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首页> 外文期刊>Infection and immunity >Impact of M49, Mrp, Enn, and C5a Peptidase Proteins on Colonization of the Mouse Oral Mucosa by Streptococcus pyogenes
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Impact of M49, Mrp, Enn, and C5a Peptidase Proteins on Colonization of the Mouse Oral Mucosa by Streptococcus pyogenes

机译：M49，Mrp，Enn和C5a肽酶蛋白对化脓性链球菌对小鼠口腔黏膜定植的影响

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Resistance to phagocytosis is a hallmark of virulentStreptococcus pyogenes (group A streptococcus). Surface-bound C5a peptidase reduces recruitment of phagocytes to the site of infection, and hyaluronic acid capsules and/or the M protein limit the uptake of streptococci. In this study the relative impact of M and M-like proteins and the C5a peptidase on the virulence of a serotype M49 strain was assessed. The capacities of isogenic strains with an insertion mutation in emm49; with a deletion mutation in scpA49 (C5a peptidase gene); and with a deletion that removes all three M-like genes, mrp49,emm49, and enn49, to colonize mice and resist phagocytosis were compared. Experiments confirmed results obtained in an earlier study, which showed that the M49 protein was not required for in vitro resistance to phagocytosis, and also showed that the M protein was not required for colonization of mice. Failure to produce all three M-like proteins, M49, Mrp, and Enn49, significantly reduced the ability of these streptococci to resist phagocytosis in vitro but did not significantly alter the persistence of streptococci on the oral mucosa. In vitro experiments indicate that M+ streptococci are phagocytized by polymorphonuclear leukocytes that have been activated with phorbol-12-myristate 13-acetate or recombinant human C5a. This observation may explain the finding that expression of M49 protein is not essential for short-term colonization of the mouse oral mucosa.
机译：对吞噬作用的抵抗力是强毒化脓性链球菌（A群链球菌）的标志。表面结合的C5a肽酶可减少吞噬细胞向感染部位的募集，并且透明质酸胶囊和/或M蛋白限制了链球菌的摄取。在这项研究中，评估了M和M样蛋白以及C5a肽酶对M49型血清型毒力的相对影响。在 emm49 中有插入突变的同基因菌株的能力;在 scpA49 （C5a肽酶基因）中有缺失突变;并删除了删除所有三个M样基因的缺失，它们分别是 mrp49 ， emm49 和 enn49 ，以定居小鼠并抵抗吞噬作用。实验证实了较早研究中获得的结果，该结果表明M49蛋白不是体外抗吞噬作用所必需的，还表明M蛋白对于小鼠的定居不是必需的。未能产生所有三种M样蛋白，M49，Mrp和Enn49，显着降低了这些链球菌在体外抵抗吞噬作用的能力，但并未显着改变链球菌在口腔粘膜上的持久性。体外实验表明M + 链球菌被多形核白细胞吞噬，该细胞已被佛波12-肉豆蔻酸酯13-乙酸酯或重组人C5a激活。该观察结果可以解释以下发现：M49蛋白的表达对于小鼠口腔粘膜的短期定居不是必需的。

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