Biomedical subjects

R Kusuda

Publications and source records attributed to R Kusuda.

7 recordsLinked to original sources

PubMed2001

G1 antigen: a cell-surface immunoprotective 96 kDa glycoprotein from the virulent fish pathogen Enterococcus seriolicida, its purification and characterization.

Strains of the fish pathogen Enterococcus seriolicida were identified as agglutinating and non-agglutinating, according to their reaction with anti-serum raised against type strain YT-3 (ATCC49156). The non-agglutinating strains are highly pathogenic in contrast to agglutinating strains. A 96 kDa immunoprotective glycoprotein G1 antigen from non-agglutinating Ent. seriolicida strain SS91-014 (N) was purified and characterized. The purification procedure entailed extraction of antigen by glass bead agitation, 80% (NH4)(2)SO4 precipitation, gel filtration and electroelution. An immunofluorescence microscopy study using monoclonal antibody M3A5 raised against G1 antigen revealed that G1 antigen is present only on the cell surface of non-agglutinating strains. Therefore, the G1 antigen of virulent Ent. seriolicida could be a potential candidate for protective vaccine against enterococcosis in fish.

Animals↗

PubMed1997

Development of DNA diagnostic methods for the detection of new fish iridoviral diseases.

A new disease of epidemic proportions caused by fish viruses within the Iridoviridae family inflicts serious damage on red sea breams (Pagrus major) and striped jack (Caranx delicatissimus) populations grown in aquacultures in Japan. A partial segment of the fish iridoviral DNA was directly amplified using the polymerase chain reaction (PCR) with synthetic primers designed from well conserved nucleotide sequences between the frog virus 3 (Ranavirus) and the silkworm iridescent virus type 6. The deduced amino acid sequence from the nucleotide sequence of the PCR fragment demonstrates a high correlation with a partial sequence from the frog virus 3. Using the PCR method with specific primers, we could detect three of four different known types of fish iridoviruses in diseased fishes. To construct more reliable detection methods specific for this viral family, DNA fragments which can specifically hybridize with all of the four known iridoviridae viral DNAs were screened from the genomic library of one iridoviridae strain. The hybridization assay, using a specific fragment which contains regions which are highly homologous with a characterized partial sequence from the frog virus 3, proved to be a reliable diagnostic tool for fish iridoviral diseases.

Animals↗

PubMed1997

Cross-reactivity of anti-yellowtail thymic lymphocyte monoclonal antibody (YeT-2) with lymphocytes from other fish species.

The monoclonal antibody YeT-2, generated in mice hyper-immunized with thymic lymphocytes of the yellowtail, Seriola quinqueradiata, reacts with the major population of peripheral blood lymphocytes, which might be putative T cells. In this study, we examined the cross-reactivity of YeT-2 with lymphocytes from various fish species. Flow cytometric analysis showed that YeT-2 reacts with 69.8% lymphocytes in the thymus, 89.7% in the peripheral blood, 87.5% in the spleen, and 59.7% in the head-kidney. Among the six fish species examined, only the red sea bream, Pagrus major, which is included in the same suborder Percoidei with the yellowtail, showed the presence of YeT-2 positive cells. Electron microscopic studies revealed that YeT-2 positive cells in the peripheral blood of the red sea bream were lymphocytes or unidentified leucocytes. Thymic lymphocytes of the red sea bream were also immunocytochemically stained with YeT-2. The molecular weight of the YeT-2 cross-reacting antigen on blood cells from the red sea bream was identical with that from the yellowtail, which was identified at approximately 115 kDa. These results suggest that the monoclonal antibody YeT-2 recognizes a conserved antigen on lymphocytes common to the red sea bream and yellowtail.

Animals↗

PubMed1996

Antigenicity and N-terminal amino acid sequence of a 35 kDa porin-like protein of Listonella (Vibrio) anguillarum: comparison among different serotypes and other bacterial species.

Listonella (Vibrio) anguillarum, an important fish pathogen, is divided into 10 serotypes according to O-antigens present on the outer membrane. However, the biochemical and immunological properties of porin proteins have not been reported. In this study, the antigenicity and N-terminal amino acid sequence of the 35 kDa porin-like-major outer membrane protein (Omp35La) were compared among different serotypes of L. anguillarum as well as other bacteria. In Western blotting analysis, antisera against Omp35La from strains of J-O-1, -2 and -3 serotypes could detect Omp35La, but not other proteins, in most L. anguillarum strains and isolated of the genera Vibrio and Photobacterium. This antigenicity of Omp35La is unrelated to the serotype and is conserved in related organisms. An N-terminal sequence showed identification with OmpF and OmpC of Escherichia coli and Salmonella typhimurium. However, this similarity was lower when compared to other human pathogens. Thus it was concluded that Omp35La does not contribute to the serotypes of L. anguillarum, although the N-terminal structure is well conserved among different serotypes.

Amino Acid Sequence↗

PubMed1994

Characteristics of porin-like major outer membrane proteins of Listonella anguillara serotypes J-O-1, -2 and -3.

Major outer membrane protein (MOMP) was prepared from fish pathogen Listonella anguillara. Triton X-100 treatment could extract the MOMP from the bacterium but not from Escherichia coli, suggesting loose association of the MOMP of L. anguillara to the membrane. Properties of purified MOMP from L. anguillara were similar to Omp C porin of E. coli. Similar antigenicity of the porin like-MOMP was found among different serotypes of L. anguillara, although the molecular sizes of the MOMP were different among the strains.

Antigens, Bacterial↗

PubMed1991

Enterococcus seriolicida sp. nov., a fish pathogen.

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 degrees 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).

Animals↗

PubMed1990

Lymphomyeloid cells, susceptibility to erythrodermatitis of carp and bacterial antigens.

Pronounced changes occur in the kidneys carp injected with extracellular product (ECP), lipopolysaccharide (LPS) of A. salmonicida subsp. salmonicida, Freund's complete adjuvant (FCA). ECP caused 50-70% decrease in macrophages and neutrophils, whereas blasts and lymphocyte-like cells increased FCA-elicited increased percentages of blasts and a left shift of neutrophils after LPS injection. After both ECP and FCA injections, the density of major leucocyte types and red blood cells (RBC) in the kidney decreased. LPS generally increased the density of leucocytes. Granulocytes were larger after LPS injection and smaller after FCA injection than control cells. Perhaps ECP eliminates those cells potentially capable of nonspecific defense and FCA stimulates their proliferation. LPS seemed to induce mainly polyclonal lymphocyte-like cell propagation and a reduced replenishment of other leucocytes. Challenge morbidity was 100% of ECP-injected groups, 54.3% of controls, 37.1% of LPS-injected fish and 11.4% of FCA-injected groups. Disease susceptibility may be correlated with availability and functional status of macrophages and neutrophils.

Aeromonas↗