Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA.
Fluxergy, Irvine, CA.
J Equine Vet Sci. 2023 Jul;126:104538. doi: 10.1016/j.jevs.2023.104538. Epub 2023 May 5.
The introduction of microfluidic card technology has opened the field for rapid point-of-care (POC) molecular assays, including fecal and environmental Salmonella spp. testing. The purpose of this study was to evaluate a novel POC PCR assay for the detection of Salmonella spp. in feces and environmental samples. A total of 143 fecal samples and 132 environmental samples were collected for POC PCR Salmonella spp. testing as well as qPCR testing. Each sample was inoculated into selenite broth and incubated for 18 to 24 hours. For the POC PCR assay, 14 μl of selenite broth were mixed with 126 μl of PCR reaction mix and pipetted into a microfluidic test card targeting the invA and ttrC gene of Salmonella enterica. For qPCR analysis, 200 µl of the selenite broth were processed for DNA purification and Salmonella spp. testing targeting the invA gene. The overall agreement between the POC PCR Salmonella spp. assay and qPCR assay was 88.1% for feces and 97.0% for environmental samples. Strong agreement and short turn-around-time make the POC device the first molecular diagnostic platform allowing detection of Salmonella spp. in a hospital setting without having to ship out samples to a veterinary diagnostic laboratory. The availability of an accurate POC PCR assay for the detection of Salmonella spp. will enhance the diagnostic capability of equine veterinarians to timely support a diagnosis of salmonellosis and also monitor the environment in order to reduce the risk of nosocomial infections.
微流控卡技术的引入为快速即时检测（POC）分子检测开辟了领域，包括粪便和环境中的沙门氏菌属检测。本研究旨在评估一种用于检测粪便和环境样本中沙门氏菌属的新型 POC PCR 检测方法。共采集了 143 份粪便样本和 132 份环境样本，用于 POC PCR 沙门氏菌属检测和 qPCR 检测。每个样本均接种到亚硒酸盐肉汤中，培养 18 至 24 小时。对于 POC PCR 检测，将 14 μl 亚硒酸盐肉汤与 126 μl PCR 反应混合物混合，然后吸入微流控测试卡中，该测试卡针对沙门氏菌属的 invA 和 ttrC 基因。对于 qPCR 分析，200 μl 亚硒酸盐肉汤用于 DNA 纯化和针对 invA 基因的沙门氏菌属检测。POC PCR 沙门氏菌属检测与 qPCR 检测的总体一致性分别为粪便样本的 88.1%和环境样本的 97.0%。POC 设备具有强烈的一致性和短的周转时间，使其成为首个可在医院环境中检测沙门氏菌属的分子诊断平台，而无需将样本运送到兽医诊断实验室。用于检测沙门氏菌属的准确 POC PCR 检测方法的可用性将增强马兽医的诊断能力，以便及时支持沙门氏菌病的诊断，并监测环境，以降低医院感染的风险。
