Rutala W A, Gergen M F, Weber D J
Division of infectious Diseases, University of North Carolina, Chapel Hill 27599-7030, USA.
Am J Infect Control. 1998 Aug;26(4):393-8. doi: 10.1016/s0196-6553(98)70034-3.
This study was undertaken to evaluate the efficacy of 4 new low-temperature sterilization technologies: ethylene oxide with hydrochlorofluorocarbons, a liquid peracetic acid immersion system (Steris System 1 Processor), and 2 plasma sterilization processes that use vaporized hydrogen peroxide (Sterrad 100 and the Sterrad 100S). The Sterrad 100S system potentially improves sterilizer efficacy by using 2 cycles of a diffusion stage and a plasma stage per sterilization cycle.
Flat stainless steel carriers were inoculated with approximately 10(6) Bacillus stearothermophilus spores. These carriers were aseptically placed in the middle of 40 cm long stainless steel lumens (hollow tubes). Two types of lumen were used:(1) a lumen test unit with a removable 5 cm center piece (1.2 cm diameter) of stainless steel sealed to the narrower steel tubing by hard rubber septums and (2) a straight lumen. Three different diameters of the lumen test unit (1, 2, and 3 mm) and a single diameter of the straight lumen (3 mm) were studied. At least 40 replicates were performed for each type of lumen and sterilization method. After inoculation, the test unit was evaluated in 1 of the low-temperature sterilization technologies. After sterilization, the carriers were cultured in trypticase soy broth for 14 days at 55 degrees C and assessed for growth of B stearothermophilus spores.
Our results demonstrated that ethylene oxide with hydrochlorofluorocarbons, the Sterrad 100s, and the Sterrad 100S half cycle were highly effective in killing approximately 10(6) B stearothermophilus spores present in the center of narrow-lumen stainless steel tubes. As the lumen diameter decreased with the lumen test unit, the Sterrad 100 demonstrated reduced ability to kill B stearothermophilus spores present on the carrier. At the smallest diameter tested (1 mm), the Sterrad 100 system failed 74% of the time. The Steris System 1 was not effective in completely eliminating the 10(6) inoculum under test conditions.
The Sterrad 100S was significantly superior to the Sterrad 100 system and equivalent to ethylene oxide with hydrochlorofluorocarbons. Introduction of this new Sterrad 100S system should improve the margin of safety and reduce processing costs by its use of a shorter cycle time. The Steris System 1 is limited by diffusion of the chemical sterilant into the interior of the lumen test unit.
本研究旨在评估4种新型低温灭菌技术的效果：含氢氯氟烃的环氧乙烷、过氧乙酸液体浸泡系统（思泰瑞系统1处理器）以及2种使用过氧化氢蒸汽的等离子体灭菌工艺（思泰瑞100和思泰瑞100S）。思泰瑞100S系统每个灭菌周期采用扩散阶段和等离子体阶段的2个循环，可能会提高灭菌器的效能。
将扁平不锈钢载体接种约10⁶嗜热脂肪芽孢杆菌孢子。这些载体无菌放置在40厘米长的不锈钢管腔（空心管）中间。使用了两种类型的管腔：（1）一种管腔测试单元，其带有一个可移除的5厘米中心部件（直径1.2厘米），由硬橡胶隔膜密封到较窄的钢管上；（2）直管腔。研究了管腔测试单元的三种不同直径（1、2和3毫米）以及直管腔的单一直径（3毫米）。每种管腔类型和灭菌方法至少进行40次重复试验。接种后，测试单元在其中一种低温灭菌技术中进行评估。灭菌后，将载体在胰蛋白酶大豆肉汤中于55℃培养14天，并评估嗜热脂肪芽孢杆菌孢子的生长情况。
我们的结果表明，含氢氯氟烃的环氧乙烷、思泰瑞100S以及思泰瑞100S半循环在杀灭存在于窄管腔不锈钢管中心的约10⁶嗜热脂肪芽孢杆菌孢子方面非常有效。随着管腔测试单元的管腔直径减小，思泰瑞100杀灭存在于载体上的嗜热脂肪芽孢杆菌孢子的能力下降。在测试的最小直径（1毫米）时，思泰瑞100系统有74%的时间失败。思泰瑞系统1在测试条件下未能有效完全消除10⁶接种物。
思泰瑞100S明显优于思泰瑞100系统，且与含氢氯氟烃的环氧乙烷相当。引入这种新的思泰瑞100S系统应能提高安全系数，并通过使用更短的循环时间降低处理成本。思泰瑞系统1受化学消毒剂向管腔测试单元内部扩散的限制。
