Rapid identification of clinically relevant Legionella spp. by analysis oftransfer DNA intergenic spacer length polymorphism

Analysis of PCR-amplified transfer DNA (tDNA) intergenic spacers was evalua ted as a rapid method for identification to the species level of 18 species of legionella known as human pathogens. Type strains (n = 19), reference s trains (n = 16), environmental strains (n = 31), and clinical strains (n = 32) were tested. PCR products using outwardly directed tDNA consensus prime rs were separated on polyacrylamide gels and analyzed with automated laser fluorescence. Test results were obtained in 8 h starting with 72-h-old bact erial growth on solid medium. Species-specific patterns were obtained for a ll 18 Legionella species tested: Legionella anisa, L. bozemanii serogroups 1 and 2, L. cincinnatiensis, L. dumoffii, L. feeleii serogroups 1 and 2, L. gormanii, L. hackeliae serogroups 1 and 2, L. jordanis, L. lansingensis, L . longbeachae serogroups 1 and 2, L. lytica, L. maceachernii, L. micdadei, L. oakridgensis, L. parisiensis, L. pneumophila serogroups 1 to I 1, L. sai nthelensi serogroup 2, L. tucsonensis, and L. wadsworthii. Computer-assiste d matching of tDNA-intergenic length polymorphism (ILP) patterns identified all 63 environmental and clinical strains to the species level and to sero group for some strains. tDNA-ILP analysis is proposed as a routinely applic able method which allows rapid identification of environmental and clinical isolates of Legionella spp. associated with legionellosis.