Identification of lactoccoccus garvieae from rainbow trout and investigation of susceptibility to antibiotics

Diseases in aquaculture are known as the most important factor for limiting production and trade. As known, it has been a rapid growth in aquaculture for over the last 20 years. During this rapid growth period, there has been an increase in bacterial, viral, fungal and parasitic illnesses together with environmental interaction. These disease factors are inseparable elements of the ecosystem largely affecting biodiversity and thus sustainable growth. Environmental factors causing stress along with high stocking density can bring about the emergence of epidemics and culture and transmission of these diseases to natural species through water exchange between cultural and natural environment. Lactococcus garvieae is an etiological factor of Lactococcosis in Rainbow trouts and is among the most important pathogenic Gram positive cocci species. In our research, it is aimed to determine the Lactococcosis encountered in culture Rainbow trouts via genotypic methods and put forth the antibiotic susceptibility of disease determinant bacterial strains. In this study, 100 samples of Rainbow trouts gathered from businesses in and around Aydın city managing culture fishing has been brought to Adnan Menderes University Veterinary Faculty Department of Microbiology Routine Diagnosis Laboratory through cold chain. Fish samples which are brought to the laboratory has been technically opened and by planting Tryptic Soy agar from their livers, hearts and kidneys, their Lactococcus garvieae strains have been isolated via genotypic methods. After the PCR process, Penicillin G, Florfenicol, Amoxicillin - Clavulonic acid, Ampicillin, Cefoperazone, Erythromycin, Methicillin, Gentamicin, Oxacillin and Cloxacillin has been used with disc diffusion method in order to determine the antibiotic susceptibility of the factors identified as Lactococcus garvieae. It's concluded that L. garvieae strains identified in the study are 90 % susceptable to Amoxicillin – Clavulanic acid, 65 % intermediate susceptable to Florfenicol and resistant to other antibiotics used.