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Biomedical subjects

P F Bartell

Publications and source records attributed to P F Bartell.

At least 19 recordsLinked to original sources
PubMed1982

Carbohydrate mediation of the biological activities of the glycolipoprotein of Pseudomonas aeruginosa.

The glycolipoprotein (GLP) extracted from the surface slime of Pseudomonas aeruginosa produces effects in mice similar to those of the viable cell. The lethal activity has been located in the lipid moiety; however, degradation of the carbohydrate moiety with sodium metaperiodate reduced the antigenicity and abolished the lethality of the GLP. Similar degradation with a phage-induced polysaccharide depolymerase reduced the antigenicity only slightly but reduced the lethality over 60%. The neutral sugar composition of the isolated polysaccharide moiety was shown to be that of the parental GLP. Of the component neutral sugars, mannose and its derivatives were capable of inhibiting the agglutination of erythrocytes coated with GLP. Inhibition also occurred with a soluble mannose polymer from the cell walls of yeast. Antiserum to GLP and to its isolated polysaccharide moiety agglutinated yeast cells, whereas antiserum to a glycolipid fragment of the GLP lacking mannose did not. The lethality of the GLP was reduced by degradation with alpha-mannosidase or by blocking the mannose residues with concanavalin A, and the glycolipid fragment showed less lethality than the native GLP. We conclude that mannose, in addition to being an immunodominant sugar, is an effector sugar in the expression of GLP lethality.

Animals↗
PubMed1982

Phagocytosis and killing of Pseudomonas aeruginosa by mouse polymorphonuclear leukocytes in vitro promoted by antiserum to the slime glycolipoprotein.

The resistance of Pseudomonas aeruginosa to phagocytosis by polymorphonuclear leukocytes was overcome by opsonization with antibody to slime glycolipoprotein or, to a lesser extent, with complement. Resistance was most effectively overcome in the presence of both. Protection against viable-cell challenge conferred by anti-glycolipoprotein serum in experimental infection is discussed briefly in the light of these findings.

Animals↗
PubMed1981

Polysaccharide of the slime glycolipoprotein of Pseudomonas aeruginosa.

The polysaccharide moiety was isolated by mild acid hydrolysis from the slime glycolipoprotein of Pseudomonas aeruginosa strain BI. After gel filtration, the polysaccharide obtained from the Carbohydrate peak fractions was found to be lipid- and protein-free. Analyses indicated that the polysaccharide contained the carbohydrate components of the parent glycolipoprotein. Molecular size of the polysaccharide was estimated by gel filtration as 70,000 to 100,000. The polysaccharide showed no indications of toxicity in mice at doses far in excess of the lethal dose for the parent glycolipoprotein, nor did the mice develop the leukopenia that characteristically follows intraperitoneal injection of glycolipoprotein. The polysaccharide acted as an inhibitor of indirect hemagglutination of glycolipoprotein-coated erythrocytes in the presence of anti-glycolipoprotein serum; however, it was not antigenic itself in rabbits. Coupled with methylated bovine serum albumin, the polysaccharide continued to lack the leukopenic and toxic properties of the parent glycolipoprotein, but the coupled polysaccharide was capable of stimulating indirect hemagglutinating antibody against both the polysaccharide and the glycolipoprotein coating erythrocytes. Moreover, the antibody to the coupled polysaccharide protected mice against challenge with lethal doses of viable P. aeruginosa with the same effectiveness as anti-glycolipoprotein serum.

Animals↗
PubMed1980

Influence of anti-slime glycolipoprotein serum on the interaction between Pseudomonas aeruginosa and macrophages.

Glycolipoprotein, a purified fraction of the exopolysaccharide slime of Pseudomonas aeruginosa, was identified as responsible for a number of the biological activities of viable cells, including toxicity and immunogenicity capable of stimulating protective antibody against the lethal effects of viable cells. Antiserum against glycolipoprotein also mediated the phagocytosis and subsequent killing of viable P. aeruginosa by unstimulated mouse peritoneal macrophages. In the absence of anti-glycolipoprotein serum, macrophages did not significantly reduce the number of bacteria. The presence of complement in the experimental mixture did not affect the reduction of bacteria by the macrophage in the presence of anti-glycolipoprotein serum. The limiting effect of antiserum concentration on macrophage activity was studied, and maximal activity was found at 2%, with no further increase in activity at 5% Preopsonization of the bacteria with anti-glycolipoprotein serum had little effect on the course of phagocytosis within the experimental conditions. Variations in bacterium-to-macrophage input ratios, ranging from 30:1 to 1:30, did not affect the capacity of the macrophages for phagocytosis.

Animals↗
PubMed1980

Slime glycolipoproteins and the pathogenicity of various strains of Pseudomonas aeruginosa in experimental infection.

