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C Svanborg-Edén

Publications and source records attributed to C Svanborg-Edén.

At least 37 records · Page 2Linked to original sources
PubMed1987

Bacterial virulence versus host resistance in the urinary tracts of mice.

The relative contributions of host resistance and bacterial virulence were analyzed in a mouse model for ascending urinary tract infection. The congenic mouse strains C3H/HeJ and C3H/HeN were used in parallel. They differ in their reactivity to lipopolysaccharide (LPS) and susceptibility to experimental urinary tract infection. C3H/HeJ cells are susceptible to infection and are nonresponders to LPS (Lpsd Lpsd), whereas C3H/HeN cells respond to LPS and are resistant to infection (Lpsn Lpsn). The Escherichia coli pyelonephritis isolate GR-12, serotype O75K5, expressing adhesins specific for globoseries glycolipids (P fimbriae) and for mannosides (type-1 fimbriae), and its derivatives deficient in these factors were used, either singly or in combination, to establish experimental infections. In C3H/HeN mice, the relative persistence of E. coli was inversely proportional to its phagocytosis in vitro. Loss of the O75 and K5 antigens increased the tendency toward hydrophobic interaction, promoted phagocytosis, and reduced persistence in the kidneys. This was not the case in C3H/HeJ mice, in which O75- and K5- serotypes persisted in the same extent as did the parent strain. The total number of bacteria recovered from the kidneys of C3H/HeJ mice was about 1,000-fold higher than the number recovered from kidneys of C3H/HeN mice 24 h after infection. Previous studies have demonstrated a delayed influx of polymorphonuclear leukocytes into the urinary tracts of C3H/HeJ mice. The results are consistent with the hypothesis that phagocyte activation through LPS is a major defense mechanism against E. coli in the kidney, a property in which C3H/HeJ mice are deficient.

Animals↗
PubMed1987

Receptor-specific agglutination tests for detection of bacteria that bind globoseries glycolipids.

Specific binding to the globoseries of glycolipid receptors explains the adherence of uropathogenic Escherichia coli to host cells. The minimal receptor disaccharide Gal alpha 1----4Gal beta [galactose alpha (1----4)galactose beta] is recognized by most attaching clinical isolates. However, wild-type isolates can express adhesins with several different receptor specificities. Bioassays do not permit separate analysis of each receptor specificity, since the target cells contain multiple potentially receptor-active molecules. In this study, bacterial adhesins were analyzed by using receptors immobilized into latex beads in one of two ways. In one way, di- and trisaccharides were covalently linked via a spacer arm to latex beads coupled with bovine serum albumin. In the other way, receptor-active glycolipids were coated onto the bovine serum albumin-latex beads. The latex beads were subsequently used for agglutination by using type strains with known receptor specificity. The composition was optimized regarding receptor structure and size of latex beads. Gal alpha 1----4Gal beta was as active as the trisaccharide derivative Gal alpha 1----4Gal beta 1----3glucose or Gal alpha 1----4Gal beta 1----3glucosamine. Among the natural glycolipids tested, globotetraosylceramide was the most active. Subsequently, the sensitivity and specificity of the Gal alpha 1----4Gal beta-latex and globotetraosylceramide-latex reagents were compared for 733 E. coli urinary isolates. Hemagglutination of human erythrocytes was used as the positive standard. No significant difference in the specificity or sensitivity of the latex reagents was found; the sensitivity ranged from 86%, when isolates agglutinating human erythrocytes of blood groups P1 and p were included, to 93%, when those isolates agglutinating erythrocytes of blood group p were excluded. These reagents provide tools for bacterial identification in patients with urinary tract infection.

Adhesins, Escherichia coli↗
PubMed1987

Binding to galactose alpha 1----4galactose beta-containing receptors as potential diagnostic tool in urinary tract infection.

