Dunkelberg Hartmut, Fleitmann-Glende Friederike
Medical Institute of General Hygiene and Environmental Health, University of Goettingen, Goettingen, Germany.
Am J Infect Control. 2006 Jun;34(5):285-9. doi: 10.1016/j.ajic.2005.09.012.
The microbial barrier properties of 216 sterilization containers of 4 central sterile supply departments of different hospitals were measured using a microbial challenge test.
Uncovered thermoresistant plates filled with Sabouraud agar were placed on the base of the containers prior to sterilization. After sterilization, the containers were exposed to a defined microbial aerosol and periodic atmospheric pressure reductions of 10 to 70 hPa in an exposure chamber. After exposure and incubation of the entire containers, colony growth was registered as colony forming units (CFU) on the plates and the control plates to calculate the barrier effectiveness in terms of the logarithmic reduction value (LRV).
Two out of 11 standard containers with paper filters and 9 out of 79 containers with textile filters showed no growth on the plates. The mean colony numbers were 222 CFU/600 cm(2) (standard container with paper filter) and 209 CFU/ 600 cm(2) (container with textile filter). Fourteen out of 15 containers with permanent plastic filters did not show any growth on the plates. No recontamination was observed in 18 of 111 half-size containers. The mean colony numbers of the recontaminated half-size containers were 110 (paper filter) and 34 CFU per 300 cm(2) (textile filter). The LRVs of the full-size and half-size containers tested ranged between 1.08 and >4.
As shown in this study, the microbial barrier effectiveness of sterilization containers in the routine clinical setting can be tested with a quantitative microbial challenge test at intervals of 1 year to eliminate defect or ineffective containers as potential causal factors for nosocomial infections. An LRV of >4 should be envisaged as the target assurance level.
采用微生物挑战试验对不同医院4个中央无菌供应部门的216个灭菌容器的微生物屏障性能进行了测定。
在灭菌前，将装有沙氏琼脂的无盖耐热平板放置在容器底部。灭菌后，将容器置于暴露室内，暴露于规定的微生物气溶胶中，并进行10至70 hPa的周期性气压降低。对整个容器进行暴露和培养后，记录平板和对照平板上的菌落生长情况，以菌落形成单位（CFU）计算对数减少值（LRV）来评估屏障效果。
11个带纸质过滤器的标准容器中有2个以及79个带织物过滤器的容器中有9个在平板上未生长。平均菌落数分别为222 CFU/600 cm²（带纸质过滤器的标准容器）和209 CFU/600 cm²（带织物过滤器的容器）。15个带永久性塑料过滤器的容器中有14个在平板上未显示任何生长。111个半尺寸容器中有18个未观察到再污染。再污染的半尺寸容器的平均菌落数分别为每300 cm² 110个（纸质过滤器）和34 CFU（织物过滤器）。所测试的全尺寸和半尺寸容器的LRV在1.08至＞4之间。
如本研究所示，灭菌容器在常规临床环境中的微生物屏障效果可通过每年一次的定量微生物挑战试验进行检测，以消除有缺陷或无效的容器，这些容器可能是医院感染的潜在病因。应将＞4的LRV设定为目标保证水平。
