Piscidin 4: Genetic expression and comparative immunolocalization in Nile tilapia (Oreochromis niloticus) following challenge using different local bacterial strains

Dev Comp Immunol. 2020 Nov:112:103777. doi: 10.1016/j.dci.2020.103777. Epub 2020 Jul 4.

Abstract

The antimicrobial activity of tilapia piscidin 4 (TP4) was determined in vitro against four bacterial strains, Aeromonas hydrophilla, Pseudomonas fluorescens, Streptococcus iniae and Vibrio anguillarum. Nile tilapia were infected with low and high doses of the tested pathogens; after 3, 6, 24 h and 7 days of the specific TP4 gene expression, tissue immunolocalization was also performed. Histopathological examination revealed septicaemia and necrosis of hemopoietic tissue for all of the tested bacteria. Immunolocalization showed abundance in S. iniae-infected fish tissues. Quantitative RT-PCR analysis revealed that high doses raised mRNA expression levels compared to low doses and expression levels increased in the infected fish, particularly after 24 h, indicating that TP4 exerts potent bactericidal activity against some fish pathogens and plays an essential role in fish immunity.

Keywords: Aeromonas hydrophilla; Oreochromis niloticus; Pseudomonas fluorescens; Streptococcus iniae; Tilapia piscidin 4; Vibrio anguillarum.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antimicrobial Cationic Peptides / genetics*
  • Antimicrobial Cationic Peptides / metabolism
  • Bacterial Infections / immunology*
  • Fish Diseases / immunology*
  • Fish Proteins / genetics*
  • Fish Proteins / metabolism
  • Organ Specificity
  • Tilapia / genetics*
  • Tilapia / immunology
  • Transcriptome
  • Up-Regulation

Substances

  • Antimicrobial Cationic Peptides
  • Fish Proteins
  • piscidin 4, striped bass