AUTHOR=Wang Junping , Kong Decong , Zhang Shengwei , Jiang Hua , Zheng Yuling , Zang Yating , Hao Huaijie , Jiang Yongqiang 

TITLE=Interaction of fibrinogen and muramidase-released protein promotes the development of Streptococcus suis meningitis

JOURNAL=Frontiers in Microbiology

VOLUME=6

YEAR=2015

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2015.01001

DOI=10.3389/fmicb.2015.01001

ISSN=1664-302X

ABSTRACT=<p>Muramidase-released protein (MRP) is as an important virulence marker of <italic>Streptococcus suis (S. suis)</italic> serotype 2. Our previous works have shown that MRP can bind human fibrinogen (hFg); however, the function of this interaction in <italic>S. suis</italic> meningitis is not known. In this study, we found that the deletion of <italic>mrp</italic> significantly impairs the hFg-mediated adherence and traversal ability of <italic>S. suis</italic> across human cerebral microvascular endothelial cells (hCMEC/D3). Measurement of the permeability to Lucifer yellow <italic>in vitro</italic> and Evans blue extravasation <italic>in vivo</italic> show that the MRP-hFg interaction significantly increases the permeability of the blood–brain barrier (BBB). In the mouse meningitis model, wild type <italic>S. suis</italic> caused higher bacterial loads in the brain and more severe histopathological signs of meningitis than the <italic>mrp</italic> mutant at day 3 post-infection. Western blot analysis and immunofluorescence observations reveal that the MRP-hFg interaction can destroy the cell adherens junction protein p120-catenin of hCMEC/D3. These results indicate that the MRP-hFg interaction is important in the development of <italic>S. suis</italic> meningitis.</p>