The diagnosis of urinary tract infection is based largely on quantitative urine cultures. The usefulness of qualitative information about the virulence of the infecting bacteria remains undefined. Ability to attach to human uroepithelial cells is one characteristic of the pyelonephritogenic clones, as well as a virulence factor per se. The identification of host cell receptors for attaching bacteria has permitted the construction of agglutination tests for simple detection of bacterial binding properties. In the present study, the reactivity with Gal alpha 1----4Gal beta-latex [galactose alpha (1----4)galactose beta-latex] and globotetraosylceramide-latex was analyzed for strains from patients with acute pyelonephritis (n = 135), acute cystitis (n = 121), and asymptomatic bacteriuria (n = 119) and from the fecal flora of healthy children (n = 120) and compared with agglutination of human blood group P1 and p, as well as guinea pig, erythrocytes. The reactivity by bioassay and the receptor-specific assays were significantly correlated. The frequency of positive reactions among the pyelonephritis isolates was 78.5% with the globotetraosylceramide-latex reagent, compared with 41% for the cystitis isolates, 25% for the asymptomatic bacteriuria isolates, and 13% for the fecal isolates. The combination of bioassays and receptor-specific assays increased the resolution of adhesins. Thus, adhesins reacting with human p erythrocytes frequently were coexpressed with Gal alpha 1----4Gal beta-specific adhesins. The receptor-specific assays provide a refined reagent to resolve bacterial binding specificities, as well as a potential tool for clinical diagnosis.

Adhesins, Escherichia coli↗
PubMed1986

Interaction of a pyelonephritogenic Escherichia coli strain with the tissue components of the mouse urinary tract.

Immediately following the introduction of cells of a pyelonephritogenic strain of Escherichia coli (expressing both GS and MS adhesins) into the mouse bladder, these cells were found to be randomly distributed on the mucosal surfaces of both the bladder and the kidney. After 24 hr. these adherent bacterial cells had proliferated to form nonrandomly distributed adherent microcolonies on both mucosal surfaces and large masses within the renal ducts. Large amounts of amorphous material, which we presume to be of both host and bacterial origin, was associated with the bacterial microcolonies on the infected tissues. The removal of urinary slime and tissue coat material by acid pretreatment increased both the degree and the apparent avidity of bacterial adhesion to the bladder mucosa. The adherent bacteria on the bladder mucosa were radically elongated, while those on the kidney mucosa usually retained their short rod-like morphological characteristics. These data suggest that pyelonephritogenic bacteria adhere to mucosal surfaces in both the bladder and kidney, and proliferate to form adherent microcolonies within which bacteria are associated with large amounts of amorphous extracellular material.

Animals↗
PubMed1986

Inhibition of attachment of Streptococcus pneumoniae and Haemophilus influenzae by human milk and receptor oligosaccharides.

Human milk inhibited the attachment of Streptococcus pneumoniae and Haemophilus influenzae to human pharyngeal or buccal epithelial cells. Infant formulas and cow and buffalo milk showed a lower inhibitory activity against pneumococci and enhanced the adhesion of H. influenzae. The antiadhesive effect against S. pneumoniae was found in both the high- and the low-molecular-weight fractions of milk. The inhibitory activity in the high-molecular-weight fraction was independent of specific antibody content; it was present after immunoadsorption and in the milk from IgA-deficient women. The inhibitory activity in the low-molecular-weight fraction was in part explained by the content of oligosaccharides corresponding to the carbohydrate moieties of the neolactoseries of glycolipids, which have previously been shown to act as receptors for attaching pneumococci. The antiadhesive activity against H. influenzae was restricted to the high-molecular-weight fraction of the milk and was unaffected by immunoadsorption. Milk may protect against otitis by reducing colonization.

Adhesiveness↗
PubMed1986

Influence of blood group on the availability of receptors for attachment of uropathogenic Escherichia coli.

