Abstract
This study investigated the occurrence of free-living amoebae (FLA) in a public hospital in
South Africa. A total of 97 water and biofilm samples from the municipal water inlet of the
hospital, theatres, theatre sterilization service unit, central sterilization service unit,
endoscopy/gastroscopy unit, intensive care unit and the renal unit were collected and examined
for the presence of FLA using an amoebal co-culture and molecular techniques. Of the 97
samples, 77 (79.4 %), 40 (52%) water and 37 (48.1%) biofilm, contained FLA. The genera
Acanthamoeba, Vermamoeba (formerly Hartmanella) and Naegleria were detected by
morphology, 18S rRNA PCR and sequence analyses. Further sequence analysis of the five
Acanthamoeba positive isolates revealed a close resemblance with the potentially pathogenic
T20 genotype. These results show a potential health risk to immuno-compromised patients and
health care workers as some of the species detected are pathogenic and may harbour potential
intracellular bacteria responsible for nosocomial infections. To date, this is the first report on the
detection of potentially pathogenic amoebae from South African hospital water systems.