Major outbreak of toxic shock-like syndrome caused by Streptococcus mitis
Major outbreak of toxic shock-like syndrome caused by Streptococcus mitis
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DOI：
10.1128/jcm.41.7.3051-3055.2003
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发表时间：
2003-07-01
影响因子：
9.4
通讯作者：
Tang, YW
中科院分区：
文献类型：
--
作者：
Lu, HZ;Weng, XH;Tang, YW
由草绿色链球菌引起的严重疾病很少发生在免疫功能正常的宿主中。 1990年12月至1991年5月期间，中国江苏省长三角地区有数千名患者患猩红热样咽炎。在相同的季节性情况下，随后几年发生的病例较少。大约一半的病例出现链球菌中毒性休克样综合征（TSLS）特征的并发症。咽喉培养发现α-溶血性链球菌主要生长。海安市人民医院收治的所有病例均已排查完毕。收集临床标本，审查医疗记录，对细菌分离株进行表型鉴定，并通过 16S rRNA 基因测序和脉冲场凝胶电泳 (PFGE) 进行分析。通过提取、硫酸铵沉淀和快速蛋白质液相色谱从培养物上清液中纯化蛋白质。通过皮下接种家兔测定蛋白质成分的生物活性。总共研究了 178 例非乙型溶血性链球菌猩红热样咽炎病例。在 111 名患者中，有 88 名（79.3%）的口咽拭子培养物培养出了形态相同的 α 溶血性链球菌。培养物上清液中的一种蛋白质对家兔具有致热性，对脾细胞具有促有丝分裂作用，并增强家兔对内毒素攻击的敏感性。该 34 kDa 蛋白质的 N 端氨基酸序列与已知的链球菌致热外毒素没有同源性。根据生化和 16S rRNA 序列分析，该生物体被鉴定为轻链球菌。 1990 年至 1995 年的代表性爆发分离株表现出相同的 PFGE 模式。中国东南部的这次 TSLS 爆发是由轻链球菌的产毒克隆引起的。一种明显新颖的毒素可能解释了这种生物体异常的毒力。
Severe illness caused by viridans streptococci rarely occurs in immunocompetent hosts. Between December 1990 and May 1991, thousands of patients in the YangZi River Delta area of Jiangsu Province, China, suffered from scarlet fever-like pharyngitis. Fewer cases occurred in subsequent years with the same seasonality. Approximately half of the cases developed complications characteristic of streptococcal toxic shock-like syndrome (TSLS). Throat cultures yielded predominant growth of alpha-hemolytic streptococci. All cases admitted to Haian People's Hospital were investigated. Clinical specimens were collected, medical records were reviewed, and bacterial isolates were identified phenotypically and analyzed by 16S rRNA gene sequencing and pulsed-field gel electrophoresis (PFGE). Proteins were purified from culture supernatants by extraction, ammonium sulfate precipitation, and fast-protein liquid chromatography. Biological activities of protein components were determined by subcutaneous inoculation into rabbits. A total of 178 cases of non-betahemolytic streptococcal scarlet fever-like pharyngitis were studied. In 88 (79.3%) of 111 patients, oropharyngeal swab cultures grew morphologically identical alpha-hemolytic streptococci. A protein in culture supernatants was pyrogenic in rabbits, was mitogenic for splenocytes, and enhanced rabbit susceptibility to endotoxin challenge. The N-terminal amino acid sequence of this 34-kDa protein showed no homology with known Streptococcus pyrogenic exotoxins. The organism was identified as Streptococcus mitis based on biochemical and 16S rRNA sequence analyses. Representative outbreak isolates from 1990 to 1995 displayed identical PFGE patterns. This TSLS outbreak in southeastern China was caused by a toxigenic clone of S. mitis. An apparently novel toxin may explain the unusual virulence of this organism.