title: Viability and morphological changes of Acanthamoeba spp. cysts after treatment with Effective microorganisms (EM).
abstract: Acanthamoeba is a free-living opportunistic protozoan parasite that is found in diverse environments. It can cause keratitis, mostly related to inappropriate use of contact lenses, as well as life threatening diseases including encephalitis, disseminated sinusitis, and skin ulcers. This study investigated morphological changes and fine structures of the cyst form of Acanthamoeba spp. after treatment with effective microorganisms (EM™) using light and scanning electron microscopies. Acanthamoeba cysts treated with 1:2, 1:4, 1:6, and undiluted EM™ showed higher percentages of non-viable cysts than those treated with 1:8, 1:10, 1:100, 1:200, and 1:400 EM™ and at 5 days post-treatment developed from cystic stage to trophozoite stage. Acanthamoeba cysts treated at concentrations of 1:2, 1:4, 1:6, and undiluted EM™ exhibited cytoplasmic clumping and shrinkage of amoeba cells away from cyst walls. The effective EM™ concentration lethal to Acanthamoeba spp. cyst could provide information to monitor the environmental control system.
authors.affiliation: Faculty of Graduate Studies, Mahidol University, Bangkok, Thailand ; Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, 420/1 Rajavithi Road, Rajathewee District, Bangkok, 10400 Thailand.
authors.forename: Tanitta
authors.initials: T
authors.lastname: Sampaotong
authors.affiliation: Department of Parasitology and Entomology, Faculty of Public Health, Mahidol University, 420/1 Rajavithi Road, Rajathewee District, Bangkok, 10400 Thailand.
authors.forename: Usa
authors.initials: U
authors.lastname: Lek-Uthai
authors.affiliation: Department of Anatomy, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Jantima
authors.initials: J
authors.lastname: Roongruangchai
authors.affiliation: Department of Parasitology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
authors.forename: Kosol
authors.initials: K
authors.lastname: Roongruangchai
keywords: Acanthamoeba spp.; Effective microorganisms; Viability and morphological changes