Biomedical subjects

H Suginaka

Publications and source records attributed to H Suginaka.

At least 55 records · Page 3Linked to original sources

PubMed1992

Effects of cefuzonam on peptidoglycan cross-linking reactions in gram-negative bacilli.

Cefuzonam [CZON, sodium (-)-(6R,7R)-7-[(Z)-2-(2-amino-4-thiazolyl)-2- methoxyiminoacetamido]-3-[(1,2,3-thiadiazol-5-yl)thiomethyl]-8-oxo -5-thia-1-azabicyclo(4.2.0)oct-2-ene-2-carboxylate] is a newly developed semisynthetic cephem with a broad antibacterial spectrum. The effects of CZON on peptidoglycan cross-linking reactions were examined in Escherichia coli, Serratia marcescens and Pseudomonas aeruginosa. The cross-linking enzyme(s) from P. aeruginosa was the most susceptible to CZON, although the bacterium was resistant to CZON. CZON was active against S. marcescens in spite of its weak inhibitory activity against the enzyme(s) from the bacterium.

Cefazolin↗

PubMed1992

Simple method for measuring the antibiotic concentration required to kill adherent bacteria.

A simple method was developed for measuring the antibiotic susceptibility of bacteria adherent to plastic surfaces. Staphylococcus aureus cells adhered to the bottom of a 96-well plastic tissue culture plate were incubated in serially diluted antibiotic solutions. After a 24-hour-incubation the solutions were removed, and fresh medium without antibiotics was added to each well. The viability of the cells was judged by their growth after a further 24-hour-incubation. The antibiotic concentration required to kill adherent bacteria was far higher than that required for planktonic cells, although we used bactericidal drugs; beta-lactam, quinolone, and aminoglycoside antibiotics. The tolerance demonstrated by adherent cells is likely to play a role in the difficulties encountered in the chemotherapy of biofilm infections.

Anti-Bacterial Agents↗

PubMed1991

Suppression of penicillin-induced lysis of Staphylococcus aureus by cibacron blue 3G-A.

The effect of cibacron blue 3G-A (CB) on bacteriolysis induced by penicillin G was investigated using Staphylococcus aureus FDA 209P. Penicillin-induced lysis was completely inhibited by 30 microM CB. However, the bactericidal effect of penicillin G was not influenced by CB. These results indicate that a bacteriolytic process is not essential for penicillin to kill S. aureus.

Bacteriolysis↗

PubMed1991

Molecular cloning and sequencing of the epidermal cell differentiation inhibitor gene from Staphylococcus aureus.

We recently purified to homogeneity a protein inhibiting differentiation of cultured keratinocytes from extracellular products of Staphylococcus aureus, and named it epidermal cell differentiation inhibitor (EDIN). In the present study, we isolated and sequenced the structural gene coding for EDIN from Staphylococcus aureus E-1 using oligonucleotide probes on the basis of the partial amino acid sequence of the purified EDIN. DNA sequencing of the cloned DNA revealed an open reading frame encoding 247 amino acids as a precursor of EDIN, which included an NH2-terminal signal sequence of 35 amino acid residues. Processing of this precursor produces a mature EDIN protein composed of 212 amino acids with a calculated Mr of 23,782. The EDIN shared 35% amino acid homology with the ADP-ribosyltransferase C3 of Clostridium botulinum. These results with biological properties of EDIN described previously indicate that EDIN is a novel protein.

Amino Acid Sequence↗

PubMed1991

Cibacron blue 3G-A inhibits cell separation of gram-positive bacteria.

A triazine dye, Cibacron blue 3G-A (CB), is an inhibitor of cell separation of staphylococcal spp. therefore, we examined the effect of CB on growth of gram-positive bacteria other than Staphylococcus. CB added to the medium of growing cultures of strains of genus Micrococcus, Streptococcus, Lactobacillus and Bacillus caused inhibition of cell separation. Moreover, in case of Bacillus and Lactobacillus, individual cells were elongated as filament. Strains of the genus Micrococcus were as sensitive to CB as genus Staphylococcus in which the minimum concentrations of CB needed for inhibition of cell separation ranged from 15 to 100 microM. Other strains belong to genus Streptococcus, Bacillus and Lactobacillus were less sensitive; the minimum concentrations were 100 microM--25 mM.

Bacillus↗

PubMed1991

Visualization of endo-beta-N-acetylglucosaminidase, lysozyme, and lysostaphin after polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate.

Bacteriolytic enzymes of different bond specificities, denatured by sodium dodecyl sulphate (SDS), were electrophoresed in polyacrylamide gels containing bacterial cells, then renatured after removal of SDS by diffusion. Enzyme activity was seen in sharp transparent bands resulting from bacteriolysis in the gels, while these sections containing bacterial cells appeared cloudy. Bacteriolytic enzymes including staphylococcal endo-beta-N-acetylglucosaminidase, lysozyme (N-acetylmuramidase), and lysostaphin (endopeptidase) were detected. The major bacteriolytic enzymes of Staphylococcus spp. were identified in gels after electrophoresis of crude enzyme preparations. This demonstrates the wide applicability of this method to the study of staphylococcal bacteriolytic enzymes. However, it should be noted that the method will fail to detect activities of bacteriolytic enzymes which are irreversibly inhibited by SDS.

