Spicher G, Peters J
Zentralbl Bakteriol Orig B. 1976 Mar;161(5-6):462-73.
For the testing of disinfectants at surfaces, the germs having survived at the surface are demonstrated by means of swabs according to the guide-lines of the Deutsche Gesellschaft fur Hygiene und Mikrobiologie (DGHM): after the period of exposure to the disinfectant, the surfaces were rubbed off with a damp swab, and the frictional surface of the swab was plated out on nutrient agar. The effectiveness of this technique was compared with the effectiveness of a rinsing method in a test model. In the rinsing process, the objects to be tested for surviving germs were shaken together with a suspension and with glass beads. Then the content of germs in the suspension was quantitatively determined by means of dilution tests and pour plates. The findings were evaluated according to the guide-lines for evaluation of the DGHM (less than or equal to 10 surviving germs = adequate efficacy). For the findings obtained by rinsing, the average number of surviving germs was also determined. For maldehyde solutions were used as disinfectants for the test models (time of exposure: 4 hours; temperature 22 to 25 degrees C). These disinfecting experiments were performed on raw smoothed as well as on varnished beech-wood. The experimental results showed that the criterion "less than or equal to X surviving germs" in itself does not mean clear evidence of the efficacy of a disinfectant. The one and only decisive criterion is the frequency of the statement that a certain disinfectant or a corresponding dilution of this disinfectant has shown adequate efficacy. Therefore, one single test according to the guide-lines of the DGHM is insufficient. The frequency of the finding "adequate efficacy" is not only dependent on the concentration of the disinfectant but also on the technique used for the demonstration of surviving germs. The swab method (according to the guide-lines of the DGHM) occasionally resulted in the finding "adequate efficacy" already if 10(4) to 10(5) surviving germs were demonstrable by the rinsing method. The range of formaldehyde concentrations for which the finding of adequate efficacy were present with a frequency between 20% (minimum) and 80% (maximum) amounted to 0.2-0.5% (varnished surface) and 1.1-2.5% (raw surface), respectively for the swab method. The respective figures for the rinsing method were 0.8-1.3% and 4.8-6.5%, respectively. When using the swab method, there is a slower increase in the efficacy of the disinfectant with concentration as compared with the rinsing method. The rinsing method is, therefore, more representative of the efficacy of a disinfectant than the swab method. On account of the results of this study, it is recommended for model experiments to recover the surviving germs quantitatively by the rinsing method and to determine their number.
对于表面消毒剂的测试，根据德国卫生与微生物学会（DGHM）的指南，通过棉签来检测在表面存活的细菌：在消毒剂作用一段时间后，用湿棉签擦拭表面，然后将棉签的摩擦面接种到营养琼脂平板上。在一个测试模型中，将该技术的有效性与一种冲洗方法的有效性进行了比较。在冲洗过程中，将待检测存活细菌的物体与悬浮液和玻璃珠一起振荡。然后通过稀释试验和平板倾注法对悬浮液中的细菌含量进行定量测定。根据DGHM的评估指南对结果进行评估（存活细菌数小于或等于10个 = 消毒效果良好）。对于通过冲洗获得的结果，也测定了存活细菌的平均数。使用甲醛溶液作为测试模型的消毒剂（作用时间：4小时；温度22至25摄氏度）。这些消毒实验在未上漆的光滑山毛榉木以及涂漆的山毛榉木上进行。实验结果表明，“存活细菌数小于或等于X”这一标准本身并不意味着消毒剂效果的明确证据。唯一决定性的标准是关于某种消毒剂或其相应稀释液显示出良好消毒效果的陈述频率。因此，仅按照DGHM的指南进行一次测试是不够的。“消毒效果良好”这一结果的频率不仅取决于消毒剂的浓度，还取决于用于检测存活细菌的技术。棉签法（根据DGHM的指南）偶尔会得出“消毒效果良好”的结果，而此时用冲洗法可检测到10⁴至10⁵个存活细菌。对于棉签法，出现消毒效果良好结果的甲醛浓度范围在频率20%（最低）至80%（最高）之间，分别为0.2 - 0.5%（涂漆表面）和1.1 - 2.5%（未涂漆表面）。冲洗法的相应数值分别为0.8 - 1.3%和4.8 - 6.5%。与冲洗法相比，使用棉签法时，消毒剂的效果随浓度增加的速度较慢。因此，冲洗法比棉签法更能代表消毒剂的效果。基于本研究的结果，建议在模型实验中通过冲洗法对存活细菌进行定量回收并确定其数量。
