Detection of Potentially Pathogenic Free-living Amoeba, from the Internal Environment of Educational Hospitals in Rasht

Introduction: Acanthamoeba, also called  amphizoic amoebae, could live in various environmental sources including water, soil, dust and also human and animal tissues. This amoeba could develop diseases such as keratitis and encephalitis in high-risk individuals. Objective: The present study was conducted considering the possible contamination of hospital wards with Acanthamoba and the lack of knowledge regarding their loads in the dust of hospital wards of Guilan province. Materials and Methods: In Guilan 2018, a total of 108 dust samples from wards including ophthalmology, ENT, hematology and chemotherapy were collected from internal environment of educational hospitals and examined for the presence of Acanthamoeba spp. by morphologic features of both trophozoites and cyst stages. Termotolerant assay was conducted in order to determine the presence of potentially pathogenic Acanthamoeba species. The collected samples were then rinsed in sterile water, and the washed solution was filtered using a vacuum pump and 0.45 μm membrane filters. In the end, the filter was cultured on Non-nutrient agar (NNA). Results: Forty out of 109 samples were positive for Acanthamoeba spp. Temperature tolerance test indicates that 13 out of 40  samples could be potentially pathogenic because they grow at high temperature (42ºC). The frequencies of free-living amoebae in chemotherapy, ophthalmology, ENT and hematology wards were 38.8%, 39% and 29.6% ,respectively. Conclusion: As revealed, potentially pathogenic Acanthamoeba was detected from dust samples of hospital wards. Presence of the potentially pathogenic and nonpathogenic Acanthamoeba in hospital wards should be a concern for health authorities. Therefore, improvement of sanitation services is recommended for the prevention of infection.