The adhesion of enterobacteria and the effect of antibodies of different immunoglobulin classes.
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Adhesiveness↗
Biomedical subjects
L Edebo
Publications and source records attributed to L Edebo.
Influence of O and K antigens on the surface properties of Escherichia coli in relation to phagocytosis.
Strains of Escherichia coli with different O and K antigens were investigated with respect to physicochemical surface characteristics and liability to phagocytosis. Using two-phase partitioning analysis for the surface characterization, three main groups of strains emerged: Group I (O1:K1, O2:K1, O3:K2ab) showing both smooth hydrophilic O antigens and negatively-charged K antigen which rendered the strains maximally resistant to phagocytosis. Group II (O55:K59, O111:K58) showed no acidic K antigen but only smooth hydrophilic O antigen properties. However, these strains were as resistant to phagocytosis as the strains in group I. A third group (O14:K7, O24:K +) contained strains with rough, hydrophobic O antigen and negatively-charged K antigen. When the K antigen was removed by heat treatment these strains became more sensitive to phagocytosis. Certain other strains (O28:K-, O56:K + and O118:K-) did not fit into the three groups. These experiments show that the physicochemical surface effects and biological significance of the K antigen must be evaluated in relation to the properties conveyed by the corresponding O antigens.
Animals↗
Reduction of phagocytosis, surface hydrophobicity and charge of Salmonella typhimurium 395 MR10 by reaction with secretory IgA (SIgA).
Binding of human colostral secretory IgA (SIgA) to Salmonella typhimurium 395 MR10 decreased the liability to hydrophobic interaction of the bacteria, as analysed by hydrophobic interaction chromatography on Octyl-Sepharose and partition in an aqueous polymer two-phase system consisting of dextran, poly(ethyleneglycol) (PEG) and poly-(ethyleneglycol)-palmitate (P--PEG). SIgA also reduced the negative charge of the bacteria. Treatment of the bacteria with centrifuged but not further fractionated colostrum added positive charge to the bacteria which was removed by treatment with pepsin. Colostral SIgA reduced the in vitro phagocytosis of S. typhimurium MR10 by polymorphonuclear leucocytes. The adhesion of the bacteria to cellulose membrane filters in the absence of phagocytes was also reduced after the interaction with SIgA. It is proposed that the binding of SIgA to bacterial surfaces has hydrophilic and anti-adhesive effects, which may serve to exclude antigen from mucosal surfaces.
Cell Membrane↗
The effect of colostrum and colostral antibody SIgA on the physico-chemical properties and phagocytosis of Escherichia coli o86.
A hydrophilic effect of human colostrum and colostral antibody SIgA binding on Escherichia coli o86 has been demonstrated by hydrophobic interaction chromatography on Octyl-Sepharose and partition in a polymer two-phase system containing dextran, poly(ethyleneglycol) and poly(ethyleneglycol)-palmitate. Furthermore, antibody SIgA binding reduced the negative surface charge of the E. coli bacteria. The reaction between centrifuged but not further purified colostrum and bacteria yielded a complex which, compared to bacteria alone, showed decreased negative and increased positive surface charges, the latter being sensitive to pepsin. Binding of SIgA or colostrum to E. coli showed no definite effect on the attachment to and phagocytosis by polymorphonuclear cells in vitro. The effects observed are discussed in relation to the structure of SIgA.
Bacteriological Techniques↗
The class of antibodies sensitizing bacteria measured by mixed reverse passive antiglobulin haemagglutination (MRPAH).
A test is described which is capable of differentiating and measuring by titration the individual classes of antibody reacting with a bacterial suspension. The serum or fluid under test is incubated with the bacteria which are then very well washed and added to indicator red cells linked with specific antiglobulin reagents. Sensitization of the bacteria by a particular class of antibody is shown by haemagglutination (passive) of the appropriate red cells. Agglutination of the bacteria themselves does not preclude an analysis. The reaction, which has been developed on a brucella system, has been designated Mixed Reverse Passive Antiglobulin Haemagglutination (or MRPAH for short).
Antibodies, Anti-Idiotypic↗
The tendency of smooth and rough Salmonella typhimurium bacteria and lipopolysaccharide to hydrophobic and ionic interaction, as studied in aqueous polymer two-phase systems.
In aqueous two-phase system, the partition of bacteria and lipopolysaccharide from a rough (R) strain (Rd-mutant) of Salmonella typhimurium is influenced by polymers with covalently linked hydrophobic groups indicating hydrophobic structures accessible at the cell surface. Furthermore, the partition of the R bacteria is influenced by a number of inorganic positive and negative ions, presumably as a consequence of interaction with negatively charged surface structures. In contrast, smooth (S) bacteria and lipopolysaccharide from the parent strain do not seem to participate in either hydrophobic or charge interaction indicating extensive hydrophilicity without charge. Thus, the S-specific polysaccharide side chain of S. typhimurium might serve the purpose of blindfolding aspecific host defence mechanisms dependent on hydrophobicity and charge. On the contrary, the R bacteria and R lipopolysaccharide have physico-chemical properties which predispose to interaction with several types of cells, organelles and molecules.
