scholarly journals Immunochemical and Biological Characterization of Three Capsular Polysaccharides from a Single Bacteroides fragilisStrain

2001 ◽  
Vol 69 (4) ◽  
pp. 2339-2344 ◽  
Author(s):  
Wiltrud M. Kalka-Moll ◽  
Ying Wang ◽  
L. E. Comstock ◽  
Sylvia E. Gonzalez ◽  
Arthur O. Tzianabos ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Basic Structure ◽  
Structural Features ◽  
Capsular Polysaccharides ◽  
Polysaccharide Complex ◽  
Abdominal Abscesses ◽  
Colonic Flora ◽  
Surface Polysaccharides ◽  
Normal Human ◽  
Net Charges

ABSTRACT Although Bacteroides fragilis accounts for only 0.5% of the normal human colonic flora, it is the anaerobic species most frequently isolated from intra-abdominal and other infections with an intestinal source. The capsular polysaccharides of B. fragilis are part of a complex of surface polysaccharides and are the organism's most important virulence factors in the formation of intra-abdominal abscesses. Two capsular polysaccharides from strain NCTC 9343, PS A1 and PS B1, have been characterized structurally. Their most striking feature is a zwitterionic charge motif consisting of both positively and negatively charged substituent groups on each repeating unit. This zwitterionic motif is essential for abscess formation. In this study, we sought to elucidate structural features of the capsular polysaccharide complex of a commonly studied B. fragilisstrain, 638R, that is distinct from strain 9343. We sought a more general picture of the species to establish basic structure-activity and structure-biosynthesis relationships among abscess-inducing polysaccharides. Strain 638R was found to have a capsular polysaccharide complex from which three distinct carbohydrates could be isolated by a complex purification procedure. Compositional and immunochemical studies demonstrated a zwitterionic charge motif common to all of the capsular polysaccharides that correlated with their ability to induce experimental intra-abdominal abscesses. Of interest is the range of net charges of the isolated polysaccharides—from positive (PS C2) to balanced (PS A2) to negative (PS 3). Relationships among structural components of the zwitterionic polysaccharides and their molecular biosynthesis loci were identified.

scholarly journals Genetic Analysis of the rkp-3 Gene Region in Sinorhizobium meliloti 41: rkpY Directs Capsular Polysaccharide Synthesis to KR5 Antigen Production

2009 ◽  
Vol 22 (11) ◽  
pp. 1422-1430 ◽  
Author(s):  
Adrienn Pálvölgyi ◽  
Veronika Deák ◽  
Véréna Poinsot ◽  
Tibor Nagy ◽  
Enik Nagy ◽  
...  
Keyword(s):  
Sinorhizobium Meliloti ◽  
Capsular Polysaccharide ◽  
Low Molecular Weight ◽  
Capsular Polysaccharides ◽  
Genetic Dissection ◽  
Sequence Determination ◽  
Polysaccharide Synthesis ◽  
Surface Polysaccharides ◽  
Pseudaminic Acid ◽  
And Function

Rhizobial surface polysaccharides, including capsular polysaccharides (KPS), are involved in symbiotic infection. The rkp-3 locus of Sinorhizobium meliloti 41 is responsible for the production of pseudaminic acid, one of the components of the KR5 antigen, a strain-specific KPS. We have extended the sequence determination and genetic dissection of the rkp-3 region to clarify the structure and function of the rkpY gene and to identify additional rkp genes. Except for rkpY, no other genes were found where mutation affected the KPS structure and symbiosis. These mutants show a unique phenotype producing a low molecular weight polysaccharide (LMW PS). Creating double mutants, we have shown that biosynthesis genes of the KR5 antigen except rkpZ are not necessary for the production of this LMW PS. Polysaccharide analysis of genetically modified strains suggests that rkpY has pleiotropic effects on polysaccharide production. It directs KPS synthesis to the KR5 antigen and influences lipo-oligo 3-deoxy-d-manno-2 octulosonic acid (Kdo) production in S. meliloti 41. In addition, rkpY suppresses the lipo-oligoKdo production when it is introduced into S. meliloti 1021.

