ChemTreat, 10041 Lickinghole Road, Ashland, VA 23005, USA.
LuminUltra Technologies Ltd., 819 Royal Road, Building B, Fredericton, NB E3G 6M1, Canada.
J Ind Microbiol Biotechnol. 2024 Jan 9;51. doi: 10.1093/jimb/kuae030.
Legionella is a bacterial genus found in natural aquatic environments, as well as domestic and industrial water systems. Legionella presents potential human health risks when aerosolized and inhaled by at-risk individuals and is commonly monitored at locations with likelihood of proliferation and human exposure. Legionella monitoring is widely performed using culture-based testing, which faces limitations including turnaround time and interferences. Molecular biology methodologies, including quantitative polymerase chain reaction (qPCR), are being explored to supplement or replace culture-based testing because of faster turnaround and lower detection limits, allowing for more rapid water remediation measures. In this study, three methods were compared by testing industrial water samples: culture-based testing by a certified lab, high throughput qPCR testing (HT qPCR), and field deployable low throughput qPCR testing (LT qPCR). The qPCR test methods reported more positive results than culture testing, indicating improved sensitivity and specificity. The LT qPCR test is portable with quick turnaround times, and can be leveraged for environmental surveillance, process optimization, monitoring, and onsite case investigations. The LT qPCR test had high negative predictive value and would be a useful tool for negative screening of Legionella samples from high-risk environments and/or outbreak investigations to streamline samples for culture testing.
ONE-SENTENCE SUMMARY: This study compared three test methods for Legionella to evaluate performance of a low throughput quantitative polymerase chain reaction (LT qPCR) test for Legionella that can be used onsite; the study found that the high throughput (HT) and LT qPCR tests used in this study gave more positive results than culture testing, and the results indicated a similar negative predictive value for the HT and LT qPCR tests, supporting that the LT qPCR method could be useful for negative screening of Legionella samples in industrial water systems onsite.
军团菌是一种存在于自然水生环境以及家庭和工业供水系统中的细菌属。当气溶胶化并被高危个体吸入时，军团菌会对人体健康造成潜在风险，并且通常在可能发生增殖和人体暴露的地方进行监测。军团菌监测广泛采用基于培养的测试方法，但该方法存在周转时间和干扰等局限性。分子生物学方法，包括实时聚合酶链反应（qPCR），正在被探索以补充或替代基于培养的测试，因为它们具有更快的周转时间和更低的检测限，从而可以更快地采取水修复措施。在这项研究中，通过测试工业用水样本比较了三种方法：经过认证的实验室进行基于培养的测试、高通量 qPCR 测试（HT qPCR）和现场部署的低通量 qPCR 测试（LT qPCR）。qPCR 测试方法报告的阳性结果比培养测试多，表明提高了灵敏度和特异性。LT qPCR 测试具有快速周转时间的便携性，可用于环境监测、工艺优化、监测和现场案例调查。LT qPCR 测试具有高阴性预测值，对于从高风险环境和/或暴发调查中筛选军团菌样本进行阴性筛查以简化培养测试的样本，将是一种有用的工具。
本研究比较了三种军团菌测试方法，以评估一种可现场使用的低通量定量聚合酶链反应（LT qPCR）测试方法的性能；该研究发现，本研究中使用的高通量（HT）和 LT qPCR 测试比培养测试给出了更多的阳性结果，并且结果表明 HT 和 LT qPCR 测试的阴性预测值相似，支持 LT qPCR 方法可用于工业用水系统现场军团菌样本的阴性筛查。
