PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “POLYSACCHARIDES, BACTERIAL”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed1992

Carbohydrate composition analysis of bacterial polysaccharides: optimized acid hydrolysis conditions for HPAEC-PAD analysis.

The capsular polysaccharide from Haemophilus influenzae type b (polyribosyl ribitol-phosphate; PRP) and the capsular polysaccharides from Streptococcus pneumoniae types 6B, 14, 18C, and 23F (Pn6B, Pn14, Pn18C, and Pn23F) were subjected to acid hydrolysis using hydrofluoric (HF) and/or trifluoroacetic acid (TFA) and high-pH anion-exchange chromatography with pulsed amperometric detection in an effort to identify optimum hydrolysis conditions for composition analysis of their carbohydrate components. With the exception of PRP, composition analyses of polysaccharides containing a phosphate moiety in the repeating unit structure (Pn6B, Pn18C, and Pn23F) are significantly improved by subjecting the sample to HF hydrolysis (65 degrees C, 1 h) followed by TFA hydrolysis (98 degrees C, 16 h). This results in essentially quantitative hydrolysis of the phosphodiester bond to the carbohydrate components, which otherwise remained predominantly phosphorylated and poorly accounted for in the analysis. Optimum analysis of PRP was achieved following a 2-h hydrolysis with TFA at 80 degrees C, whereas Pn14 showed optimum results after a 16-h hydrolysis with TFA at 98 degrees C. These analyses also provide information about the relative susceptibility to acid hydrolysis of the various glycosidic and phosphodiester bonds in these polysaccharides, with evidence to suggest that the acid lability of a given bond can be dramatically different from one polysaccharide to another.

Bacteria↗
PubMedDate not supplied

[Effect of the bacterial polysaccharide pyrogenal on embryogenesis in noninbred white rats].

Pyrogenal was administered intramuscularly to albino rats in different terms of pregnancy in a single dose of 1000-1250 MTD/kg, twice with a 24-hour interval in a dose of 500-625 MTD/kg and repeatedly on 3rd-18th days of pregnancy in doses of 1.0-1.2, 5.0-6.3, 50.0-63.0 MTD/kg. Fetuses were studied on 20th day of pregnancy. Pyrogenal produced in embryos depending on the time of administration and dose congenital developmental defects, a decrease of body weight, thrombohemorrhagic syndrome, and erythrocytic hemolysis.

Abnormalities, Drug-Induced↗
PubMed1983

Immunoelectrophoretic characterization of the molecular weight polydispersion of polysaccharides in multivalent bacterial capsular polysaccharide vaccines.

The molecular weight polydispersion of single antigens present in multivalent bacterial capsular polysaccharide vaccines has been characterized by an immunoelectrophoretic method. Chromatographic effluents from Sepharose gel of bacterial capsular polysaccharide vaccines were tested by fused-rocket immunoelectrophoresis and the distribution coefficient (Kd) of each polysaccharide present in the mixture was calculated. The method appeared to be efficient and reproducible. However, different Kd values were obtained by immunoelectrophoretic and chemical or physical analysis of the chromatographic effluents of each single polysaccharide component. The use of this immunoelectrophoretic procedure was extended to the potency control of multivalent meningococcal and pneumococcal polysaccharide vaccines in order to detect changes in the molecular weight polydispersion of each antigen with time.

Bacterial Vaccines↗
PubMed2002

The effect of ruminal fluid preparations on the growth and health of newborn, milk-fed dairy calves.

The objective of this study was to determine the effect of oral doses of ruminal fluid (RF) on the growth and health of newborn, milk-fed heifer dairy calves (0 to 6 wk of age). Calves given 8 ml of RF each day until weaning gained more weight and had fewer scours than controls that did not receive RF. Because RF that was exposed to oxygen or was autoclaved also gave a response, it is unlikely that the preparations were acting as a probiotic. When the RF was centrifuged to separate the cells (RFC) from the fluid (RFS), both fractions had similar activity, and this result indicated that the response was not nutritional; that is, 1) RFC supplied a small amount of protein (approximately 8 mg/d), but RFS had much less protein, and 2) RFS had volatile fatty acid, but RFC had little if any volatile fatty acid. However, both RFS and RFC had bacterial polysaccharide, and bacterial polysaccharide has strong antigenic properties. In the first three studies, treated calves were given RF preparations each day until weaning (6 wk), but a subsequent experiment indicated that calves given autoclaved RF for only 5 d (d 1 to 5) also had greater body weight gains during the first 2 wk of life and fewer scours than untreated controls. Given that the dosage of RF was small and the material could be autoclaved to prevent disease transmission, RF supplementation could be a practical tool for improving calf health.

