title: Application of RNA polymerase beta-subunit gene (rpoB) sequences for the molecular differentiation of Legionella species.
abstract: The nucleotide sequences of the partial rpoB gene were determined from 38 Legionella species, including 15 serogroups of Legionella pneumophila. These sequences were then used to infer the phylogenetic relationships among the Legionella species in order to establish a molecular differentiation method appropriate for them. The sequences (300 bp) and the phylogenetic tree of rpoB were compared to those from analyses using 16S rRNA gene and mip sequences. The trees inferred from these three gene sequences revealed significant differences. This sequence incongruence between the rpoB tree and the other trees might have originated from the high frequency of synonymous base substitutions and/or from horizontal gene transfer among the Legionella species. The nucleotide variation of rpoB enabled more evident differentiation among the Legionella species than was achievable by the 16S rRNA gene and even by mip in some cases. Two subspecies of L. pneumophila (L. pneumophila subsp. pneumophila and subsp. fraseri) were clearly distinguished by rpoB but not by 16S rRNA gene and mip analysis. One hundred and five strains isolated from patient tissues and environments in Korea and Japan could be identified by comparison of rpoB sequence similarity and phylogenetic trees. These results suggest that the partial sequences of rpoB determined in this study might be applicable to the molecular differentiation of Legionella species.
authors.affiliation: Department of Microbiology and Cancer Research Institute, Institute of Endemic Diseases, SNUMRC, Seoul National University College of Medicine, and Clinical Research Institute, Seoul National University Hospital, Seoul 110-799.
authors.forename: Kwan Soo
authors.initials: KS
authors.lastname: Ko
authors.forename: Hae Kyung
authors.initials: HK
authors.lastname: Lee
authors.forename: Mi-Yeoun
authors.initials: MY
authors.lastname: Park
authors.forename: Keun-Hwa
authors.initials: KH
authors.lastname: Lee
authors.forename: Yeo-Jun
authors.initials: YJ
authors.lastname: Yun
authors.forename: So-Yon
authors.initials: SY
authors.lastname: Woo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyamoto
authors.forename: Yoon-Hoh
authors.initials: YH
authors.lastname: Kook
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D005798:Genes, Bacterial; D006801:Humans; D020104:Immunophilins / Q000235:genetics; D007875:Legionella / Q000145:classification / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D008565:Membrane Proteins / Q000235:genetics; D019696:Peptidylprolyl Isomerase; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012703:Serotyping; D013045:Species Specificity
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D008565:Membrane Proteins; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012321:DNA-Directed RNA Polymerases; C105078:RNA polymerase beta subunit; D020104:Immunophilins; C512922:Mip protein, Legionella pneumophila; D019696:Peptidylprolyl Isomerase