Several strains of Pseudomonas aeruginosa were differentiated on the basis of the surface properties of the cells. Fisher immunotype, phage type, polysaccharide depolymerase type, and indirect hemagglutination reactions were used for this purpose. Each strain was then studied with respect to events known to occur during the experimental infection of mice with P. aeruginosa. The virulence of the viable cells varied significantly, although all strains were virulent. Glycolipoproteins were isolated from the slime of each strain, and they appeared similar chemically when they were analyzed for gross composition. The toxicity of the isolated glycolipoproteins varied insignificantly, except for that of one strain. Viable cells of each strain and their respective glycolipoproteins caused leukopenia, which occurs in the course of the lethal infection. The antisera to the glycolipoproteins protected mice in every case against infection by the homologous strains. In some cases, various degrees of cross-protection were observed.

Antibodies, Bacterial↗
PubMed1979

Phage-related surface modifications of Pseudomonas aeruginosa: effects on the biological activity of viable cells.

Lysogenic [EI(8)3] and phage 8-resistant mutant (EI/8S17) strains of Pseudomonas aeruginosa EI were isolated. Besides lacking the capacity to adsorb phage 8, strains EI(8)3 and EI/8s17 did not contain surface substrate for the depolymerase that is produced de novo when phage 8 infects wild-type strain. EI. The glycolipoprotein (GLP) in the wild type contains phage 8 receptors and surface substrate for the depolymerase, as well as possesses characteristics of a virulence factor; therefore, the chemical and biological characteristics of the derived strains were investigated. The neutral-sugar, amino sugar, and protein content of the GLPs from the derived strains differed quantitatively from that of the wild type. In spite of some cross-reactivity, the GLPs from all strains were antigenically distinct in the indirect hemagglutination inhibition test. In mice, the toxicity of the GLP from strain EI(8)3 equaled that of the wild type, but the GLP of strain EI/8s17 was threefold less toxic. Significantly fewer viable EI(8)3 cells were required for the mouse 50% lethal dose than for the cells of either the wild type or the phage-resistant mutant.

Antigens, Bacterial↗
PubMed1977

In vivo distribution of Pseudomonas aeruginosa slime glycolipoprotein: association with leukocytes.

Intraperitoneal injection of slime glycolipoprotein (GLP) from Pseudomonas aeruginosa induced leukopenia and death of mice, similar to the effect of infection with viable organisms. Differential counts established that the leukopenia was characterized by a decrease in the number of polymorphonuclear leukocytes, followed by death of mice. Mice immunized with GLP survived challenge and responded with a leukocytosis that had a substantial increase in circulating polymorphonuclear leukocytes. Leukocytes from GLP-injected mice were agglutinated by anti-GLP serum, indicating an association between GLP and leukocytes. Other results indicated that 14C-labeled GLP is deposited mainly in the liver. Normal leukocytes labeled with 51Cr were injected intravenously into mice receiving an intraperitoneal injection of GLP. As with GLP, the 51Gr-labeled leukocytes were sequestered in the liver. These results indicate that GLP enters the blood stream and becomes associated mainly with neutrophils, and that the neutrophil-GLP complex is deposited in the liver, possibly accounting for the leukopenia in mice.

Agglutination Tests↗
PubMed1977

Glycolipoprotein from Pseudomonas aeruginosa as a protective antigen against P. aeruginosa infection in mice.

After primary subcutaneous immunization of rabbits with glycolipoprotein from Pseudomonas aeruginosa BI, indirect hemagglutinating and bacterial agglutinating activities appeared in the antiserum 6 days after immunization and reached a peak between 15 and 20 days. Both these in vitro activities paralleled in vivo antipseudomonas-induced leukopenia and mouse passive-protection activities. Further experiments indicated that a functional association exists between the hemagglutinating and passive-protection activities, and that passive protection depends on activity levels in the plasma rather than in the peritoneum. After intraperitoneal injection in mice, in vitro and in vivo activities of antiglycolipoprotein serum declined in the peritoneal cavity as the plasma levels increased. After intravenous injection of the antiglycolipoprotein serum, initially high levels of in vitro and in vivo activity declined at approximately equal rates. Immunoglobulin G (IgG) and immunoglobulin M (IgM) fractions from 15-day antiglycolipoprotein serum were assayed for biological activity. Most of the hemagglutinating and bacterial agglutinating activity and all of the mouse passive-protection activity were found in the IgM fraction. Assay of antiglycolipoprotein serum after 2-mercaptoethanol inactivation of IgM showed that most of the in vitro and all of the passive-protection activities had been destroyed, again locating these activities principally in the IgM fraction of the original antiserum.

