1. Lancefield group C Streptococcus dysgalactiae infection responsible for fish mortalities in Japan.
- Author
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Nomoto, R, Munasinghe, L I, Jin, D-H, Shimahara, Y, Yasuda, H, Nakamura, A, Misawa, N, Itami, T, and Yoshida, T
- Subjects
STREPTOCOCCUS dysgalactiae ,STREPTOCOCCUS ,FISHES ,MORTALITY ,LACTOCOCCUS - Abstract
A Lancefield serological group CStreptococcussp. was isolated from cultured amberjack,Seriola dumeriliRisso, and yellowtail,Seriola quinqueradiataTemminck and Schlegel, immunized withLactococcus garvieaecommercial vaccines in Japan. The isolated bacteria were Gram-positive cocci, auto-aggregating in saline, morphologically long chains in growth medium, catalase negative andα-haemolytic on blood agar. An almost complete gene sequence of the 16S rDNA of two isolates was determined and compared with that of bacterial strains in the database. The isolates were identified asStreptococcus dysgalactiaebased on the results of the 16S rDNA sequence, the bacteriological properties and the Lancefield serological grouping. Oligonucleotide primers specifically designed for the 16S–23S rDNA intergenic spacer region ofS. dysgalactiaeamplified a gene from all the fish isolates, as well as the type strainsα-haemolyticS. dysgalactiaesubsp.dysgalactiaeATCC430738 andβ-haemolyticS. dysgalactiaesubsp.equisimilisATCC35666, but not those ofS. equiATCC33398,Lactococcus garvieaeATCC43921 andL. garvieaeKG9408. The severe necrotic lesions of the caudal peduncle seen in experimentally infected fish were similar to those seen in naturally infected fish. [ABSTRACT FROM AUTHOR]
- Published
- 2004
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