3M, Medical Markets Laboratory EMEA, Neuss, Germany.
J Appl Microbiol. 2009 Sep;107(3):1054-60. doi: 10.1111/j.1365-2672.2009.04290.x. Epub 2009 Apr 9.
To develop a model, based on microbiological principles, to safely optimize steam sterilization processes.
The minimum exposure time F for a decontamination process at a certain temperature is usually calculated from an empirical model with the decimal reduction time D and the temperature resistance coefficient z as parameters. These are implicitly assumed to be independent of temperature. Using a microbiological approach, it is shown that also D and z depend on temperature, indicating that the usual models provide only reliable results in a limited temperature region. The temperature dependence of F resulting from this approach describes the available experimental data very well. Safety margins to assure sterility can be included in a straightforward way.
The results from the present approach can be used to safely optimize decontamination processes. The corresponding mathematical model can be implemented rather directly in process control systems.
Our results show that for steam sterilization and disinfection processes the values of F predicted by the usual models largely underestimate the required minimum exposure times at temperatures below 120 degrees C. This has important consequences for the optimization of such processes.
基于微生物学原理，开发一种模型以安全优化蒸汽灭菌工艺。
在一定温度下，消毒过程的最短暴露时间 F 通常根据经验模型计算得出，该模型的参数为十进制减少时间 D 和温度抗性系数 z。这些参数被隐含地假定为与温度无关。通过微生物学方法，表明 D 和 z 也随温度而变化，这表明通常的模型仅在有限的温度范围内提供可靠的结果。该方法得出的 F 随温度的变化很好地描述了可用的实验数据。可以直接包括确保无菌性的安全裕度。
本方法的结果可用于安全优化消毒过程。相应的数学模型可以直接在过程控制系统中实现。
我们的结果表明，对于蒸汽灭菌和消毒工艺，通常模型预测的 F 值在 120°C 以下的温度下大大低估了所需的最短暴露时间。这对这些过程的优化具有重要意义。