Dextrans↗
Association of some enterobacteria with the intestinal mucosa of mouse in relation to their partition in aqueous polymer two-phase systems.
The association of enterobacteria with mouse intestinal mucosa has been investigated by pumping heat-killed, radioactively-labelled bacteria through the gut lumen in vitro. Approximately 20 cm of the small intestine proximal to the ileo-caecal valve was rinsed, excised and maintained in an organ bath. By using two different bacteria labelled with different radioactive isotopes, the relative association of the two bacterial pumped through the same piece of gut was determined. Cross-labelling showed that choice of isotope did not affect the association. Salmonella typhimurium 395 MR10 was used as reference and the other bacteria investigated related to it. S. typhimurium MR10 and Escherichia coli O 14 K7, which are relatively lipophilic, showed greater association than S. typhimurium 395 MS and E. coli O 111 K58, which are more hydrophilic. Prolonged incubation of bacteria with the length of intestine in vitro leading to damage of the brush border of the mucosal epithelium enhanced the association of the bacteria. These data suggest that similar physico-chemical surface properies govern the association certain enterobacteria to the intestinal mucosa as in phagocytosis with professional phagocytes.
Acetylglucosaminidase↗
Surface-charge characteristics of smooth and rough Salmonella typhimurium bacteria determined by aqueous two-phase partitioning and free zones electrophoresis.
Aqueous biphasic partitioning of Salmonella typhimurium S and R bacteria in a system containing 6.2 per cent (w/w) dextran 500 and 4.4 per cent (w/w) poly(ethyleneglycol) 6000 (PEG) was similar to the partition of the corresponding surface lipopolysaccharide (LPS). Further partition analysis with charged PEG showed that S bacteria and their LPS exposed very little charge, whereas R bacteria and their LPS showed a conspicuous negative charge at neutral pH. Free zone electrophoresis also indicated that the S bacteria have a much lower surface charge density than the R bacteria and accordingly a different surface structure. Thus, the physico-chemical properties of the bacterial surface seem to be determined to a great extent by the characteristics of the cell surface LPS.
Cell Wall↗
Physiochemical consequences of opsonization of Salmonella typhimurium with hyperimmune IgG and complement.
Partition in an aqueous, two-polymer phase system containing dextran and polyethylene glycol was employed to investigate the physico-chemical changes inflicted upon the cell surface of a smooth strain of Salmonella typhimurium by the binding of antibody IgG and complement. The minimum antibody concentration for increased phagocytosis in vitro was approximately the same as that for a significant change in two-phase partition, ca 8000 mol/bacterium, whereas a lower concentration, less than 4000 mol/bacterium, was sufficient to increase clearance in vivo. After pepsin digestion of IgG, larger quantities, ca 35,000 mol/bacterium, was required for opsonization and to influence two-phase partition. Addition of normal rabbit or guinea-pig serum to bacteria sensitized with a low concentration of antibody IgG conspicuously enhanced phagocytosis and affinity for the dextran-rich phase. The results show that binding of 8000 IgG antibody molecules or more to smooth S. typhimurium generates physicochemical changes of the bacterial surface which from studies on S leads to R mutations are known to correlate with hydrophobicity, negative charge and phagocytosis. Such results support the view that one important function of IgG antibody and complement is to decrease the hydrophilic properties of the bacteria which is thought to be a prerequisite for phagocytosis.
Binding Sites, Antibody↗
Influence of salts and gelatin on disintegration of Saccharomyces cerevisiae by freeze-pressing.
The disintegration by freeze-pressing of a low concentration of Saccharomyces cerevisiae suspended in aqueous solutions of gelatin and different salts has been studied at different temperatures. In the freeze-pressing process deionized water and salt solutions flow in pulses, whereas samples with increasing concentrations of gelatin or cells tend to flow more smoothly. This smooth flow enhances the disruption efficiency particularly at lower temperatures, which seems to be of great practical importance. The addition of salts also promotes disintegration. The presence of both gelatin and salts works antagonistically on disintegration presumably because of different modes of action at disruption of cells.
Cell Fractionation↗
Influence of cell concentration, temperature, and press performance on flow characteristics and disintegration in the freeze-pressing of Saccharomyces cerevisiae with the X-press.
