Detection of Legionella pneumophila in water samples by quantitative culture and an antigen detection assay.
We evaluated the new Legionella pneumophila antigen detection assay Binax Equate for quantitative determination of legionellae in potable water samples. Seventy-seven water samples from different sources were investigated by Binax Equate and quantitative culture. Our culture assay is able to detect 20 to 40 cfu per 100 ml water. The rates of detection of legionellae were 1% (1 of 77) for the antigen detection assay and 25% (19 of 77) by culture. We were able to detect antigen in one water sample with 28 cfu per ml L. pneumophila serogroup 1. In in-vitro experiments the antigen assay had a sensitivity of about 333 cfu per ml when the bacteria were added directly to the test tubes and about 1000 cfu per ml when a simulated water sample was investigated. None of the water samples positive for L. pneumophila serogroup 2 to 14 was positive in the Binax Equate. The new antigen assay proved to be a valuable tool for investigating heavy L. pneumophila Serogroup 1 contamination in potable water systems but lacks sufficient sensitivity to be used in the surveillance of water supplies.
Lück
Paul Christian
PC
Institut für Medizinische Mikrobiologie und Hygiene, TU Dresden, Fiedlerstr. 42, D-01307 Dresden, Germany. Christian.Lueck@mailbox.tu-dresden.de
Liebscher
Barbara
B
D000942:Antigens, Bacterial / Q000032:analysis*; D001681:Biological Assay; D004784:Environmental Monitoring / Q000379:methods; D006801:Humans; D016952:Legionella pneumophila / Q000276:immunology / Q000302:isolation & purification*; D014871:Water Microbiology; D014881:Water Supply
D000942:Antigens, Bacterial