Agglutinins↗
PubMed1976

Localization and functional role of the pseudomonas bacteriophage 2 depolymerase.

The adsorption apparatus of phage 2 consits of a symmetrical base plate of snowflake appearance, composed of six droplike spikes 7.0 to 7.5 nm in length with a maximum diameter of 4.5 to 5.0 nm. The spikes are attached by their narrow ends to a central ring 7.0 to 7.5 nm in diameter. Phage 2 deopolymerase, a phage 2-induced hydrolytic enzyme, was found to be a structural protein of phage 2 or in close association with the base plate. Pdp1, a phage 2 mutant, possesses a polypeptide that is antigenically similar to the depolymerase, but devoid of hydrolytic activity. This polypeptide was found to be located in the region of the base plate of pdp1. Treatment of intact cells of strain BI with purified phage 2 depolymerase inhibited the adsorption of phage 2. When phage receptor-containing fractions of slime glycolipoprotein and lipopolysaccharide were hydrolyzed by the depolymerase, amino sugars were released, and the phage-inactivating activities of these fractions were lost. The depolymerase was also observed to induce the lysis of strain BI cells in hypotenic medium. The phage 2 depolymerase appears to play a role in adsorption and release of phage.

Adsorption↗
PubMed1975

Biological activity of fragments derived from the extracellular slime glycolipoprotein of Pseudomonas aeruginosa.

Glycolipoprotein, obtained from the extracellular slime layer of Pseudomonas aeruginosa, was purfied and subjected to chemical and enzymatic treatment in an attempt to assign certain of its biological activities to chemical moieties comprising the glycolipoprotein molecule. Treatment of the glycolipoprotein with phenol, although removing all detectable protein, yielded a fragment capable to exerting the biological activities associated with the untreated glycolipoprotein (leucopenia, lethality, inhibition of phagocytosis, antigenic specificity). Acetic acid treatment resulted in a fragment composed mainly of carbohydrate and a small amount of protein, but no detectable lipid. This fragment was devoid of leucopenic and lethal activity, but retained antigenic specificity and the ability to inhibit phagocytosis. The fragments release from the glycolipoprotein after treatment with phage 2-depolymerase were low-molecular-weight products and were devoid of the biological activities associate with the glycolipoprotein.

Animals↗
PubMed1974

Slime of Pseudomonas aeruginosa: in vivo production.

Indirect hemagglutination inhibition tests were employed to detect slime in concentrations as low as 1 mug/ml. Increasing concentrations of slime resulted in proportionately greater inhibition of hemagglutination. Peritoneal aspirates and plasma of mice injected with slime were shown to exhibit the inhibitory activity of slime. The rapid dissemination of slime into the peripheral circulation was also indicated by the hemagglutination of mouse erythrocytes by specific anti-slime serum. By similar methods, the inhibitory activity of slime was also detected in peritoneal aspirates and plasma of mice infected with lethal doses of viable Pseudomonas aeruginosa. Furthermore, the inhibitory activity was found to increase with time after viable cell infection, whereas such increases were not detected after the injection of heat-killed organisms. Ferritin-labeled slime antibodies were found to completely surround cells of Pseudomonas aeruginosa obtained from the peritoneal cavity of mice 5 h postinfection.

Animals↗
PubMed1974

Factors influencing the adsorption of bacteriophage 2 to cells of Pseudomonas aeruginosa.

Phage 2 adsorbed to Pseudomonas aeruginosa strain BI in 5 mM Tris buffer, providing that cations like Na(+), Mg(2+), or Ca(2+) were present. Adsorption was observed over a broad pH range, reaching a maximum level around pH 7.5, which coincided with the pH required for maximal activity of the phage 2-associated slime polysaccharide depolymerase. Mutants of strain BI and other strains of P. aeruginosa possessing slime layers that were devoid of phage 2 depolymerase substrate were incapable of adsorbing phage 2. On the other hand, those strains containing substrate for the phage 2 depolymerase in the slime layer were capable of adsorbing phage 2. The same relationship of phage depolymerase-substrate interaction to phage adsorption was observed with Pseudomonas phage 8, which possesses a depolymerase that differs in its specificity from the phage 2 depolymerase. The receptor-like activity of purified slime containing the specific substrate for the phage-associated depolymerase was demonstrable by its ability to inactivate phage. However, receptor-like activity or phage inactivation was not observed with those slimes that were devoid of the depolymerase substrate.

Adsorption↗
PubMed1974

Studies on the bacteriophage 2 receptors of Pseudomonas aeruginosa.