scholarly journals Bacteroides fragilis NCTC9343 Produces at Least Three Distinct Capsular Polysaccharides: Cloning, Characterization, and Reassignment of Polysaccharide B and C Biosynthesis Loci

2000 ◽  
Vol 68 (11) ◽  
pp. 6176-6181 ◽  
Author(s):  
Michael J. Coyne ◽  
Wiltrud Kalka-Moll ◽  
Arthur O. Tzianabos ◽  
Dennis L. Kasper ◽  
Laurie E. Comstock
Keyword(s):  
Animal Models ◽  
Capsular Polysaccharide ◽  
Bacteroides Fragilis ◽  
Prototype Strain ◽  
Rodent Model ◽  
Type Structure ◽  
Capsular Polysaccharides ◽  
Chromosomal Deletion ◽  
Polysaccharide Complex

ABSTRACT Bacteroides fragilis produces a capsular polysaccharide complex (CPC) that is directly involved in its ability to induce abscesses. Two distinct capsular polysaccharides, polysaccharide A (PS A) and PS B, have been shown to be synthesized by the prototype strain for the study of abscesses, NCTC9343. Both of these polysaccharides in purified form induce abscesses in animal models. In this study, we demonstrate that the CPC of NCTC9343 is composed of at least three distinct capsular polysaccharides: PS A, PS B, and PS C. A previously described locus contains genes whose products are involved in the biosynthesis of PS C rather than PS B as was originally suggested. The actual PS B biosynthesis locus was cloned, sequenced, and found to contain 22 genes in an operon-type structure. A mutant with a large chromosomal deletion of the PS B biosynthesis locus was created so that the contribution of PS B to the formation of abscesses could be assessed in a rodent model. Although purified PS B can induce abscesses, removal of this polysaccharide does not attenuate the organism's ability to induce abscesses.

scholarly journals Analysis of a Capsular Polysaccharide Biosynthesis Locus of Bacteroides fragilis

1999 ◽  
Vol 67 (7) ◽  
pp. 3525-3532 ◽  
Author(s):  
Laurie E. Comstock ◽  
Michael J. Coyne ◽  
Arthur O. Tzianabos ◽  
Annalisa Pantosti ◽  
Andrew B. Onderdonk ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Bacteroides Fragilis ◽  
Open Reading Frames ◽  
Capsular Polysaccharides ◽  
Nucleotide Sugar ◽  
Polysaccharide Biosynthesis ◽  
Abdominal Abscesses ◽  
Intra Abdominal Infection ◽  
Reading Frames ◽  
Nucleotide Sugar Biosynthesis

ABSTRACT A major clinical manifestation of infection with Bacteroides fragilis is the formation of intra-abdominal abscesses, which are induced by the capsular polysaccharides of this organism. Transposon mutagenesis was used to locate genes involved in the synthesis of capsular polysaccharides. A 24,454-bp region was sequenced and found to contain a 15,379-bp locus (designated wcf) with 16 open reading frames (ORFs) encoding products similar to those encoded by genes of other bacterial polysaccharide biosynthesis loci. Four genes encode products that are similar to enzymes involved in nucleotide sugar biosynthesis. Seven genes encode products that are similar to sugar transferases. Two gene products are similar toO-acetyltransferases, and two products are probably involved in polysaccharide transport and polymerization. The product of one ORF, WcfH, is similar to a set of deacetylases of the NodB family. Deletion mutants demonstrated that the wcf locus is necessary for the synthesis of polysaccharide B, one of the two capsular polysaccharides of B. fragilis 9343. The virulence of the polysaccharide B-deficient mutant was comparable to that of the wild type in terms of its ability to induce abscesses in a rat model of intra-abdominal infection.

