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Biomedical subjects

K Jann

Publications and source records attributed to K Jann.

At least 91 records · Page 5Linked to original sources
PubMed1988

Tamm Horsfall glycoprotein interferes with bacterial adherence to human kidney cells.

The effect of Tamm Horsfall protein (THP) of 18 healthy subjects and 14 diabetics on adherence of Escherichia coli (06:K13) 2699 strain to human kidney cells (HUK) was studied. Adhesion of bacteria (without additions: 100 bacteria per cell) was reduced dose-dependently by THP, half maximal inhibition occurring with 250 micrograms THP ml-1. Maximal inhibition (-84% at 1000 micrograms ml-1) exceeded inhibition by alpha-methyl-mannoside (36% at 50 mM), was specific (not reproduced by other glycoproteins, e.g. ovalbumin, mucin or thyroglobulin) and reversible (abolished by washing THP off HUK cells). Anti-adherence property of THP was not abolished by neuraminidase treatment. No significant difference of anti-adherence activity of THP was found between controls and diabetics, despite altered carbohydrate composition of THP in diabetes.

Adult↗
PubMed1988

Tamm Horsfall glycoprotein in diabetes mellitus: abnormal chemical composition and colloid stability.

Tamm Horsfall glycoprotein (THP) was isolated, using sodium chloride precipitation technique, from 24-h urine of 19 non-proteinuric insulin-dependent diabetics and 19 matched controls. Tamm Horsfall glycoprotein was pure, as judged by PAGE electrophoresis, by Ouchterlony double diffusion against anti-THP or anti-albumin antibodies, and by isoelectric focusing. Content of carbohydrates (gas-chromatography), amino acids or amino sugars (AA-analyser), N-acetylneuraminic acid (thiobarbituric acid method) and lysyl-bound glucose (furosine method) were determined and showed the following abnormalities: THP of diabetics had significantly higher glucose content (d: 2.55 +/- 0.66 g 100 g-1 THP; CO: 0.99 +/- 0.23; P less than 0.05) and increased lysyl-bound glucose, but diminished N-acetyl-neuraminic acid content (3.54 +/- 0.25 vs. 4.96 +/- 0.15; P less than 0.01) with no significant differences of amino acids or amino sugars. Low N-acetyl-neuraminic acid content was paralleled by reduced surface charge density of THP, as revealed by polyelectrolyte titration. No abnormality of the protein core was revealed by amino acid analysis and by probing reactivity to seven different monoclonal antibodies to human THP. Altered colloid stability, i.e. greater precipitation of THP of diabetic patients, was demonstrated by laser nephelometry. The data are consistent with abnormal post-translational modification of THP in diabetes.

Adult↗
PubMed1988

A block of urovirulence genes encoding multiple fimbriae and hemolysin in Escherichia coli O4:K12:H-.

Cosmid gene libraries were constructed from a uropathogenic isolate of Escherichia coli O4:K12:H- that secretes alpha-hemolysin and produces the F14, F12-rel, F1C, and F13 fimbrial antigens. A series of overlapping clones was generated, and individual cosmid clones were found to express various combinations of fimbriae and hemolysin, suggesting that the genes for these potential virulence factors are closely linked. By using Southern hybridization analysis and restriction endonuclease mapping, it was demonstrated that the cosmid clones carried a nested set of overlapping, cloned, genomic DNA fragments. A comparison of the phenotypic properties of individual cosmid clones and subclones allowed the order of the gene clusters encoding these factors to be deduced. The cloning also revealed the presence of a fifth fimbria that had P-adhesin specificity.

Antigens, Bacterial↗
PubMed1988

Induction of inflammation by Escherichia coli on the mucosal level: requirement for adherence and endotoxin.

