Detection of Legionella Soluble Antigen in Urine by Enzyme-Linked Immunosorbent Assay

Basic Studies on Antigen Detection by ELISA

Abstract

The basic studies of detection and quantification of soluble antigen of legionella from urine samples infected with legionella by ELISA were performed.
Polyclonal antilegionella antibody was used as the first antibody and alkaline-phosphatase conjugated monoclonal antibody was used as the second antibody in this sandwich assay.
Heat solube antigen of L. pneumophila serogroupl (106 CFU/ml) was detectable by conventional ELISA.
Heat soluble antigen of L. pneumophila serogroupl (10⁶ CFU/ml) was detectable by the fluorescent ELISA. The sensitivity of fluorescent ELISA method was better than that of the conventional ELISA.
Soluble antigen in rabbit urine infected with L. pneumophila was detected from six hours after inoculation of bacteria, and the antigen titer which was equivalent to 10⁶ CFU of heat treated L. pneumophila reached to the maximum at one day after inoculation.
The detection of soluble antigen in the urine sample by ELISA was a rapid method and was very useful for the early clinical diagnoses of Leginella disease.