Revisiting the Acanthamoeba species that form star-shaped cysts (genotypes T7, T8, T9, and T17): characterization of seven new Brazilian environmental isolates and phylogenetic inferences

Autor(es)

Magliano, Ana C. M. ^[1] ; Teixeira, Marta M. G. ^[1] ; Alfieri, Silvia C. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Parasitol, Inst Ciencias Biomed, BR-05508000 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Parasitology; v. 139, n. 1, p. 45-52, JAN 2012.
• Citações Web of Science: 5

Resumo

Free-living amoebae of the genus Acanthamoeba are the agents of both opportunistic and non-opportunistic infections and are frequently isolated from the environment. Of the 17 genotypes (T1-T17) identified thus far, 4 (T7, T8, T9, and T17) accommodate the rarely investigated species of morphological group I, those that form large, star-shaped cysts. We report the isolation and characterization of 7 new Brazilian environmental Acanthamoeba isolates, all assigned to group I. Phylogenetic analyses based on partial (similar to 1200 bp) SSU rRNA gene sequences placed the new isolates in the robustly supported clade composed of the species of morphological group I. One of the Brazilian isolates is closely related to A. comandoni (genotype T9), while the other 6, together with 2 isolates recently assigned to genotype T17, form a homogeneous, well-supported group (2-0% sequence divergence) that likely represents a new Acanthamoeba species. Thermotolerance, osmotolerance, and cytophatic effects, features often associated with pathogenic potential, were also examined. The results indicated that all 7 Brazilian isolates grow at temperatures up to 40 degrees C, and resist under hvperosmotic conditions. Additionally, media conditioned by each of the new Acanthamoeba isolates induced the disruption of SIRC and HeLa cell monolayers. (AU)

• Processo FAPESP: 09/53574-9 - Cultivo axênico e caracterização de organismos do gênero Acanthamoeba isolados no Brasil: genotipagem, inferências filogenéticas e potencial patogênico
• Beneficiário: Silvia Celina Alfieri
• Modalidade de apoio: Auxílio à Pesquisa - Regular