Yukio Ohshima

The role of lectins and lipoteichoic acid in adherence of staphylococcus saprophyticus

Staphylococcus saprophyticus strains S 1 and S 35 demonstrated lectin like surface receptors specific for N-acetylgalactosamine (S 1) or N-acetylneuraminic acid (S 35). Adhesion assays with human uroepithelial cells together with blocking experiments with competitive carbohydrates suggested that specific attachment of S. saprophyticus to host cells is apparently mediated by lectins. Staphylococcal lipoteichoic acid (LTA) was also shown to interfere with S. saprophyticus adherence to human uroepithelial cells.

Platelet aggregation by group B streptococci.

Forty-six strains of group B streptococci (GBS), including various serotypes and non-serotypable strains, were tested for their ability to induce platelet aggregation in human platelet-rich plasma; four strains, all belonging to type III, showed a positive reaction. The characteristics of the reaction were investigated in these four positive strains. Aggregation was dependent on the ratio of bacteria to platelets, being maximal at a ratio of 4.3. Platelet aggregation was inhibited by EDTA (100% inhibition at 3.1 mM), indomethacin (100% inhibition at 10 mM), acetylsalicylic acid (93-100% inhibition at 5.0 mM) and quinacrine (100% inhibition at 0.25 mM). Thus the reaction was cation-dependent and required cyclooxygenase activity. Assays for cytosolic lactate dehydrogenase did not indicate platelet lysis. GBS induced the release of [3H]serotonin, which was maximal (68-78%) at 10 min after the reaction was started. Experiments with gel-filtered platelets suggested that GBS-induced platelet aggregation required both fibrinogen and heat-resistant (56 degrees C, 30 min) serum factors. Type-specific antisera prevented the platelet aggregation activity of heat-killed bacteria, but not of live bacteria. Trypsin digestion of the bacterial cells caused an almost complete loss of the platelet aggregation activity.

Intestinal Microflora of BALB/c-Mice and Function of Local Immune Cells

BALB/c-mice were treated for 7 days with oral nonabsorbable dosages of mezlocillin to achieve digestive tract decontamination. Such a procedure resulted in rapid eradication of most species of aerobic and anaerobic intestinal microflora. Various functions of peritoneal macrophages (e.g. chemiluminescence response, chemotactic motility, bactericidal and cytostatic ability) and lymphocyte proliferation were decreased in decontaminated animals as compared to non-treated controls.

Activation of mononuclear immune cells in response to staphylococcal lipoteichoic acid

The goal of the present study was to evaluate the influence of staphylococcal lipoteichoic acid (LTA) on the activation of mononuclear immune cells. A murine tumor necrosis-like factor (TNF-like) was induced in the sera of CD-1 mice which had been primed with heat/formalin-inactivated Propionibacterium avidum KP-40 and subsequently exposed to LTA extracted from Staphylococcus saprophyticus strain S 1. Monoclonal antibody against murine TNF (anti-TNF) significantly inhibited the cytostatic activity of mice sera against transformed L-929 cells. Freshly isolated lymphocytes did not display interleukin 2 (Il-2) receptors, but receptors were expressed on Con A incubated cells and in significantly higher numbers after coexposure to staphylococcal LTA in vitro. Since the induction of TNF (macrophages) and Il-2 receptors (lymphocytes) represent stimulation of the mononuclear immune system, staphylococcal LTA may be considered to be an immunomodifier.

Biological Properties of Staphylococcal Lipoteichoic Acid and Related Macromolecules

Lipoteichoic acids (LTAs) and related macromolecules (e.g. cell surface substance, CSS; cell surface antigen, CSA; cell surface complex, CSC) are a group of phosphate-containing polymers associated with the cell walls of Gram-positive bacteria (32). They may be considered as surface-reactive antigens (immunogens, biological response modyfiers) as well as membrane components which mediate the attachment of certain bacteria (S. saprophyticus, S. aureus, group A streptococci) to host cell tissues.

Lectins: Mediators of Adhesion for Bacteria In Infectious Diseases and for Tumor Cells in Metastasis

Adhesion of bacteria and adhesion of tumor cells have much in common, especially the participation of lectins in this process. In the future it might be possible to inhibit the metastatic process into the liver (e.g. during surgical operations of malignant tumors) and bacterial adherence to mucosal linings or plastic devices by blocking of adhesion molecules (lectins) with appropriate glycoconjugates. Initial clinical trials are very promising.