Animal Feed↗
PubMed1997

Identification of specific recognition molecules on murine mononuclear phagocytes and B lymphocytes for Vi capsular polysaccharide: modulation of MHC class II expression on stimulation with the polysaccharide.

Vi bacterial polysaccharide is a homopolymer of alpha 1-4 N-acetyl polygalacturonic acid with variable O-acetylation at position C-3 and forms a capsule around many bacteria. It has been referred to as the virulence factor of Salmonella typhi and is also a candidate vaccine against typhoid fever. The present study reports the interaction of this polysaccharide with murine mononuclear phagocytes and lymphocytes, and with human monocytes. Vi showed a dose-dependent binding to the murine monocyte cell lines WEHI-274.1 and J774. This binding was abrogated if the polysaccharide was deacetylated, suggesting involvement of acetyl groups in this interaction. Vi also bound to the murine B-cell lymphoma line A20, to peritoneal exudate cells and to a lesser degree to spleen cells and thymocytes from BALB/c mice. The polysaccharide also interacted with the human histiocytic lymphoma line U937 but not with the human monocyte cell line THP-1. Stimulation with Vi led to up-regulation of surface major histocompatibility complex (MHC) class II expression on A20 cells. Immunoprecipitation of Vi-bound molecules from cell surface biotinylated A20 and WEHI-274.1 revealed two bands with MW of about 32,000 and 36,000. The study demonstrates that Vi capsular polysaccharide can interact with mononuclear phagocytes and lymphocytes through specific cell surface molecules and modulate MHC class II expression.

Animals↗
PubMed2004

Capsule polysaccharide mediates bacterial resistance to antimicrobial peptides.

The innate immune system plays a critical role in the defense of areas exposed to microorganisms. There is an increasing body of evidence indicating that antimicrobial peptides and proteins (APs) are one of the most important weapons of this system and that they make up the protective front for the respiratory tract. On the other hand, it is known that pathogenic organisms have developed countermeasures to resist these agents such as reducing the net negative charge of the bacterial membranes. Here we report the characterization of a novel mechanism of resistance to APs that is dependent on the bacterial capsule polysaccharide (CPS). Klebsiella pneumoniae CPS mutant was more sensitive than the wild type to human neutrophil defensin 1, beta-defensin 1, lactoferrin, protamine sulfate, and polymyxin B. K. pneumoniae lipopolysaccharide O antigen did not play an important role in AP resistance, and CPS was the only factor conferring protection against polymyxin B in strains lacking O antigen. In addition, we found a significant correlation between the amount of CPS expressed by a given strain and the resistance to polymyxin B. We also showed that K. pneumoniae CPS mutant bound more polymyxin B than the wild-type strain with a concomitant increased in the self-promoted pathway. Taken together, our results suggest that CPS protects bacteria by limiting the interaction of APs with the surface. Finally, we report that K. pneumoniae increased the amount of CPS and upregulated cps transcription when grown in the presence of polymyxin B and lactoferrin.

Antimicrobial Cationic Peptides↗
PubMed1989

Chromotropic character of bacterial acidic polysaccharides: Part II--Induction of metachromasy in cationic dye pinacyanol chloride by Klebsiella K10 capsular polysaccharide.

The acidic capsular polysaccharide isolated from Klebsiella K10 exhibited chromotropic character with respect to induction of metachromasy in the cationic dye pinacyanol chloride (1-ethyl-2-[3-(1-ethyl-2(1H)-quinolylidene)propenyl]quinolinium chloride). Klebsiella K10 polymer consists of hexasaccharide repeating units containing one residue of glucuronic acid along with other neutral sugars in each repeating unit. It induces a metachromatic blue shift in the visible absorption spectrum of the dye from 600 nm to 500 nm. The spectral changes have been studied during interaction of the dye cations with the polyanions at different polymer/dye molar ratios. The polyanion-dye compounds are formed with polymer/dye stoichiometry of 1:1, indicating formation of stacking conformation. The complete reversal of polymer-induced metachromasy has also been observed by the addition of ethanol and urea.

Carbocyanines↗