Bacterial infection of the mouse urinary tract is followed by the recruitment of leukocytes to the mucosal surface. This study examined the bacterial components involved in the induction of this response. Escherichia coli of serotype O75:K5:H- expressing adhesins specific for the Gal alpha 1-4Gal beta- (Gal, galactose) and mannose-containing receptors were instilled into the urinary bladder of lipopolysaccharide responder (C3H/HcN) and lipopolysaccharide nonresponder (C3H/HeJ) mice. The inflammation was quantitated as the number of leukocytes excreted into the urine at various times after infection. The response was first shown to depend on the Lps genotype of the mouse. The leukocyte excretion that occurred within 24 h after infection of C3H/HeN mice was absent in C3H/HeJ mice. The components triggering the response were present on both live and Formalin-killed bacterial cells, and the response was mimicked by intravesical inoculation of isolated lipid A. Pretreatment of bacteria with soluble receptor oligosaccharides resulted in inhibition of attachment in vitro and of the inflammation in vivo. A direct synergy between adhesins specific for Gal alpha 1-4Gal beta receptors and lipid A was demonstrated. Mixtures of these components induced a leukocyte response higher than the sum of the responses to each component alone. These results suggest that the inflammation induced by gram-negative bacteria in the urinary tract can be triggered at the level of the epithelial cells by endotoxin presented by an attaching bacterial cell and that intact function at the Lps locus of the host is required for this to occur.

Animals↗
PubMed1988

Gene clusters for S fimbrial adhesin (sfa) and F1C fimbriae (foc) of Escherichia coli: comparative aspects of structure and function.

Fimbrial adhesins enable bacteria to attach to eucaryotic cells. The genetic determinants for S fimbrial adhesins (sfa) and for F1C ("pseudotype I") fimbriae (foc) were compared. Sfa and F1C represent functionally distinct adhesins in their receptor specificities. Nevertheless, a high degree of homology between both determinants was found on the basis of DNA-DNA hybridizations. Characteristic differences in the restriction maps of the corresponding gene clusters, however, were visible in regions coding for the fimbrial subunits and for the S-specific adhesin. While a plasmid carrying the genetic determinant for F1C fimbriae was able to complement transposon-induced sfa mutants, a plasmid carrying the genetic determinant for a third adhesin type, termed P fimbriae, was unable to do so. Proximal sfa-specific sequences carrying the S fimbrial structural gene were fused to sequences representing the distal part of the foc gene cluster to form a hybrid cluster, and the foc proximal region coding for the structural protein was ligated to sfa distal sequences to form a second hybrid. Both hybrid clones produced intact fimbriae. Anti-F1C monoclonal antibodies (MAbs) only recognized clones which produced F1C fimbriae, and an anti-S adhesin MAb marked clones which expressed the S adhesin. However, one of four other anti-S fimbriae-specific MAbs reacted with both fimbrial structures, S and F1C, indicating a common epitope on both antigens. The results presented here support the view that sfa and foc determinants code for fimbriae that are similar in several aspects, while the P fimbriae are members of a more distantly related group.

Adhesins, Escherichia coli↗
PubMed1988

DNA probes for K-antigen (capsule) typing of Escherichia coli.

DNA restriction fragments derived from the polysaccharide biosynthesis regions of cloned Escherichia coli K1, K5, and K12 capsular antigen genes hybridized only with DNA of strains determined by conventional methods to be of the same K serotype. A probe derived from the common transport region hybridized to all encapsulated E. coli strains.

Antigens, Bacterial↗
PubMed1987

Isolation and characterization of the alpha-sialyl-beta-2,3-galactosyl-specific adhesin from fimbriated Escherichia coli.

The alpha-sialyl-beta-2,3-galactosyl-specific adhesin (S adhesin) was isolated from cells of a recombinant Escherichia coli K-12 strain expressing the S-fimbrial adhesin complex. A crude cell extract was partially dissociated into fimbriae and an adhesin-enriched fraction by heating to 70 degrees C. From the latter, adhesin was purified to apparent homogeneity (by fast protein liquid chromatography, immunoblot, and NaDodSO4/PAGE) by differential ammonium sulfate precipitation, dissociation in 8 M guanidine hydrochloride, and high-resolution anion-exchange chromatography in 8 M urea. The purified adhesin formed an aggregate of Mr approximately 10(6) that was made up of one type of 12-kDa polypeptide (fimbrillin is 16.5 kDa). It had pI value of 4.7 (fimbriae has a pI value of 6). Adhesin and fimbrillin had different amino acid compositions. The purified adhesins agglutinated human and bovine erythrocytes with the same specificity as the whole bacteria; purified fimbriae were not adhesive. Monoclonal anti-adhesin and anti-fimbriae antibodies were obtained. Monoclonal anti-adhesin, but none of the anti-fimbriae, antibodies inhibited the agglutination of erythrocytes. The anti-adhesive antibodies were used in immuno-gold electron microscopy to localize adhesin exclusively on the fimbriae, with a possible preference to their tips.

