Phenotypic, genotypic characterisation and antimicrobial susceptibility determination of Lactococcus garvieae Strains

Abstract

In this study, phenotypic and genotypic features of 10 L. garvieae strains isolated from rainbow trout farms were examined with 3 reference strains (Spain, England and ATCC 43921) comperativly. Rapid 32 STREP and conventional microbiologic tests were used for determining phenotipic features of L. garvieae strains. Altough there are differences, in Rapid 32 STREP system, between strains in terms of beta-Glucuronidase, D-ribose, sorbitol, lactose, raffinose, alanyl-phenylalanyl-proline arylamidase, pyrrolidonyl arylamidase, hippurate hydrolysis, urease tests, all strains have been confirmed as L. garvieae by API web. In RAPD PCR analysis, in which ERIC 2 primer is used, L. garvieae isolates were genotyped within 3 separate clusters according to similarity coefficient index of 70%, and it was detected that a vast majority of isolates with Turkey-origin (8 isolates) belongs to predominant type LG1 genotype. In addition to this, antimicrobial tests of L. garvieae strains shows that there are resistance against gentamycin, neomycin, lincomycin, sulfamethoxazole-trimethoprim, oxytetracycline, erythromycin, amoxicillin, florfenicol and doxycycline, which are frequently used on fish in our country.