Implant Infections Due to Enterococci: Role of Capsular Polysaccharides and Biofilm

2005 ◽  
Vol 28 (11) ◽  
pp. 1079-1090 ◽  
Author(s):  
F. Fabretti ◽  
J. Huebner
Keyword(s):  
Antimicrobial Agents ◽  
Capsular Polysaccharide ◽  
Female Genital Tract ◽  
Teichoic Acid ◽  
Capsular Polysaccharides ◽  
Human Pathogens ◽  
Artificial Joints ◽  
Artificial Hearts ◽  
Intravascular Catheters ◽  
Enterococcal Infections

Enterococci are natural inhabitants of the gastrointestinal tract and of the female genital tract of humans and many animals. In recent years, enterococci have been increasingly recognized as important human pathogens causing infections associated with medical devices. Their resistance to most antimicrobial agents and their ability to form biofilm has contributed to the increasing incidence of nosocomial enterococcal infections. Enterococci possess a capsular polysaccharide composed of a glycerol-teichoic acid-like molecule consisting of repeating units of 6-α-D-glucose-1-2-glycerol-3-PO4, substituted on carbon 2 with a α-2,1-linked molecule of glucose. Using both immunologic and genetic data E. faecalis can be assigned to specific serotypes based on capsular polysaccharides. Clinical examples of foreign-body infections due to enterococci are described, comprising infections of artificial joints, implanted intravascular catheters, artificial hearts and artificial valves, stents, liquor shunt devices, and intraocular infections. Methods to prevent and/or treat enterococcal infections are presented.

Biomimetic Microsystems for Cardiovascular studies

2021 ◽  
Author(s):  
Shelby C. Inbody ◽  
Bridgett E Sinquefield ◽  
Joshua P. Lewis ◽  
Renita E. Horton
Keyword(s):  
Basic Structure ◽  
Structural Features ◽  
The Body ◽  
Dynamic Features ◽  
Culture Methods ◽  
Implementation Challenges ◽  
Design Considerations ◽  
Drug Studies ◽  
Cell Culture Methods

Tissue culture platforms have been around for several decades and have enabled numerous key findings in the cardiovascular field. However, these platforms fail to recreate the mechanical and dynamic features found within the body. Organs-on-chips (OOCs) are cellularized microfluidic based devices that can mimic the basic structure, function, and responses of organs. These systems have been successfully utilized in disease, development, and drug studies. OOCs are designed to recapitulate the mechanical, electrical, chemical, and structural features of the in vivo microenvironment. Here, we review cardiovascular-themed OOC studies, design considerations, and techniques used to generate microtissues within these devices. Further, we will highlight the advantages of OOCs over traditional cell culture methods, discuss implementation challenges, and provide perspectives on the state of the field.

Assembly of Bacterial Capsular Polysaccharides and Exopolysaccharides

2020 ◽  
Vol 74 (1) ◽  
pp. 521-543 ◽  
Author(s):  
Chris Whitfield ◽  
Samantha S. Wear ◽  
Caitlin Sande
Keyword(s):  
Structural Biology ◽  
Biomedical Applications ◽  
Capsular Polysaccharide ◽  
Strong Association ◽  
Capsular Polysaccharides ◽  
Physical Chemical ◽  
Wide Range ◽  
Bacterial Surfaces ◽  
Genomic Studies ◽  
Long Chain

Polysaccharides are dominant features of most bacterial surfaces and are displayed in different formats. Many bacteria produce abundant long-chain capsular polysaccharides, which can maintain a strong association and form a capsule structure enveloping the cell and/or take the form of exopolysaccharides that are mostly secreted into the immediate environment. These polymers afford the producing bacteria protection from a wide range of physical, chemical, and biological stresses, support biofilms, and play critical roles in interactions between bacteria and their immediate environments. Their biological and physical properties also drive a variety of industrial and biomedical applications. Despite the immense variation in capsular polysaccharide and exopolysaccharide structures, patterns are evident in strategies used for their assembly and export. This review describes recent advances in understanding those strategies, based on a wealth of biochemical investigations of select prototypes, supported by complementary insight from expanding structural biology initiatives. This provides a framework to identify and distinguish new systems emanating from genomic studies.

