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Biomedical subjects

Y Ichiman

Publications and source records attributed to Y Ichiman.

At least 37 records · Page 2Linked to original sources
PubMed1988

Cross protection between an encapsulated strain of Staphylococcus hyicus and encapsulated strains of Staphylococcus aureus.

Strain ST67P of Staphylococcus hyicus grew diffusely in regular serum-soft agar. With the addition of rabbit antisera prepared with Staph. aureus strains, Smith, NS58D or NS41D, capsular type A, B or C, respectively, the organisms converted to compact type growth. Mice immunized with heat-killed vaccine of strain ST67P showed significant resistance against either homologous or heterologous strains, Smith, NS58D and NS41D. Passive protective activities in rabbit antisera prepared with strains Smith, NS58D and NS41D were absorbed out with either homologous cell surface polysaccharide fraction or cell surface polysaccharide fraction extracted from strain ST67P. Well-defined large capsules were observed in ultra-thin sections treated with rabbit antiserum prepared with homologous strain conjugated with ferritin. Also, the capsule surrounded by ferritin granules was shown in ultra-thin sections treated with ferritin conjugated with antisera prepared with those heterologous strains although the capsular size was significantly smaller than those observed by homologous antiserum.

Animals↗
PubMed1988

Demonstration of capsule in a strain of Staphylococcus hyicus by an electron microscope.

A compact type variant designated as strain ST67V was isolated by a high-temperature subculture method from strain ST67P of Staphylococcus hyicus, which was a diffuse type in serum-soft agar. The parent strain was relatively virulent in mice and resisted ingestion by mouse peritoneal cells. The variant strain, however, was avirulent in mice and no antiphagocytic activity was observed in the peritoneal cavity. In ultra-thin sections of the organisms treated with anti-ST67P rabbit anti-serum conjugated with ferritin, the outermost layer of the cell wall of the parent strain was covered with a well-defined capsule while no capsule was shown in the variant strain.

Animals↗
PubMed1988

Possible common biological and immunological properties for detecting encapsulated strains of Staphylococcus epidermidis.

Twenty strains of capsular type II Staphylococcus epidermidis, determined by the method of Ichiman, were obtained from clinical specimens. Among them, 5, 5, and 10 strains were 4+, 3+, and 2+ in the intensities of their reactions against fluorescent antibody, respectively. Strains exhibiting 4+ and 3+ intensities were mouse virulent and phage nontypable, while 2+ strains were mouse avirulent and phage typable. When three strains randomly selected from each of the mouse-virulent and mouse-avirulent strains were compared in terms of their cell volume indices, all mouse-virulent strains had significantly higher indices (average, 1.86 times) than the mouse-avirulent strains. With intraperitoneal injection of the strains into mice, strains with higher cell volume indices resisted ingestion by peritoneal cells, while strains with low cell volume indices were sensitive to phagocytosis. When the capacity to absorb a definite amount of passive protective activity in rabbit antiserum prepared with capsular type II strains was compared among these strains, 10 to 20 mg of mouse-virulent strains was capable of completely absorbing the passive protective activity, whereas more than 80 mg of the cells was required for similar absorption by mouse-avirulent strains. In ultra-thin sections of three mouse-virulent strains stained with ferritin-conjugated rabbit antiserum, well-defined capsules were detected around cell walls; however, no capsule was seen around the walls of three mouse-avirulent strains.

Animals↗
PubMed1988

Positive reaction in mouse ligated intestinal loop assay with nonenterotoxigenic and nonhemolytic strains of Staphylococcus aureus.

Nonenterotoxigenic and nonhemolytic strains of Staphylococcus aureus exhibited a positive reaction in the mouse intestinal loop assay except for a strain negative for the egg yolk reaction. Edema and swelling in all positive loops, increased bacterial cell numbers within intestinal loops, and extremely close adhesion to or inclusion of numerous bacterial cells in HeLa cells after inoculation of the strains were observed. These results suggest a possible invasive ability of the strains.

Animals↗
PubMed1988

Cross protection between a strain of Staphylococcus epidermidis and eight other species of coagulase-negative staphylococci.

