Friedrich Schiller University Jena, Faculty of Biology and Pharmacy, D-07743 Jena, Germany, and University of Oklahoma Health Sciences Center, Department of Microbiology and Immunology, Oklahoma City, OK 73190.
Microbiol Spectr. 2019 Mar;7(2). doi: 10.1128/microbiolspec.GPP3-0002-2017.
Of the eight phylogenetic groups comprising the genus , Lancefield group C and G streptococci (GCS and GGS, resp.) occupy four of them, including the Pyogenic, Anginosus, and Mitis groups, and one Unnamed group so far. These organisms thrive as opportunistic commensals in both humans and animals but may also be associated with clinically serious infections, often resembling those due to their closest genetic relatives, the group A streptoccci (GAS). Advances in molecular genetics, taxonomic approaches and phylogenomic studies have led to the establishment of at least 12 species, several of which being subdivided into subspecies. This review summarizes these advances, citing 264 early and recent references. It focuses on the molecular structure and genetic regulation of clinically important proteins associated with the cell wall, cytoplasmic membrane and extracellular environment. The article also addresses the question of how, based on the current knowledge, basic research and translational medicine might proceed to further advance our understanding of these multifaceted organisms. Particular emphasis in this respect is placed on streptokinase as the protein determining the host specificity of infection and the Rsh-mediated stringent response with its potential for supporting bacterial survival under nutritional stress conditions.
在包含 Lancefield 组 C 和 G 链球菌（GCS 和 GGS，分别）的 8 个系统发育群中，有 4 个群包括化脓性、咽峡炎和温和群链球菌，以及一个尚未命名的群。这些生物体在人类和动物中作为机会性共生菌而茁壮成长，但也可能与临床严重感染有关，通常与它们最接近的遗传亲属，即 A 组链球菌（GAS）相似。分子遗传学、分类学方法和系统基因组学研究的进展导致至少确定了 12 个种，其中一些种又分为亚种。这篇综述总结了这些进展，引用了 264 篇早期和近期的参考文献。它重点介绍了与细胞壁、细胞质膜和细胞外环境相关的临床重要蛋白的分子结构和遗传调控。本文还探讨了基于目前的知识、基础研究和转化医学如何进一步推进我们对这些多面生物体的理解的问题。在这方面，特别强调了链激酶作为决定感染宿主特异性的蛋白，以及 Rsh 介导的严格反应，其具有在营养胁迫条件下支持细菌生存的潜力。
