Pathogenic soil bacterium is influenced by land management
Melioidosis is a severe disease affecting humans and animals in the tropics. It is caused by the bacterium Burkholderia pseudomallei, which lives in tropical soil and especially occurs in southeast Asia and northern Australia. Despite the recognition that melioidosis is an emerging infectious disease, little is known about the habitat of B. pseudomallei in the environment.
Researchers from Menzies School of Health Research in Darwin, Australia have found that the soil bacterium Burkholderia pseudomallei, which causes the emerging infectious disease melioidosis in humans and animals, is associated with land management changes such as livestock husbandry or residential gardening. They performed a survey in the Darwin area in tropical Australia, screening 809 soil samples for the presence of these bacteria using molecular methods. The study sheds light on the environmental occurrence of this bacterium in the soil.
B. pseudomallei lives in tropical soil and is endemic in southeast Asia and northern Australia, where it can be a common cause of fatal community-acquired bacterial pneumonia. In predisposed hosts such as those with diabetes, it can also lead to systemic sepsis, with mortality rates over 50 percent. Through a large survey in the tropical Darwin area of Australia, the authors found that environmental factors describing the habitat of these bacteria differed between environmentally undisturbed and disturbed sites. At undisturbed sites, B. pseudomallei was primarily found in close proximity to streams and in grass- and roots-rich areas. In disturbed soil, B. pseudomallei was associated with the presence of animals, farming or irrigation. Highest B. pseudomallei counts were retrieved from paddocks, pens and kennels holding livestock and dogs. This study contributes to the elucidation of the habitat of B. pseudomallei in northern Australia. It also raises concerns that B. pseudomallei may spread due to changes in land management.
These findings raise concerns that B. pseudomallei may spread due to the influence of land management changes. This would increase the risk of human and livestock exposure to these potentially deadly bacteria which are transmitted by contact with contaminated soil or surface water through cuts in the skin or inhalation. In-depth analysis of the influence of anthropogenic factors upon B. pseudomallei and further studies in other endemic areas are needed to confirm the results of this study.
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Tags: Agriculture, Bacteria, Biology, Emerging disease, Environment, Microbiology, Science
