title: Potentially human pathogenic Acanthamoeba isolated from a heated indoor swimming pool in Switzerland.
abstract: Some free-living amoebae, including some species of the genus Acanthamoeba, can cause infections in humans and animals. These organisms are known to cause granulomatous amebic encephalitis (GAE) in predominantly immune-deficient persons. In the present study, we isolated a potentially human pathogenic Acanthamoeba isolate originating from a public heated indoor swimming pool in Switzerland. The amoebae, thermophilically preselected by culture at 37 degrees C, subsequently displayed a high thermotolerance, being able to grow at 42 degrees C, and a marked cytotoxicity, based on a co-culture system using the murine cell line L929. Intranasal infection of Rag2-immunodeficient mice resulted in the death of all animals within 24 days. Histopathology of brains and lungs revealed marked tissue necrosis and hemorrhagic lesions going along with massive proliferation of amoebae. PCR and sequence analysis, based on 18S rDNA, identified the agent as Acanthamoeba lenticulata. In summary, the present study reports on an Acanthamoeba isolate from a heated swimming pool suggestive of being potentially pathogenic to immunocompromised persons.
authors.affiliation: Institute of Parasitology, University of Bern, Faculty of Veterinary and Medicine, Bern, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Gianinazzi
authors.forename: Marc
authors.initials: M
authors.lastname: Schild
authors.forename: Fritz
authors.initials: F
authors.lastname: Wüthrich
authors.forename: Norbert
authors.initials: N
authors.lastname: Müller
authors.forename: Nadia
authors.initials: N
authors.lastname: Schürch
authors.forename: Bruno
authors.initials: B
authors.lastname: Gottstein
mesh_terms: D000048:Acanthamoeba / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity; D000562:Amebiasis / Q000469:parasitology* / Q000473:pathology / Q000635:transmission; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000469:parasitology / Q000473:pathology; D002460:Cell Line; D005618:Fresh Water / Q000469:parasitology*; D006358:Hot Temperature; D006801:Humans; D008168:Lung / Q000469:parasitology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016415:Sequence Alignment; D013551:Swimming Pools