Adhesins, Escherichia coli↗
PubMed1987

Nonfimbrial, mannose-resistant adhesins from uropathogenic Escherichia coli O83:K1:H4 and O14:K?:H11.

Nonfimbrial, mannose-resistant hemagglutinins (nonfimbrial adhesions [NFA] NFA-1 and NFA-2) were extracted from two agar-grown urinary isolates of Escherichia coli strains 827 (O83:K1:H4) and 54 (O14:K?:H11). The proteins were purified to homogeneity by ammonium sulfate precipitation and column chromatography. Nonfimbrial adhesins are soluble proteins, which tend to form aggregates of molecular weight above 10(6). NFA-1 and NFA-2 consist of subunits of 21,000 and 19,000 molecular weight, respectively. Both hemagglutinins caused hemagglutination of human erythrocytes and bound to human kidney cell monolayers. The binding of bacteria and hemagglutinins was assessed by using suitable antisera as detectors in an enzyme-linked immunosorbent assay. NFA-1 and NFA-2 inhibited the adherence of their respective strains to human kidney cells in a linear dose response. NFA-2 also inhibited heterologous strain adherence, but NFA-1 did not. Hemabsorption of bacterial suspension with erythrocytes at 4 degrees C, followed by differential centrifugation, enabled us to obtain a bacterial suspension lacking nonfimbrial adhesins in the supernatant and an adhesin-enriched bacterial suspension that was eluted from erythrocytes at 40 degrees C. Bacteria eluted from erythrocytes exhibited a higher adherence capacity than unfractionated cells. Bacteria of the fraction lacking adhesins did not adhere to human kidney cells. Electron microscope examinations showed the presence of an extracellular capsule-like layer in adhering E. coli 827, but not in nonadhering bacteria. E. coli 54 did not express the adhesin as a capsule. We conclude that E. coli 827 and 54 produce extracellular adhesins consisting of soluble proteins which are differently expressed and antigenically distinct. The adhesins seem to share a common receptor and mediate the adherence of two uropathogenic E. coli strains to epithelial cells.

Adhesins, Escherichia coli↗
PubMed1987

Lipopolysaccharides of Pseudomonas spp. that stimulate plant growth: composition and use for strain identification.

The outer membrane proteins of a series of fluorescent, root-colonizing, plant-growth-stimulating Pseudomonas spp. having been characterized (L. A. de Weger et al., J. Bacteriol. 165:585-594, 1986), the lipopolysaccharides (LPSs) of these strains were examined. The chemical composition of the LPSs of the three best-studied plant-growth-stimulating Pseudomonas strains WCS358, WCS361, and WCS374 and of P. aeruginosa PAO1 as a reference strain was determined and appeared to differ from strain to strain. The 2,6-dideoxy-2-aminosugar quinovasamine was the most abundant compound in the LPS of strain WCS358. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified LPS and of proteinase K-treated cell envelopes revealed ladderlike patterns for most of these strains. These patterns were not substantially influenced by differences in culture conditions. Analysis of proteinase K-treated cell envelopes of 24 root-colonizing Pseudomonas spp. revealed a unique band pattern for each strain, suggesting a great variety in the LPS structures present in these root colonizers. Therefore, electrophoretic analysis of LPS can be used for characterization and identification of the fluorescent root-colonizing Pseudomonas strains.

Electrophoresis, Polyacrylamide Gel↗
PubMed1986

Structure of the serine-containing capsular polysaccharide K40 antigen from Escherichia coli O8:K40:H9.

The structure of the K40 antigenic capsular polysaccharide (K40 antigen) of E. coli O8:K40:H9 was elucidated by determination of the composition, 1H- and 13C-n.m.r. spectroscopy, periodate oxidation and Smith degradation, and methylation analysis. The K40 polysaccharide consists of [(O-beta-D-glucopyranosyluronic acid)-(1----4)-O-(2-acetamido-2-deoxy-alpha-D-glucopyranosyl)-(1----6)-O -(2-acetamido-2-deoxy-alpha-D-glucopyranosyl)-(1----4)] repeating units. All of the glucuronic acid residues are substituted amidically with L-serine.

