Isolation of Acanthamoeba T5 from Water: Characterization of Its Pathogenic Potential, Including the Production of Extracellular Vesicles

Pathogens. 2020 Feb 21;9(2):144. doi: 10.3390/pathogens9020144.


Acanthamoeba is a genus of free-living amoebae widely distributed in nature, associated with the development of encephalitis and keratitis. Despite the fact that it is common to find genotype T5 in environmental samples, only a few cases have been associated with clinical cases in humans. The wide distribution of Acanthamoeba, the characteristic of being amphizoic and the severity of the disease motivate researchers to focus on the isolation of these organisms, but also in demonstrating direct and indirect factors that could indicate a possible pathogenic potential. Here, we performed the characterization of the pathogenic potential of an Acanthamoeba T5 isolate collected from a water source in a hospital. Osmo- and thermotolerance, the secretion of proteases and the effect of trophozoites over cell monolayers were analyzed by different methodologies. Additionally, we confirm the secretion of extracellular vesicles (EVs) of this isolate incubated at two different temperatures, and the presence of serine and cysteine proteases in these vesicles. Finally, using atomic force microscopy, we determined some nanomechanical properties of the secreted vesicles and found a higher value of adhesion in the EVs obtained at 37 °C, which could have implications in the parasite´s survival and damaging potential in two different biological environments.

Keywords: atomic force microscopy; cytopathic effect; extracellular vesicles; pathogenic potential; proteases.