AUTHOR=He Lvqin , Dai Ke , Wen Xintian , Ding Lingqiang , Cao Sanjie , Huang Xiaobo , Wu Rui , Zhao Qin , Huang Yong , Yan Qigui , Ma Xiaoping , Han Xinfeng , Wen Yiping 

TITLE=QseC Mediates Osmotic Stress Resistance and Biofilm Formation in Haemophilus parasuis

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.00212

DOI=10.3389/fmicb.2018.00212

ISSN=1664-302X

ABSTRACT=<p><italic>Haemophilus parasuis</italic> is known as a commensal organism discovered in the upper respiratory tract of swine where the pathogenic bacteria survive in various adverse environmental stress. QseC, a histidine protein kinase of the two-component regulatory systems CheY/QseC, is involved in the environmental adaptation in bacteria. To investigate the role of QseC in coping with the adverse environment stresses and survive in the host, we constructed a <italic>qseC</italic> mutant of <italic>H. parasuis</italic> serovar 13 strain (Δ<italic>qseC</italic>), MY1902. In this study, we found that QseC was involved in stress tolerance of <italic>H. parasuis</italic>, by the Δ<italic>qseC</italic> exhibited a decreased resistance to osmotic pressure, oxidative stress, and heat shock. Moreover, the Δ<italic>qseC</italic> weakened the ability to take up iron and biofilm formation. We also found that the QseC participate in sensing the epinephrine in environment to regulate the density of <italic>H. parasuis</italic>.</p>