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Biomedical subjects

R Lindstedt

Publications and source records attributed to R Lindstedt.

23 records · Page 2Linked to original sources
PubMed1991

Mechanism of adherence of Moraxella (Branhamella) catarrhalis.

We examined the mechanisms of adherence of Moraxella catarrhalis to nasopharyngeal epithelial cells. Fimbriae were detected by electron microscopy on most of the strains studied. A role of fimbriae in adherence was supported by the reduction in adherence by treatments denaturing the fimbriae or by antifimbrial antibodies. There was, however, no significant difference in adhesive capacity or hemagglutination between fimbriated and non-fimbriated strains. Furthermore, there was no correlation between hemagglutination and adherence. The possibility that receptor epitopes were provided by cell surface glycolipids was examined by thin-layer chromatography. Glycolipids from various sources, including nasopharyngeal cells were separated by thin layer chromatography plates and overlayed with bacteria. No binding was detected. The results suggest that lectin-glycolipid interactions do not explain the attachment of M. catarrhalis to epithelial cells.

Adult↗
PubMed1990

Anti-adhesive activity of human casein against Streptococcus pneumoniae and Haemophilus influenzae.

The casein fraction of human milk was found to inhibit the attachment of Streptococcus pneumoniae and Haemophilus influenzae human respiratory tract epithelial cells. The inhibitory activity for S. pneumoniae remained after heat and trypsin treatment of the casein and was found in oligosaccharides released from casein. kappa-Casein, which is the most highly glycosylated casein component, inhibited pneumococcal attachment at concentrations similar to the whole casein fraction. The results are consistent with the known recognition of GlcNAc beta 1-3Gal by S. pneumoniae, since human milk and bovine colostrum, which contain GlcNAc, inhibited attachment, but mature bovine milk lacking GlcNAc did not. The effect on H. influenzae was similar to that on S. pneumoniae in that the attachment was inhibited by human casein and bovine colostrum, but not by either mature bovine milk or by the bovine casein fraction. The kappa-casein component of human milk was a less efficient inhibitor of H. influenzae attachment than the whole casein fraction and the free oligosaccharides were inactive. This anti-microbial effect of human casein represents a new mechanism for the protection by breast-milk against respiratory tract infection.

Animals↗
PubMed1989

Binding specificities of wild-type and cloned Escherichia coli strains that recognize globo-A.

In this study we compared the specificity for the globoseries of glycolipids of Escherichia coli expressing the O-negative, A-positive (ONAP) adhesin and clones transformed with the pap-like (prs or pap-2) gene cluster. Receptor-active glycolipids were identified by the ability of radiolabeled bacteria to bind to the glycolipids on thin-layer chromatogram plates. The ONAP adhesin and pap-like clones bound with high affinity to the globo-A and Forssman glycolipids. The ONAP strains did not recognize other glycolipids of the globoseries. In contrast, the pap-like clones also showed weak binding to globotriaosylceramide and reacted weakly with Gal alpha 1----4 Gal beta-latex beads. We suggest that the pap-like and ONAP adhesins recognize an epitope shared by the globo-A and Forssman structures, e.g., terminal GalNAc alpha 1----3 bound to Gal alpha 1----4Gal beta-containing glycolipids.

Adhesins, Escherichia coli↗
PubMed1988

Globo-A--a new receptor specificity for attaching Escherichia coli.

Uropathogenic Escherichia coli strains designated as ONAP, based on their O negative A positive agglutination of human P1 erythrocytes, were shown to prefer the globo-A glycolipid as a receptor structure. The dependence on both the A terminal and the globoseries chain was confirmed by agglutination of human AP1, but not Ap or OP1 erythrocytes and by binding to the globo-A glycolipid on TLC plates. Neither Gal alpha 1----4Gal beta nor the A trisaccharide GalNAc alpha 1----3(Fuc alpha 1----2)Gal beta alone functioned as receptors. The bacteria thus appeared to recognize an epitope resulting from the combination of the terminal and internal structures.

Animals↗