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Background & objectives: Impaired immune system provides favorable conditions for colonization by Acanthamoeba in the human body. In this case control study, we compared the molecular and culture methods in identifying Acanthamoeba in the nasal and oral secretions of HIV⁺/HIV^­ human.
Methods: In a current case control study, nasal and oral discharge of 53, HIV⁺ patients and 53, HIV^­ people were evaluated. The nasal and oral secretions of each patient were prepared by sterile swabs and transferred to the laboratory. All samples were cultured but only the positive samples used for molecular analysis.
Results: By cultivation method, of the 53, HIV⁺ patients, a total of 11 samples, including 5 nasal and 6 oral samples, were contaminated with Acanthamoeba. Of the 53, HIV­­ people, 3 samples of nasal discharge were contaminated with this parasite. The molecular method approved the contamination of 10 samples, including 5 oral and 5 nasal samples from HIV⁺ patients with this parasite. Statistical analysis showed the rate of infection in HIV⁺ patients was significantly different compared to HIV^­ people
Conclusion: The results of the current study showed that the rate of Acanthamoeba infection in HIV⁺ patients was higher than that of HIV^- individuals. Also, considering that in the control group (HIV- individuals) only the nasal discharge were infected with the parasite, it seems that in the case group (HIV + patients) the infection of the oral discharge with the parasites is due to the  entry of its cysts into the nose and transmission to the mouth

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Background & Objectives: Cold Plasma is an emerging non-thermal, chemical-free, environmentally friendly disinfection technology. Plasma-activated water has received considerable attention from researchers in recent years. Despite extensive studies on the antibacterial effects of plasma-activated water, its anti-eukaryotic effects have not been identified. In humans, Acanthamoeba causes granulomatous encephalitis, skin ulcers, and Acanthamoeba keratitis. Considering the health importance of Acanthamoeba, this study investigated the anti-amoeba  effect of plasma-activated water on trophozoites and cysts of Acanthamoeba castellanii.
Methods: In this study, plasma-activated water prepared by the cold atmospheric plasma method.Physicochemical properties of produced water were evaluated by measuring pH, hydrogen peroxide, nitrite, and nitrate. To assess the effect of plasma-activated water on A. castellanii, trophozoites and cysts were exposed to plasma-activated water for 0.5, 1, 2, 3, 4, and 5 hours. Three replicates were examined each time. At the mentioned times, cell viability was calculated by trypan-blue staining and counting on a hemocytometer, and the results were statistically analyzed.
Results: Based on the physicochemical results, the mean pH of plasma-activated water in this study was about 3.4, and the amount of hydrogen peroxide, nitrate, and nitrite were 102, 737, and 36.94 μM, respectively. The present study showed that plasma-activated water killed A. castellanii trophozoites after three hours of exposure and A. castellanii cysts after four hours of exposure. On the other hand, some trophozoites gradually became cysts after exposure to plasma-activated water. These cysts became more resistant to plasma-activated water and inactivated after five hours of exposure.
Conclusion: In this study, for the first time, the effect of plasma-activated water on A. castellanii was investigated. The results of the present study showed that plasma-activated water is able to inactivate A. castellanii trophozoites and cysts. Therefore, plasma-activated water can be used to disinfect and inactivate A. castellanii.