Partial sequencing of sodA gene and its application to identification of Streptococcus dysgalactiae subsp. dysgalactiae isolated from farmed fish.
OBJECTIVE
To investigate the difference between Lancefield group C Streptococcus dysgalactiae (GCSD) strains isolated from diseased fish and animals by sequencing and phylogenetic analysis of the sodA gene.


RESULTS
The sodA gene of Strep. dysgalactiae strains isolated from fish and animals were amplified and its nucleotide sequences were determined. Although 100% sequence identity was observed among fish GCSD strains, the determined sequences from animal isolates showed variations against fish isolate sequences. Thus, all fish GCSD strains were clearly separated from the GCSD strains of other origin by using phylogenetic tree analysis. In addition, the original primer set was designed based on the determined sequences for specifically amplify the sodA gene of fish GCSD strains. The primer set yield amplification products from only fish GCSD strains.


CONCLUSIONS
By sequencing analysis of the sodA gene, the genetic divergence between Strep. dysgalactiae strains isolated from fish and mammals was demonstrated. Moreover, an original oligonucletide primer set, which could simply detect the genotype of fish GCSD strains was designed.


CONCLUSIONS
This study shows that Strep. dysgalactiae isolated from diseased fish could be distinguished from conventional GCSD strains by the difference in the sequence of the sodA gene.
Nomoto
R
R
The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, Japan.
Kagawa
H
H
Yoshida
T
T
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004696:Endocarditis / Q000382:microbiology / Q000662:veterinary; D005399:Fishes / Q000382:microbiology*; D005784:Gene Amplification; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA / Q000379:methods*; D012689:Sequence Homology, Nucleic Acid; D013290:Streptococcal Infections / Q000382:microbiology / Q000662:veterinary*; D013291:Streptococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D013482:Superoxide Dismutase / Q000235:genetics*; D013552:Swine / Q000382:microbiology
D001426:Bacterial Proteins; D017931:DNA Primers; C095500:SodA protein, Bacteria; D013482:Superoxide Dismutase