Bacteriolysis↗

PubMed1991

Mechanism of aminoglycoside enhancement of Staphylococcus aureus adherence to HeLa cells.

There is enhanced adherence of Staphylococcus aureus to HeLa cells if the organism is grown in the presence of sub-lethal concentration of aminoglycosides. In this study, we investigated the mechanism of this enhancement. Cell surface components obtained by lysosaphin digestion under hypertonic conditions were examined for binding to HeLa cells. The components considered responsible for the adherence were recovered more from aminoglycoside treated cells than from control, benzylpenicillin or chloramphenicol treated cells. Using a contact angle measurement, the bacterial cell surface was found to be more hydrophobic after growing in the presence of some aminoglycosides, and hydrophilic which decreased adherence, after growing in the presence of benzylpenicillin and ofloxacin. Spectinomycin and kasugamycin, which are both aminoglycosides which do not cause misreading, failed to enhance adherence suggesting that misreading caused by aminoglycosides plays an important role in the enhancement of adherence.

Aminoglycosides↗

PubMed1991

Effects of antibiotics on nonopsonized adherence of Staphylococcus aureus to human polymorphonuclear leukocytes.

We investigated the effects of several antibiotics on the adherence of Staphylococcus aureus FDA 209P to polymorphonuclear leukocytes. Sublethal concentrations of aminoglycosides enhanced staphylococcal adherence to polymorphonuclear leukocytes, whereas beta-lactams, minocycline, ofloxacin and clindamycin decreased the adherence. Chloramphenicol and rokitamycin had no effect. It is likely that the adherence following antibiotic treatment is related to cell surface hydrophobicity determined by the measurement of the contact angle of 1-bromonaphthalene on a monolayer of staphylococcal cells.

Aminoglycosides↗

PubMed1991

In vitro susceptibility of Ureaplasma urealyticum clinical isolates to new macrolides.

Nine antimicrobial agents, the new macrolides, rokitamycin and midecamycin acetate, and seven other antibiotics, tetracycline, minocycline, doxycycline, josamycin, erythromycin, spiramycin, and norfloxacin, were studied for their antimicrobial activity against 100 strains of Ureaplasma urealyticum, using a microtiter broth dilution technique. The new macrolides, rokitamycin and midecamycin acetate, had the highest activity, with the MIC against 90% of isolates tested (MIC90) being less than or equal to 0.05 microgram/ml. MICs90 of erythromycin, josamycin, doxycycline, minocycline and tetracycline ranged from 0.1 to 0.78 micrograms/ml. Norfloxacin was least active, with a MIC90 of 12.5 micrograms/ml. Five of 100 strains tested were resistant (MIC greater than or equal to 12.5 micrograms/ml) to tetracycline, and two were resistant to minocycline and doxycycline; all of these were susceptible to rokitamycin and midecamycin acetate.

Drug Resistance, Microbial↗

PubMed1991

Incidence and characterization of Staphylococcus aureus from the tongues of children.

Three hundred and seven children who had no diseases other than dental disease were examined for their oral carriage of Staphylococcus aureus, the most common persistent human pathogen. Eighty-four percent of them were positive for staphylococci, and 33% were positive for S. aureus. Among the 100 strains of S. aureus isolated, 40 strains produced enterotoxin, and 19 strains produced exfoliative toxin. Their susceptibility to antibiotics was also investigated: Six strains demonstrated resistance to methicillin (MIC greater than or equal to 12.5 microgram/mL), and 50% of the isolates were borderline resistant (MIC of 3.13 to 6.25 micrograms/mL) to the drug. These data suggest that the mouths of children could be reservoirs of pathogenic S. aureus.

Child, Preschool↗

PubMed1991

Mode of antibacterial action of cefprozil, a new cephalosporin, on Escherichia coli, Serratia marcescens and Morganella morganii.

The mode of antibacterial action of cefprozil (CFPZ, BMY-28100), a newly developed cephalosporin, was investigated using Escherichia coli K12, Serratia marcescens IFO 12648 and Morganella morganii IFO 3848 as test organisms, in comparison with the action of cefaclor (CCL). The minimum inhibitory concentrations (MICs) of CFPZ for these organisms were 1.56, 800 and 25 micrograms/ml, whereas those of CCL were 1.56, 800 and 100 micrograms/ml, respectively. The addition of a subinhibitory concentration (1/4 MIC) of ethylenediaminetetraacetic acid (EDTA), which damages the permeability barrier of the outer membrane, markedly reduced the MICs of CFPZ for E. coli and S. marcescens, compared with those of CCL, whereas the MICs of both antibiotics for M. morganii were hardly affected by the presence of EDTA. CFPZ was more stable to beta-lactamase activities from these organisms than CCL. The cross-linking reactions of peptidoglycan synthesis catalyzed by the ether-treated cells from these organisms were inhibited by a lower concentration of CFPZ than of CCL.

