Eiamphungporn Warawan, Laohabutr Pattrathip, Kaewsai Noramon, Pornsuwan Sudarat, Yainoy Sakda, Chatupheeraphat Chawalit
Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, Thailand.
Department of Medical Technology and Clinical Pathology, Ban Pong Hospital, Ban Pong, Ratchaburi, Thailand.
Sci Rep. 2025 Mar 26;15(1):10442. doi: 10.1038/s41598-025-95480-2.
Streptococcus suis is a major pathogen in pigs, causing diseases like meningitis, septicemia, and pneumonia, and has become a serious zoonosis in humans, particularly in countries with intensive swine production. Human infections have risen significantly, especially in Thailand, where serotype 2 is most commonly associated with disease in both pigs and humans. Traditional methods of identifying S. suis and its serotypes, such as bacterial culture, biochemical testing, and agglutination tests, face challenges due to variability and limited antisera availability, leading to the need for alternative approaches. In this study, we developed a novel RPA-NALFIA assay targeting the recN and cps2J genes of S. suis serotype 2. This method demonstrated accurate identification without cross-reactivity among 28 other bacterial species, with a detection limit of 10 CFU/mL, comparable to PCR methods. Food safety concerns are heightened by the discovery of S. suis contamination in pork, a major infection route when consumed undercooked. Our surveillance in central Thailand revealed that 49.3% of pork samples were contaminated with S. suis, with serotype 2 detected in 2.6% of samples. The RPA-NALFIA method proved effective, showing 100% sensitivity and 97.5% specificity. This assay offers rapid, reliable detection suitable for point-of-care testing in resource-limited settings.
猪链球菌是猪的主要病原体，可引发脑膜炎、败血症和肺炎等疾病，并且已成为人类的一种严重人畜共患病，在集约化养猪的国家尤为如此。人类感染显著增加，特别是在泰国，2型血清型在猪和人类疾病中最为常见。传统的鉴定猪链球菌及其血清型的方法，如细菌培养、生化检测和凝集试验，由于变异性和抗血清供应有限而面临挑战，因此需要替代方法。在本研究中，我们开发了一种针对猪链球菌2型recN和cps2J基因的新型RPA-NALFIA检测方法。该方法在28种其他细菌物种中未出现交叉反应，鉴定准确，检测限为10 CFU/mL，与PCR方法相当。猪肉中发现猪链球菌污染加剧了食品安全问题，食用未煮熟的猪肉是主要感染途径。我们在泰国中部的监测显示，49.3%的猪肉样本被猪链球菌污染，2.6%的样本检测到2型血清型。RPA-NALFIA方法被证明是有效的，灵敏度为100%，特异性为97.5%。该检测方法提供了快速、可靠的检测，适用于资源有限环境下的即时检测。
