Deleting qseC downregulates virulence and promotes cross-protection in Pasteurella multocida

Veterinary Research

Philip R. Hardwidge¹  Pei Hu²  Yang Yang²  Tian Li²  Yuanyi Peng²  Fang He²  Pan Li²  Nengzhang Li²  Xiang Yuan²  Lixu Gao² 

[1]College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA

[2]College of Veterinary Medicine, Southwest University, 400716, Chongqing, China

关键词: Quorum sensing gene;    Deletion;    Virulence;    Vaccine;    Cross-protection;   

DOI  :  10.1186/s13567-021-01009-6

来源: Springer

【 摘 要 】

QseC, a histidine sensor kinase of the QseBC two-component system, acts as a global regulator of bacterial stress resistance, biofilm formation, and virulence. The function of QseC in some bacteria is well understood, but not in Pasteurella multocida. We found that deleting qseC in P. multocida serotype A:L3 significantly down-regulated bacterial virulence. The mutant had significantly reduced capsule production but increased resistance to oxidative stress and osmotic pressure. Deleting qseC led to a significant increase in qseB expression. Transcriptome sequencing analysis showed that 1245 genes were regulated by qseC, primarily those genes involved in capsule and LPS biosynthesis and export, biofilm formation, and iron uptake/utilization, as well as several immuno-protection related genes including ompA, ptfA, plpB, vacJ, and sodA. In addition to presenting strong immune protection against P. multocida serotypes A:L1 and A:L3 infection, live ΔqseC also exhibited protection against P. multocida serotype B:L2 and serotype F:L3 infection in a mouse model. The results indicate that QseC regulates capsular production and virulence in P. multocida. Furthermore, the qseC mutant can be used as an attenuated vaccine against P. multocida strains of multiple serotypes.

【 授权许可】

CC BY