First Report of Vannellidae Amoebae (Vannella Spp.) Isolated From Biofilm Source

Background: Members of the Vannellidae family are free-living amoebae (FLA) distributed mainly in water and soil sources. The present study reports the first isolation of this genus in the biofilm source from hospital environment in Tehran, Iran.Methods: Biofilm samples were collected from hospital environment. Cultivation was performed in non-nutrient agar covered with a heat-killed Escherichia coli. Cloning of the suspected amoe­bae was done. PCR amplification and Homology analysis using the Basic Local Alignment Search Tool (BLASTn) was performed to search for the most similar reference sequences.Results: Microscopic examination showed numerous fan-shaped amoebae and peculiar cysts differ­ent to the usual shape of typical FLA. Sequence analysis of the PCR- product revealed that the suspected amoebae are highly homologous with Vannella spp. gene (99% identity and 100% query coverage) available in the gene bank database.Conclusion: Although Vannella spp. is not proved to be pathogenic itself, but they are capable of har­boring pathogenic intracellular organisms such as Microsporidian parasites. Thus, identifica­tion of such amoebae can be of clinical importance, as they could lead to transmission of other pathogens to human.