Mig-14 may contribute to Salmonella enterica serovar Typhi resistance to polymyxin B by decreasing the permeability of the outer-membrane and promoting the formation of biofilm

Int J Med Microbiol. 2019 Mar;309(2):143-150. doi: 10.1016/j.ijmm.2019.01.001. Epub 2019 Jan 16.

Abstract

Mig-14 is essential for Salmonella enterica serovar Typhimurium (S. Typhimurium) resistance to antimicrobial peptides, including polymyxin B (PB). However, the molecular mechanism is as yet unknown. In this study, we demonstrated that mig-14 also played a crucial role in Salmonella enterica serovar Typhi (S. Typhi) resistance to PB. A series of genes associated with drug-resistance controlled by Mig-14 were identified in the presence of PB. Among which, ompF and ompC were up-regulated 8 and 6 folds in mig-14 mutant (Δmig-14) strains, respectively. Further, the deletion of ompF or/and ompC in Δmig-14 strains decreased their sensitivity to PB. Besides, the biofilm formation ability was reduced in Δmig-14 strains. Our results indicate that Mig-14 may contribute to PB resistance in S. Typhi by decreasing the permeability of the outer membrane and promoting biofilm formation.

Keywords: Antimicrobial resistance; Biofilm; S. Typhi; mig-14; ompC; ompF.

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / metabolism*
  • Biofilms / growth & development*
  • Cell Membrane / drug effects*
  • Drug Resistance, Bacterial*
  • Gene Deletion
  • Gene Expression Profiling
  • Gene Expression Regulation, Bacterial
  • Permeability
  • Polymyxin B / pharmacology*
  • Salmonella typhi / drug effects*
  • Salmonella typhi / genetics
  • Salmonella typhi / growth & development

Substances

  • Anti-Bacterial Agents
  • Bacterial Outer Membrane Proteins
  • Polymyxin B