Publications by authors named "Syun-Ichirou Oshima"

The upsurge in havoc being wreaked by antibiotic-resistant bacteria has led to an urgent need for efficacious alternatives to antibiotics. This study assessed the antibacterial efficacy of two isobutyl cyanoacrylate nanoparticles (iBCA-NPs), D6O and NP30, against major bacterial pathogens of fish. In vivo tests on rainbow trout were preceded by in vitro tests of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).

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In this paper, we describe the draft genome sequence of Flavobacterium psychrophilum strain KTEN-1510, with genotype A/G-C. This strain was isolated in October 2015 from the gills of an ayu (Plecoglossus altivelis altivelis) in the upper Kagami River in central Kochi Prefecture on Shikoku Island, Japan.

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In Japan, the emergence of macrolide- and oxytetracycline-resistant strains of Nocardia seriolae has previously been reported. Here, we describe the draft genome sequence of N. seriolae strain U-1, isolated in 2011 from a diseased yellowtail in Kagoshima Prefecture.

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We report the draft genome sequence of Nocardia seriolae strain N-2927 (NBRC 110360), isolated from cultured yellowtail Seriola quinqueradiata. RAST annotation of the genome revealed 117 genes involved in the virulence, disease, and defense subsystem. Eleven of these genes were predicted as antibiotic resistance genes.

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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.

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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.

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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%.

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We performed a molecular cytogenetic investigation of the scleractinian coral Acropora solitaryensis, which is dominant in the temperate region of Japan (30-35°N). Molecular cytogenetic analysis, using fluorescence in situ hybridization (FISH), was carried out for karyotyping and gene mapping. We propose the karyotype of this coral (2n = 30) based on C-banding and FISH analyses.

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In Japan, a Mycobacterium marinum-like mycobacterium was isolated from the yellowtail, Seriola quinqueradiata. The species was identified as M. marinum by a commercial mycobacterial DNA-DNA hybridization kit.

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Megalocytivirus infections cause serious mass mortality in marine fish in East and Southeast Asian countries. In this study the immunogenicity of crude subunit vaccines against infection by the Megalocytivirus RSIV was investigated. Three capsid proteins, 18R, 351R and a major capsid protein, were selected for use as crude subunit vaccines.

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Megalocytivirus is causing economically serious mass mortality by infecting fish in and around the Pacific region of Asia. The recent emergence of many new iridoviruses has drawn attention to the marked taxonomic variation within this virus family. Most studies of these viruses have not included extensive study of these emergent species.

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Edwardsiella tarda glyceraldehyde-3-phosphate dehydrogenase (GAPDH) may be an effective vaccine candidate against infection by E. tarda in Japanese flounder Paralichthys olivaceus. The GAPDH of E.

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Yellowtail ascites virus (YTAV) is the causative agent of ascites and deformity in fish and causes serious losses to the fish-farming industry of yellowtail fry and fingerling Seriola quinqueradiata in Japan. In 2006, cultured yellowtail died from ascites in Kochi, Japan. We isolated and characterized a virus from the diseased fish.

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Red sea bream iridovirus (RSIV) is a causative agent of red sea bream iridoviral disease (RSIVD) in marine fish species in Japan. Fibroblast cells were developed from a tail fin of red sea bream, Pagrus major, and then underwent single cell cloning. The successful cloned cells were named CRF-1 cells.

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Flavobacterium psychrophilum is the causative agent of bacterial cold water disease (BCWD) and rainbow trout (Oncorhynchus mykiss) fry syndrome (RTFS). Logarithmic phase formalin-killed cells (FKC) of F. psychrophilum induced immunity to BCWD in ayu (Plecoglossus altivelis) by using an oral administration.

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Flavobacterium psychrophilum infection in salmonid fish, known as rainbow trout fry syndrome (RTFS) or bacterial coldwater disease (BCWD), is widespread in fish farms and natural waters. Despite many studies in which attempts at infection were made, an adequate method of infection has not yet been established. In this study, we evaluated a bath infection method in which we used bacteria at different stages of growth in the infection of rainbow trout Oncorhynchus mykiss.

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Marine birnavirus (MABV) is a member of the genus Aquabirnavirus of the family Birnaviridae. MABV is an unenveloped icosahedral virus about 60 nm in diameter with two genomes of double-stranded RNA. MABV adsorbed not only onto the cell surfaces of susceptible (CHSE-214 and RSBK-2) cells but also onto resistant (FHM and EPC) cells.

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Article Synopsis
  • Researchers identified GAPDH from Edwardsiella tarda as a potential vaccine candidate due to its effectiveness against infections.
  • The study involved sequencing the gene encoding GAPDH and producing it in large amounts using E. coli.
  • Immunizing Japanese flounder with recombinant GAPDH demonstrated significant protection against E. tarda, supporting its use in vaccine development.
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Article Synopsis
  • Real-time reverse transcription (RT)-PCR successfully detects and quantifies aquatic birnaviruses (ABVs) in fish tissue and seawater samples, specifically identifying marine birnavirus (MABV) RNA.
  • Monitoring the MABV strain Y-6 with this method revealed replication patterns after infection, demonstrating its effectiveness in studying virus behavior.
  • The technique proved reliable in detecting ABVs across various fish species, highlighting its potential for understanding viral infections in aquatic animal breeding environments.
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Infectious pancreatic necrosis virus (IPNV), a member of the genus Aquabirnavirus and family Birnaviridae, is an unenveloped icosahedral virus with two segments of double-stranded RNA. IPNV causes acute infection in salmonid fry and fingerlings with high mortality. However, this mortality is low as the age increases and survivors become IPNV-carrier fish.

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An effective vaccine against Edwardsiella tarda has not been reported, one of main reasons is the variation in its serotypes. This study aimed to develop an effective vaccine against different serotypes of E. tarda.

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Red sea bream iridovirus (RSIV) of the Iridoviridae family is a causative agent of lethal infections in many cultured marine fish species in southwestern Japan. RSIV-induced apoptosis was divided as follows: (1). cell shrinkage and rounding at the early apoptotic stage, (2).

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Article Synopsis
  • Researchers developed a vaccination method for bacterial coldwater disease (BCWD) in ayu fish (Plecoglossus altivelis) by using formalin-killed cells (FKCs) of Flavobacterium psychrophilum.
  • The FKC was administered orally at a dose of 0.1-0.2 g/kg body weight to juvenile ayu for either two weeks continuously or five days within that period.
  • The vaccinated fish showed significantly higher survival rates after being subjected to immersion challenges compared to control groups, demonstrating the effectiveness of oral vaccination against BCWD.
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Marine birnavirus (MABV), a member of the genus Aquabirnavirus, family Birnaviridae, is an unenveloped icosahedral virus with two genomes of double-stranded RNA. The mechanisms of MABV adsorption and penetration are still undetermined. This work examined MABV infection in susceptible and resistant fish cell lines.

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Bacterial cold water disease in the ayu Plecoglossus altivelis caused by Flavobacterium psychrophilum is a serious problem in the Japanese freshwater culture industry. The distribution and activity of this bacterium on the body surface of the ayu in the infection process was investigated. The survival of F.

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