Extracellular polysaccharide production by Klebsiella pneumoniae and its relationship to virulence

1985 ◽  
Vol 31 (5) ◽  
pp. 472-478 ◽  
Author(s):  
Philip Domenico ◽  
Dana L. Diedrich ◽  
David C. Straus
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Gel Filtration ◽  
Extracellular Polysaccharide ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Extracellular Polysaccharides ◽  
Capsular Polysaccharides ◽  
Separation And Purification ◽  
Serotype 1

Klebsiella pneumoniae serotype 1 and serotype 2 and their capsular variants were examined for production of cell-associated capsular polysaccharides and extracellular capsular polysaccharides. The virulence of these organisms in experimental animals was examined via intraperitoneal injection in mice and transtracheal inoculation into the lungs of rats. It was found that the production of either polysaccharide component correlated with the observed virulence. The extracellular polysaccharides were purified by ethanol precipitation, electrodialysis, extraction with quaternary ammonium salts, and gel filtration. These purification steps allowed for the separation and purification of both the extracellular lipopolysaccharide and the extracellular capsular polysaccharide. Purified extracellular capsular polysaccharide and extracellular lipopolysaccharide were co-injected with K. pneumoniae intraperitoneally into mice to determine if either of these substances would produce an effect on the natural course of infection in these animals. These studies showed that only purified extracellular lipopolysaccharide enhanced the virulence of K. pneumoniae when co-injected into mice, and this virulence enhancement correlated with the content of extracellular lipopolysaccharide, but not extracellular capsular polysaccharide in mixtures of these polysaccharides. Saponification of K. pneumoniae serotype 1 extracellular polysaccharides significantly decreased their virulence-enhancing capabilities in mice, further suggesting that extracellular lipopolysaccharide may play a role in these infections.

scholarly journals Serum immunoglobulins and anti-pneumococcal antibody levels in patients with bronchiectasis of unknown aetiology

2020 ◽  
Vol 19 (2) ◽  
pp. 200-207
Author(s):  
Mustafa Norhazlin ◽  
Asrul Abdul Wahab ◽  
Mohd Faisal Abdul Hamid ◽  
Hamzaini Abdul Hamid ◽  
Husyairi Harunarashid
Keyword(s):  
Streptococcus Pneumoniae ◽  
Specific Antibody ◽  
Capsular Polysaccharide ◽  
Medical Science ◽  
Asian Population ◽  
Immunoglobulin Therapy ◽  
Female Gender ◽  
Total Serum ◽  
Capsular Polysaccharides ◽  
Serum Immunoglobulins

Background: Bronchiectasis is a chronic condition which can result in significant physical and social morbidity. The exact prevalence in Malaysia is unknown although several studies have shown a higher prevalence in the Asian population. Several causative factors have been identified but there are many patients with unknown aetiologies. This study looks into the level of serum immunoglobulins and antipenumococcal antibody in bronchiectasis patients where they were not part of prior routine investigations. Methodology: Four hundred fifteen bronchiectasis patients were screened and 26 patients who fulfilled the inclusion and exclusion criteria were enrolled for this study. The serum immunoglobulins (IgG, IgA and IgM) concentrations were measured using nephelometry and interpreted according to age-matched reference range. The integrity of antibody production against specific antibody to capsular polysaccharides of Streptococcus pneumoniae were assessed using ELISA method and the level of ≥ 10mg/L is considered as reactive. Results: The twenty six bronchiectasis patients have the mean age of 62 years and a predilection of female gender. Majority of patients presented with typical bronchiectasis symptoms which were further supported by radiological findings. One of 26 patients (4%) had low total serum IgG level. The vaccinated group has higher anti-pneumococcal capsular polysaccharide antibody level (median: 224.2 mg/L) compared to the unvaccinated group (median: 100.4 mg/L). However there is no statistical difference between the anti-PCP levels of both groups (p> 0.05). All of the selected patients had reactive specific antibody to capsular polysaccharides of Streptococcus pneumoniae regardless of the vaccination status, which may reflect the natural acquisition of anti-pneumococcal immunity. Conclusion: Although immunoglobulin deficiency is an uncommon aetiological cause of bronchiectasis, the immunoglobulin parameters can be helpful in selecting patients who should receive the appropriate treatment of immunoglobulin therapy for the prevention of subsequent complications and better quality of life. Bangladesh Journal of Medical Science Vol.19(2) 2020 p.200-207

