DNA-based diagnostic approaches for identification of Burkholderia cepaciacomplex, Burkholderia vietnamiensis, Burkholderia multivorans, Burkholderia stabilis, and Burkholderia cepacia genomovars I and III

Mahenthiralingam, E Bischof, J Byrne, SK Radomski, C Davies, JE Av-Gay, Y Vandamme, P

E. Mahenthiralingam et al., DNA-based diagnostic approaches for identification of Burkholderia cepaciacomplex, Burkholderia vietnamiensis, Burkholderia multivorans, Burkholderia stabilis, and Burkholderia cepacia genomovars I and III, J CLIN MICR, 38(9), 2000, pp. 3165-3173

31

INGLESE

Article

Clinical Immunolgy & Infectious Disease",Microbiology

JOURNAL OF CLINICAL MICROBIOLOGY

0095-1137 → ACNP

38

9

2000

3165 - 3173

ISI

0095-1137(200009)38:9<3165:DDAFIO>2.0.ZU;2-0

Bacteria of the Burkholderia cepacia complex consist of five discrete genom ic species, including genomovars I and III and three new species: Burkholde ria multivorans (formerly genomovar II), Burkholderia stabilis (formerly ge nomovar IV), and Burkholderia vietnamiensis (formerly genomovar V). Strains of all five genomovars are capable of causing opportunistic human infectio n, and microbiological identification of these closely related species is d ifficult, The 16S rRNA gene (16S rDNA) and recA gene of these bacteria were examined in order to develop rapid tests for genomovar identification. Res triction fragment length polymorphism (RFLP) analysis of PCR-amplified 16S rDNA revealed sequence polymorphisms capable of identifying B. multivorans and B. vietnamiensis but insufficient to discriminate strains of B. cepacia genomovars I and III and B. stabilis, RFLP analysis of PCR-amplified recA demonstrated sufficient nucleotide sequence variation to enable separation of strains of all five B. cepacia complex genomovars. Complete recA nucleot ide sequences were obtained for 20 strains representative of the diversity of the B. cepacia complex. Construction of a recA phylogenetic tree identif ied six distinct clusters (recA groups): B. multivorans, B. vietnamiensis, B. stabilis, genomovar I, and the subdivision of genomovar III isolates int o two recA groups, III-A and III-B, Alignment of recA sequences enabled the design of PCR primers for the specific detection of each of the six latter recA groups. The recA gene was found on the largest chromosome within the genome of B. cepacia complex strains and, in contrast to the findings of a previous study, only a single copy of the gene was present. In conclusion, analysis of the recA gene of the B. cepacia complex provides a rapid and ro bust nucleotide sequence-based approach to identify and classify this taxon omically complex group of opportunistic pathogens.