Arbutin interacts with Vibrio harveyi hemolysin to alleviate damage from associated infection

Abstract

Vibrio harveyi, an opportunistic pathogen, is a major causative agent of vibriosis in aquatic organisms. Many research conducted both domestically and internationally has revealed the significant multidrug resistance exhibited by V. harveyi. Among its important virulence factors, V. harveyi hemolysin (VHH) plays a crucial role in the infection process of this bacterium within the host. Due to the limitations of traditional antimicrobial drugs and the need to prevent bacterial resistance, alternative approaches are being explored worldwide. In this study, VHH was targeted, and through drug screening, it was discovered that arbutin, a plant glycoside, effectively inhibits the hemolytic activity of the VHH. The findings indicate that arbutin does not impede the growth of V. harveyi in vitro, nor does it affect the transcription of related virulence factors such as vhh and luxR. Instead, arbutin counteracts the hemolytic activity of VHH by directly binding to key amino acid residues, including Tyr227, Asn159, and Trp200, thereby influencing the function of the cytotoxic protein. In the context of V. harveyi infection, the presence of arbutin enhances cell survival in vitro and mitigates pathological damage to the gills and kidneys of experimental animals. The results show that arbutin, has the potential to be a promising anti-virulence therapy.