Carbohydrate Conformation↗
PubMed1986

Genetic and biochemical analysis of Shigella dysenteriae 1 O antigen polysaccharide biosynthesis in Escherichia coli K-12: 9 kb plasmid of S. dysenteriae 1 determines addition of a galactose residue to the lipopolysaccharide core.

Production of the somatic antigen, O-specific polysaccharide of Shigella dysenteriae 1 is determined by the chromosomal rfb gene cluster and the rfp gene located on the 9 kb plasmid pHW400 carried by this organism. When transferred to Escherichia coli K-12, which produces lipopolysaccharide consisting only of core oligosaccharide linked to lipid A, rfp gene-containing plasmids caused modification of the core oligosaccharide leading to the appearance of core molecules with new electrophoretic mobilities. Chemical analysis of the modified core has shown that it is substituted with a galactose residue which is the first sugar of the O-polysaccharide repeat unit.

Antigens, Bacterial↗
PubMed1986

Genetic and biochemical analysis of Shigella dysenteriae 1 O antigen polysaccharide biosynthesis in Escherichia coli K-12: structure and functions of the rfb gene cluster.

The genetic organization and functions of the Shigella dysenteriae 1 rfb gene cluster, which specifies the somatic O antigen in this organism, have been studied in Escherichia coli K-12 by insertion and deletion mutagenesis of pSS9, a pBR322 hybrid containing the Shigella rfb genes. On the basis of the sensitivity/resistance to rough-specific bacteriophage T3 of E. coli K-12 derivatives containing mutant pSS9 plasmids, of the banding patterns and immunoreactivity of LPS isolated from such derivatives and electrophoresed on SDS-polyacrylamide gels, and of the sugar composition of the polysaccharide portion of the LPS determined by chemical analysis, six determinants for O antigen production were identified and localized. At least two determinants are involved in synthesis of TDP-rhamnose and the transfer of a rhamnose residue to the galactose-substituted core. One of these functions is probably TDP-rhamnose synthetase. A third function effects the transfer of a second rhamnose residue to the rha----gal-substituted core. A fourth function, for which evidence was obtained for two determinants (cistrons), is N-acetylglucosamine transferase, whereas a sixth determinant is necessary for extension of the first completed side chain repeat unit to the full O antigen polymer. These results confirmed the previously-determined chemical composition of the S. dysenteriae 1 O antigen and demonstrated that the order of the sugars is glcNAc----rha----rha----gal with gal as the first sugar linked to the core. Evidence was obtained for at least two transcriptional units in the rfb gene cluster and the approximate locations of two promoters are suggested. The detection of new electrophoretic species of LPS that may correspond to LPS biosynthetic intermediates, and the finding on the cell surfaces of structures corresponding to LPS core substituted with one or more O-specific sugars, appear to be novel findings.

Antigens, Bacterial↗
PubMed1986

Monoclonal antibodies against the nonhemagglutinating fimbrial antigen 1C (pseudotype 1) of Escherichia coli.

Hybridoma-derived monoclonal antibodies were produced with fimbrial preparations from Escherichia coli 20025 (04:K12:H-) with fimbrial (F) antigens 1C, 13, one related to 12, and one preliminarily termed y and from E. coli 2980 (018ac:K5:H-) with F antigens 1C and 8. Two clones of subclonal hybrid cells were studied which produced monoclonal antibodies (mc-20025-F2b, immunoglobulin G2b [IgG2b]; mc-2980-F2, IgG1) that were reactive with E. coli 20025, 2980, and a number of additional strains which exhibited the F1C antigen. Results of enzyme-linked immunosorbent assay and Western blot analysis indicated that the antibodies had F1C specificity, and competitive enzyme-linked immunosorbent assay with 125I-labeled antibodies showed that they recognized different epitopes on the fimbrial subunit. Neither of the antibodies agglutinated F1C-fimbriated E. coli but bound to the bacteria. There was no binding to E. coli without F1C fimbriae.

Adhesiveness↗
PubMed1986

A reexamination of the O1 lipopolysaccharide antigen group of Escherichia coli.

