Mild alkaline hydrolysis of lipopolysaccharide endotoxin enhances its mitogencity for murine B cells

Mild alkaline hydrolysis was found to enhance the mitogenicity of lipopolysaccharide endotoxin for murine B lymphocytes. Alkaline treated lipopolysaccharide also retained its property as a polyclonal activator. Whereas this treatment reduced the lethality of endotoxin for mice, its toxicity for lymphocytes cultured in the absence of fetal calf serum was increased. Lipid analysis indicated that there were no significant changes in the fatty acids of lipid A, but particle size was significantly reduced and the material was more homogeneous and soluble than untreated lipopolysaccharide. The relationship of these effect on the structure of lipopolysaccharide endotoxin to the mechanism of B-lymphocyte activation is discussed.

Structural analysis of the surface polysaccharide of Staphylococcus aureus M

The chemical structure of the surface polysaccharide from Staphylococcus aureus M was investigated by a combination of methanolytic, hydrolytic, and chromatographic techniques. The repeating unit that was most consistent with the data was a hexasaccharide composed of N-acetyl-D-aminogalacturonic acid, N-acetyl-D-fucosamine, and taurine in molar ratios of 4:2:1. A disaccharide was isolated and characterized, by combined gas-liquid chromatography-mass spectrometry, as N-acetyl-D-aminogalacturonyl-(1 leads to 3)-N-acetyl-D-fucosamine. Taurine is linked to a carboxyl group of N-acetyl-D-aminogalacturonic acid via an amide bond.

Identification of lipopolysaccharides and phospholipids of Escherichia coli in polyacrylamide gels

Polyacrylamide gel electrophoresis of unfractionated lysates of radioactively labeled cells resolves not only proteins and polynucleotides into discrete bands but also cellular lipopolysaccharides and phospholipids. This allows a determination of the intracellular amounts of all of these macromolecules. In addition, this technique is sensitive enough to detect mutational alterations in lipopolysaccharide structure. Polyacrylamide gel electrophoresis is herein shown to be a useful tool for investigations into the structure of lipopolysaccharides and the synthesis of lipopolysaccharides and phospholipids.

Multiple polysaccharide antigens of group B streptococcus, type Ia: emphasis on a sialic acid type-specific polysaccharide

Group B streptococci, type Ia (strain 090/14/4), were subjected to sequential extraction procedures and the various extracts were fractionated by a combination of DEAE-cellulose chromatography and gel-filtration. Three major antigens were isolated: the conventional group-specific and type-specific carbohydrates and an acidic polysaccharide consisting of galactose, glucose, glucosamine, and sialic acid. Immunochemical data suggest that the acidic antigen, with the exception of the immunodominant sialic acid, is structurally similar to the conventional pH 2.0 extracted type-specific antigen. Removal of the terminal sialic acid residues from the acidic antigen by mild acid hydrolysis resulted in a residual polymer which was chemically and immunologically analogous to the type-specific carbohydrate. Precipitin analysis focused attention to the cross-reactivity between thia acidic antigen and anti-types Ib, Ic, and III sera.

Biological and physicochemical properties of the lipopolysaccharide of Chromatium vinosum

The lipopolysaccharide (LPS) of Chromatium vinosum has anticomplementary activity. This anticomplementary activity is destroyed by alkaline digestion of the LPS and is suppressed by both Mg2+ and Ca2+ ions. Treatment of the LPS with ethylenediaminetetraacetic acid, sodium deoxycholate, or dimethyl sulfoxide did not affect its toxicity toward mice; however, alkaline-treated LPS was not toxic. Treatment of the LPS with sodium deoxycholate, dimethyl sulfoxide, or sodium dodecyl sulfate resulted in reversible dissociation into subunits. Aggregation of the subunits into the original form was achieved by removing the dispersing agent by dialysis against distilled water followed by freezing and thawing. Electron micrographs of phenol-extracted LPS showed long filaments. Electron micrographs of sodium deoxycholate- and sodium dodecyl sulfate-treated and dialyzed LPS showed a mixture of small subunits and short filaments, whereas dimethyl sulfoxide-treated and dialyzed LPS contained only small ovoid spheres. The LPS produced an ordered series of multiple bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A similar banding pattern was observed for Salmonella abortus-equi and Proteus mirabilis LPS. The C. vinosum LPS appears to be mitogenic for mouse spleen cells.

