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PubMed1998

Spectrophotometric and spectrofluorometric studies on interaction of cationic dyes with bacterial capsular polysaccharide.

Interaction of Klebsiella K14 capsular polysaccharide with cationic dyes pinacyanol chloride, acridine orange and phenosafranin has been studied by spectrophotometric and spectrofluorometric techniques. The polymer containing both glucuronic acid and pyruvic acid in its repeating unit behaved as a unique polyelectrolyte. It induced blue shift of the absorption band of pinacyanol chloride indicating strong metachromasy. Stoichiometry of the polyanion and the dye cations in the polymer-dye compound (1:2) indicated that both glucuronic acid and pyruvic acid acted as potential anionic sites for interaction with the cationic dye molecules. The stoichiometry of anionic site (of polyanion): cationic site (of dye) in the polymer dye compound was calculated as 1:1. Interaction of the polymer with acridine orange and phenosafranin dyes studied by fluorescence measurements demonstrated Stern-Volmer type of quenching. Equivalent weight of the polymer was determined by spectrophotometric and spectrofluorometric titrations. From the present studies chromotropic property of the polymer was established.

Acridine Orange↗

PubMed2002

Recognition of bacterial capsular polysaccharides and lipopolysaccharides by the macrophage mannose receptor.

The in vitro binding of the macrophage mannose receptor to a range of different bacterial polysaccharides was investigated. The receptor was shown to bind to purified capsular polysaccharides from Streptococcus pneumoniae and to the lipopolysaccharides, but not capsular polysaccharides, from Klebsiella pneumoniae. Binding was Ca(2+)-dependent and inhibitable with d-mannose. A fusion protein of the mannose receptor containing carbohydrate recognition domains 4-7 and a full-length soluble form of the mannose receptor containing all domains external to the transmembrane region both displayed very similar binding specificities toward bacterial polysaccharides, suggesting that domains 4-7 are sufficient for recognition of these structures. Surprisingly, no direct correlation could be made between polysaccharide structure and binding to the mannose receptor, suggesting that polysaccharide conformation may play an important role in recognition. The full-length soluble form of the mannose receptor was able to bind simultaneously both polysaccharide via the carbohydrate recognition domains and sulfated oligosaccharide via the cysteine-rich domain. The possible involvement of the mannose receptor, either cell surface or soluble, in the innate and adaptive immune responses to bacterial polysaccharides is discussed.

Animals↗

PubMed1990

Molecular size characterization of bacterial capsular polysaccharide vaccines by high performance liquid chromatography.

Bacterial capsular polysaccharides are major virulence factors and some are used as vaccinal antigens. Their molecular size is an important physicochemical criterion which correlates with immunogenicity. This article describes a new application of high performance liquid chromatography (HPLC), based on molecular sieving, for such an evaluation. This HPLC method is rapid, accurate, reproducible, requires only very low amounts of product and presents good correlation with conventional gel permeation chromatography.

Bacterial Capsules↗

PubMed1994

Iron-binding affinity of bacterial vaccine polysaccharides which contain phosphodiester linkages as part of the polymer chain and of other polyphosphates, including DNA.

The interaction of iron (II) with bacterial polysaccharides, possessing phosphodiester bonds as part of their polymer chain, has been studied by equilibrium binding dialysis using atomic absorption spectrophotometry. Ferrous ions were found to bind with a stoichiometry of one per two phosphates and with a binding constant of about 2.5 x 10(3) M-1. Similar results, but with larger (ca 1 x 10(4) M-1) binding constants were observed with DNA. This interaction helps explain the depolymerization of polyphosphates which has been observed in the presence of iron salts, and highlights the need to avoid iron contamination of vaccines (and other substances) which contain phosphodiester bonds. The interaction may also be a means of iron sequestration in bacteria which possess these cell-surface polyphosphates.

Bacterial Vaccines↗

PubMed1964

PATHWAYS FOR BIOSYNTHESIS OF A BACTERIAL CAPSULAR POLYSACCHARIDE. IV. CAPSULE RESYNTHESIS BY DECAPSULATED RESTING-CELL SUSPENSIONS.

Juni, Elliot (Emory University, Atlanta, Ga.), and Gloria A. Heym. Pathways for biosynthesis of a bacterial capsular polysaccharide. IV. Capsule resynthesis by decapsulated resting-cell suspensions. J. Bacteriol. 87:461-467. 1964.-Methods were devised for stripping capsules from encapsulated bacteria. By use of stripped resting-cell suspensions of a gram-negative capsule-forming coccus, it was shown that polysaccharide capsule resynthesis depends upon the presence of air and an oxidizable substrate. Capsule resynthesis proceeds linearly with time. For a given quantity of stripped cells, the net amount of polysaccharide capsule synthesized is a linear function of the amount of substrate oxidized. The only factor that appears to limit the extent of capsule synthesis by resting cells is the amount of substrate utilized. A series of photomicrographs of wet mounts made in India ink show the appearance of stripped cells and resynthesized capsules formed during oxidation of pyruvate and glucose by stripped resting-cell suspensions.

