Isolation of Balamuthia mandrillaris from urban dust, free of known infectious involvement
The free-living amoeba Balamuthia mandrillaris can cause fatal encephalitis in humans and other mammals. The organism is associated with soils, and soil exposure has been identified as a risk factor for this pathogen. However, B. mandrillaris has been isolated only once from soils believed to be the source of the infection in child from California, USA who died of Balamuthia amoebic encephalitis and once from another unrelated soil source. We report for a third time the isolation of B. mandrillaris from the environment and for the second time its isolation from a sample not known to be involved with pathogenicity. We have established the new clonal B. mandrillaris strain (ID-19) in axenic media. The identity of our isolate was originally by morphology using a light microscope and this has been confirmed by 16S rRNA gene PCR. The new strain ID-19 groups with others of the species. The fact that our isolate came from dust particles deposited on surfaces from the air in an urban environment may suggest that it is not just soil exposure that constitutes a risk factor for Balamuthia infection. This is the first report of this organism from Iran.
KeywordsDust Sample Axenic Culture Immunocompetent Individual Urban Dust Soil Exposure
The authors gratefully thank Dr Naveed Khan (University of Nottingham, UK) for the reference B. mandrillaris strain. Miss C.M. Martin-Navarro was funded by a grant from the Agencia Canaria de Investigación, Innovación y Sociedad de la Información from the Canary Islands government co-funded by the Fondo Social Europeo (FSE, FEDER) 2009. Dr. Maryam Niyyati was supported by an overseas fellowship in Spain from The Ministry of Health, Treatment and Medical Education of Iran. This project was funded by project no. 85-02-27-3784 from Tehran University of Medical Sciences and also by the project RICET (project no. RD06/0021/0005 of the programme of Redes Temáticas de Investigación Cooperativa, FIS), Spanish Ministry of Health, Madrid, Spain.
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