Structural investigation of Klebsiella serotype K36 polysaccharide

Klebsiella D36 capsular polysaccharide has been investigated by methylation, Smith-periodate oxidation and partial hydrolysis techniques. The structure was found to consist of a hexasaccharide repeating unit as shown. The anomeric configurations of the sugar residues were determined by 1H and 13Cn.m.r.spectroscopy on isolated oligomers obtained during the degradative studies and on the intact polysaccharide.

[Chemical composition of cells of a chemostatic culture of Bacillus megaterium during exposure to an alkaline pH value]

The culture of Bacillus megaterium was grown under chemostat conditions at a rate of 0.2, 0.4 and 0.7 hr-1, the growth being limited by a low content of citrate, and at alkaline pH values. Critical pH values were obtained for each growth rate: 9.6, 9.2 and 7.6, respectively. The content of protein decreased at alkaline pH, while the synthesis of total lipids, poly-beta-hydroxybutric acid and phospholipids was stimulated. Some changes were found in the ratio between polyphosphates of high molecular weight.

Analytical characterization of lipopolysaccharide antigens from seven strains of Pseudomonas aeruginosa

Lipopolysaccharide antigens from seven different serotype strains (antigen immunotypes Nos. 1-7 in the classification of Fisher et al.3) of Pseudomonas aeruginosa have been analyzed for neutral carbohydrate, amino sugars, lipid, protein, 3-deoxy-manno-octulosonic acid, and phosphorus. The individual amino sugars were determined for each antigen type; all contained 2-amino-2-deoxy-D-glucose and -D-galactose, together with 2-amino-2,6-dideoxygalactose; the latter as isolated from the type 2 antigen was identified as the DL form. In addition, 2-amino-2,6-dideoxy-D-glucose was present in the types 3, 4, and 5 antigens. Mild, acid hydrolysis of the antigens gave the lipid A component containing all of the lipid and 2-amino-2-deoxy-D-glucose, together with lipid A-free polysaccharides that contained principally carbohydrate. The lipid A-free polysaccharides all contained L-rhamnose and D-glucose, together with 2-amino-2,6-dideoxygalactose in all except those from types 1, 5, and 7; that from type 6 also contained D-xylose.

Purification and immunochemical characterization of the outer membrane complex of Bacteroides melaninogenicus subspecies asaccharolyticus

Morphologic study of Bacteroides melaninogenicus subspecies asaccharolyticus by electron microscopy disclosed the presence of a capsule and a cell wall structure otherwise typical of a gram-negative organism. An outer membrane complex was isolated with use of gentle methods. Relative purity of the preparation was confirmed by electron microscopy and by the formation of a single band in a sucrose density gradient. Gel chromatography was used for separation of the major components of the membrane. Antigenicity of the first component, a protein-polysaccharide complex, which cross-reacted with antiserum to another strain of the same subspecies. This component probably represents the capsular antigen and may prove to be the basis for serogrouping. The second membrane fraction differed chemically from the first fraction and represents the lipopolysaccharide component of the outer membrane. Notably, this component lacks 2-keto-3-deoxyoctonate, one of the backbone sugars of aerobic, gram-negative lipopolysaccharides.

Polysaccharide capsule of Escherichia coli: microscope study of its size, structure, and sites of synthesis

This report describes the structure, size, and shape of the uncollapsed polysaccharide capsule of Escherichia coli strain Bi 161/42 [O9:K29(A):H-], its ultrastructural preservation as well as the filamentous components of the isolated capsular material. In a temperature-sensitive mutant, sites were localized at which capsular polysaccharide is "exported" to the cell surface. The highly hydrated capsule of the wild-type cells was visible in the uncollapsed state after freeze-etching, whereas dehydration in greater than or equal to 50% acetone or alcohol caused the capsule to collapse into thick bundles. This was prevented by pretreatment of the cell with capsule-specific immunoglobulin G; the capsule appeared as a homogeneous layer of 250- to 300-nm thickness. The structural preservation depended on the concentration of the anti-capsular immunoglobulin G. Temperature-sensitive mutants, unable to produce capsular antigen at elevated temperatures, showed, 10 to 15 min after shift down to permissive temperature, polysaccharide strands with K29 specificity appearing at the cell surface at roughly 20 sites per cell; concomitantly, capsule-directed antibody started to agglutinate the bacteria. The sites at which the new antigen emerged were found in random distribution over the entire surface of the organism. Spreading of purified polysaccharide was achieved on air-water interfaces; after subsequent shadow casting with heavy metal, filamentous elements were observed with a smallest class of filaments measuring 250 nm in length and 3 to 6 nm in width. At one end these fibers revealed a knoblike structure of about 10-nm diameter. The slimelike polysaccharides from mutants produced filamentous bundles of greater than 100-microns length, with antigenic and phage-receptor properties indistinguishable from those of the wild-type K29 capsule antigen.

