IDENTIFICATION OF LEGIONELLA SPECIES BY LIPOPOLYSACCHARIDE ANTIGEN PATTERN

Electrophoretic analysis of lipopolysaccharide (LPS) er;tracts from 43 0 previously serotyped Legionella isolates and 28 American Type Cultur e Collection (ATCC) non-Legionella pneumophila Legionella reference st rains representing different Legionella species and serogroups has bee n performed. LPS was prepared from Legionella suspensions by sonicatio n and proteinase Ii digestion. Following sodium dodecyl sulfate-polyac rylamide gel electrophoresis, LPS bands were either stained with silve r nitrate or transferred onto a nitrocellulose membrane and detected w ith rabbit antibodies raised against L. pneumophila serogroup 5, which was known to cross-react with L. pneumophila serogroups 1 to 14. Silv er staining revealed that each of the 28 ATCC non-L. pneumophila Legio nella strains possessed an individual and characteristic LPS banding p attern. The LPS profile was defined by the molecular weight of the vis ualized bands and/or the individual ladder-like LPS pattern. It was de monstrated by immunoblotting that non-L. pneumophila Legionella strain s did not react with the serogroup 5 antiserum, thus allowing for the differentiation between,een L. pneumophila and non-L. pneumophila spec ies.