Bacteria↗

PubMed1990

A novel epidermal cell differentiation inhibitor (EDIN): purification and characterization from Staphylococcus aureus.

A factor inhibiting the calcium-induced terminal differentiation of cultured mouse keratinocytes was purified to homogeneity from the extracellular products of S. aureus E-1 and designated 'epidermal cell differentiation inhibitor' (EDIN). EDIN activity was sensitive to trypsin and heat-labile, suggesting that EDIN is a protein. EDIN gave a single band with a molecular weight of 27,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was found to be a single chain polypeptide, having an isoelectric point higher than 9. The N-terminal amino acid sequence of EDIN was determined as A-D-V-K-N-F-T-D-L. EDIN inhibited the differentiation of not only mouse but also human keratinocytes in culture.

Amino Acids↗

PubMed1990

Antifungal drugs affect adherence of Candida albicans to acrylic surfaces by changing the zeta-potential of fungal cells.

The effect of sub-inhibitory concentrations of antifungal drugs on the adherence of Candida albicans to acrylic surfaces was investigated. Among five antifungals tested, azalomycin F and aculeacin A significantly enhanced the adherence. The zeta-potential of fungal cells was affected by antifungal drugs, whereas no significant change in cell surface hydrophobicity was observed. The relationship obtained between the change in the adherence and that in zeta-potential suggests that the enhanced adherence was caused by decreased electric repulsive forces.

Acrylates↗

PubMed1990

A triazine dye, cibacron blue 3G-A induces Staphylococcus aureus to form giant clusters.

Cibacron blue 3G-A (CB), one of the triazinyl dyes commonly used as a ligand for affinity chromatography, induced staphylococci to form giant clusters without affecting cell viability. It was demonstrated that the cluster formation was not a mechanical aggregation of cells by CB, but a consequence of its biological effect on staphylococcal growth. Clusters induced by CB did not form a regular arrangement, and were different from clusters induced by SDS or polyanethole sulfonate.

Cell Division↗

PubMed1990

Purification of staphylococcal exfoliative toxin by high pressure liquid chromatography.

Exfoliative toxin (ET) isolated from a clinical strain of Staphylococcus aureus was purified to homogeneity, using a 3-step HPLC system. NH2-terminal 20 amino residues of purified ET was found to be identical with ETA of S. aureus TA (7), S. aureus TC16 (9) and S. aureus ZM (10), but stability of purified ET was completely different from that of ETA. This purification system gave a high yield of pure ET, which exhibited higher purity than specimens purified by more complicated and time-consuming procedures. It is useful for small-scale purification for the comparative study of ET and easy to scale up for preparative purification.

Amino Acid Sequence↗

PubMed1990

Adherence of Staphylococcus aureus to cultured epidermal cells during differentiation.

The adherence of clinical isolates of Staphylococcus aureus to cultured mouse epidermal cells was studied. Adherence of the isolates to the cells varied from strain to strain. When epidermal cell differentiation was induced by raising the calcium concentration in the medium, three out of 10 strains tested adhered better to calcium-induced differentiated cells than to undifferentiated cells, and one strain demonstrated higher adherence to undifferentiated cells than to differentiated cells. No significant difference between the adherences to both types of epidermal cells was observed with the other six strains. No relationship was observed between adherence and surface hydrophobicity with bacterial cells. Lipoteichoic acid and N-acetyl sugars caused limited inhibition of adherence. The adherence assay method employed in this study is useful for investigating the effects of epidermal cell differentiation on bacterial adherence in vitro.

Animals↗

PubMed1990

Binding specificity of Fusobacterium nucleatum to human erythrocytes, polymorphonuclear leukocytes, fibroblasts, and HeLa cells.

Eighteen strains of Fusobacterium nucleatum were studied with respect to their adherence to human erythrocytes, polymorphonuclear leukocytes, fibroblasts, and HeLa cells. Four types of adherence were found: 1) sugar-sensitive adherence 2) amino acid-sensitive adherence 3) unknown adherence 4) weak adherence. There was no obvious correlation between the patterns of hemagglutination and adherence to other cells. The results indicate not only a complex network of bacterial receptors on human cells, but also a variety of types of bacterial adherence as expressed by the selectivity of the bacterial binding to specific cell surfaces.

Acetylgalactosamine↗

PubMed1990

In vitro susceptibility of Campylobacter jejuni to rokitamycin.

The susceptibilities of 100 clinical isolates of Campylobacter jejuni to rokitamycin, a new macrolide, and eight other oral antibiotics were tested by using a broth microdilution method. Rokitamycin demonstrated antibacterial activity that was higher than those of fosfomycin and the tetracyclines and comparable to those of erythromycin and clindamycin, whereas it was slightly less active than the quinolones.

Anti-Bacterial Agents↗