scholarly journals Production of Capsular Polysaccharide ofStreptococcus pneumoniae Type 14 and Its Purification by Affinity Chromatography

2001 ◽  
Vol 67 (2) ◽  
pp. 969-971 ◽  
Author(s):  
Norma Suárez ◽  
Laura Franco Fraguas ◽  
Esther Texeira ◽  
Hugo Massaldi ◽  
Francisco Batista-Viera ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Affinity Chromatography ◽  
Efficient Method ◽  
Capsular Polysaccharide ◽  
Capsular Polysaccharides ◽  
Affinity Adsorbent ◽  
Soybean Lectin

ABSTRACT We describe a rapid and efficient method for producing the capsular polysaccharide of Streptococcus pneumoniae by fermentation on tryptic soy broth and purification of this compound by using immobilized soybean lectin as an affinity adsorbent. In principle, the same strategy can be used to produce purified capsular polysaccharides from other streptococcal serotypes by selecting the appropriate lectin adsorbents.

scholarly journals Effects of Ageing and Gender on Naturally Acquired Antibodies to Pneumococcal Capsular Polysaccharides and Virulence-Associated Proteins

2008 ◽  
Vol 15 (9) ◽  
pp. 1391-1397 ◽  
Author(s):  
Birgit Simell ◽  
Mika Lahdenkari ◽  
Antti Reunanen ◽  
Helena Käyhty ◽  
Merja Väkeväinen
Keyword(s):  
Bacterial Infections ◽  
The Elderly ◽  
Capsular Polysaccharides ◽  
Protein Antigens ◽  
Pneumococcal Infections ◽  
Younger Adults ◽  
Associated Proteins ◽  
Normal Human ◽  
And Gender ◽  
Increased Susceptibility

ABSTRACT Elderly individuals are susceptible to pneumococcal infections. Although factors contributing to the increased susceptibility of the elderly to bacterial infections may be several, compromised immune function, a consequence of normal human ageing, is widely accepted to play a role. We evaluated the effect of ageing on the concentrations of naturally acquired antibodies to pneumococcal capsular polysaccharides (PPS) and protein antigens. The concentrations of immunoglobulin G (IgG) and IgM antibodies to the PPS of serotypes 3, 4, 6B, 9V, 14, and 23F and IgG antibodies to the pneumococcal virulence-associated proteins CbpA, LytC, PhtD and its C-terminal fragment (PhtD C), NanA, PspA fam1, and PspA fam2 were measured by enzyme immunoassay in the sera of younger (30 to 64 years of age) and elderly (65 to 97 years of age) adults. The concentrations of anti-PPS IgG against serotypes 3 and 6B, of anti-PPS IgM against serotypes 3, 4, 6B, 9V, and 23F, and of anti-protein IgG against all tested antigens were significantly lower in the elderly than in younger adults. A stronger decline in anti-PPS antibody concentrations was seen with age in women compared to men, while anti-protein antibody concentrations were mainly similar between the genders. Age, gender, and the nature of the antigen have substantial and varying effects on the antibody concentrations in the sera of adults.

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