Moorhead Sian, Maclean Michelle, Coia John E, MacGregor Scott J, Anderson John G
The Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST), University of Strathclyde, Glasgow, UK.
The Robertson Trust Laboratory for Electronic Sterilisation Technologies (ROLEST), University of Strathclyde, Glasgow, UK.
Anaerobe. 2016 Feb;37:72-7. doi: 10.1016/j.anaerobe.2015.12.006. Epub 2015 Dec 18.
The ability of Clostridium difficile to form highly resilient spores which can survive in the environment for prolonged periods causes major contamination problems. Antimicrobial 405 nm light is being developed for environmental decontamination within hospitals, however further information relating to its sporicidal efficacy is required. This study aims to establish the efficacy of 405 nm light for inactivation of C. difficile vegetative cells and spores, and to establish whether spore susceptibility can be enhanced by the combined use of 405 nm light with low concentration chlorinated disinfectants. Vegetative cells and spore suspensions were exposed to increasing doses of 405 nm light (at 70-225 mW/cm(2)) to establish sensitivity. A 99.9% reduction in vegetative cell population was demonstrated with a dose of 252 J/cm(2), however spores demonstrated higher resilience, with a 10-fold increase in required dose. Exposures were repeated with spores suspended in the hospital disinfectants sodium hypochlorite, Actichlor and Tristel at non-lethal concentrations (0.1%, 0.001% and 0.0001%, respectively). Enhanced sporicidal activity was achieved when spores were exposed to 405 nm light in the presence of the disinfectants, with a 99.9% reduction achieved following exposure to 33% less light dose than required when exposed to 405 nm light alone. In conclusion, C. difficile vegetative cells and spores can be successfully inactivated using 405 nm light, the sporicidal efficacy can be significantly enhanced when exposed in the presence of low concentration chlorinated disinfectants. Further research may lead to the potential use of 405 nm light decontamination in combination with selected hospital disinfectants to enhance C. difficile cleaning and infection control procedures.
艰难梭菌形成高度有弹性的孢子的能力，使其能够在环境中长期存活，这引发了严重的污染问题。用于医院环境净化的405纳米抗菌光正在研发中，然而，关于其杀孢子功效还需要更多信息。本研究旨在确定405纳米光对艰难梭菌营养细胞和孢子的灭活效果，并确定低浓度含氯消毒剂与405纳米光联合使用是否能增强孢子的敏感性。将营养细胞和孢子悬液暴露于递增剂量的405纳米光（70 - 225毫瓦/平方厘米）下以确定敏感性。剂量为252焦/平方厘米时，营养细胞数量减少了99.9%，然而孢子表现出更高的弹性，所需剂量增加了10倍。将孢子悬浮于医院消毒剂次氯酸钠、Actichlor和Tristel中，以非致死浓度（分别为0.1%、0.001%和0.0001%）重复进行照射。当孢子在消毒剂存在下暴露于405纳米光时，实现了增强的杀孢子活性，与单独暴露于405纳米光相比，在少33%的光照剂量照射后，孢子数量减少了99.9%。总之，使用405纳米光可成功灭活艰难梭菌营养细胞和孢子，在低浓度含氯消毒剂存在下暴露时，杀孢子功效可显著增强。进一步的研究可能会使405纳米光净化与选定的医院消毒剂联合使用，以加强艰难梭菌的清洁和感染控制程序。
