Biótica, Bioquímica Analítica, S.L, Science and Technology Park of Jaume I University, Campus Riu Sec - Espaitec 2, planta baja, E12071, Castellón de la Plana, Spain.
BMC Microbiol. 2013 Apr 22;13:88. doi: 10.1186/1471-2180-13-88.
Legionellosis is an uncommon form of pneumonia. After a clinical encounter, the necessary antibiotic treatment is available if the diagnosis is made early in the illness. Before the clinical encounter, early detection of the main pathogen involved, Legionella pneumophila, in hazardous environments is important in preventing infectious levels of this bacterium. In this study a qualitative test based on combined magnetic immunocapture and enzyme-immunoassay for the fast detection of Legionella pneumophila in water samples was compared with the standard method, in both comparative and collaborative trials. The test was based on the use of anti-Legionella pneumophila antibodies immobilized on magnetic microspheres. The final protocol included concentration by filtration, resuspension and immunomagnetic capture. The whole assay took less than 1 hour to complete.
A comparative trial was performed against the standard culture method (ISO 11731) on both artificially and naturally contaminated water samples, for two matrices: chlorinated tap water and cooling tower water. Performance characteristics of the test used as screening with culture confirmation resulted in sensitivity, specificity, false positive, false negative, and efficiency of 96.6%, 100%, 0%, 3.4%, and 97.8%, respectively. The detection limit at the level under which the false negative rate increases to 50% (LOD50) was 93 colony forming units (CFU) in the volume examined for both tested matrices. The collaborative trial included twelve laboratories. Water samples spiked with certified reference materials were tested. In this study the coincidence level between the two methods was 95.8%.
Results demonstrate the applicability of this immunosensing technique to the rapid, simple, and efficient detection of Legionella pneumophila in water samples. This test is not based on microbial growth, so it could be used as a rapid screening technique for the detection of L. pneumophila in waters, maintaining the performance of conventional culture for isolation of the pathogen and related studies.
军团病是一种罕见的肺炎形式。如果在疾病早期做出诊断，在临床接触后，就可以获得必要的抗生素治疗。在临床接触之前，在危险环境中早期检测主要病原体嗜肺军团菌对于防止这种细菌的感染水平很重要。在这项研究中，一种基于磁免疫捕获和酶免疫测定相结合的快速检测水中嗜肺军团菌的定性试验与标准方法进行了比较，同时进行了对比和协作试验。该试验基于固定在磁性微球上的抗嗜肺军团菌抗体的使用。最终方案包括过滤、再悬浮和免疫磁捕获浓缩。整个检测过程不到 1 小时即可完成。
在人工和自然污染水样的对比试验中，与标准培养方法（ISO 11731）进行了比较，比较了两种基质：氯化自来水和冷却塔水。用作培养确认的筛选试验的性能特征导致灵敏度、特异性、假阳性、假阴性和效率分别为 96.6%、100%、0%、3.4%和 97.8%。在假阴性率增加到 50%（LOD50）的水平下的检测限（LOD50）在两个测试基质中分别为 93 个菌落形成单位（CFU）。协作试验包括 12 个实验室。用认证参考材料对水样进行了测试。在这项研究中，两种方法的符合率为 95.8%。
结果表明，该免疫传感技术可用于快速、简单、高效地检测水样中的嗜肺军团菌。该试验不基于微生物生长，因此可作为水中嗜肺军团菌的快速筛选技术，同时保持传统培养对病原体和相关研究的分离性能。
