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Accelerating Time to Detection of Legionella in Environmental Samples


Phase I SBIR proposals will be accepted. Fast-Track proposals will not be accepted. Phase I clinical trials will be accepted. Number of anticipated awards: 1 Budget (total costs): Phase I: up to $150,000 for up to 6 months PROPOSALS THAT EXCEED THE BUDGET OR PROJECT DURATION LISTED ABOVE MAY NOT BE FUNDED. Background Legionnaires’ disease is a severe pneumonia typically caused by inhalation of aerosolized water containing Legionella bacteria. In the United States, more than 8,000 illnesses are reported annually, though this likely underestimates the true burden of disease. This represents an increase of more than 500% since 2000. When complex building water systems are not well maintained, Legionella bacteria can grow and spread, creating a risk for infection. Common sources of exposure to Legionella include showers, hot tubs, water misters, and large air conditioning devices known as cooling towers. During outbreak investigations, public health professionals often collect environmental samples from these and other devices to identify potential sources of exposure. Testing for Legionella bacteria is time-consuming, requires specific expertise, and typical takes between 7-14 days before results are available. Recently, PCR-based technologies have been introduced that have the potential speed up the testing process. Unfortunately, current tests that rely solely on detecting Legionella genetic material cannot distinguish between live and dead bacteria, limiting their usefulness. A test that could rapidly identify viable Legionella in environmental water samples has the potential to accelerate detection of exposure sources. This would significantly improve the ability of public health professionals to halt outbreaks of Legionnaires’ disease when they occur. Project Goals The goal of this research is to develop a test that can rapidly detect viable Legionella bacteria in water samples collected from environmental sources. Ideally, this test would be simple to perform, have the ability to detect and identify all species of Legionella in a sample, and require minimal processing of the sample. The true innovation of this research would be shortening the time to detection and quantification of Legionella bacteria. A true breakthrough would require this time to be shortened considerably from the current 7-14 day requirement for traditional Legionella culture. A successful test would not need to be purely culture-independent if other project goals were met. This test would also not need to generate Legionella isolates. Phase I Activities and Expected Deliverables The expected deliverables are: 1. Develop a laboratory assay that detects viable Legionella bacteria in environmental (water) samples. The approach may use molecular, serological, or chemical procedures singly or in combination. Minimum performance criteria are: • Time to result less than 72 hours • Discrimination of strains of clinical interest (i.e., Legionella pneumophila serogroup 1.) • Detailed typing information is not necessary, but at minimum, the procedure must be able to differentiate between Legionella pneumophila and all other Legionella spp. 2. Demonstrate proof of principle by comparing results with traditional Legionella culture methods. This could be accomplished using laboratory-generated, Legionella-containing water samples using multiple water sample sources (e.g. potable water, cooling tower basin water, utility distribution system water, etc.). 3. Determine ranges of sensitivity and specificity for all water sample sources tested. If the procedure provides quantification of viable Legionella, the limit of detection and precision should also be determined. 4. Develop a protocol to validate the assay in the field. Impact The development of a rapid assay would significantly advance public health response. The current 7-14 day wait time associated with Legionella culture testing can lead to additional cases of disease, limits the ability of public health to identify the exposure source, and delay recommendations that could protect the public. Shortening this time can speed up the response to cases and outbreaks of Legionnaires’ disease. It could also lead to more widespread testing to identify risky exposure sources before they cause disease. The wait for testing results can delay the time before action can be taken to eliminate any risk that might be present. A more rapid test with actionable results could solve this problem. Finally, successful completion of this project could expand environmental Legionella testing to more public health, academic, hospital, and private labs. Currently Legionella culture testing is difficult to perform and requires significant expertise. A simpler test could lead to adoption of Legionella testing in more labs, increasing the ability for healthcare facilities, hotel owners, cooling tower operators, and state and local public health jurisdictions to obtain results during outbreak investigations or for routine testing purposes. Commercialization Potential A test developed as part of this research proposal has significant commercialization potential. Cases and outbreaks of Legionnaires’ disease have increased significantly over the past 10 years. This has resulted in more investigations, which typically require testing of environmental samples. A product that simplified and sped up this process would be useful to both public health labs and private consulting companies. Recently, the Centers for Medicare & Medicaid Services (CMS) released a memorandum stating that all acute care facilities must implement a water management program to prevent the growth and spread of Legionella bacteria. While not required, many of these facilities may choose to begin routinely testing their water systems for presence of Legionella. A rapid, easy to administer, reliable test to detect Legionella could prove very useful for these facilities. Recent reports have estimated that the market for Legionella testing eclipsed $180 million in 2016. This number is expected to increase to nearly $400 million by 2025. The advent of a Legionella test that solves many of the problems associated with the current technologies could prove extremely lucrative from a commercial standpoint.
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