1. Comparison of free-living amoebae in hot water systems of hospitals with isolates from moist sanitary areas by identifying genera and determining temperature tolerance
- Author
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Susanne Weber, Ute Rohr, Fidelis Selenka, Rolf Michel, and Michael Wilhelm
- Subjects
Veterinary medicine ,food.ingredient ,Acanthamoeba ,Vahlkampfia ,Applied Microbiology and Biotechnology ,Naegleria ,Hartmannella vermiformis ,Microbiology ,food ,Genus ,Agar ,Animals ,Amoeba ,Hartmannella ,Ecology ,biology ,Temperature ,Water ,biology.organism_classification ,Hospitals ,Environmental and Public Health Microbiology ,Protozoa ,Food Science ,Biotechnology - Abstract
Legionella-contaminated hot water systems and moist sanitary areas in six hospitals were sampled for amoebae by following a standardized collection protocol. Genus identifications and temperature tolerance determinations were made. Amoebae identified as Hartmannella vermiformis (65%), Echinamoebae spp. (15%), Saccamoebae spp. (12%), and Vahlkampfia spp. (9%) were detected in 29 of 56 (52%) hot water samples. Twenty-three of 49 (47%) swabs obtained from moist areas were amoeba positive. The following genera were identified: Acanthamoeba (22%), Naegleria (22%), Vahlkampfia (20%), Hartmannella (15%), and Vanella (7%). The temperature tolerance of amoebae from hot water systems was strikingly different from that of amoebae from moist areas. At 44°C on agar, 59% of amoebic isolates sampled from hot water systems showed growth. The corresponding value for isolates from moist areas was only 17%. Six Acanthamoeba isolates from the moist areas were considered potential pathogens. Four Hartmannella and two Saccamoeba isolates from hot water could be cultured at 53°C.
- Published
- 1998