The lysogenization of Pseudomonas aeruginosa strain BI with phage 2 resulted in the loss of the capacity to adsorb the same phage. The absence of phage 2 receptors on the surface of the lysogenized strain BI(2)(8) was confirmed by the failure of purified slime polysaccharide (SPB) or lipopolysaccharide (LPS) to inactivate phage 2. SPB and LPS from a phage 2-resistant strain also failed to inactivate phage 2 in contrast to the phage inactivation exhibited by the SPB and LPS obtained from the wild-type strain BI. Chemically, quantitative differences were apparent when the SPB and LPS of strains BI(2)(8) and BI/2S(2) were compared with those of the wild-type strain BI. The most striking difference noted was the absence of amino sugars in the SPB of strain BI/2S(2). The SPB of strain BI(2)(8) also contained a lower percentage of amino sugars compared with the SPB of the wild-type strain BI.

Adsorption↗
PubMed1971

Interaction of Pseudomonas bacteriophage 2 with the slime polysaccharide and lipopolysaccharide of Pseudomonas aeruginosa strain B1.

Purified slime polysaccharide B and lipopolysaccharide of Pseudomonas aeruginosa strain BI were shown to possess receptor-like properties in inactivating Pseudomonas phage 2, whereas lipoprotein and glycopeptide fractions were devoid of activity. On a weight basis, slime polysaccharide B was more effective than lipopolysaccharide in inactivating phage. The specificity of the reaction with slime polysaccharide B was indicated by the fact that slime polysaccharide A of P. aeruginosa strain EI failed to inactivate phage 2. Electron micrographs showed phage 2 in typical, tail-first position of attachment on intact cells of strain BI, slime polysaccharide B, and lipopolysaccharide. Tail fibers were discernible during phage attachment.

Adsorption↗
PubMed1970

Purification and Chemical Composition of the Protective Slime Antigen of Pseudomonas aeruginosa.

The slime obtained from Pseudomonas aeruginosa strain BI was purified by a system of ethanol precipitation, gel filtration, and ion-exchange chromatography. The slime polysaccharide was eluted as a single peak at a potassium chloride molarity of 0.30 to 0.40. The purification procedure was monitored by immunodiffusion techniques, and the number of bands was reduced from four to one, indicating the elimination of antigenic impurities that were present in the crude extracts of slime. The purified slime behaved as a homogeneous antigen, stimulating the production of a single species of antibody in rabbits. Hydrolyzed preparations of purified slime contained rhamnose, glucose, mannose, glucosamine, galactosamine, and glucuronic acid, as well as N-acetyl and O-acetyl groups. Only trace amounts of nucleic acids were detectable. A significant amount of protein was found to be associated with the carbohydrate moiety. The substrate characteristic of the slime was reaffirmed by measuring the release of hexosamines in the presence of the Pseudomonas phage 2 depolymerase PDB(2), and its activity as a protective antigen was demonstrated in passive-protection tests of mice.

Journal Article↗
PubMed1969

Origin of polysaccharide depolymerase associated with bacteriophage infection.

Analyses, by construction of phage growth curves, indicated that the polysaccharide depolymerase was synthesized by Pseudomonas aeruginosa strains B and BI after infection with phage 2. The kinetics of biosynthesis of the depolymerase were found to parallel closely the rate of formation of phage-directed virions, and alterations in the experimental conditions of infection were reflected by alterations in the production of enzyme. Infection with other Pseudomonas phages, 84 and 1197, did not result in the synthesis of depolymerase. The enzyme was not detectable in uninfected cultures, and no evidence was obtained for the existence of inhibitors or activators of enzyme activity in extracts of uninfected or infected cells. The results of experiments employing chloramphenicol or an auxotorphic mutant (BI arg(-)) suggested that protein synthesis de novo was essential for production of the enzyme. Various mutants of phage 2 (pdp(1), pdp(2)), which alter the synthesis of the polysaccharide depolymerase, have been isolated. These experimental results strongly support the role of the phage genome in the synthesis of this enzyme.

Arginine↗
PubMed1969

Distinct slime polysaccharide depolymerases of bacteriophage-infected Pseudomonas aeruginosa: evidence of close association with the structured bacteriophage particle.

Five new polysaccharide depolymerases were isolated from cultures of Pseudomonas aeruginosa infected with phages 6, 7, 8, 9, and 10. The production of enzyme paralleled the release of phage. Depolymerase associated with phage 8 was active on slime polysaccharide A, whereas depolymerases associated with phages 6, 7, 9, and 10, like pseudomonas phage 2, hydrolyzed slime polysaccharide B. None of the depolymerases was active on slime polysaccharide C. Despite exhaustive purification, depolymerase activity was found to band with the phage particles at a density of 1.49 to 1.51 g/ml in a density gradient composed to cesium chloride. These results suggest that the depolymerases are firmly bound to the phage particles.

Bacteriophages↗