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K Otsuki

Publications and source records attributed to K Otsuki.

At least 109 records · Page 6Linked to original sources
PubMed1983

Ecological studies of Yersinia enterocolitica. I. Dissemination of Y. enterocolitica in pigs.

Pigs were examined on five farms for carrier status of Yersinia enterocolitica. Yersinia enterocolitica biovar 4, serovar 3, phagovar VIII was isolated consistently from the feces of fattening pigs on one farm and sporadically from those of similar pigs on the other farms and of sows on all five farms, during a one-year period of weekly surveys. Seasonal variation was not a feature of fattening pigs on a highly contaminated farm. In other pigs, however, the organisms were not isolated during the summer months. On a highly contaminated farm, the organisms were excreted in the feces of 8 to 15-week-old pigs within 1-3 weeks of entering pens which were thought to be contaminated with the organisms. On a detailed observation of natural infection of Y. enterocolitica in eight pigs, the organism appeared in the pigs' feces within 2-7 weeks of them being moved to a pen which had been washed thoroughly after becoming contaminated, by a previous group of pigs, with feces containing 10(5) viable organisms per g. Thus, Y. enterocolitica is apparently transmitted from infected feces or picked up from the floor of a contaminated pen, and the regular schedule of pig movement among the pens is an important factor in the spread of Y. enterocolitica within a piggery. Intestinal colonization continues for a long time and does not occur by re-infection. The organisms were not isolated from eight pigs at the time of slaughter, and their serum O-agglutinin titers were 1/40 or less. Thus, circulating antibody may not inhibit intestinal colonization by Y. enterocolitica.

Age Factors↗
PubMed1983

Growth temperature-dependent variation in the bacteriophage-inactivating capacity and antigenicity of Yersinia enterocolitica lipopolysaccharide.

Growth temperature affected the structure of Yersinia enterocolitica Ye 3827 lipopolysaccharide (LPS). Although Y. enterocolitica Ye 3827 synthesized smooth LPS when grown at a low temperature (25 degrees C), partial smooth-rough transition occurred when the bacteria were grown at the physiological temperature (37 degrees C). The structural alteration was detected by bacteriophage-inactivation assay and chemical and immunological analyses. LPS prepared from bacteria grown at 25 degrees C inactivated a number of bacteriophages that recognize the O-antigenic polysaccharide portion of LPS, whereas more than 3000 times the amount of LPS from bacteria grown at 37 degrees C was required for the same degree of inactivation. The antigenic determinant(s) responsible for the major reaction between 25 degrees C-LPS and anti-25 degree C-bacteria was located on the O-antigenic polysaccharide portion of LPS, but those responsible for the major reaction between 37 degrees C-LPS and anti-37 degrees C-bacteria were located on the R-core or inner portion of LPS.

Antigens, Bacterial↗
PubMed1983

Serological evidence that Yersinia enterocolitica lipopolysaccharide produced during growth in vivo resembles that produced during growth in vitro at 25 degrees C.

Partial smooth-rough transition was observed in 30 strains of Yersinia enterocolitica O:3 cultivated at 37 degrees C. Immunodiffusion and haemagglutination inhibition tests with eight patients' sera demonstrated that the immunogenicity of the lipopolysaccharide of Yersinia enterocolitica in vivo was similar to that of the bacteria grown in vitro at 25 degrees C.

Adolescent↗
PubMed1983

Isolation of Yersinia spp. from bovine feces.

Yersinia spp. were sought in 618 fecal samples from cows. Four strains of Yersinia enterocolitica, serotype O:12,26 (one), O:13,7 (two), and O:18 (one); seven strains of Yersinia kristensenii, serotype O:11,24 (five) and O:12,26 (two); and one strain of Yersinia pseudotuberculosis serotype IIB, were isolated. This is the first time that Y. pseudotuberculosis has been isolated from cows in Japan, and the isolation of serotype IIB of this organism from cows seems to be the first in the world.

Animals↗
PubMed1983

Homologous interference by avian infectious bronchitis virus, inhibition of plaque formation of the Beaudette-42 strain by mixed inoculation with the KH strain.

Inhibition of plaque formation by avian infectious bronchitis virus (IBV) Beaudette-42 (Be-42) strain occurred in chick kidney cells with the inoculation of the same cell culture with the KH strain of IBV. For the complete inhibition of approximately 10(2) plaque-forming units (pfu) of the Be-42 strain, at least 10(5) pfu of the KH strain was required. The KH strain would inhibit plaque formation by the Be-42 strain if used as long as six hours after the inoculation of the Be-42 strain. The inactivated KH strain did not inhibit the plaque formation of the Be-42 strain.

Animals↗
PubMed1982

Temperature-dependent variation in the synthesis of the receptor for Yersinia enterocolitica bacteriophage XI.

Growth temperature affected the synthesis of the receptor for Yersinia enterocolitica bacteriophage XI. The cell wall preparation from the cells grown at 25 degrees C inactivated the bacteriophage, whereas cell walls grown at 37 degrees C did not. The alkaline extraction was performed with 0.03 M sodium hydroxide. The alkaline extract from the 25 degrees C-grown cells required for 50% phage inactivation amounted to 10 micrograms, whereas the compound from the 37 degrees C-grown cells did not inactivate the bacteriophage. It was indicated by diethylaminoethyl cellulose column and Sephadex G-200 column chromatographic analyses that the receptor material was extracted as a sugar-protein complex by the alkaline treatment.

Adsorption↗
PubMed1982

Characteristics of Yersinia enterocolitica bacteriophages.

The characteristics of Yersinia enterocolitica bacteriophages were revealed. Phages I, IV, and VIII belonged to Bradley's morphological group A. The bacteriophages adsorbed to the cells grown at 25 degrees C but not to those grown at 37 degrees C. Phages I, IV, and VIII required 50, 80, and 100 times as much amount of the cell wall prepared from the cells grown at 37 degrees C as that from the cells grown at 25 degrees C for the same inactivation. Phage VIII was stable over the range of pH 6 to 11 and below 45 degrees C, whereas phages I and IV were extremely labile at higher temperatures (above 37 degrees C) and in basic medium.

Adsorption↗
PubMed1981

Plaque formation by avian infectious bronchitis virus in primary chick embryo fibroblast cells in the presence of trypsin.

Ten strains of avian infectious bronchitis virus (IBV) were titrated as plaque-forming units in primary chick embryo fibroblast cells. In the absence of trypsin, plaques were only formed by Beaudette-42 and Iowa-609 strains. When trypsin was incorporated in the overlay medium of cell monolayers, all the IBV strains tested produced plaques within 4 days after inoculation. Incorporation of 20-40 microgram of trypsin per ml of the overlay medium seemed to be suitable for plaque formation of IBV. A preliminary investigation was made of the mode of action of trypsin.

Animals↗
PubMed1981

Isolation of an Hswl Nav4 influenza virus from a tufted duck (Aythya fuligula) in Japan.

A hemagglutinating agent was isolated from a tufted duck captured in Lake Shinji, Shimane Prefecture, Japan, and identified as influenza A by double immunodiffusion tests with the antiserum to influenza A virus ribonucleoprotein. The hemagglutinin in the isolate was antigenically related to that of A/New Jersey/8/76 but was not identical with it. The neuraminidase antigen of this Hswl subtype was closely related to that of A/turkey/Ontario/6118/68 and was shown to be Nav4 subtype. After experimental infection of 5-week-old SPF-chickens with the isolate, virus was recovered from various organs including the brain, despite the absence of signs of disease.

Animals↗