Frontiers in Cellular and Infection Microbiology (Mar 2018)

The CpxA/CpxR Two-Component System Affects Biofilm Formation and Virulence in Actinobacillus pleuropneumoniae

  • Huan Li,
  • Huan Li,
  • Huan Li,
  • Feng Liu,
  • Feng Liu,
  • Feng Liu,
  • Wei Peng,
  • Wei Peng,
  • Wei Peng,
  • Kang Yan,
  • Kang Yan,
  • Kang Yan,
  • Haixu Zhao,
  • Haixu Zhao,
  • Haixu Zhao,
  • Ting Liu,
  • Ting Liu,
  • Ting Liu,
  • Hui Cheng,
  • Hui Cheng,
  • Hui Cheng,
  • Peixi Chang,
  • Peixi Chang,
  • Peixi Chang,
  • Fangyan Yuan,
  • Huanchun Chen,
  • Huanchun Chen,
  • Huanchun Chen,
  • Weicheng Bei,
  • Weicheng Bei,
  • Weicheng Bei

DOI
https://doi.org/10.3389/fcimb.2018.00072
Journal volume & issue
Vol. 8

Abstract

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Gram-negative bacteria have evolved numerous two-component systems (TCSs) to cope with external environmental changes. The CpxA/CpxR TCS consisting of the kinase CpxA and the regulator CpxR, is known to be involved in the biofilm formation and virulence of Escherichia coli. However, the role of CpxA/CpxR remained unclear in Actinobacillus pleuropneumoniae, a bacterial pathogen that can cause porcine contagious pleuropneumonia (PCP). In this report, we show that CpxA/CpxR contributes to the biofilm formation ability of A. pleuropneumoniae. Furthermore, we demonstrate that CpxA/CpxR plays an important role in the expression of several biofilm-related genes in A. pleuropneumoniae, such as rpoE and pgaC. Furthermore, The results of electrophoretic mobility shift assays (EMSAs) and DNase I footprinting analysis demonstrate that CpxR-P can regulate the expression of the pgaABCD operon through rpoE. In an experimental infection of mice, the animals infected with a cpxA/cpxR mutant exhibited delayed mortality and lower bacterial loads in the lung than those infected with the wildtype bacteria. In conclusion, these results indicate that the CpxA/CpxR TCS plays a contributing role in the biofilm formation and virulence of A. pleuropneumoniae.

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