Molecular study and determine the sensitivity of Lactococcus garvieae the causative agent of lactococosis in rainbow trout on essential oils

Authors
Milad Adel
Reza Safari
Amin Nematolahi
Vahideh Taghdosi
Abstract
Lactococcus garvieae is the one of the most causative agent of economic losses in fish farms in Iran. In this study, frequency of L. garvieae from 10 rainbow trout fish farms in Mazandaran Province was studied using biochemical tests and PCR. Then, Serial dilutions of essential oils of Artemisia annua L, Mentha piperita, Achillea wilhelmsii C. Koch and Bunium persicum was prepared to determine minimum bacteriocidal concentration (MBC) and minimum inhibitory concentration (MIC) of isolated bacteria. Also, inhibition zone diameter of bacteria were determined by disc diffusion method and compared to each other. The results indicated that fish from 7 out of 10 studied farms were infected to lactococosis and 38 isolates were identified as L. garvieae from the fish. The results also represented that essential oils of B. persicum, M. piperita and A.annua L showed good antibacterial activity on L. garvieae that comparable to streptomysin. Results of the present study demonstrated that mention essential oils after more studies could be a replaced than common industrial antibiotics to treatmente infections caused by L. garvieae.

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