPA, M. terrae was slightly more susceptible than one test suspension of M. bovis, but not significantly different from the other. M. chelonae was significantly less resistant than the other species at both OPA concentrations. At their respective minimum effective concentration, OPA achieved a 6-log10 reduction of M. bovis in nearly one sixth the time required by glutaraldehyde (5.5 minutes vs. 32 minutes).
These data, along with other recent studies, lend support to the idea that M. terrae may be a suitable test organism for use in the tuberculocidal efficacy testing of disinfectants. They also confirm the relatively rapid tuberculocidal activity of OPA.
评估一种相对新型的消毒剂邻苯二甲醛（OPA）的杀分枝杆菌效力，并比较三种分枝杆菌的耐药性。将牛分枝杆菌（卡介苗菌株）与龟分枝杆菌和土地分枝杆菌进行比较，以研究使用后两种菌中的任何一种进行杀结核测试的可行性。龟分枝杆菌（快速生长菌）和土地分枝杆菌（中等生长菌）都比牛分枝杆菌（缓慢生长菌）生长得更快且毒性更低。
本研究自始至终采用美国环境保护局（EPA）规定的定量悬浮规程，即杀结核活性测试方法（EPA测试）。以类似方式制备所有三种菌的标准悬浮液。使用了在不同实验室制备的两种牛分枝杆菌悬浮液。将它们与两种浓度的碱性戊二醛进行测试以提供参考数据。针对所有分枝杆菌测试悬浮液评估两种浓度的OPA。对每种微生物 - 消毒剂组合进行四次重复实验。
通过方差分析评估结果。土地分枝杆菌对0.05% OPA的耐药性明显高于牛分枝杆菌或龟分枝杆菌。在0.21% OPA时，土地分枝杆菌比一种牛分枝杆菌测试悬浮液稍敏感，但与另一种无显著差异。在两种OPA浓度下，龟分枝杆菌的耐药性均明显低于其他菌种。在各自的最低有效浓度下，OPA使牛分枝杆菌数量减少6个对数级所需的时间几乎是戊二醛所需时间的六分之一（5.5分钟对32分钟）。
这些数据以及其他近期研究支持了土地分枝杆菌可能是用于消毒剂杀结核效力测试的合适测试微生物这一观点。它们还证实了OPA相对快速的杀结核活性。
