Free-living amoebae and their relationship to air quality in hospital environments: characterization of Acanthamoeba spp. obtained from air-conditioning systems

Abstract

Free-living amoebae (FLA) are widely dispersed in the environment, can cause opportunistic and non-opportunistic infections in humans and other animals. The aim of the present study was characterize FLA obtained from air-conditioners of a public hospital in the city of Florianópolis, SC, Brazil. Fifty-four dust samples were collected of air conditioners, and were inoculated on 1.5% non-nutrient agar, overlaid with layers of Escherichia coli. Subsequently the isolates were axenised in PYG growth medium. The morphological and molecular characterization of the isolates was performed, as well as the tolerance (physiological) assays were used to evaluate the pathogenic potential. The results revealed the presence of FLA in 42 (77.8%) of the collected samples. Of these, 39 (92.9%) axenic isolates of FLA were obtained for morphological and genotypic studies. All the isolates characterized belong to the genus Acanthamoeba. Nineteen (48.7%) isolates belong to the genotype T4, 16 (41.0%) to the T5 genotype and 4 (10.3%) to genotype T11. Seven (18.0%) isolates were considered potentially pathogenic in tolerance assays. These findings require attention, considering the isolation environment and immunocompromised characteristics of many hospitalized patients.

Genotype distribution of Acanthamoeba in keratitis: a systematic review

“…Free-living amoebae (FLA) from the genus Acanthamoeba are ubiquitously distributed in nature . This parasite can be isolated from virtually any natural or artificial environment including soil, dust, water, air, medical equipment, lens fluids, air-conditioning, and nasopharyngeal mucosa from healthy individuals (Clarke and Niederkorn 2006;Nagyová et al 2010a;Khezri et al 2016;Tawfeek et al 2016;Król-Turmińska and Olender 2017;Lass et al 2017;Wopereis et al 2020). Acanthamoeba spp.…”

Isolation and molecular identification of Acanthamoeba spp. from hospital dust and soil of Khomein, Iran, as reservoir for nosocomial infection.

“…The high frequency of Acanthamoeba spp. in various environment especially in hospital environmental resources, represents a high risk of infection such as skin lesions, keratitis, encephalitis, and pneumonia in immunocompromised and immunocompetent patients, which were exposed to this sources ( Wopereis et al, 2020 ; Carlesso et al, 2010 ; Martinez and Janitschke, 1985 ). Furthermore, Acanthamoeba spp.…”

Growth comparison of Acanthamoeba genotypes T3 and T4 in several culture media

“…In a study by Rahdar et al., while amoeba growth in PYG medium was not successful, efficient culturing in TYI-S-33 could be achieved, Therefore, they conclude that TYI-S-33 could be a substitute for PYG medium ( Rahdar et al., 2012 ). PYG and NNA media are used daily by researchers working with Acanthamoeba , both for the isolation and identification of Acanthamoeba spp ., in addition to its maintenance over many years ( Milanez et al., 2020 ; Wopereis et al., 2020 ; Retana et al., 2020 ). Few studies have been conducted comparing Acanthamoeba growth in different culture media.…”