Genetic and morphological diversity of vietnamese population of Burkholderia thailandensis
Introduction. Burkholderia thailandensis and B. pseudomallei are closely related gram-negative saprophytic microbes. Recently, the variant strains of B. thailandensis bearing a capsular polysaccharide gene cluster (Bp-like CPS) exhibiting high similarity to the corresponding cluster in B. pseudomallei were discovered. In the present study, we aimed to determine the presence of B. thailandensis capsular variant strains (BTCV) in the environment of Vietnam. Methods. Multilocus species-specific PCR and MLST used to identify the strains. 87 B. thailandensis soil isolates from Southern and Central Vietnam were investigated. Results. The six pairs of primers were designed to detect genes of Bp-like CPS cluster. 11 BTCV strains have been revealed. The strains bearing Bp-like CPS cluster formed mainly a pseudomallei-like rough and wrinkled colonies. Conclusion. Also found that L1629S and T1942A polymorphisms in type I polyketide synthase WcbR are closely associated with pseudomallei-like colony morphology in EPS-expressing strains of the main population of B. thailandensis in Vietnam. The obtained data indicate a high degree of genetic heterogeneity accompanied by phenotypic diversity of B. thailandensis in Vietnam.