A culture of Burkholderia pseudomallei bacteria, the pathogen that causes melioidosis.
NIAID-funded researchers developed a new rapid diagnostic for the tropical disease melioidosis, a disease caused by the bacterium Burkholderia pseudomallei. Melioidosis affects approximately 165,000 people worldwide, mainly in Southeast Asia and northern Australia, and causes 89,000 deaths annually. It is primarily contracted through direct contact with contaminated water or soil.
Symptoms of melioidosis overlap with other viral and parasitic diseases which has made it difficult to diagnose, and, in turn, hindered treatment efforts. Melioidosis is frequently misdiagnosed as sepsis, and the standard therapies used to treat sepsis are ineffective for B. pseudomallei.
A new diagnostic for melioidosis, called Rapid Melioidosis, takes only 15 minutes and can be administered in a point-of-care (POC) setting. The test can detect infection at a very early stage from just one drop of blood or serum. Instead of a lengthy lab test that requires the bacteria to be isolated from a clinical specimen and cultured, the new test yields rapid results. Rapid Melioidosis is an immunochromatography test that uses an antigen for hemolysin-coregulated protein (Hcp1) to detect antibodies against Hcp1 in the blood. Hcp1 is a protein secreted by the bacteria that plays a role in its intracellular functions. Studies have shown that this new melioidosis test kit is highly sensitive and specific. The test was developed by researchers at Mahidol University in Bangkok, Thailand and at the University of Washington in Seattle, Washington. The test is currently licensed and available for commercial use in Thailand under the name Active Melioidosis Detect. The test is currently licensed by the Thailand Food and Drug Administration and available for commercial use in Thailand and other South Asian countries including Cambodia, Malaysia, Vietnam, Singapore and Indonesia under the name Mahidol University Tropical Medicine Melioidosis Antibody Test (MUTM Melioidosis Antibody Test). The current antigen is recombinant protein which is more sensitive and specific than the initial kit and is linked to a second O-polysaccharide for added specificity.
Mahidol University has also launched a real-time polymerase-chain-reaction (PCR) test kit, called Melimo, for identifying B. pseudomallei based on a Type 3 Secretion System Gene marker-1 (TTS1). Combining Hcp1-ICT with type-3 secretion system 1 quantitative PCR (TTS1-qPCR) significantly enhances diagnostic performance. The research team is also examining the use of the plasma IL-1R2 protein as an effective biomarker for predicting sepsis-related mortality and determining treatment regimens.
Researchers hope the newly developed diagnostic test will greatly accelerate diagnosis and treatment of melioidosis, improve the quality of patient care, and illustrate the importance of increased availability of rapid, POC diagnostics.