A total of 64 Escherichia coli strains of the O1 serogroup were tested for the migration pattern of their lipopolysaccharides (LPS) on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. O1:K1 and O1:K51 strains of the OMP5 outer membrane protein pattern possessed LPS with a doublet pattern (O1A1) or the lowermost band of the O1A1 doublet (O1A2). O1:K1 strains of the OMP9 pattern possessed LPS referred to as O1A, which corresponded to the uppermost band of the O1A1 doublet pattern. A few O1:K? strains possessed LPS of different migration patterns (O1B and O1C). O1A and O1A1 LPS were indistinguishable by chemical techniques, and both reacted with each of 10 different monoclonal antibodies tested. However, O1A1 had an additional epitope within the additional band in each doublet, as demonstrated by adsorption experiments with hyperimmune rabbit sera followed by Western blotting. Furthermore, purified polysaccharide from O1A bacteria was incapable of inhibition in enzyme-linked immunosorbent assays performed with O1A1 LPS as antigen and adsorbed, specific anti-O1A1 antibodies, whereas O1A1 polysaccharide inhibited this reaction. O1B and O1C LPS differed in all respects tested, including chemical composition, from O1A and O1A1 LPS.

Animals↗
PubMed1986

Molecular cloning and analysis of genes for production of K5, K7, K12, and K92 capsular polysaccharides in Escherichia coli.

With a DNA fragment from within the region encoding the transport functions for K1 production as a hybridization probe in Southern blot experiments, homologous DNA sequences were detected in the DNA from Escherichia coli strains producing K5, K7, K92, and K100 capsular polysaccharides. No homology with the laboratory strain LE392 was detected. The same DNA probe was used to prescreen cosmid libraries in LE392 by colony hybridization, as a rapid method to isolate clones encoding the genes for K5, K7, K12, and K92 antigen production. Clones carrying sequences homologous to the probe that also produced capsular material were identified by using polyclonal and monoclonal antibodies raised against the K antigen in question and K antigen-specific phages. By restriction enzyme mapping of the appropriate cosmid clones it was possible to align the genes for the production of different K antigens in terms of common restriction endonuclease cleavage sites. A DNA fragment encoding the postulated transport functions for K7 antigen production could complement deletion mutations in the transport functions for K1 antigen production. Thus the transport to the cell surface of chemically distinct polysaccharides may be by a common process. Analysis in E. coli of the proteins produced by plasmids carrying the likely transport functions for K1, K5, and K7 antigen production revealed that each region coded for a similar polypeptide.

Antigens, Bacterial↗
PubMed1985

Structure of the K95 antigen from Escherichia coli O75:K95:H5, a capsular polysaccharide containing furanosidic KDO-residues.

The structure of the K95 antigenic capsular polysaccharide (K95 antigen) of Escherichia coli O75:K95:H5 was elucidated by determination of the composition, 1H- and 13C-n.m.r. spectroscopy, periodate oxidation, and methylation analysis. The K95 polysaccharide, which contains furanosidic 3-deoxy-D-manno-2-octulosonic acid (KDOf) residues, consists of----3)-beta-D-Rib-(1----8)-KDOf-(2----repeating units, has a molecular weight of approximately 25,000 (approximately 65 repeating units), and is randomly O-acetylated (1 acetyl group per repeating unit at unknown positions).

Carbohydrate Conformation↗
PubMed1985

Structural studies of the capsular polysaccharide of Acinetobacter calcoaceticus BD4.

Compositional analysis of the intact and carboxyl-reduced capsular polysaccharide of Acinetobacter calcoaceticus BD4 (PS-4) showed it to consist of L-rhamnose, D-glucose, D-glucuronic and D-mannose in molar ratios of 4:1:1:1. 13C-nuclear magnetic resonance spectroscopy, methylation analysis, oligosaccharide analysis and base-catalyzed beta-elimination were used to elucidate the primary structure. Oligosaccharides were obtained by enzymatic depolymerization with a specific bacteriophage-induced depolymerase and by partial acid hydrolysis. Form the results it is concluded that PS-4 consists of repeating units of the heptasaccharide (Formula: see text). The bacteriophage-induced depolymerase was found to be an endo-beta-D-glucosidase that hydrolyzed the bond beta-D-Glc-(1----3)-L-Rha to generate a heptasaccharide in 40% yield.

Acinetobacter↗