Molecular phylogeny of Burkholderia pseudomallei

In terms of population structure, the species Burkholderia pseudomallei con tains both clonal and non-clonal elements. By indexing variation in rRNA lo ci using the restriction endonuclease BamHI, we found that two ribotypes (t ypes 1 and 3) are predominant in nature. Ribotype 3 is prevalent in Asian c ountries while ribotype 1 is more widespread. Some disease association was suggested for 4 ribotypes and strains of ribotype 4 were markedly associate d with a fatal outcome. DNA macrorestriction (XbaI) profiles resolved by pu lsed-field gel electrophoresis revealed great heterogeneity within the prev alent ribotypes and these profiles appeared to be reliable strain markers. Arabinose environmental strains were characterised by BamHI ribotypes that were markedly distinct form clinical and environmental isolates of the arab inose negative phenotype. (C) 2000 Elsevier Science B.V. All rights reserve d.