Prevalence and characteristics of Cyprinid herpesvirus 3 (CyHV-3) infection in common carp (Cyprinus carpio L.) inhabiting three rivers in Kochi Prefecture, Japan.

Cyprinid herpesvirus 3 (CyHV-3) causes lethal disease in common and koi carp. Mortality by CyHV-3 disease has not been reported since 2011 in Kochi Prefecture, Japan. Here, we detected and quantified CyHV-3 in common carp inhabiting three rivers in the prefecture to examine if the carp are carriers of CyHV-3 as a source of infection. CyHV-3 DNA was detected in 16.7% (12/72) of brain samples in Kagami River, 3.9% (3/76) of brain and 3.9% (3/76) of gill samples in Monobe River, and 5.1% (4/79) of brain and 1.3% (1/79) of gill samples in Wajiki River. CyHV-3 genotypes identified in the 23 samples were classified as the J genotype A1 that has been found in Japan. The CyHV-3 DNA load did not differ statistically between sampling months, indicating that CyHV-3 has been silent in common carp, unlike Lake Biwa where the annual reactivation occurs in spring. Taken together, our results represented definitive evidence that seasonal changes in water temperature do not affect CyHV-3 activity in carp. Considering that infectious virus was not isolated from CyHV-3 DNA-positive samples, it was suggested that CyHV-3 establishes a latent infection in carp populations inhabiting Kagami River, Monobe River and Wajiki River. Further, the presence of circular or concatameric CyHV-3 DNA was detected in five of 23 CyHV-3 DNA-positive samples. Common carp inhabiting Lake Biwa were reported previously to harbor linear but not circular CyHV-3 DNA. This difference suggested that the CyHV-3 genome may be circularized for long-term maintenance without active viral replication.

Draft Genome Sequence of Streptococcus parauberis Strain SK-417, Isolated from Diseased Sebastes ventricosus in Kagoshima, Japan.

Streptococcus parauberis strain SK-417 was isolated from the brain of a diseased Sebastes ventricosus, collected from an aquaculture farm in April 2013 in Kagoshima Prefecture, Japan. The draft genome sequence, obtained with a 454 GS Junior sequencing system, consists of 33 large contigs of >500 bp, totaling 1,958,836 bp, and has a G+C content of 35.4%.

Draft Genome Sequences of Two Genetic Variant Strains of Edwardsiella piscicida, JF1305 and RSB1309, Isolated from Olive Flounder (Paralichythys olivaceus) and Red Sea Bream (Pagrus major) Cultured in Japan, Respectively.

Edwardsiella piscicida is a new species discovered within the group of organisms traditionally classified as Edwardsiella tarda. We present draft genome sequences of two variant strains of E. piscicida, JF1305 and RSB1309. Differences in protein-coding sequence between these isolates are associated with virulence, disease, and defense, suggesting differences in pathogenicity.