Resistance of Acanthamoeba spp. cysts to disinfection treatments used in healthcare settings

Free-living amoebae that belong to the genus Acanthamoeba are widespread in the environment, including water. They are responsible for human infections and can host pathogenic micro-organisms. In unfavourable conditions they form cysts with high resistance to disinfection methods, thus potentially representing a threat for public health. This study evaluates the efficacy of various biocides against trophozoites and cysts of several Acanthamoeba strains. It demonstrates that disinfectant efficacy varies depending on strains tested, with environmental strains demonstrating greater resistance than collection strains. The results highlight the need to consider the effective disinfection of protozoa in their vegetative and resistant forms due to their intrinsic resistance. This is not only important to prevent the transmission of protozoa themselves, but also due to the risks associated with a range of microbial pathogens that are found to be associated intracellularly with these micro-organisms. J Clin Microbiol. 2010 Jun 2. [Epub ahead of print]