Enterococcus seriolicida sp. nov., a Fish Pathogen

Abstract

The properties and taxonomic position of bacterial strains isolated from diseased specimens of cultured yellowtail and eels were examined. The isolates were gram-positive, short-chain-forming, catalase-negative, facultatively anaerobic cocci. Growth at 10 and 45°C in 6.5% NaCl (pH 9.6) with 40% bile and in 0.1% methylene blue-milk were both positive. The isolates could be distinguished from other species of the genus Enterococcus by several biochemical characteristics and by Lancefield's group antigen. Guanine-plus-cytosine content of DNA was 44 mol% as determined by the thermal melting temperature. The value for DNA-DNA hybridization was sufficiently low to warrant distinguishing this species from reported Enterococcus species. The name Enterococcus seriolicida is proposed. The type strain is YT-3 (=ATCC 49156).

Invasive Infections Due to a Fish Pathogen,Streptococcus iniae

“…[3][4][5][6][7][8] Outbreaks in Japan, Taiwan, Israel, and the United States have affected tilapia (oreochromis species), yellowtail ( Seriola quinqueradiata ), rainbow trout, and coho salmon. [3][4][5][6][7][8][9][10] Several bacteria, includ-S ing S. iniae, S. agalactiae, 6,11 and Lactococcus garvieae, 12,13 have been shown to cause meningoencephalitis in fish grown by aquaculture. S. iniae may colonize the surface of fish or cause invasive disease associated with 30 to 50 percent mortality in affected fishponds.…”

Drug Resistance and Broad Geographical Distribution of Identical R Plasmids of Pasteurella piscicida Isolated from Cultured Yellowtail in Japan

“…The extensive use has led to an increase in drug resistant strains among fish pathogens. A transferable R plasmid has been suggested to be responsible for the drug resistance of several fish pathogenic bacteria including Aeromonas hydrophila (1), Aeromonas salmonicida (4), Edwardsiella tarda (7), Enterococcus seriolicida (9,18), and Vibrio anguillarum (5). Thus, the spread of R plasmids encoding multiple drug resistance has made chemotherapy of bacterial infections difficult in many fish farms (8).…”

Streptococcus australis sp. nov., a novel oral streptococcus.

“…DNA-DNA hybridization values were obtained under stringent (0n1i SSC) or relaxed (0n5i SSC) conditions as described previously (Willcox, 1996 ;Kusuda et al, 1991 …”