Phenotypic methods for determining genomovar status of the Burkholderia cepacia complex

Recent taxonomic advances have demonstrated that Burkholderia cepacia is a cluster of at least seven closely related genomic species (or genomovars) c ollectively referred to as the B. cepacia complex, all of which may cause i nfections among cystic fibrosis patients and other vulnerable individuals. Thus, it is important for clinical microbiologists to be able to differenti ate genomovars. Prior to this study, 361 B. cepacia complex isolates and 51 isolates easily confused with B. cepacia complex previously had been ident ified using a polyphasic approach, and in this study, a comparison of pheno typic and biochemical tests was carried out. It was determined that Burkhol deria multivorans and Burkholderia stabilis could reliably be separated fro m other members of the B. cepacia complex by phenotypic methods. A combinat ion of phenotypic and molecular tests such as recA PCR and 16S rRNA RFLP ar e recommended for differentiation among the genomovars of the B. cepacia co mplex. A biochemical reaction scheme for the identification of B. gladioli, Pandoraea species, and Ralstonia pickettii and the differentiation of thes e species from the B. cepacia complex is also presented.