TOXIN PRODUCTION BY BURKHOLDERIA-PSEUDOMALLEI STRAINS AND CORRELATIONWITH SEVERITY OF MELIOIDOSIS

An exotoxin lethal to cells in culture (cytolethal toxin, CLT) was ide ntified in culture filtrates of Burkholderia in pseudomallei, the caus ative organism of melioidosis, CLT could pass through a 10-kDa cut-off ultrafilter and its properties suggest that it is a peptide, Isolates from soil, animals and man showed differential cytolethality in vitro . The isolates were divided into low, medium and high CLT producers wi th soil isolates being low producers and isolates from patients with m elioidosis encephalitis being high producers, CLT levels are subject t o regulation, as a strain isolated from an infected goat was one of th e highest producers whereas the same strain isolated from soil was a l ow producer, In addition to CLT, all isolates produced a protein with cell-elongating activity which was also present in culture filtrates.