Escherichia coli strains with defined receptor specificity were used as probes to analyze the individual variation in host cell receptors with respect to blood groups. The adhesins were initially characterized as mannose sensitive (MS), mannose resistant (MR), or nonagglutinating (-). The receptor specificity of the strains with MR adhesins was defined by agglutination of synthetic Gal alpha 1----4Gal beta covalently linked via a spacer arm, (CH2)2S(CH2)2CO approximately H-bovine serum albumin (BSA) to BSA-latex beads as specific for the globoseries glycolipid receptors (MR:GS). Strains with MR adhesins not reacting with Gal alpha 1----4Gal beta-BSA-latex were designated MR:nonGS. The attachment and hemagglutination of the MR:GS strains was strictly dependent on Gal alpha 1----4Gal beta-containing receptors, as shown by the absence of binding to cells from individuals of blood group P lacking these structures. Previous reports showed differences in the composition of globoseries glycolipids between erythrocytes from individuals of P1 and P2. No significant difference was found, However, in the mean adhesion to P1 and P2 epithelial cells or in the agglutination titer for P1 and P2 erythrocytes. The MR:GS receptors were equally distributed on squamous and transitional epithelial cells. In contrast, the distribution of MR:nonGS receptors was skewed. Attachment occurred mostly to squamous epithelial cells. The attachment of strains with MR:nonGS adhesins was independent of the P blood group of the cell donor. The binding ability of MR:GS and MR:nonGS adhesins appeared independent and additive. The attachment was not influenced by the ABH blood group. However, increased binding to epithelial cells from nonsecretors occurred regardless of the P blood group, suggesting a shielding of receptors by products controlled by the secretor genes. These results illustrate how individual variation in cell surface components with and without receptor activity determine the interaction of a ligand with a known receptor.

Adhesins, Escherichia coli↗
PubMed1986

Application of multilocus enzyme gel electrophoresis to Haemophilus influenzae.

Multilocus enzyme electrophoresis was adapted to the study of Haemophilus influenzae. Protein extracts from sonicated whole bacteria were subjected to starch gel electrophoresis. After staining with substrates, the position of each isoenzyme (electromorph) was registered. Each isolate was assigned an electrophoretic type (ET) by the combination of electromorphs for the enzymes stained. Twenty-seven enzymes were tested; 12 were expressed in H. influenzae. Six enzymes were selected for subsequent study: malate dehydrogenase (MDH), phenylalanylleucine peptidase (PE2), 6-phosphogluconate dehydrogenase (6PG), adenylate kinase (AK), glucose 6-phosphate dehydrogenase (G6P), and phosphoglucose isomerase (PGI). They were polymorphic and occurred in all isolates. Six electromorphs were found for PE2, G6P, and PGI, five for MDH, four for 6PG, and three for AK. PE2, G6P, and PGI contributed most of the ET resolution (48 of 49 ETs). Multilocus enzyme electrophoresis showed several advantages over previous typing techniques. An ET could be assigned to both typable and nontypable (NT) isolates. The technique was powerful in resolving differences among isolates. The 94 isolates comprised 49 ETs, five biotypes, and six capsular types and NT isolates. Strains known to be related expressed the same ET, e.g., RAB b+ and b-, ET12; Ma a+ and a-, ET1. ET variability among type b isolates was low; 26 of 28 clinical isolates expressed ET14; 2 of 28 expressed ET13 and ET15, differing from ET14 by one electromorph each. In contrast, the 47 NT isolates comprised 38 different ETs. No ETs were shared between non-type b capsulated strains and type b or NT strains. Interestingly, five NT isolates expressed the same ET as type b strains. (iv) Strains of the same capsular type but different biotypes expressed different ETs. ET determinations will thus be useful in studying the epidemiology and evolution of H. influenzae.

Bacterial Proteins↗
PubMed1986

Difference in structure between type b and nontypable Haemophilus influenzae populations.

The extent of chromosomal genetic variability and the genetic structure of Haemophilus influenzae populations was analyzed. A total of 119 isolates from humans in Göteborg, Sweden, and Birmingham, Ala., and 16 strains from a type culture collection were characterized for capsular type, biotype, outer membrane protein profile, and enzyme electrophoretic type (ET). The results of this study indicate that the bacteria identified as H. influenzae are a genetically extremely variable array of organisms. For the six enzymes studied, the estimated mean genetic diversity was 0.57 (approximately 20% higher than the corresponding estimate for Escherichia coli). Two lines of evidence indicate that despite its ability to recombine by transformation, H. influenzae maintains a largely clonal population structure. Although there is considerable potential for generating different genotypes, there were only 88 distinct ETs among the 135 strains, and isolates of the same ET and biotype were recovered at frequencies greater than would be anticipated at random. This evidence for a clonal population structure holds for uncapsulated as well as capsulated strains. However, these data also suggest that the stability of H. influenzae clones (clone persistence time) may be less than that of the nontransforming species E. coli. The ET data indicate that there is somewhat less variability among H. influenzae strains that express the same capsular antigens, biotype, and outer membrane proteins than among randomly chosen isolates. Nevertheless, there is substantial genetic variation among isolates within each of these classes and combinations thereof. There is also variation in these typing characteristics among strains of the same ET. These observations and those on genetic variability and population structures have implications for the characterization of H. influenzae isolates in clinical and epidemiological studies.

