ABSTRACT

Streptococcus pyogenes is a Gram-positive human-specific pathogen that asymptomatically colonizes the human respiratory tract. The factors affecting the colonization to the host is not clearly understood. Adherence of the pathogen to host epithelial cell is the initial step for a successful colonization process. In the host, bacteria live in a polymicrobial community; thus, the signaling mediated between the bacteria plays a significant role in the colonization of the pathogen to the host. Thus, the effect of acyl-homoserine lactone, secreted by Gram-negative bacteria on the adhesion properties of S. pyogenes M3 strain was examined. N-(3-Oxododecanoyl)-L-homoserine lactone (Oxo-C12) increased the cell size as well as hydrophobicity of S. pyogenes. qPCR data revealed that the expression of sagA and hasA was negatively affected by Oxo-C12. Moreover, Oxo-C12 leads to changes in the morphological characteristic of S. pyogenes, further promoting adherence to host epithelia and biofilm formation on abiotic surface. The study demonstrates the role of Oxo-C12 as a factor that can promote virulence in S. pyogenes M3.

中文翻译：

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种间信号影响化脓性链球菌 M3 毒力相关的形态学特征

摘要

化脓性链球菌 是一种革兰氏阳性人类特异性病原体，无症状地定植于人类呼吸道。影响宿主定植的因素尚不清楚。病原体对宿主上皮细胞的粘附是成功定植过程的第一步。在宿主中，细菌生活在一个多微生物群落中；因此，细菌之间介导的信号传导在病原体向宿主的定殖中起着重要作用。因此，检查了由革兰氏阴性菌分泌的酰基高丝氨酸内酯对化脓性链球菌 M3 菌株粘附特性的影响 。N-(3-Oxododecanoyl)-L-高丝氨酸内酯 (Oxo-C12) 增加了化脓链球菌的细胞大小和疏水 性. qPCR 数据显示sagA和hasA的表达受到 Oxo-C12 的负面影响。此外，Oxo-C12 导致化脓性链球菌形态特征的变化 ，进一步促进对宿主上皮的粘附和非生物表面生物膜的形成。该研究证明了 Oxo-C12 作为可以促进化脓性链球菌M3毒力的因子的作用 。