Cell wall disruption, membrane damage, and decrease in the expression of Yrp1 virulence factor in Yersinia ruckeri by propolis ethanol extract

Fardin Sheydai; Amir Tukmechi

doi:10.18502/ijm.v15i4.13507

Fardin Sheydai Department of Microbiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
Amir Tukmechi Department of Microbiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran

DOI: https://doi.org/10.18502/ijm.v15i4.13507

Keywords: Animals; Yersinia ruckeri; Propolis; Virulence factor; Anti-bacterial agents; Gene expression

Abstract

Background and Objectives: Instead of antibiotics, propolis is a promising alternative for treating bacterial diseases. The aim of this study was to evaluate the effect of propolis ethanol extract (PEE) on Yersinia ruckeri (Y. ruckeri), a fish pathogen, by examining its impact on the cell wall, cytoplasmic membrane, and gene expression.

Materials and Methods: The effect of propolis on the bacterial cell wall, membrane, and DNA using scanning electron mi- croscopy (SEM) was investigated. Its effect on the NAD+/NADH ratio, reactive oxygen species (ROS) production, as well as the expression of a virulence factor (yrp1) was also determined.

Results: It was demonstrated that PEE has multiple antibacterial mechanisms against Y. ruckeri involving cell wall damage, membrane lysis, and a decrease in gene expression.

Conclusion: The obtained results indicated that the mode of propolis actio against Y. ruckeri is both structural and function- al, while others showed propolis only could inactivate bacteria in a structural way.