Bacterial Outer Membrane Proteins↗
PubMed1985

Method for testing adherence of Haemophilus influenzae to human buccal epithelial cells.

A method for testing adherence of Haemophilus influenzae strains to buccal mucosal cells is described. Bacteria grown in broth for 4 h were mixed with buccal mucosal cells. After elimination of unattached bacteria by repeated cycles of centrifugation and resuspension in PBS, the number of attached bacteria was counted microscopically. Optimal results were obtained with an early log-phase bacterial culture at a concentration of 10(9) bacteria/ml mixed with 2 X 10(4) cells/ml and incubated at 37 degrees C for 60 min. This assay showed an at least ten times higher rate of adherence for Haemophilus influenzae than previous studies. Nontypeable strains attached in higher numbers than strains with the type b capsule. Adherence was related to the frequency of nontypeable strains rather than to the site of isolation or type of infection. Thus all the isolates from middle ear fluid were nontypeable, and all but one adhered. The results suggest a difference in virulence mechanisms between type b and nontypeable Haemophilus influenzae strains.

Adhesiveness↗
PubMed1984

Mutations in E coli cistrons affecting adhesion to human cells do not abolish Pap pili fiber formation.

A chromosomal DNA fragment which mediates Pap (pili associated with pyelonephritis) pili formation, mannose-resistant hemagglutination ( MRHA ) and binding to uroepithelial cells has been isolated from the uropathogenic Escherichia coli clinical isolate J96 , and genetically studied. Analysis of polypeptides expressed by the Pap DNA led to detection of a number of polypeptides ranging in mol. wt. from 13 000 to 81 000 daltons. The gene order and transcriptional orientation for four of the corresponding cistrons was: 13 000 ( papB ) 19 500 ( papA , structural gene for the Pap pilus subunit), 81 000 ( papC ) and 28 500 ( papD ). Analyses of a lacZ- papA gene fusion located a promoter upstream from papA within the cloned DNA. Transposon Tn5 insertions in any of these four cistrons decreased or eliminated Pap pili formation. A number of transposon Tn5 mutations were identified in a region distal to papD that expressed normal levels of the papA protein on the cell surface in the form of recognizable pili structures but did not agglutinate human erythrocytes or adhere to uroepithelial cells. This region expressed polypeptides of 15 000, 24 000, 26 000 and 35 000 daltons. This finding shows that Pap pili formation and binding properties can be genetically dissociated.

Antigens, Bacterial↗
PubMed1982

Experimental Escherichia coli ascending pyelonephritis in rats: changes in bacterial properties and the immune response to surface antigens.

Systemic and urinary antibody responses were examined in rats with experimental ascending pyelonephritis caused by Escherichia coli O6K13H1. During 12-month follow-up of the infections, bacterial characteristics of the urinary and renal isolates were followed: O and K antigenicity, sensitivity to the bactericidal effect of normal human serum, capacity to attach to urinary tract epithelial cells, hemolytic activity, biochemical pattern, and virulence. During the long-term infection, the urinary and renal bacterial isolates changed in O and K antigenicity, serum sensitivity, and virulence. The adhesive capacity of the bacterial isolates did not change, possibly explaining the persistence of the bacteria in the urinary tract. The serum anti-O6 antibody levels remained high during the entire 1-year observation period, especially in the rats with renal involvement. Urinary anti-O6 antibodies were also found. The serum and urinary antibodies could have played a role in bringing about the observed changes in bacterial characteristics. Antibodies to lipid A were recorded in 9 of 16 rats with pyelonephritis and renal scarring and in 1 of 9 rats not having pyelonephritis or renal bacterial growth.

Adhesiveness↗
PubMed1982

O, K, H and fimbrial antigens in Escherichia coli serotypes associated with pyelonephritis and cystitis.

