Agroscope, Food Microbial Systems, Group Microbiological Safety of Foods of Animal Origin, 3003 Berne, Switzerland; Animal Physiology Group, ETH Zurich, Institute of Agricultural Sciences (IAS), 8092 Zurich, Switzerland.
Agroscope, Food Microbial Systems, Group Microbiological Safety of Foods of Animal Origin, 3003 Berne, Switzerland; Federal Food Safety and Veterinary Office, 3003 Berne, Switzerland.
J Dairy Sci. 2017 Oct;100(10):7834-7845. doi: 10.3168/jds.2017-12820. Epub 2017 Jul 26.
The specific and reliable diagnosis of mastitis pathogens is essential for successful sanitation programs. The aim of the present study was to develop and evaluate a new real-time quantitative PCR (qPCR) assay for the very sensitive and specific detection of Staphylococcus aureus genotype B in cow milk samples. This mastitis pathogen is contagious and particularly prevalent in Switzerland and other central European countries. The new test is based on a rapid preparation of bacteria, followed by DNA isolation and qPCR for a unique target gene coding for the adhesion-like bovine protein (adlb). The inclusivity of the new target gene was 97% and the exclusivity 98%, meaning that other genotypes and bacterial species could be excluded with high reliability. The limit of detection of the new assay was 235 staphylococcal cell equivalents/mL of culture. The new test shows high intra- and interassay repeatability. Results are available within 2 d after sampling, allowing farmers and veterinarians to apply sanitation measures immediately. Based on the results of a preliminary field study, the diagnostic sensitivity and specificity of the new qPCR assay are 99 and 100%, respectively. The new analytical procedure is straightforward and can be applied for routine diagnostics.
乳腺炎病原体的准确可靠诊断对于成功的卫生清洁方案至关重要。本研究旨在开发和评估一种新的实时定量 PCR（qPCR）检测方法，用于非常敏感和特异性地检测奶牛乳样中的 B 型金黄色葡萄球菌。这种乳腺炎病原体具有传染性，在瑞士和其他中欧国家尤为普遍。该新检测基于细菌的快速制备，随后进行 DNA 分离和针对编码类似黏附蛋白的独特靶基因（adlb）的 qPCR。新靶基因的包容性为 97%，排他性为 98%，这意味着可以高度可靠地排除其他基因型和细菌物种。该新检测方法的检测限为 235 个金黄色葡萄球菌细胞当量/mL 的培养物。新检测具有较高的内和间试验重复性。采样后 2 天内即可获得结果，使农民和兽医能够立即采取卫生措施。根据初步现场研究的结果，新 qPCR 检测方法的诊断灵敏度和特异性分别为 99%和 100%。新的分析程序简单直接，可用于常规诊断。
