Genotyping, physiological features and proteolytic activities of a potentially pathogenic Acanthamoeba sp. isolated from tap water in Brazil.

Full Abstract

Acanthamoeba spp., known to cause keratitis and granulomatous encephalitis in humans, are frequently isolated from a variety of water sources. Here we report for the first time the characterization of an Acanthamoeba sp. (ACC01) isolated from tap water in Brazil. This organism is currently being maintained in an axenic growth medium. Phylogenetic analysis based on SSU rRNA gene sequences positioned the new isolate in genotype T4, closest to the keratitis-causing isolate, A. polyphaga ATCC 30461 ( approximately 99% similarity). Acanthamoeba ACC01 and A. polyphaga 30461 both grew at 37 degrees C and were osmotically resistant, multiplying in hyperosmolar medium. Both isolates secreted comparable amounts of proteolytic enzymes, including serine peptidases that were optimally active at a near neutral/alkaline pH and resolved identically in gelatin gels. Incubation of gels at pH 4.0 with 2mM DTT also indicated the secretion of similar cysteine peptidases. Altogether, the results point to the pathogenic potential of Acanthamoeba ACC01.

Author information

Author/s: Magliano, Ana C M (AC); da Silva, Flávia Maia (FM); Teixeira, Marta M G (MM); Alfieri, Silvia C (SC);

Affiliation: Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, CEP 05508-000 São Paulo, SP, Brazil.

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Experimental parasitology (Exp Parasitol), published in United States. (Language: eng)

Reference: 2009-Nov; vol 123 (issue 3) : pp 231-5

Dates: Created 2009/09/07; Completed 2009/09/18;

PMID: 19646440, status: MEDLINE (last retrieval date: 9/18/2009, IMS Date: )

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