Passive protective activity of rabbit antiserum prepared by a representative capsular type II strain of Staphylococcus epidermidis in mice was absorbed out with homologous capsular type strains of S. simulans, S. cohnii, S. xylosus, S. hominis, S. capitis, S. hyicus, S. haemolyticus, and S. saprophyticus in addition to the homologous strain. The minimum amount of the strains required for absorption differed greatly, depending upon the strain. No absorption of the activity was shown with a strain of capsular type I and III of S. epidermidis, S. simulans, and S. cohnii, and a strain of capsular type III of S. hominis. These results suggest a possible capsular type specificity in the cross protection between strains of S. epidermidis and other species of coagulase-negative staphylococci.

Animals↗
PubMed1987

Immunostimulating cell surface substance from Staphylococcus epidermidis strain ATCC-31432 prevents metastatic lung colonization in Balb/c-mice.

The antineoplastic activity of cell surface substance from Staphylococcus epidermidis ATCC-31432 (CSS-subfraction 2) in mice and its influence on the activation of human leucocytes was studied. After in vitro incubation with CSS-subfraction 2, human polymorphonuclear leucocytes were evidently stimulated. In vivo (Balb/c-mice) intraperitoneal application of subfraction 2 of CSS induced a considerable splenomegaly and greatly increased IgM levels indicating a strong immuno-stimulating activity. In order to evaluate antineoplastic effects of CSS-subfraction 2, we used sarcoma L-1 cells (Balb/c-mouse origin) which cause heavy tumor colonization of the lung. After single systemic injection of subfraction 2 of CSS, the number of lung tumor-cell colonies drastically decreased. The combination of this immunomodulating therapy with a temporary anticoagulation resulted in a further reduction of tumor colonies in the lungs of Balb/c-mice.

Adjuvants, Immunologic↗
PubMed1987

Protective antibodies in human sera against encapsulated strains of Staphylococcus epidermidis.

Passive protective antibodies in 100 samples of normal human sera against challenge with three representative capsular type strains of Staphylococcus epidermidis in mice were examined. Six of them passively protected mice against capsular type I; 17 protected against capsular type II; one against capsular type III; and one against both capsular types I and II. The activities were sensitive to 2-mercaptoethanol and were absorbed out either with rabbit anti-human IgG serum, rabbit anti-human IgA serum or rabbit anti-human IgM serum. Also, the sera activities absorbed out with cell surface polysaccharide extracted from three representative capsular type strains. These results indicate that the protective activities were specifically related to three major immunoglobulins against the above cell surface polysaccharides.

Animals↗
PubMed1987

Cell surface antigen of encapsulated Staphylococcus epidermidis ATCC 31432.

The cell surface antigen (CSA) from encapsulated Staphylococcus epidermidis ATCC 31432 was isolated and fractionated by DEAE-Sephadex ion-exchange chromatography. It yielded a single precipitin line against rabbit antiserum and was composed of galactose, glucosamine, and two (so far) unidentified carbohydrates linked to a protein backbone. Glycerol could not be detected. In an experimental mouse infection, CSA showed some protective activities, enhancing the stimulation of granulocytes as well as the immunoglobulin M response. Apparently, CSA is different from teichoic acid.

Animals↗
PubMed1986

Passive protection by human sera in mice against challenge with strains of group B streptococci.

The passive protective activity of 100 human sera in mice challenged with strains of group B streptococci (GBS), types Ia, Ib, Ic, II and III, was investigated. The number of sera which offered protection against type strains III, II and Ib were 10, 6 and 1, respectively, while 5 sera gave protection against type strains Ia and Ic. The activity was 2-mercaptoethanol sensitive while anti-human IgG, IgA and IgM rabbit sera were capable of negating the protective activity. Furthermore, type antigens removed the protective activity, resulting in the reduction of the amounts of IgG, IgA and IgM in normal human serum. These findings suggest that the protective activity of human sera is related to specific immunoglobulins against type antigens of GBS.

Animals↗
PubMed1986

Possible induction of disseminated intravascular coagulation in the mouse by group B streptococcal clumping factor.

A hydrochloric acid extract, the clumping factor fraction, obtained from a clumping factor-positive strain of group B streptococci, was capable of killing mice by administration after injection of heat-killed cells of group B streptococci or Escherichia coli intravenously. In mice killed between 24 and 48 h later, fibrin thrombi were observed in the renal glomeruli, as well as in the heart, lung, liver, and pancreas. These findings suggest the possible induction of disseminated intravascular coagulation by these organisms in the mouse.

