Interspecies signaling affects virulence related morphological characteristics ofStreptococcus pyogenes M3.

Abstract

Streptococcus pyogenesis 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 ofS. pyogenesM3 strain was examined. N-(3-Oxododecanoyl)-L-homoserine lactone (Oxo-C12) increased the cell size as well as hydrophobicity ofS. 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 ofS. 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 inS. pyogenes M3.