Burkholderia pseudomallei is a major cause of bacterial septicemias in many parts of the world, particularly Thailand; the known geographic range of the organism appears to be enlarging as awareness of the organism and the disease it causes--melioidosis--increases. B. pseudomallei is intrinsically resistant to most antibiotics, and our knowledge of B. pseudomallei pathogenesis is lacking. Thus, the long-term objective of our research is to define at a molecular level the pathogenesis by combining genetic, immunologic, and biochemical approaches with animal model studies. Basic studies on B. pseudomallei pathogenesis are acutely needed to provide a knowledge base to rationally design new modes of therapy directed against this organism.