Acetates↗

PubMed1987

Bacterial capsular polysaccharides--biochemistry, immunity and vaccine.

The biochemical basis of immunogenicity to bacterial capsular polysaccharides (PSs) has been extensively studied. Antibody responses to PS antigens can be greatly affected by their physico-chemical properties, e.g. molecular size, specific determinants, conformation etc. At present, three bacterial PS vaccines, including meningococcal, pneumococcal, and H. influenzae type b, have been licensed in the U.S.A. Many other PSs, such as group B Streptococcus, Pseudomonas aeruginosa and Klebsiella, are still in various stages of vaccine development. Studies on the type distribution of pneumococcal isolates from Asian populations showed that the types included in the 23-valent pneumococcal vaccine were considerably fewer in Asia than that observed in the U.S.A.: the proportion of types was 62.9% in Taiwan, 72.9% in Japan and 87.9-92.8% in the U.S.A. A large number of pneumococcal types found in Taiwan and Japan, such as 15A, 23A, 24F and 34, are not present in the pneumococcal vaccine. Immunization with one type of group 9 or 19F PS induced a poor antibody response to the other type. All 9N, 9V, 19F and 19A PSs are required in the vaccine to induce sufficient antibodies against group 9 and 19 infection. Extensive cross-reactions have been found between pneumococcal PSs and PSs from other bacteria. Klebsiella K2 PS could enhance the magnitude of the antibody response to 19F PS. The structure of streptococcal 14636/74 was found to be identical to pneumococcal 19F PS. A difficult problem in the development of vaccines against bacterial diseases is the poor immune response of young children to purified PSs. Antibodies against the PSs can be elicited when PS antigens are conjugated to a protein carrier. In mice, the maternal immunization with pneumococcal PS during pregnancy or before mating, did not cause suppression or other observable harmful effect, rather it may provide sufficient antibodies for protection against infection during early life.

Animals↗

PubMed1975

Immunological enhancement of chemotherapy in advanced brain cancer.

Three hundred C3H mice were used to ascertain the validity of treatment of brain cancer with arsenicals and bacterial polysaccharide. It was found that this method of therapy was efficacious. Also, that a prophylactic effect was demonstrated. 2. In 14 patients with advanced intracranial neoplasm it was found: a) that no curative effect could be brought about once the cancer had spread beyond a certain point. This "point of no return" depends on tumor type, location and degree of brain destruction and general state of debility. b) That subjective and even some temporary objective improvement was possible even in advanced cancer. Necrosis of cancer tissue, that could be attributed to the therapy, was found in a number of cases. c) That some cases of brain cancer showed remarkable response to this form of therapy; more so if radiation therapy was given at the time of administration of the arsenical and bacterial polysaccharide. d) That some cases of brain metastasis showed "complete" destruction of the neoplasms in the brain although the patient subsequently died of the primary neoplasm and multiple metastasis. e) That the principle of enhancing the deposition of the curative material in the neoplasm by the use of bacterial polysaccharide is valid. f) That if this method of treatment (i.e. arsenical, bacterial polysaccharide and radiation) is instituted in the "early" cancer cases we may find it to be an efficacious mode of attack. g) That aresnical by mouth and bacterial polysaccharide by I.M. injection may be useful as a prophylactic to the formation of cancer. This may be contemplated for use in families that seem to show a predisposition to cancer formation. A mode of administration would probably be somewhat similary to the maintencance therapy described in the body of this paper. h) That bacterial polysaccharides have been shown to have the ability to destroy cancers.3,9 This method of enhancing the patients antigen-antibody reaction may eventually be used as a means of gaining an efficient vaccine in cancer therapy. i) Wherever possible definitive surgery should be carried out before the arsenical-bacterial polysaccharide-radiation method is instituted. j) In brain cancer, after craniotomy with removal of all or part of the neoplasm where feasible, the patient should be left with a subtemporal decompression. This will allow for the oedema of the brain that occurs with cerebral radiation therapy. k) That the principle of destruction of the cancer by certain special substances is valid. That the increase of affinity between cancer and destructive (curative) material can be brought about by administering a bacterial polysaccharide at the same time and that radiation therapy may enhance the beneficial effects of this method. 1) That the principle of brining the greatest toxicity to the cancer cells and the least toxic effect to the organism has been applied in the use of this method of treatment. m) That in some cases the cancer may not be destroyed by this therapy but may be made to retrogress or be held in check.

Adolescent↗

PubMed1978

Degradation of polysaccharides by intestinal bacterial enzymes.

