title: Rapid identification of the species of the Bacteroides fragilis group by multiplex PCR assays using group- and species-specific primers.
abstract: We report a rapid and reliable two-step multiplex polymerase chain reaction (PCR) assay to identify the 10 Bacteroides fragilis group species - Bacteroides caccae, B. distasonis, B. eggerthii, B. fragilis, B. merdae, B. ovatus, B. stercoris, B. thetaiotaomicron, B. uniformis and B. vulgatus. These 10 species were first divided into three subgroups by multiplex PCR-G, followed by three multiplex PCR assays with three species-specific primer mixtures for identification to the species level. The primers were designed from nucleotide sequences of the 16S rRNA, the 16S-23S rRNA intergenic spacer region and part of the 23S rRNA gene. The established two-step multiplex PCR identification scheme was applied to the identification of 155 clinical isolates of the B. fragilis group that were previously identified to the species level by phenotypic tests. The new scheme was more accurate than phenotypic identification, which was accurate only 84.5% of the time. The multiplex PCR scheme established in this study is a simple, rapid and reliable method for the identification of the B. fragilis group species. This will permit more accurate assessment of the role of various B. fragilis group members in infections and of the degree of antimicrobial resistance in each of the group members.
authors.affiliation: Research Service, VA Medical Center West Los Angeles, Room E3-237, Bldg 304, 11301 Wilshire Blvd, Los Angeles, CA 90073, USA. chengxu66@yahoo.com
authors.forename: Chengxu
authors.initials: C
authors.lastname: Liu
authors.forename: Yuli
authors.initials: Y
authors.lastname: Song
authors.forename: Maureen
authors.initials: M
authors.lastname: McTeague
authors.forename: Ann W
authors.initials: AW
authors.lastname: Vu
authors.forename: Hannah
authors.initials: H
authors.lastname: Wexler
authors.forename: Sydney M
authors.initials: SM
authors.lastname: Finegold
mesh_terms: D001431:Bacteriological Techniques; D001441:Bacteroides fragilis / Q000145:classification* / Q000235:genetics* / Q000254:growth & development; D004251:DNA Transposable Elements / Q000235:genetics; D010641:Phenotype; D016133:Polymerase Chain Reaction / Q000379:methods*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics
chemical_list: D004251:DNA Transposable Elements; D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S