O:K:H serotype determination of 267 E. coli strains from patients with pyelonephritis or cystitis led us to tentatively consider some O:K:H types, e.g. O6:K2:H1 as pyelonephritis and e.g. O6:K13:H1 as cystitis associated types. By means of crossed immunoelectrophoresis (CIE) several strains of such special O:K:H serotypes were examined for presence of the previously described fimbrial antigens, F7 and F8. Three new F antigens were designated F10, F11 and F12. The fimbrial structures of these antigens were demonstrated by immunoelectron microscopy (IEM). Based on the haemagglutinating (HA) capacity of the strains it was possible to separate differently fimbriated organisms of the same strain. The bacteria which agglutinate human erythrocytes could be absorbed out of the mixture when the erythrocytes were removed by sedimentation. When the bacteria in the supernatant no longer agglutinated human erythrocytes they were regarded as HA absorbed and were compared with non-HA absorbed bacteria for their ability to attach to epithelial cells from the urinary tract. Hence, it was concluded that F7, F8 and F10 caused haemagglutination and were responsible for the attachment to urinary epithelial cells, while the fimbriae antigenically termed pseudotype 1 did not induce haemagglutination and played little or no role for the attachment to this kind of epithelial cells.

Adhesins, Escherichia coli↗
PubMed1982

The role of pili in the adhesion of Escherichia coli to human urinary tract epithelial cells.

Pili or fimbriae were purified by a new technique involving solubilization from the bacterial outer membrane by deoxycholate and separation from flagella by 6M urea. This technique was employed to clarify the role of pili for the adherence of urinary tract pathogenic E. coli; a virulence factor in urinary tract infection. The isolated pili formed single bands in SDS gels and were pure by serologic criteria. They retained the binding properties of the whole piliated bacteria, since they bound to uroepithelial cells and agglutinated erythrocytes. Antibodies to purified pili blocked adhesion. The adhesion and hemagglutination reactions by the strains used for pilus purification were mannose-resistant but globotetraos-sensitive, i.e. the strains recognized globoseries glycolipid receptors in the target cells. The occurrence of this property in a freshly collected material of strains was tested using erythrocytes of blood groups P1, P2k and p.

Cross Reactions↗
PubMed1982

Chemical and clinical studies on the interaction of Escherichia coli with host glycolipid receptors in urinary tract infection.

The role of glycosphingolipids as host receptors, and fimbriae as bacterial ligands, for the adhesive and hemagglutinating reactions of uropathogenic E. coli was assessed. Glycolipids including globotetraosylceramide and globotriaosylceramide, which contain the disaccharide Gal alpha 1 leads to 4Gal were bound by many strains isolated from patients with pyelonephritis and cystitis. The fimbriae of one strain were shown to serve as ligands for these receptors. Although most pyelonephritic E. coli recognized globotetraosylceramide, as measured by the agglutination of glycolipid coated erythrocytes, some also recognized D-mannose residues (i.e. mannose-sensitive hemagglutination). Several strains were exclusively mannose-sensitive or bound neither globotetraosylceramide nor mannose. A genetic basis for susceptibility to infection was indicated. The erythrocytes of blood group P2 have lower amounts of Gal alpha 1 leads to 4Gal containing glycolipids than individuals of blood group P1. Blood group P2 was significantly less frequent (1/28) among patients with recurrent urinary tract infection compared to the normal population (10/40, p less than 0.02). Therefore, globoseries glycolipids may be determinants of susceptibility to urinary tract infection.

Binding Sites↗
PubMed1982

Adhesion inhibition by antibodies.

The barrier function of the mucous membranes is exerted through unspecific defense mechanisms like mechanic washing and by specific immunity. Antibodies in secretion do not mainly act through bactericidal mechanisms, but rather by binding to antigens, neutralizing, agglutinating and immobilizing them. The net result will be a decreased chance for bacteria to reach and bind to host epithelial cells. Antibodies directed against bacterial adhesions will specifically interfere with the adhesion process. On E. coli causing urinary tract infection, the surface structures responsible for adhesion may be pili or fimbriae. Evidence is accumulating that different parts of the pilus are involved in attachment and immune response. Thus, poor cross-reactivity was found between E. coli 3660 and 3048 pili, although they react with the same P blood group receptor antigens. Little cross-inhibition of adhesion was found, although each anti-pili antibody totally blocked attachment of the homologous strain. In children with acute pyelonephritis, an antibody response to pili of the infecting E. coli strain was found in serum and urine. No consistent antibody response to MS pili was found in 25 children tested.

Animals↗