Comparison of antibacterial effect of ethanolic extract of Persian oak fruit Quercus brantii with common antibiotics used in the breeding of Oncorhynchus mykiss in vitro.

Plants can be considered as a suitable substitute for chemical drugs such as antibiotics due to less side effects. Quercus brantii fruit is one of the nutritional, rangeland andnative plants of Iran with antibacterial effects. The present study was performed by comparing the bactericidal effect of ethanolic extract of Quercus brantii fruit witherythromycin and enrofloxacin antibiotics against Streptococcus iniea isolated from rainbow trout. For this purpose, first treatments were designed with three replications at ۱۰۰, ۵۰ and ۲۵ μg / μl of extract . Then, to determine the antibacterial potency of the extracts, well diffusion method was used and the diameter of growth inhibition zone or bacterial MBC was measured by placing antibiotic disks of erythromycin and enrofloxacin in Müller Hinton culture medium containing bacteria. The collected data were statistically analyzed using one-way analysis of variance tests at a significance level of p <۰.۰۵. The results showed that ethanolic extract of Persian oak ۲۵ μg / μl had no effect on the studied bacteria. The highest diameter of growth inhibition zone was measured in ۱۰۰ and then ۵۰ μg / μl of Quercus brantii fruit extract, respectively, which showed a significant difference with other concentrations.

Keywords:

Antibiotics , Rainbow trout , Streptococcus , Quercus brantii