Potentially pathogenic Acanthamoeba genotype T4 isolated from dental units and emergency combination showers

Abstract

BACKGROUND Acanthamoeba is the genus of free-living amoebae that is most frequently isolated in nature. To date, 20 Acanthamoeba genotypes have been described. Genotype T4 is responsible for approximately 90% of encephalitis and keratitis cases. Due to the ubiquitous presence of amoebae, isolation from environmental sources is not uncommon; to determine the clinical importance of an isolation, it is necessary to have evidence of the pathogenic potential of amoebae.OBJECTIVEThe aim of this study was to physiologically characterise 8 Acanthamoeba T4 isolates obtained from dental units and emergency combination showers and to determine their pathogenic potential by employing different laboratory techniques.METHODSEight axenic cultures of Acanthamoeba genotype T4 were used in pathogenic potential assays. Osmotolerance, thermotolerance, determination and characterisation of extracellular proteases and evaluation of cytopathic effects in MDCK cells were performed.FINDINGSAll of the isolates were osmotolerant, thermotolerant and had serine proteases from 44-122 kDa. Two isolates had cytopathic effects on the MDCK cell monolayer.MAIN CONCLUSIONThe presence of Acanthamoeba T4 with pathogenic potential in areas such as those tested in this study reaffirms the need for adequate cleaning and maintenance protocols to reduce the possibility of infection with free-living amoebae.

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

“…Acanthamoeba isolated from a water sample of a hospital was axenically grown in 25 cm 2 cell culture flasks with 0.75% proteose peptone, 0.75% yeast extract and 1.5% glucose (PYG) medium. Amoebae were cultured and maintained as reported by Castro Artavia et al in 2017 [63].…”

“…Areas of gelatin digestion, which indicate protease activity, were seen as nonstained regions in the gel. To characterize the type of proteases produced, we followed the methodology described by Castro Artavia et al [63], using phenylmethylsulfonyl fluoride (PMSF) 1 mM (Sigma Aldrich Co., St.…”

Description of Virulent Factors and Horizontal Gene Transfers of Keratitis-Associated Amoeba Acanthamoeba Triangularis by Genome Analysis

“…Based on the 18S rRNA gene, the genus Acanthamoeba is defined and distributed into 22 different ribo-genotypes (T1-T22) [5,8]. Most of the human infections due to Acanthamoeba are related to ribo-genotype T4 [9]. Indeed, several studies have estimated that 90% of AK amoebic keratitis cases have been linked to this genotype [9].…”

“…Most of the human infections due to Acanthamoeba are related to ribo-genotype T4 [9]. Indeed, several studies have estimated that 90% of AK amoebic keratitis cases have been linked to this genotype [9]. Acanthamoeba triangularis strain SH 621 is a ubiquitous FLA belonging to genotype T4, the most pathogenic group of Acanthamoeba species [10].…”

Combined Amoebicidal Effect of Atorvastatin and Commercial Eye Drops against Acanthamoeba castellanii Neff: In Vitro Assay Based on Mixture Design

“…Current molecular classification is based on the sequences of the nuclear small ribosomal subunit gene (18S rDNA) that classifies Acanthamoeba strains within 22 genotypes known as T1 to T22 [4]. Although genotype T4 is the most common in both clinical and environmental samples, other genotypes-namely T2, T3, T5, T6, T11, T13, and T15, among others-have been also related to AK and amoebic encephalitis [5,6].…”