Rapid identification of legionellae by a colony blot assay based on a genus-specific monoclonal antibody

We recently developed a monoclonal antibody immunoglobulin G2a (2125) recognizing a genus-specific epitope on the 60-kDa heat shock protein of all Legionella species. In the current study, this antibody was used in a colony blot enzyme-linked immunosorbent assay for the rapid identification of Legionella cultures on agar plates. The whole protocol was completed in less than 2 h. All 59 Legionella species and serogroups that were tested gave a positive signal. No unspecific reactions with nonlegionellae were observed. This test is a rapid procedure for the identification of legionellae growing on agar medium to the genus level.