BACKGROUND: The soil-dwelling saprophyte bacterium Burkholderia pseudomallei is 
the cause of melioidosis, a severe disease of humans and animals in southeast 
Asia and northern Australia. Despite the detection of B. pseudomallei in various 
soil and water samples from endemic areas, the environmental habitat of B. 
pseudomallei remains unclear.
METHODOLOGY/PRINCIPAL FINDINGS: We performed a large survey in the Darwin area 
in tropical Australia and screened 809 soil samples for the presence of these 
bacteria. B. pseudomallei were detected by using a recently developed and 
validated protocol involving soil DNA extraction and real-time PCR targeting the 
B. pseudomallei-specific Type III Secretion System TTS1 gene cluster. 
Statistical analyses such as multivariable cluster logistic regression and 
principal component analysis were performed to assess the association of B. 
pseudomallei with environmental factors. The combination of factors describing 
the habitat of B. pseudomallei differed between undisturbed sites and 
environmentally manipulated areas. At undisturbed sites, the occurrence of B. 
pseudomallei was found to be significantly associated with areas rich in 
grasses, whereas at environmentally disturbed sites, B. pseudomallei was 
associated with the presence of livestock animals, lower soil pH and different 
combinations of soil texture and colour.
CONCLUSIONS/SIGNIFICANCE: This study contributes to the elucidation of 
environmental factors influencing the occurrence of B. pseudomallei and raises 
concerns that B. pseudomallei may spread due to changes in land use.