Background: The soil-dwelling pathogen Burkholderia pseudomallei is the cause of melioidosis. In this study, the geographical and temporal distributions of predominant molecular patterns occurring in clinical and environmental isolates of B. pseudomallei were characterised.
Methods: A collection of 194 human and 59 soil B. pseudomallei isolates obtained in Taiwan were analysed by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST).
Results: Five predominant PFGE types (VI, X, XI, XV and XVI) among human isolates were identified between 2004 and 2010. Among them, types VI, X and XI correspond to ST58, and types XV and XVI correspond to ST99. The distribution of B. pseudomallei with distinct PFGE or MLST types was clustered in different towns in southern Taiwan. Clusters of B. pseudomallei have successively appeared in the town of Jiading, which is located in the Er-Ren River Basin of southern Taiwan.
Conclusions: Burkholderia pseudomallei isolates were geographically and temporally clustered in Taiwan. This finding supports the contention that the Er-Ren River Basin now constitutes the highest risk area for melioidosis in Taiwan.