Residue L193P Mutant of RpoS Affects Its Activity During Biofilm Formation in Salmonella Pullorum

Frontiers in Veterinary Science

Muhanad El Hag⁴  Daxin Peng⁴  Sujuan Chen⁴  Tao Qin⁴  Zheng Feng⁴  Yinping Du⁴ 

[1] College of Veterinary Medicine, Yangzhou University, Yangzhou, China;Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China;Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, China;Joint Laboratory Safety of International Cooperation of Agriculture and Agricultural-Products, Yangzhou University, Yangzhou, China;

关键词: Salmonella pullorum;    rpoS;    biofilm;    promoter;    mutation;   

DOI  :  10.3389/fvets.2020.571361

来源: DOAJ

【 摘 要 】

The role of alternative sigma factor RpoS in regulating biofilm formation may differ in various Salmonella Pullorum strains. In this study, the biofilm-forming ability of two Salmonella Pullorum strains S6702 and S11923-3 were compared. The biofilm forming ability of S11923-3 was much stronger than that of S6702. After knocking out the rpoS gene, S11923-3ΔrpoS had significantly reduced biofilm while S6702ΔrpoS demonstrated similar biofilm compared with each parent strain. The analysis of RpoS sequences indicated two amino acid substitutions (L193P and R293C) between S6702 and S11923-3 RpoS. A complementation study confirmed that the expression of S11923-3 RpoS rather than S6702 RpoS could restore the biofilm-forming ability of ΔrpoS strains and the L193P mutation contributed to the restoration of the biofilm-forming ability. Further study indicated that RpoS with the L193P mutant had significantly improved expression level and binding activity to RNAP and csgD gene promoter, which increased the efficacy of the csgD gene promoter and biofilm-forming ability. Therefore, the L193P mutation of RpoS is critical for stronger biofilm formation of Salmonella Pullorum.

【 授权许可】

Unknown