부산대학교 도서관

ABSTRACTBurkholderia cepacia, which is an important pathogen in cystic fibrosis (CF) owing to the potential severity of the infections and the high transmissibility of some clones, has been recently shown to be a complex of five genomic groups, i.e., genomovars I, II (B. multivorans), III, and IV and B. vietnamiensis. B. gladioliis also involved, though rarely, in CF. Since standard laboratory procedures fail to provide an accurate identification of these organisms, we assessed the ability of restriction fragment length polymorphism (RFLP) analysis of amplified 16S ribosomal DNA (rDNA), with the combination of the patterns obtained with six endonucleases, to differentiateBurkholderiaspecies. This method was applied to 16 type and reference strains of the genus Burkholderiaand to 51 presumed B. cepaciaclinical isolates, each representative of one clone previously determined by PCR ribotyping. The 12 Burkholderiatype strains tested were differentiated, including B. cepacia, B. multivorans, B. vietnamiensis, and B. gladioli, but neither the genomovar I and III reference strains nor the genomovar IV reference strain and B. pyrrociniaTwere distinguishable. CF clinical isolates were mainly distributed in RFLP group 2 (which includesB. multivoransT) and RFLP group 1 (which includes B. cepaciagenomovar I and III reference strains, as well as nosocomial clinical isolates). Two of the five highly transmissible clones in French CF centers belonged to RFLP group 2, and three belonged to RFLP group 1. The remaining isolates either clustered with other Burkholderiaspecies (B. cepaciagenomovar IV or B. pyrrocinia, B. vietnamiensis, and B. gladioli) or harbored unique combinations of patterns. Thus, if further validated by hybridization studies, PCR-RFLP of 16S rDNA could be an interesting identification tool and contribute to a better evaluation of the respective clinical risks associated with each Burkholderiaspecies or genomovar in patients with CF.