Laboratory evaluation of antifungal effect of extracts of thyme (Thymusvulgaris) and Origanum (Origanum valgare) on the isolated Saprolegniafungus from rainbow trout

Saprolegnia fungus diseases is common diseases on breeding and rearingworkshop, that involve the eggs, larvae , fish breeding and generating , and lead tocasualties among them .and in our country also this workshop spent a great costand work to fight this disease. So the aim of the present study is the Laboratoryevaluation of antifungal effect of extracts of thyme (Thymus vulgaris) andOriganum (Origanum valgare) on the isolated Saprolegnia fungus of the rainbowtrout.Methods:In ۲۰۱۲, to evaluate the antifungal effects of thyme and marjoram extract On thefungus Saprolegnia, we referred to the martyr Motahari research breeding andrearing workshop Center of Yasooj and of ۵۰ randomly rainbow trout fungalsamples of fins, gills and their skin were taken and on Subro- dextrose agarmedium was cultivated and was transferred to veterinary medicine of Kazeroonuniversity. Fungi grown are based on the identification key of Saprolegnia thatwere diagnosed and then in the environment of Sevi broth Trypton were recultured.Also anti fungal effect of herbal extracts on serial dilution method on thepipe was investigated to determine the minimum inhibitory concentration (MIC)and determining the minimum bacterial concentration (MBC).Results:The results showed that minimum inhibitory concentration of thyme extract on theconcentrations of ۴۰ percent, ۵۰ percent, ۶۰ percent, ۷۰ percent and ۸۰ percent wasrespectively ۱۶, ۱۶, ۸, ۴ and ۲ and the minimum inhibitory concentration (MIC) ofOriganum extracts on the concentrations of ۴۰ percent, ۵۰ percent, ۶۰ percent, ۷۰percent and ۸۰ percent was ۱۶, ۸, ۸, ۴ and ۲, respectively. The minimum lethalconcentration (MBC) of Thyme extract at a concentration of ۶۰ percent, ۷۰ percentand ۸۰ percent, was respectively, ۱۶, ۴ and ۴ and minimum lethal concentration(MBC)) of Origanum extract at a concentration of ۶۰ percent, ۷۰ percent and ۸۰percent, was respectively, ۱۶, ۸, ۸ .Discussion and conclusions:both the Origanum and Thyme extract have an effect on the Saprolegnia fungusand there is a significant relationship between the concentration of extract and theirimpact (۰۵/۰ ≥ P).

Keywords:

anti-fungal , thyme , Origanum , Saprolegnia fungus , rainbow trout.