Fedorko Daniel P, Brocious Jeffrey M, Adams Katherine D, Hitchins Victoria M, Hampton Denise L, Eydelman Malvina B
Food and Drug Administration (D.P.F., J.M.B., D.L.H., and M.B.E.), Center for Devices and Radiological Health, Office of Device Evaluation, Silver Spring, MD; Food and Drug Administration (K.D.A.), Winchester Engineering Analytical Center, Winchester, MA; and Food and Drug Administration (V.M.H.), Center for Devices and Radiological Health, Office of Science and Engineering Laboratories, Silver Spring, MD.
Eye Contact Lens. 2018 Nov;44(6):367-371. doi: 10.1097/ICL.0000000000000477.
To evaluate the interlaboratory and intralaboratory reproducibility of a proposed protocol for multipurpose contact lens solution (MPS) disinfection efficacy against Acanthamoeba.
Acanthamoeba castellanii and Acanthamoeba polyphaga and four MPS with different biocidal agents were used to evaluate the protocol in two different laboratories. In addition to the negative control, a positive control and neutralization control were used. One experiment was performed in triplicate, and all other experiments were performed in duplicate in each laboratory. Acanthamoeba trophozoites were grown axenically, and cysts were generated using the starvation method. Trophozoites and cysts at a concentration of 2.0 × 10 to 2.0 × 10 organisms per milliliter were exposed to the test MPS for 0, 4 or 6 (manufacturer's recommended soak time [MRST]), 8, and 24 hr. Survivors were determined by a limiting dilution method that used a most probable number evaluation.
The positive and negative controls displayed consistent results and trends both within each laboratory and between each laboratory for trophozoites and cysts of both A. castellanii and A. polyphaga. The neutralization control consistently demonstrated the ability of the neutralizing agents to neutralize the MPS and the positive control and demonstrated no inhibition of Acanthamoeba by the negative control. Testing in triplicate and duplicate demonstrated the reproducibility of the protocol both within each laboratory and between the laboratories. Our results demonstrated that the MPS at the MRST and at 8 hr (likely overnight soak time) are generally more effective against trophozoites than they are against cysts. Only the MPS with hydrogen peroxide as the biocidal agent was able to provide a greater than three-log kill of cysts at the MRST and longer. Among the MPS we tested, trophozoites of A. castellanii and A. polyphaga showed similar responses. Some variability was observed when testing cysts of both species. In both laboratories, one nonhydrogen peroxide containing MPS had some effect (>1 log kill) on A. polyphaga cysts. This solution had no effect (<1 log kill) on A. castellanii cysts, A. castellanii trophozoites, and A. polyphaga trophozoites.
The protocol that we have revised and evaluated is a well-controlled and reproducible procedure that can effectively evaluate the efficacy of MPS against Acanthamoeba trophozoites. Some variability was observed when testing the cyst stage.
评估一种针对多功能隐形眼镜护理液（MPS）对棘阿米巴消毒效果的拟议方案在不同实验室间和同一实验室内的可重复性。
使用卡氏棘阿米巴和多食棘阿米巴以及四种含有不同杀菌剂的MPS，在两个不同实验室评估该方案。除阴性对照外，还设置了阳性对照和中和对照。每个实验室中，一个实验重复进行三次，其他所有实验重复进行两次。棘阿米巴滋养体在无菌条件下培养，并采用饥饿法产生包囊。将浓度为每毫升2.0×10至2.0×10个生物体的滋养体和包囊暴露于测试的MPS中0、4或6小时（制造商推荐的浸泡时间[MRST]）、8小时和24小时。通过使用最可能数评估的限量稀释法确定存活者数量。
对于卡氏棘阿米巴和多食棘阿米巴的滋养体和包囊，阳性和阴性对照在每个实验室内以及各实验室之间均显示出一致的结果和趋势。中和对照始终证明中和剂能够中和MPS和阳性对照，并且阴性对照未显示出对棘阿米巴的抑制作用。重复三次和两次的测试证明了该方案在每个实验室内以及各实验室之间的可重复性。我们的结果表明，在MRST和8小时（可能是过夜浸泡时间）时，MPS对滋养体的效果通常比对包囊的效果更好。只有以过氧化氢作为杀菌剂的MPS在MRST及更长时间能够对包囊实现大于三个对数级的杀灭。在我们测试的MPS中，卡氏棘阿米巴和多食棘阿米巴的滋养体表现出相似的反应。在测试两种棘阿米巴的包囊时观察到了一些变异性。在两个实验室中，一种不含过氧化氢的MPS对多食棘阿米巴包囊有一定效果（>1个对数级杀灭）。该溶液对卡氏棘阿米巴包囊、卡氏棘阿米巴滋养体和多食棘阿米巴滋养体均无效果（<1个对数级杀灭）。
我们修订和评估的方案是一个控制良好且可重复的程序，能够有效评估MPS对棘阿米巴滋养体的消毒效果。在测试包囊阶段时观察到了一些变异性。
