Geographical comparison on different methods for identification of Streptococcus parauberis isolated from cultured olive flounder, Paralichthys olivaceus

Abstract

Non-hemolytic Streptococcus parauberis isolated from diseased olive flounder, Paralichthys olivaceus in the South coast of Korea were identified by physiological, biochemical and genetic analysis in order to define the different characteristics geographically. First, twelve strains of S. parauberis were isolated from catalase-negative gram-positive cocci by multiplex PCR assay. Phenotypic identifications were performed with commercially available kit (API 20 Strep and API ZYM system). Analysis of API profiles of the isolates showed that strains were identified as either of Lactococcus lactis, S. constellatus or S. uberis. Moreover, S. parauberis isolated from olive flounder differed from that of turbot (X89967) to the test of not Voges-Proskauer, arginine, hippurate, alkiline phosphatase and pyrroidonyl arylamidase but β-glucuronidase. All S. parauberis isolates were sensitive to florfenicol, ampicillin, ofloxacin and vancomycin but were resistant to oxolinic acid, flumequine, nalidixic acid and sulfisoxazol. However, the 16S rDNA sequences of the isolates showed 99% similarity to S. parauberis KCTC 3651 (AY584477) and a great homogenecity among the flounder isolates.