Isolation, characterization, and pathogenicity assay of Acanthamoeba and its endosymbionts in respiratory disorders and COVID-19 hospitalized patients, northern Iran

• Published in: Experimental parasitology 2024-07, Vol.262, p.108774, Article 108774
• Main Authors: Soleymani, Eissa, Fakhar, Mahdi, Davoodi, Lotfollah, Motavallihaghi, Seyedmousa, Sharifpour, Ali, Maghsood, Amir Hossein
• Format: Article
• Language: English
• Subjects: Acanthamoeba; Acanthamoeba - isolation & purification; Acanthamoeba - pathogenicity; Adult; Aged; Amebiasis - parasitology; Chlorocebus aethiops; COVID-19; Cytopathic effect assays; Endosymbiont; Female; Hospitalization; Humans; Iran; Male; Middle Aged; Osmo-tolerance; Polymerase Chain Reaction; SARS-CoV-2; SARS-COV-2 virus; Stenotrophomonas maltophilia - isolation & purification; Stenotrophomonas maltophilia - pathogenicity; Symbiosis; Thermo-tolerance; Vero Cells
• ISSN: 0014-4894; 1090-2449; 1090-2449
• DOI: 10.1016/j.exppara.2024.108774

Acanthamoeba spp., are common free-living amoebae found in nature that can serve as reservoirs for certain microorganisms. The SARS-CoV-2 virus is a newly emerged respiratory infection, and the investigation of parasitic infections remains an area of limited research. Given that Acanthamoeba can act as a host for various endosymbiotic microbial pathogens and its pathogenicity assay is not fully understood, this study aimed to identify Acanthamoeba and its bacterial and fungal endosymbionts in patients with chronic respiratory disorders and hospitalized COVID-19 patients in northern Iran. Additionally, a pathogenicity assay was conducted on Acanthamoeba isolates. Urine, nasopharyngeal swab, and respiratory specimens were collected from two groups, and each sample was cultured on 1.5% non-nutrient agar medium. The cultures were then incubated at room temperature and monitored daily for a period of two weeks. Eight Acanthamoeba isolates were identified, and PCR was performed to confirm the presence of amoebae and identify their endosymbionts. Four isolates were found to have bacterial endosymbionts, including Stenotrophomonas maltophilia and Achromobacter sp., while two isolates harbored fungal endosymbionts, including an uncultured fungus and Gloeotinia sp. In the pathogenicity assay, five isolates exhibited a higher degree of pathogenicity compared to the other three. This study provides significant insights into the comorbidity of acanthamoebiasis and COVID-19 on a global scale, and presents the first evidence of Gloeotinia sp. as a fungal endosymbiont. Nevertheless, further research is required to fully comprehend the symbiotic patterns and establish effective treatment protocols. [Display omitted] •Acanthamoeba, a free-living amoeba, may be found in the clinical samples of patients with COVID-19 and chronic respiratory disorders.•Due to the fact that the immune system is sometimes weakened in patients with chronic respiratory disorders and COVID-19, the Acanthamoeba can become pathogenic due to its opportunistic nature.•Acanthamoeba carries bacteria and fungi as endosymbionts in these patients and makes these patients prone to fungal and bacterial infections.•Most of the isolated Acanthamoeba in this study were pathogenic and this parasite should not be neglected.