Sutton S V, Franco R J, Porter D A, Mowrey-McKee M F, Busschaert S C, Hamberger J F, Proud D W
Bausch & Lomb Incorporated, Rochester, New York 14692.
Appl Environ Microbiol. 1991 Jul;57(7):2021-6. doi: 10.1128/aem.57.7.2021-2026.1991.
Determination of a D value for specific test organisms is a component of the efficacy evaluation of new contact lens disinfecting solutions. This parameter is commonly defined as the time required for the number of surviving microorganisms to decrease 1 logarithmic unit. The assumption made in establishing a D value is that the rate of kill exhibits first-order kinetics under the specified conditions. Such exponential kill rates are seen with thermal contact lens disinfection system. A comparison of the death rate kinetics for a variety of chemical contact lens disinfecting solutions was undertaken to ascertain the suitability of D-value determination for these chemical disinfectants. The active agents of these different solutions included hydrogen peroxide, thimerosal, chlorhexidine, tris(2-hydroxyethyl)tallow ammonium chloride, thimerosal, polyaminopropyl biguanide, and polyquaternium-1. The solutions were challenged with 10(6) CFU of either Pseudomonas aeruginosa, Serratia marcescens, or Staphylococcus hominis per ml, and survival rate was determined. This study clearly demonstrates the nonlinear nature of the inactivation curves for most contact lens chemical disinfecting solutions for the challenge organisms. D-value determination is, therefore, an inappropriate method of reporting the biocidal activity of these solutions.
确定特定测试微生物的D值是新型隐形眼镜消毒溶液功效评估的一个组成部分。该参数通常定义为存活微生物数量减少1个对数单位所需的时间。确定D值时所做的假设是，在指定条件下，杀灭速率呈现一级动力学。这种指数杀灭速率在热隐形眼镜消毒系统中可见。对多种化学隐形眼镜消毒溶液的死亡率动力学进行了比较，以确定D值测定对这些化学消毒剂的适用性。这些不同溶液的活性剂包括过氧化氢、硫柳汞、氯己定、三（2-羟乙基）牛脂氯化铵、硫柳汞、聚氨基丙基双胍和聚季铵盐-1。将这些溶液分别用每毫升10(6) CFU的铜绿假单胞菌、粘质沙雷氏菌或人葡萄球菌进行挑战，并测定存活率。这项研究清楚地表明，对于所挑战的微生物，大多数隐形眼镜化学消毒溶液的灭活曲线具有非线性性质。因此，D值测定是报告这些溶液杀菌活性的一种不恰当方法。
