Burkholderia pseudomallei is a motile, gram-negative, aerobic bacterium of the Burkholderiaceae family. B. pseudomallei is commonly found in soil and muddy water in tropical regions of Australia. It can infect humans and animals and cause the disease Melioidosis.
Melioidosis is a potentially fatal disease affecting both humans and animals. It is endemic in Northern Australia and Southeast Asia. Common symptoms of the disease are pneumonia, skin abscesses or ulcers, abscesses in internal organs and unusual neurological illnesses such as brainstem encephalitis and acute paraplegia (NHMRC 2011). The greatest risk of exposure to B. pseudomallei occurs when humans or animals come in contact with contaminated soil or muddy water, generally after heavy rainfall (NHMRC 2011). Transmission of the bacterium most commonly occurs via skin abrasions coming in contact with contaminated soil or water. Human to human transmission, inhalation of contaminated dust or water droplets, and contact with contaminated groundwater have also been reported but are less likely to occur (Foong 2014).
The AWQC's culture-independent, DNA molecular method allows direct detection of B. pseudomallei from water, sludge and soil samples using two independent gene targets.
The gene targets are a type three secretion system 1 single-copy gene and hypothetical protein gene only present in B. pseudomallei (Knappik, 2015; Limmathurotsakul, 2012; Trung, 2011). The assay for these genes has been shown to be equivalent to direct culture of B. pseudomallei, including an internal DNA extraction control, probe polymerase chain reaction (PCR) efficiency and reaction controls (Knappik, 2015; Limmathurotsakul, 2012; Trung, 2011).
The AWQC analysis includes the broadest detection profile possible whilst remaining specific to the B. pseudomallei genome. The primers and probe sequences have 100% homology with a broad range of B. pseudomallei sequencesbased on a comprehensive bioinformatics analysis and on publication reviews.
Our PCR-based system provides a highly specific and sensitive tool for environmental surveillance of B. pseudomallei.
Dectection of Burkholderia pseudomallei by probe PCR.
References
Foong Y.C., Tan M., Bradbury R.S. (2014). Melioidosis: a review. Rural and Remote Health 14: 2763.
Knappik M., Dance D.A.B., Rattanavong S., Pierret A., Ribolzi O., Davong V., Silisouk J., Vongsouvath M., Newton P.N., Dittricha S. (2015). Evaluation of molecular methods to improve the detection of Burkholderia pseudomallei in soil and water samples from Laos. Applied and Environmental Microbiology 81(11):3722 3727.
Limmathurotsakul D., Wuthiekanun V., Amornchai P., Wongsuwan G., Day N.P.J., Peacock S.J. (2012). Effectiveness of a simplified method for isolation of Burkholderia pseudomallei from soil. Applied and Environmental Microbiology 78(3): 876-877.
National Health and Medical Research Council (2011). Australian Drinking Water Guidelines 6. Fact Sheets – Microorganisms (Bacteria): Burkholderia pseudomallei, pp. 277-278.
Trung T.T., Hetzer A., Göhler A., Topfstedt E., Wuthiekanun V., Limmathurotsakul D., Peacock S.J., Steinmetz I. (2011). Highly sensitive direct detection and quantification of Burkholderia pseudomallei bacteria in environmental soil samples by using real-time PCR. Applied and Environmental Microbiology 77(18):6486 6494.