Genotyping of Lactococcus garvieae strains from rainbow trout (Oncorhynchus mykiss) by 16s rDNA sequencing

In this study, eight Lactococcus garvieae isolates were characterized genotypically by PCR assay and DNA sequencing, and phenotypically by API 32 Strep System and conventional tests. Four of these were from diseased rainbow trout (Onchorhynchus mykiss) from Turkey, two from Spain, one from England and one from American Type Culture Collection 43921 (NCDO 2155) 16S rDNA amplification by original primers produced the expected amplicon of 612 bp. Although phenotypic characteristics of all strains were identical, the sequence analysis of 16s rDNA of five of the isolates including the reference strain revealed 100 % similarity / identical, whereas 3 strains, two of which were from Spain and one from Turkey (K1) were 99 % identical to L. garvieae compared to GenBank data (EMBL accession No: X54262). For determining epidemiological characteristics of L. garvieae DNA sequence analysis is a reliable and reproducable technique and it can be used as a substitute for RAPD, PFGE and ribotyping techniques.