High prevalence of Streptococcus suis serotype ۲ contamination in raw pork and edible organs from retail markets in Phayao, Thailand

Streptococcus suis (S. suis) is a Gram-positive bacterium that is causing public health concern worldwide, especially in Northern Thailand. In Phayao province, the cultural preference for consuming raw or undercooked pork has led to a persistent risk of severe human infections. This study aimed to investigate the prevalence and distribution of S. suis contamination in retail pork products sole in Phayao province. We reported the prevalence of S. suis contamination in raw pork samples, fresh pig blood and edible pork organ samples (livers, lungs, hearts, and pharynx) collected from retail markets in ۷ districts in Phayao province, Thailand between April to June ۲۰۲۵. From a total of ۲۰۰ samples, S. suis and S. suis serotypes ۱, ۲, ۱/۲ and ۱۴ were identified using the multiplex PCR method. The result revealed a high contamination rate, with ۱۱۴ (۵۷.۰ %) of the samples identified as S. suis; specifically, ۳ % were serotype ۲ and ۵۴ % comprised unknown serotypes. Among the S. suis-positive samples, serotype ۲ was identified at ۵.۳ % (۶/۱۱۴). Notably, serotypes ۱, ۱/۲, and ۱۴ were absent in this study. Analysis of sample types showed that the highest contamination rate of S. suis was found in the pharynx, while the lungs exhibited the highest prevalence of serotype ۲. These findings underscore the critical need for increased public awareness regarding the dangers of consuming uncooked pork and highlight the necessity for more stringent food safety policies and continuous monitoring within the pork supply chain to prevent future outbreaks.

کلیدواژه ها:

Food safety ، Swine pathogens ، microbial contamination ، Health risk