Homogeneity of lipopolysaccharides from Acholeplasma

Five methods were employed to determine the heterogeneity or homogeneity of lipopolysaccharides from four acholeplasmal species, Acholeplasma axanthum, A. granularum, A. laidlawii, and A. modicum. A axanthum lipopolysaccharide behaved as a single component in all tests. A. granularum exhibited two components of identical composition and antigenic specificity. A. modicum lipopolysaccharide behaved as three components in two tests, but all three were similar in composition and identical serologically. The separable components of lipopolysaccharides from A. granularum and A. modicum probably represent size differences only. A. laidlwii lipopolysaccharide contained two distinct components by all methods. One was identified as the previously reported amino sugar polymer, whereas the other was a lipopolysaccharide containing both neutral and amino sugars.

Klebsiella serotype 25 capsular polysaccharide: primary structure and depolymerization by a bacteriophage-borne glycanase

By partial acid hydrolysis, methylation and gas-liquid chromatography-mass spectrometry of the methylated monomers (as the alditol acetates), mass spectrometry of trimethylsilylated disaccharide alditols, as well as proton magnetic resonance, the primary structure of the Klebsiella serotype 25 capsular polysaccharide was elucidated. A glycanase activity, associated with the particles of newly isolated Klebsiella bacteriophage no. 25, was shown to catalyze the hydrolysis of the glycan.

Presence of 3-O-methyl-l-xylose in the lipopolysaccharide of Pseudomonas maltophilia N.C.T.C. 10257

3-O-Methyl-L-xylose was isolated from whole cells of Pseudomonas maltophilia N.C.T.C. 10257. The sugar is a component of lipopolysaccharide from which a polysaccharide also containing L-rhamnose and L-xylose was released by mild acid hydrolysis. 3-O-Methyl-L-xylose was absent from five other strains of Ps. maltophilia and one strain of Pseudomonas geniculata.

Determination of bacterial number and biomass in the marine environment

Three techniques for the measurement of bacterial numbers and biomass in the marine environment are described. Two are direct methods for counting bacteria. The first employs an epifluorescence microscope to view bacteria that have been concentrated on membrane filters and stained with acridine orange. The second uses a transmission electron microscope for observing replicas of bacteria that are concentrated on membrane filters. The other technique uses Limulus amebocyte lysate, an aqueous extract from the amebocytes of the horseshoe crab, Limulus polyphemus, to quantitate lipopolysaccharide (LPS) in seawater samples. The biomass of gram-negative (LPS containing) bacteria was shown to be related to the LPS content of the samples. A factor of 6.35 was determined for converting LPS to bacterial carbon.

The capsule of the gonococcus

16 strains of Neisseria gonorrhoeae were subjected to several established techniques for capsule demonstration by light microscopy. In all strains examined, encapsulation of the gonococcus was demonstrated. Although the capsules were somewhat more easily seen in strains recently isolated from clinical material, organisms that had been passaged for several years also were encapsulated as were all the colony types within these strains. The gonococcal capsule is easily disrupted by mechanical forces.

Screening for cross-reacting capsular polysaccharide K antigens of Escherichia coli using antiserum agar

Agar plates containing antiserum against group B meningococcus or Haemophilus influenzae type b were used to determine the prevalence of cross-reacting K1 and K100 capsular polysaccharide antigens in 265 isolates of disease-causing Escherichia coli. K1 antigen was found in 22% of isolates from various sites. K100 antigen was found in only three isolates. This technique is a convenient method to detect specific E. coli K antigens for evaluation as possible factors important in the virulence of the organism.

