链球素S和由G组链球菌产生的死菌感染
Deepali Humar1, Vivekananda Datta, Darrin J Bast
1Department of Medicine, Division of Infectious Diseases, University of California, San Diego 92093, USA. vnizet@ucsd.edu
Lancet (London, England)
|January 26, 2002
概括
贝塔-血液溶解型群 G 链球菌会导致严重的死软组织感染,类似于A组链球菌. 这是由于Streptolysin S (SLS) 外毒素,由共享基因操作子编码,有助于疾病的发病.
科学领域:
- 微生物学 微生物学
- 传染性疾病 传染性疾病
- 病变的发生和发病.
背景情况:
- 在三名患者中观察到严重的死性软组织感染 (NSTI).
- 感染是由β-血液溶解组G菌株造成的.
- 临床表现模仿了入侵性A组链球菌感染.
研究的目的:
- 确定G组链球菌中β-血液溶解活性的遗传基础.
- 为了调查G组Streptococcus beta-haemolysin在引起死感染中的作用.
- 为了比较G组和A组链球菌的致病机制.
主要方法:
- 杂交,DNA测序和向突变发生被用来识别负责β血解的基因.
- 补充研究证实了观察到的表型的遗传基础.
- 一个小鼠模型被用来评估在感染发展中对β-hemolysin的必要性.
主要成果:
- 集团G型链球菌具有A型链球菌的同类Streptococcus sag operon,编码链球菌素S (SLS).
- 萨格A基因的突变性取消了G组Streptococcus中的β-血液溶解活性.
- 被野生型突变菌株感染的小鼠发生了亡,而被SLS阴性突变菌株感染的小鼠没有.
结论:
- 贝塔-血液溶解型群 G 链球菌可以引起严重的死性软组织感染,在临床上无法与A组链球菌引起的感染区分.
- 通过功能性sag operon同类体编码的外毒素Streptolysin S (SLS) 负责G组Streptococcus中的β-血液溶解表型.
- SLS的表达是链球菌致死软组织感染的致病的一个关键因素.
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