Magnolol protects channel catfish from Aeromonas hydrophila infection via inhibiting the expression of aerolysin

Vet Microbiol. 2017 Nov:211:119-123. doi: 10.1016/j.vetmic.2017.10.005. Epub 2017 Oct 13.

Abstract

Aeromonas hydrophila is a common zoonotic pathogen which can cause several infections both in human and animals, particular aquatic animals. Antibiotics have been widely used in the treatment of A. hydrophila infections, however, the development of resistance has limited the treatment for these infections. There is an urgent need for novel agents and strategies against these infections. Aerolysin, a pore-forming toxin secreted by most pathogenic A. hydrophila, is known to contribute to the pathogenesis of A. hydrophila infections. Therefore, aerolysin has been identified as a potential target for drug discovery. In this paper, we found that magnolol, a natural compound without anti -A. hydrophila activity, could significantly inhibit the hemolytic activity of A. hydrophila culture supernatants by inhibiting the transcription of the aerolysin encoding gene aerA at low concentrations. Furthermore, the survival assay showed that magnolol could significantly reduce the mortality induced by A. hydrophila infection in channel catfish (Ictalurus punctatus). Taken together, these findings provide a potent agent against A. hydrophila infections.

Keywords: Hemolytic activity; Ictalurus punctatus; Pathogenicity; Virulence factor.

MeSH terms

  • Aeromonas hydrophila / drug effects*
  • Aeromonas hydrophila / pathogenicity
  • Animals
  • Bacterial Toxins / antagonists & inhibitors*
  • Biphenyl Compounds / chemistry
  • Biphenyl Compounds / pharmacology*
  • Fish Diseases / microbiology
  • Fish Diseases / prevention & control*
  • Gram-Negative Bacterial Infections / microbiology
  • Gram-Negative Bacterial Infections / prevention & control
  • Gram-Negative Bacterial Infections / veterinary*
  • Hemolysis / drug effects
  • Ictaluridae
  • Lignans / chemistry
  • Lignans / pharmacology*
  • Microbial Sensitivity Tests / veterinary
  • Pore Forming Cytotoxic Proteins / antagonists & inhibitors*
  • Virulence Factors

Substances

  • Bacterial Toxins
  • Biphenyl Compounds
  • Lignans
  • Pore Forming Cytotoxic Proteins
  • Virulence Factors
  • magnolol
  • aerolysin