Molecular Identification of Free-living Amoebae Isolated from Hospital Water Systems in Southwest Iran.

Introduction: Free-living amoebae are opportunistic amoebae that usually live freely in various environmental conditions, including warm water and even in water supply network pipes and reservoirs connected to water. In addition to living freely, these protozoa are able to attack the host's body when they enter a human or animal body. Therefore, it is necessary to identify their presence in water resources. So, this study aimed to identify free-living amoebae isolated from water reservoirs of hospitals in southwest Iran.

Methods: A total of 80 water samples were isolated from the hospitals of Ahvaz city, southwest Iran, and their physical and chemical parameters were measured. The samples were then put into non-food agar culture medium and stained using the Wright-Giemsa staining. Finally, the samples were identified by the PCR molecular method.

Results: The mean pH and turbidity values were 7.57 ± 0.03 and 3.31 ± 0.26 nephelometric turbidity unit (NTU), respectively. The mean residual chlorine and electrical conductivity were 0.91 ± 0.02 and 1122.39 ± 24.31, respectively. In addition, 9 (11.25%) and 3 (3.75%) samples were contaminated with Acanthamoeba spp. and Naegleria spp., respectively. However, no positive cases of Balamuthia spp. infection were observed. Moreover, two samples were co-infected with Acanthamoeba spp. and Naegleria spp.

Conclusion: Due to the existence of free-living amoebae in water storage tanks at hospitals, it is necessary to prevent possible contamination with these amoebae and infectious agents by using new methods of disinfection and purification of water resources.