Combined effect of florfenicol with linalool via bath in combating Aeromonas hydrophila infection in silver catfish (Rhamdia quelen)

The phytochemical linalool has synergistic activity with florfenicol against Aeromonas hydrophila in an in vitro study. However, there is a lack of in vivo studies to confirm this finding. Therefore, the aim of this study was to evaluate the in vivo effect of the combination of florfenicol with linalool via bath against aeromonosis in silver catfish (Rhamdia quelen) and their responses in redox balance and histology of gills, liver, and caudal kidney. In a previous test, a survival curve of silver catfish infected with A. hydrophila and treated with different concentrations of florfenicol via bath was performed. Florfenicol via bath at low concentration (12 mg/L) was able to increase the survival of infected fish. In the main test, the combined effect of florfenicol with linalool was evaluated. Bath with both substances decreased thiobarbituric acid reactive substances - TBARS levels and prevented histological alterations in gills and liver of infected fish. However, the use of these substances via bath was not able to modify the changes observed in other parameters related to the redox balance of infected fish. There was still a satisfactory concentration of linalool 1 d after the bath. In general, the use of florfenicol with linalool would be an appropriate combination for treatment of fish aeromonosis.

Automated summary

The combination of florfenicol with linalool via bath showed promising results in treating aeromonosis in silver catfish, reducing oxidative stress and histological changes.