The environmental microbiology of melioidosis

Melioidosis is an unusual bacterial infection. While on the one hand melioidosis can present as an acute, rapidly fatal septicaemia, the causative agent, Burkholderia pseudomallei, can also cause localised soft tissue infection or seroconversion without clinically evident infection. Distinctive epidemiological features of melioidosis include a high prevalence in southeast Asia and northern Australia, a predilection for those with prior co-morbidities such as diabetes mellitus, and an association with soil or surface water exposure. Melioidosis is also notable for primary infection or secondary recurrence after an interval of many years. The ability of B, pseudomallei to survive in soil or water for prolonged periods may explain the relevance of soil or water exposure to melioidosis. However, the means of transmission, definitive reservoir, principal means of exposure and mechanisms of pathogenesis have yet to be fully understood. Careful attention to the environmental microbiology of B. pseudomallei will provide important insights into the normal behaviour of this species and help to explain the environmental origins of melioidosis. (C) 2001 Lippincott Williams & Wilkins.