Polysaccharides with structures resembling components of dietary fiber were fermented by a number of species of anaerobic bacteria from the human colon. Some strains also fermented glycoprotein mucins. The strains that fermented the widest range of polysaccharide substrates were in the two genera Bacteroides and Bifidobacterium. Polysaccharide degrading enzymes from several Bacteroides species have been studied, and in most cases the enzyme activities were cell bound rather than extracellular. In all cases, the polysaccharide degrading enzymes were inducible rather than constitutive. Thus the metabolic activity of the flora could be altered considerably by the amount and type of fiber in the diet, even though the composition of the flora itself remained unchanged. The products of enzyme action included monosaccharides and oligosaccharides of varying chain lengths.

Bacteroides↗

PubMed1988

Bacterial extracellular polysaccharides.

The synthesis of extracellular polysaccharides has been recognized in certain bacterial cultures since the 1880s. It is now apparent that a wide range of bacteria produce these polymers and an equally wide range of chemical structures are possible. Their surface location, together with the range of available monosaccharide combinations, noncarbohydrate substituents, and linkage types, make extracellular polysaccharides excellent agents of diversity. As a result, much effort has been directed towards elucidating their structure in pathogenic bacteria and in enteric organisms in particular. Commercial applications of microbial polysaccharides have now broadened the scope of structural information. Most recently, technological advances in molecular biology have created the possibility of manipulating desired polymer characteristics, and with these advances, our knowledge of the mechanisms of synthesis and regulation of cell surface polysaccharides has improved. Ultimately more information regarding the function of extracellular polysaccharides in natural environments may result.

Bacteria↗

PubMed1991

The compositional analysis of bacterial extracellular polysaccharides by high-performance anion-exchange chromatography.

A high-performance liquid chromatography (HPLC) method with pulsed-amperometric detection (PAD) was developed for the compositional analysis of the acidic, neutral, and basic monosaccharides recovered from the acid hydrolysis of bacterial cell wall polysaccharides. This HPLC-PAD method involved the chromatography of the acid hydrolysis products on a CarboPac PA-1 anion-exchange column of pellicular resin, with PAD detection following postcolumn addition of alkali. Complete resolution of a mixture of 19 monosaccharides, comprising 9 neutral, 3 basic, and 7 acidic sugars, frequently found in bacterial polysaccharides was achieved within 60 min by the system. The presence of amino acids in the mixture was shown not to affect the analysis. This protocol was applied to the compositional analysis of 2 extracellular polysaccharides produced by Escherichia coli, colanic acid, and K30 antigen, which share constituent monosaccharides. The overproduction of extracellular polysaccharide in E. coli CWG56 was shown to be a consequence of deregulation of K30 biosynthesis and not of coexpression of an additional polymer.

Chromatography, High Pressure Liquid↗

PubMed1996

The biochemistry and genetics of capsular polysaccharide production in bacteria.

Bacterial polysaccharides are usually associated with the outer surface of the bacterium. They can form an amorphous layer of extracellular polysaccharide (EPS) surrounding the cell that may be further organized into a distinct structure termed a capsule. Additional polysaccharide molecules such as lipopolysaccharide (LPS) or lipooligosaccharide (LOS) may also decorate the cell surface. Polysaccharide capsules may mediate a number of biological processes, including invasive infections of human beings. Discussed here are the genetics and biochemistry of selected bacterial capsular polysaccharides and the basis of capsule diversity but not the genetics and biochemistry of LPS biosynthesis (for reviews see 100, 140).

Antigens, Bacterial↗

PubMed2003

Role of water-soluble polysaccharides in bacterial cellulose production.

Acetobacter xylinum BPR2001 produces water-insoluble bacterial cellulose (BC) and a water-soluble polysaccharide called acetan in corn steep liquor-fructose medium. Acetobacter xylinum EP1, which is incapable of acetan production was derived by disrupting the aceA gene of BPR2001. The BC production by EP1 (2.88 g/L) was lower than that by BPR2001 (4.6 g/L) in baffled-flask culture. When purified acetan or agar was added to the medium from the start of cultivation, the BC production by EP1 was enhanced and the final BC yield of EP1 was almost the same as that of BPR2001. A similar improvement of BC production by EP1 by the addition of agar was also confirmed by cultivation in a 50-L airlift reactor. From these results, the role of acetan in BC production is associated with the increase in the viscosity of the culture medium which may hinder coagulation of BC and cells in the culture, thereby accelerating the growth of BPR2001 and BC production by BPR2001.

Cellulose↗

PubMed1975

[The effect of piromen on the flial-mesenchymal scar in the cortex of hamsters].

