The prevalence of free-living amoebae in a South African hospital water distribution system

Abstract

The purpose of this study was to investigate the occurrence of free-living amoebae in the water system of a teaching hospital in Johannesburg (South Africa). Water and biofilm samples were collected from the theatres, theatre sterilisation service unit, central sterilisation service unit and endoscopy/bronchoscopy unit. The samples were filtered and seeded on non-nutrient agar spread with heat-killed Escherichia coli. Of the 71 samples collected, 63 (88.7%) were positive for free-living amoeba. Acanthamoeba spp., Balamuthia spp. and Hartmanella spp. were identified by morphology. The presence of free-living amoeba in the hospital water network may be a potential health risk.