A rapid coagglutination test for the detection and serogrouping of Legionellae

The applicability of coagglutination for the rapid detection and serogrouping of Legionellae has been investigated. The coagglutination reaction is carried out with the aid of self-made preparations of protein A containing staphylococci, sensitized with specific antibodies against the antigens of L. pneumophila (serogroups I to 6), L. bozemanii and L. micdadei. Preliminary heating of Legionella suspensions at 100% C for 15 min was used to prevent cross coagglutination reactions and ensure greater safety of laboratory personnel during the performance of the test. The results obtained demonstrate a high specificity of coagglutination. With the aid of the coagglutination reactions it has been shown that L. pneumophila strains isolated in Bulgaria belong to serogroup I. The coagglutination method is characterized by its rapidity, simplicity and feasibility. It is a useful and convenient means for the rapid detection and serogrouping of Legionellae.