In the present work the effect of Piromen is studied on the formation of the glial-mesenchymal scar in the experimentally injuried cortex of hamsters. The uniform effect of the bacterial polysaccharide is suggested in a strong and lasting stimulation of proliferating reactive cells in the traumatic area. The excessive proliferation is combined with a decrease of differentiation in the reactive cells. A reduction of specific activities (phagocytosis, production of collagen and glial filaments) of these cells was also observed. Finally a porous mesenchymal scar develops with a great many of dedifferentiated cells. On the other hand a spongy glial scar is formed, which is due to a desintegration of astrocytic processes in the peritraumatic area. A so far not precisely understood transformation of reactive astrocytes plays an important role herein. The changes of the glial-mesenchymal scar after administration of Piromen, reported in the literature, were on the whole confirmed.

Animals↗

PubMed1996

Acute inflammatory changes in subcutaneous microtumors in the ears of mice induced by intravenous CM101 (GBS toxin).

CM101, a bacterial polysaccharide derived from group B streptococcus, induces pronounced inflammatory changes in and around tumor blood vessels 60 min after i.v. injection. A technique has been developed for implanting small numbers of tumor cells in the ear skin of mice. This allows macroscopic examination of the tumor and its supporting blood vessels as it reaches the 10000 cell size and greater. Treatments can be monitored in this model for effects on small "metastatic-like" tumor nodules by direct observation and by histological examination. Inflammatory changes were indicated by increased numbers of polymorphonuclear leukocytes (PMN) adjacent to and marginating within thin-walled blood vessels and within the tumor tissue. PMN were seen in the process of migrating through venules and enlarged capillaries, each with prominent endothelial cells. Tumor morphology was variable with evidence of occasional single necrotic cells. This contrasted with tumors in ears of dextran-treated or untreated mice, which had uniform tumor morphology, and acute inflammatory cells were rarely present.

Acute Disease↗

PubMed2000

Liver resistance to CCl(4)-induced injury after stimulation of macrophages with various preparations.

Acute toxic hepatitis in male Wistar rats was produced by single injection of 40% CCl(4) (0.2 ml per 100 g body weight in oil). Pretreatment with various immunostimulators (bacterial polysaccharides prodigiozan and salmozan; yeast polysaccharides zymosan, peptidoglycan, and mannan; and hydrolytic enzyme egg lysozyme) produced a hepatoprotective effect correlating which the stimulatory influence on macrophages and increasing in the following order: mannan<peptidoglycan<zymosan<lysozyme<salmozan<prodigiozan.

Adjuvants, Immunologic↗

PubMed1996

Dependence of the content of unsubstituted (cellulosic) regions in prehydrolysed xanthans on the rate of hydrolysis by Trichoderma reesei endoglucanase.

Removal of side chains from the bacterial polysaccharides xanthan and xylinan (acetan) results in the formation of unsubstituted cellulosic regions that are susceptible to hydrolysis by cellulases (beta-1,4-endoglucanases). In contrast to cellulose derivatives, low degrees of substitution (DS) may be obtained in xanthan without affecting the solubility in water, and longer unsubstituted regions are obtained for the same DS due to the regular distribution of side chains. By varying the fraction of cellobiosic residues carrying a side chain from 1.0 to 0.54, the viscosimetrically detected rate of hydrolysis by cellulase of conformationally disordered xanthan, increased by 4 orders of magnitude. An increase was also obtained by removing side chains from xylinan. An analysis of the kinetic data suggests that very long unsubstituted regions (more than 10 glucose residues) are required for maximum rate of hydrolysis by cellulase.

Carbohydrate Sequence↗

PubMed1995

NMR studies of succinoglycan repeating-unit octasaccharides from Rhizobium meliloti and Agrobacterium radiobacter.

Complete 1H and 13C-nuclear magnetic resonance assignments have been obtained for the octasaccharide repeating units of the bacterial polysaccharide succinoglycan from Rhizobium meliloti Rm1021 and Agrobacterium radiobacter NCIB 11883. The assignments were used to determine the locations of the O-succinyl and O-acetyl substituents. The O-acetyl substituent in Rm1021 was attached to the 3rd residue from the reducing end, and the O-succinyl group was attached to the 7th residue in both octasaccharides. The structure of the Rm1021 octasaccharide is as shown below: [formula: see text] A small amount of succinate was also attached to C6 of the 6th residue in both octasaccharides.

Carbohydrate Conformation↗

PubMed1993

Zinc in etiology of periodontal disease.

Microbial plaque is the main etiological factor of periodontal disease. The bacterial polysaccharides stimulate gingival neutrophils and macrophages to interleukin-1 (IL-1) production. IL-1 causes a complex of redistribution processes with liver as the central organ. Accumulation of zinc in liver and their copper and ceruloplasmin production also elicits increase of copper and decrease of zinc in gingiva. The elevated level of copper in connection with zinc deficiency in gingiva causes the increase of permeability of gingival epithelium for bacteria. The stimulated inflammatory infiltrate produces more IL-1 and the vicious circle is complete.

Ceruloplasmin↗