cell wall disruption, membrane damage, and decrease in the expression of yrp1 virulence factor in yersinia ruckeri by propolis ethanol extract

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 microscopy (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 action against y. ruckeri is both structural and functional, while others showed propolis only could inactivate bacteria in a structural way.