The pressure required for initiation of flow when freeze-pressing with the X-press is related to the phase boundaries of water, particularly those between ice I and liquid even at temperatures around -25 degrees C and lower. Widening the orifice of the pressure chamber to diameters larger than 2.5 mm leads to lower pressures and less extensive cell disintegration. Pressing Saccharomyces cerevisiae slowly with the aid of a manual hydraulic jack at -25 degrees C produces a disintegration of 60-75% irrespective of cell concentration. Pressing at -35 degrees C shows no clear differences. Pressing more rapidly with the aid of a motor-driven hydraulic press produces a similar extent of disruption of diluted cell suspensions (5.4 mg/g) as slow pressing. However, freeze-pressing a paste of baker's yeast (270 mg/g) increases the degree of disintegration. Under these conditions the disintegration is further enhanced by a lower temperature, -35 degrees C, and by a high velocity of flow through the orifice, such that more than 95% of the S. cerevisiae is disrupted by one pressing at less than 2 X 10(8) Pa. Mechanisms for flow through the X-press are suggested and discussed in relation to the phase diagram of water.
Cell Fractionation↗
Large-scale disintegration of microorganisms by freeze-pressing.
A semicontinuous press has been constructed for the disintegration of microorganisms and other biological material by freeze-pressing, i.e., pressure extrusion of frozen material through a narrow hole. The material to be freeze-pressed is frozen in the form of cylindrical rods, which fit into the pressure chamber and are extruded by a piston forced back and forth by means of a hydraulic pump. At a sample temperature of -35 degrees C and a press temperature of -20 degrees C, about 90% disruption is achieved in a single passage of undiluted baker's yeast (Saccharomyces cerevisiae, 270 mg/g) through the orifice of the pressure chamber. With this press about 10 kg of material can be freeze-pressed per hour.
Cell Fractionation↗
Association of viable and inactivated Salmonella typhimurium 395 MS and MR 10 with HeLa cells.
The mouse-virulent Salmonella typhimurium 395 MS, containing a complete lipopolysaccharide (LPS) structure with S-specific repeating units, and the nonvirulent, LPS-defective mutant 395 MR 10 (chemotype Rd), derived from it, were studied for their tendency to interact with HeLa cells. In the definition of interaction no distinction has been made between intracellular and cell membrane-attached bacteria. R10 bacteria were found to have a greater tendency to interact than MS bacteria. This difference was seen as early as 1 h after the start of incubation, but it became more pronounced beyond 3 h. Heat-killed and ultraviolet-killed R10 bacteria interacted with HeLa cells less than living ones. Killed MS bacteria interacted to an extent similar to that of living ones. These results are discussed in relation to the susceptibility of the bacteria to phagocytosis by professional phagocytic cells and to the physiochemical properties of the bacteria as measured by their distribution in a two-polymer, aqueous-phase system.
Animals↗
On the physical-chemical effect of colostral antibody binding to Escherichia coli O 86.
Sensitization of Escherichia coli O 86 with colostrum or purified colostral sIgA antibody produces a physical-chemical change of the bacterial surface detectable as a change in partition in dextran-polyethylene glycol polymer two-phase systems. Sensitization with colostrum or sIgA reduces affinity for the dextran-rich phase. In contrast immune serum, IgG and complement increase the affinity for that phase. The results are compatible with the hypothesis that hydrophilic particles, e.g. certain strains of bacteria, are less liable to attachment to and phagocytosis by animal cells than hydrophobic particles, e.g. other bacterial strains. Sensitization with secretory IgA enhances the hydrophilicity thereby making possible an escape mechanism operating at the mucosal surfaces.
ABO Blood-Group System↗
Estimation of the disruption in freeze-pressed Saccharomyces cerevisiae by an electronic particle counter.
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Cell Count↗
Influence of hyperimmune immunoglobulin G on the physicochemical properties of the surface of Salmonella typhimurium 395 MS in relation to interaction with phagocytic cells.
Partition in an aqueous, two-polymer phase system containing dextran and polyethylene glycol was employed to investigate the physicochemical changes inflicted by the presence of immunoglobulin G (IgG) antibodies on the cell surface of a smooth strain of Salmonella typhimurium. Adding increasing amounts of anti-Salmonella IgG to the bacteria decreased the affinity for the polyethylene glycol-rich top phase, with a concomitant increase in in vivo clearance and in vitro phagocytosis by rabbit polymorphonuclear cells. Similarly, S --> R mutations in the same S. typhimurium strain decrease the affinity for the top phase and increase the liability to phagocytosis. The limiting antibody concentration to demonstrate increase of in vitro phagocytosis was approximately the same as that to produce a significant effect in the phase system, whereas lower concentrations were needed to increase the in vivo clearance. The results show that adsorption of IgG antibodies to bacteria brings about physicochemical changes of the cell surface which seem to promote the phagocytosis by polymorphonuclear cells and uptake in the reticuloendothelial system.
Animals↗
The antibactericidal effect of rabbit antiserum on the killing of a smooth strain of Salmonella enteritidis by cattle normal serum.
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Animals↗
Disintegration of single cells in suspension. Isolation of rabbit polymorphonuclear leucocyte granules.
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Alkaline Phosphatase↗