Animals↗
PubMed1985

Pseudodiffuse-type growth of a Staphylococcus aureus strain in serum-soft agar.

Strain MC31 of Staphylococcus aureus showed diffuse-type growth in regular serum-soft agar (SSA) (pH 7.2), but in alkaline SSA (pH 8.4) the type of growth was compact. The organisms were of extra low virulence in the mouse and were unencapsulated. Based on three properties, the growth type of the S. aureus strains in SSA was designated as pseudodiffuse type.

Agar↗
PubMed1985

[Studies on minimum antibiotic concentration of cephapirin against clinically isolated strain SMK-101 of Klebsiella pneumoniae].

Using strain SMK-101 of K. pneumoniae its nephelometric absorbencies, viable cell numbers and morphological changes were studied during the time course cultured in a broth medium containing cephapirin (CEPR), and following results were obtained. After 1 to 3 hours culture in the presence of varying concentration of the antibiotic, the absorbency increased in spite of without change in the viable cell number. Morphologically, elongation and swelling of central portion of the cells were observed though differences of the degree of these findings varied depending upon the concentration of the antibiotic. At the concentration higher than 1/4 MIC, indistinct structure was shown in cytoplasm. After 6 hours culture, 3 directions of absorbence curves, ascending, descending and no change, and 2 directions of viable cell numbers, decreasing and increasing were shown. As the morphological changes of the cells, filamentation, leaking of intracellular components were shown in rather upper concentration of the antibiotic. Fission was demonstrated around the end of cells cultured in rather lower concentration of the antibiotic. After 9 hours culture, absorbency and viable cell number were parallel. In this period, structural findings of cytoplasm became clear and fission was also demonstrated by light microscope except for the cells cultured in more than 1 MIC of the antibiotic. After 24 hours culture, both absorbency and viable cell number increased again and fission was observed in the cell which showed filamentation in 1 MIC of the antibiotic.

Cephalosporins↗
PubMed1985

[Studies on sub-MIC activities of beta-lactam antibiotics and aminoglycoside antibiotics against clinically isolated strain].

Sub-MIC range of 8 kinds of beta-lactam antibiotics and 3 kinds of aminoglycoside antibiotics against strain of Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa isolated from clinical source were determined by nephlometic method, and following results were obtained. When 10 strains of S. aureus tested to ampicillin (ABPC), hetacillin (IPABPC), mecillinam (MPC), cephalexin (CEX), cefotaxime (CTX), latamoxef (LMOX), cefatrizine (CFT), cephapirin (CEPR), gentamicin (GM), dibekacin (DKB) and amikacin (AMK), ratio of MIC to MAC were 36.8, 53.6, 156.8, 29.6, 61.6, 34.4, 50.0, 111.2, 9.2, 20.0 and 13.6, respectively. When 10 strains of K. pneumoniae tested to MPC, CEX, CTX, LMOX, CFT, CEPR, GM, DKB and AMK, ratio of MIC to MAC were 409.6, 10.4, 34.4, 123.2, 39.2, 167.2, 5.2, 5.6 and 13.2, respectively. When 10 strains of P. aeruginosa tested against CTX, LMOX, GM, DKB and AMK, ratio of MIC to MAC were 16.8, 38.4, 6.8, 3.2 and 10.4, respectively.

Aminoglycosides↗
PubMed1984

Applications of fluorescent antibody for detecting capsular substances in Staphylococcus epidermidis.

A fluorescent antibody technique was developed for the determination of the type of capsule of strains of Staphylococcus epidermidis. Many mouse virulent and avirulent strain populations were investigated. Of 300 fresh isolates of Staph. epidermidis, 27 were mouse virulent strains and of these 74.1% and 25.9% were mono- and polyvalent, respectively. The frequency of capsular type antigens I, II and III, produced by the 27 virulent strains was found to be 18.5%, 88.9% and 18.5%, the majority being capsular type II. In the mouse avirulent strains, capsular type antigen production was demonstrated in 263 out of 273 strains examined and mono- and polyvalent capsular types comprised 52.3% and 44.0%, respectively. Capsular type I, II, III strains and non-typable strains occurred at frequencies of 15.0%, 95.2%, 34.9% and 3.7% respectively, the majority of mouse avirulent strains also being capsular type II. These results indicate that a majority of ordinary Staph. epidermidis produced capsular type antigens although the capability is quantitatively different according to strain.

Animals↗