Organism that Causes Buruli Ulcer Isolated and Characterized

Buruli ulcer is a neglected, devastating, necrotizing disease, and sometimes produces massive, disfiguring ulcers. It has long been believed that it is caused by Mycobacterium ulcerans, an environmental pathogen transmitted to humans from aquatic niches, but until now, the organism has not been isolated in pure culture from environmental sources.

The disease occurs predominantly in impoverished, humid, tropical, rural areas of Africa, where the incidence has been increasing, surpassing tuberculosis, and leprosy (two other diseases caused by mycobacteria) in some regions. Besides being a disease of the poor, Buruli ulcer is a poverty-promoting chronic infectious disease.

An international team of 17 researchers from four countries isolated from the environment and fully characterized the organism that causes Buruli ulcer. The study, published March 26, 2008, in the open-access journal PLoS Neglected Tropical Diseases, lends support to the idea that the organism, M. ulcerans, is transmitted to humans from environmental aquatic niches, rather than from person to person.

Françoise Portaels, from the Institute of Tropical Medicine (Antwerp, Belgium), and colleagues in Ghana, Portugal, and the United States, described how they isolated and characterized a M. ulcerans strain from the environment. The strain has microbiological features typical of African strains of M. ulcerans and it was isolated from an aquatic insect (the Water Strider) from a Buruli ulcer-endemic area in Benin, West Africa.

"Our findings support the concept that Mycobacterium ulcerans is a pathogen of humans with an aquatic environmental niche,” said the authors "and will have positive consequences for the control of this neglected and socially important tropical disease.”

In a related commentary, Tim Stinear, from Monash University (Clayton, Australia), and Paul Johnson, from the Austin Hospital (Heidelberg, Australia), who were not involved in the study, say that the new study is "a major achievement and will serve as the definitive reference point for scientists' intent on revealing the ecology, environmental reservoir, and precise mode of transmission of Mycobacterium ulcerans.”


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Institute of Tropical Medicine
Monash University
Austin Hospital