Platelet Aggregation Induced by Strains of Various Species of Coagulase-Negative Staphylococci

Major species of coagulase‐negative staphylococci (CNS) were tested for their ability to induce platelet aggregation in rabbit platelet‐rich plasma (PRP). Among 11 species of CNS tested, a majority of the strains of 10 species of CNS (S. epidermidis, S. simulans, S. capitis, S. hyicus, S. sciuri, S. cohnii, S. xylosus, S. hominis, S. haemolyticus, S. warneri) caused induction of the platelet aggregation and serotonin release, while S. saprophyticus did not show such activity. The addition of aspirin (10 mM) or quinacrine (1 mM) to PRP resulted in no remarkable effect on the platelet aggregation induced by these strains and it was shown that the platelet aggregation did not require arachidonate pathways. Complement system components were shown to be one of the plasma factors required for platelet aggregation by ten strains of each species of CNS. The bacterial substance participating in the platelet aggregation by ten species of CNS tested was indicated to be heat‐stable and trypsin‐resistant, while the activity of a strain of S. epidermidis was susceptible to trypsin.

Studies on Fungal Polysaccharides : The Immunological Determinant of the Serologically Active Substances from Absidia cylindrospora, Mucor hiemalis and Rhizopus nigricans

Summary: Six manno-oligosaccharides were isolated from the partial acid hydrolysate of pronase-treated extracellular glycan (pt-ACE-11) of Absidia cylindrospor by gel filtration on Bio Gel P-2 and descending paper chromatography. The pentasaccharide and the higher molecular weight oligosaccharides significantly inhibited the precipitation reaction of intracellular glycans from Absidia cylindrospora (ACI-B), Mucor hiemalis (MhI-B) and Rhizopus nigricans (RnI-B) with anti-ACE serum. Structural analysis showed that these six oligosaccharides were composed of linear (1·6)-α-linked mannopyranosyl residues.

Characterisation of fucomannopeptide and mannoprotein from Absidia cylindrospora

Abstract Serologically active mannoprotein (MP, minor fraction) and weak or inactive fucomannopeptide (FMP, major fraction) from the mycelia of Absidia cylindrospora were characterised by methylation analysis and 1 H-n.m.r. spectroscopy. MP contained a significant proportion of (1→2)-linked α- d -mannopyranosyl residues with mannopyranosyl non-reducing terminals, whereas FMP consisted of (1→6)-linked α- d -mannopyranosyl residues. MP did not contain a significant amount of mannose branch-units; when treated with 0.1 m NaOH, it was largely fragmented into mannobiose, mannotriose, mannotetraose, and higher oligosaccharides, as shown by gel-permeation chromatography. FMP released 10% of oligosaccharides on treatment by the same procedure. FMP gave a p.m.r. signal for O -acetyl (δ 2.2), its 13 C- and 1 H-n.m.r. data accorded with the results of the methylation analysis, and the fucopyranosyl residues were shown be α. Acetolysis of FMP gave large proportions of mannose and fucose, and small proportions of Fuc(Man) 3 , Fuc(Man) 2 , and Fuc-Man. Mild, acid hydrolysis of FMP released fucose and (1→6)-linked, linear α- d -mannosaccharides. Thus, FMP is composed of a (1→6)-linked α- d -mannan to which are attached single fucopyranosyl residues at O-3 of some mannosyl residues, and MP is composed of (1→2)-linked α- d -mannosaccharides which may be linked to the peptide via O -glycosylic linkages. Antibody-precipitating activity of MP with anti- A. cylindrospora serum was twice that of (1→6)-linked α- d -mannan and confirmed that the structure of the mannan moiety of FMP differs from that of serologically active MP.

Comparison of cell wall teichoic acid fractions isolated from three different encapsulated strains of Staphylococcus epidermidis.

Teichoic acid preparations extracted from the cell wall of three serologically different encapsulated strains of Staphylococcus epidermidis, ATCC-31432 (capsular type I), SE-360 (capsular type II) and SE-10 (capsular type III) were purified by DEAE-cellulose and Sephadex G-50 column chromatography. The preparations showed immunological heterogeneity by an agar diffusion test. The chemical properties of the cell wall teichoic acid preparations of capsular types I and III were regarded as N-acetyl-glucosaminyl glycerol-phosphate polymers containing N-acetylglucosamine and phosphate at molar ratios of 0.22-1.0 and 0.33-1.0, respectively. The preparation of capsular type II was assumed to be an alpha-glucosyl glycerol-phosphate polymer containing glucose and phosphate at a molar ratio of 0.49-1.0, and it reacted strongly with concanavalin A. Moreover, alanine, glycine, serine and lysine were shown, among these preparations, to be a common amino acid composition. These results indicate that cell wall teichoic acids obtained from these strains were biochemically and immunologically different from each other.