Prevalence of potentially pathogenic free-living amoebae from Acanthamoeba and Naegleria genera in non-hospital, public, internal environments from the city of Santos, Brazil

Abstract

Acanthamoeba and Naegleria species are free-living amoebae (FLA) found in a large variety of natural habitats. The prevalence of such amoebae was determined from dust samples taken from public non-hospital internal environments with good standards of cleanliness from two campuses of the same University in the city of Santos (SP), Brazil, and where young and apparently healthy people circulate. The frequency of free-living amoebae in both campuses was 39% and 17% respectively, with predominance of the genus Acanthamoeba. On the campus with a much larger number of circulating individuals, the observed frequency of free-living amoebae was 2.29 times larger (P< 0.00005). Two trophozoite forms of Naegleria fowleri, are the only species of this genus known to cause primary amoebian meningoencephalitis, a rare and non-opportunistic infection. We assume that the high frequency of these organisms in different internal locations represents some kind of public health risk.

Acanthamoeba contamination of hemodialysis and dental units in Alexandria, Egypt: A neglected potential source of infection

“…These low concentrations are used to prevent corrosion of the machines, according to the instructions from the machines' distributors (personal communication). In addition, cysts of these amoebae are resistant to changes in temperature and pH and exposure to chlorine, detergents and common disinfectants [29]. The contamination of hemodialysis hydraulic systems could be partly attributed to biofilm formation as a result of water stagnation in the long bending drain connecting the water treatment unit to the hemodialysis unit [8].…”

Potentially pathogenic free-living amoebae isolated from hospital wards with immunodeficient patients in Tehran, Iran

“…However, these earlier studies focused on only a single ophthalmology hospital and analyzed five dust samples of ophthalmology wards, which contained the Acanthamoeba T4 genotype (Niyyati et al 2009a). The present study was a comprehensive survey with 70 samples and also included biofilms as a potential source of proliferation of FLA. Airborne dust, combined with high levels of air pollution, is frequent in Tehran, enabling cysts to be transferred by visitors from outside to the indoor environment of hospital wards (Teixeira et al 2009;Chan et al 2011;Costa et al 2010).…”

Microbial Communities Associated with House Dust

“…In fact, there are few reports of detection of free-living amoebae in indoor dust (Carlesso et al, 2010;Lasjerdi et al, 2011;Niyyati et al, 2009;Teixeira et al, 2009). In fact, there are few reports of detection of free-living amoebae in indoor dust (Carlesso et al, 2010;Lasjerdi et al, 2011;Niyyati et al, 2009;Teixeira et al, 2009).…”