Li Junhong, Tu Bowen, Mao Xujian, Zhao Ying, Du Qiang, Wang Fengming, Chen Cong, Tang Hongbing, Ji Junmin, Yang Hongmei
Changzhou Center for Disease Control and Prevention, Jiangsu, 213000, China.
Changzhou Central Blood Station, No. 118 Yunhe Road, Zhonglou District, Changzhou City, 213012, Jiangsu Province, China.
J Health Popul Nutr. 2025 Jun 15;44(1):201. doi: 10.1186/s41043-025-00957-5.
Streptococcus dysgalactiae subsp. equisimilis (SDSE), a Gram-positive, beta-hemolytic group G Streptococcus, possesses virulence factors such as M protein, streptolysin O, streptolysin S, streptokinase, and hyaluronidase. This study reports a foodborne outbreak caused by SDSE infection recently occurred in China.
In April 2019, an acute tonsillitis outbreak involving 155 patients occurred in a company in Changzhou, Jiangsu Province, China. Epidemiological surveys and laboratory investigations were conducted to identify the cause.
All patients were clinically diagnosed with acute suppurative tonsillitis or acute pharyngitis. SDSE was identified as the causative pathogen, isolated form 81.4% (35/43) of patients, 12.5% (1/8) of canteen staff, and 33.3% (1/3) of tested food samples (fried meat). Multilocus sequence typing (MLST) and emm typing confirmed all isolates as ST98-stG480.0, suggesting contamination of fried meat by an SDSE-carrying canteen staff member as the source of the outbreak. The mean onset time was 45.8 h, with an SDSE prevalence rate of 27.2%.
This study is the first to report a foodborne outbreak caused by SDSE in Changzhou city since 2003. The identified strain, ST98-stG480.0, was exclusively associated with respiratory infections and exhibited no gastrointestinal symptoms. These findings underscore the importance of enhanced surveillance and in-depth investigation into the characteristics and public health implications of this strain.
马链球菌兽疫亚种（SDSE）是一种革兰氏阳性、β溶血的G群链球菌，具有M蛋白、链球菌溶血素O、链球菌溶血素S、链激酶和透明质酸酶等毒力因子。本研究报告了近期在中国发生的一起由SDSE感染引起的食源性疾病暴发。
2019年4月，中国江苏省常州市一家公司发生了一起涉及155名患者的急性扁桃体炎暴发。开展了流行病学调查和实验室检测以确定病因。
所有患者临床诊断为急性化脓性扁桃体炎或急性咽炎。SDSE被确定为病原体，从81.4%（35/43）的患者、12.5%（1/8）的食堂工作人员以及33.3%（1/3）的检测食品样本（炸肉）中分离得到。多位点序列分型（MLST）和emm分型证实所有分离株均为ST98-stG480.0，提示携带SDSE的食堂工作人员污染炸肉是此次暴发的源头。平均发病时间为45.8小时，SDSE患病率为27.2%。
本研究首次报告了自2003年以来常州市由SDSE引起的食源性疾病暴发。鉴定出的菌株ST98-stG480.0仅与呼吸道感染有关，未表现出胃肠道症状。这些发现强调了加强监测以及深入调查该菌株特征和公共卫生影响的重要性。