Synthesis of "group polysaccharide" by membranes from Streptococcus pyogenes and its stabilized L-form

Rhamnose and N-acetylglucosamine (GlcNAc) are incorporated from thymidine 5'-diphosphorhamnose and uridine 5-diphospho-N-acetylglucosamine (UDPGlcNAc) into membrane fragments prepared from Streptococcus pyogenes but not into membrane fragements prepared from a stabilized L-form of this organism. Incorporation from TDPrhamnose is partially dependent upon UDPGlcNAc and vice versa. The oligomeric GlcNAc and rhamonose-containing products are easily extracted from membrane particles by sedimentation through detergent solutions. They are substantially extracted into methanol but not into chloroform-methanol (2:1). When product containing both radioactive rhamnose and GlcNAc is deacetylated and hydrolyzed briefy in acid, glucosaminyl rhamnose is obtained, byt not higher oligomers, suggesting that oligomer synthesis in vitro is terminated because unidentified wnzymatic requirements are not satisfied. The data are consistent with the assembly of group A-specific polysaccharide at the cellular membrane with participation of a lipoid anchor (acceptor) molecule.

Capsular polysaccharide of Clostridium perfringens Hobbs 9

Several closely related capsular polysaccharides were isolated from a strain of Clostridium perfringens Hobbs 9 type A by extraction of encapsulated cells with cold 0.85% NaCl. The soluble polymers were precipitated with alcohol and purified by (NH4)2SO4 fractionation, enzymatic digestion with papain and ribonuclease, and chromatography on diethylaminoethyl-Sephadex A25. The polysaccharides were composed mainly of glucose, galactose, and galactosamine. The major fraction contained these constituents (representing 77% of the dry weight) in a molar ratio of 1:1.6:1.1. All of the fractions contained phosphate and peptide material that was not removed during purification. The polysaccharides were closely related but not identical as indicated by double-diffusion-in-gel experiments. Immunoelectrophoresis in agarose demonstrated that the polysaccharides had identical mobilities and that no resolution into additional fractions occurred. The immunological activity of all the purified polysaccharides was destroyed by periodate oxidation but was unaffected by protease.

Isolation of the capsular polysaccharide from culture supernatant of Haemophilus influenzae type b

The capsular polysaccharide (CP) of Haemophilus influenzae type b is known to be spontaneously released from the cells in culture. The CP is precipitable from culture supernatant by the cationic detergent hexadecyltrimethylammonium. Most of the nucleic acid and some of the protein, but almost none of the endotoxin, in the supernatant are co-precipitated. Extraction of the precipitate with progressively stronger NaCl solutions separates nucleic acid and protein from the CP and also effects a molecular size fractionation. Residual endotoxin and protein can be reduced by extraction with cold phenol and ultracentrifugation. The resulting preparation has ribose, ribitol, and phosphate as principal components and contains less than 1% other sugars, protein, or nucleic acid; it elutes on Sepharose 2B as a symmetrical peak with Kav 0.51.

Distribution of lipopolysaccharide and the detection of a new subfraction in the cell envelope of a marine pseudomonad

The three outer layers of the cell envelope of marine pseudomonad B-16, the loosely bound outer layer, the outer membrane, and the periplasmic space layer, are the only ones containing appreciable amounts of both lipid and carbohydrate. These layers and a fraction released into the medium during growth of the cells were examined for the presence of common antigens by double immunodiffusion using anti-whole serum. Each of the layers, the medium fraction, and lipopolysaccharide (LPS) isolated from the organism were shown to contain two or more diffusible components showing reactions of identity. Thus LPS is found in each of the three outer layers of the cell envelope of this gram-negative bacterium. The periplasmic space layer was found to contain a fraction accounting for 20% of the dry weight of the layer, which was sedimentable at 30,000 x g and contained lipid, protein, and carbohydrate. Double-immunodiffusion tests indicated that the fraction contained at least one of the two antigens present in isolated LPS. A particulate material was released by the cells during growth which gave a positive test for 2-keto-3-deoxyoctulosonic acid and cross-reacted serologically with LPS.

Characterization of an immunogenic fraction of Pasteurella multocida culture filtrates

An immunogenic fraction (IF) of Pasteurella multocida strain P-1059 was separated from culture filtrate by Sephadex gel filtration. Additional fractionation of IF with aqueous ether resulted in the glycoprotein-like preparation (GLP) while extraction with aqueous phenol provided the lipopolysaccharide-like preparation (LPP). The unextracted IF contained carbohydrate, protein, and lipid; the GLP contained carbohydrate and protein; and the LPP contained carbohydrate and lipid. The GLP was maximally protective for mice against homologous challenge, and was medially toxic in rabbit skin when compared to the other culture-filtrate preparations; the LPP was maximally toxic in rabbit skin, and was least protective for mice; and the unextracted IF was medially protective for mice, and was least toxic in rabbit skin.