The genus Sappinia: History, phylogeny and medical relevance (original) (raw)
Phylogenetic position and notes on the ultrastructure of Sappinia diploidea (Thecamoebidae)
2007
Summary An unusual amoeba, Sappinia diploidea, possessing diplokaryonlike nuclear apparatus and a complex life cycle, was isolated from the bark of trees and a freshwater pond, identified and reinvestigated. The phylogenetic analysis based on SSU rRNA gene sequences shows close relatedness of this species to the members of the genus Thecamoeba. It suggests the existence of the monophyletic family Thecamoebidae,
Free-living amoebae (FLA) are protozoa widely distributed in the environment, found in a great diversity of terrestrial biomes. However, few genera of FLA are linked to human infections. Within these genera, Acanthamoeba spp., classified by genotypes (T1-T23), being T1, T2, T4, T5, T10, T12, and T18 as capable of causing granulomatous amoebic encephalitis (GAE) in immunocompromised patients mostly and Acanthamoeba keratitis related to genotypes T2, T3, T4, T5, T6, T10, T11, T12 and T15 in apparently healthy patients. Meanwhile, Naegleria fowleri is the causative agent of an acute infection called primary amoebic meningoencephalitis (PAM), while Balamuthia mandrillaris, like some Acanthamoeba genotypes, causes GAE, differing from the latter in the description of numerous cases in patients immunocompetent. Finally, other FLA related to the pathologies mentioned above have been reported; Sappinia pedata is responsible for one case of amoebic encephalitis; Vermamoeba vermiformis has bee...