AUTHOR=Gao Yuanyuan , Chen Zhongyu , Yao Wei , Li Daliang , Fu Xinmiao 

TITLE=Gentamicin Combined With Hypoionic Shock Rapidly Eradicates Aquaculture Bacteria in vitro and in vivo

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.641846

DOI=10.3389/fmicb.2021.641846

ISSN=1664-302X

ABSTRACT=Bacterial pathogens are a major etiology of aquatic animal infectious diseases. The abuse of antibiotics in the aquatic industry has led to the spread of antibiotic resistance. It is urgent to develop more effective and safer strategies to increase the efficacy and extend the life span of existing antibiotics in aquaculture. In this study, we show that stationary-phase cells of six aquaculture bacterial pathogens (i.e., Aeromonas hydrophila, Vibrio alginolyticus, Edwardsiella tarda, Streptococcus iniae, Vibrio harveyi and Vibrio fluvialis) could be rapidly killed when bacteria were immersed in gentamicin- or neomycin-containing, ion-free solutions for a few minutes. Such hypoionic shock treatment enhances the bacterial uptake of gentamicin in an ATP-dependent manner. Importantly, we demonstrate, as a proof of concept, that gentamicin under hypoionic shock conditions could effectively eradicate A. hydrophila in vivo in a skin infection model of zebrafish (Brachydanio rerio) such that infected fishes could be cured 100% by the combined treatment. Because pathogenic bacteria generally adhere and localize on the skin surface or intrude into the gills of fish, our sterilization strategy is of potential importance for bacterial infection control in aquaculture animals, especially for small-scale economic fish farming and ornamental fish farming. Besides, the combined treatment could be completed within 5 minutes in a relatively small volume of solution such that residues antibiotics might be potentially minimized in animals and the environment.