scholarly journals Carbon Source-Dependent Changes of the Structure of Streptococcus pneumoniae Capsular Polysaccharide with Serotype 6F

2021 ◽  
Vol 22 (9) ◽  
pp. 4580
Author(s):  
Joel P. Werren ◽  
Lukas J. Troxler ◽  
Oluwaseun Rume-Abiola Oyewole ◽  
Alban Ramette ◽  
Silvio D. Brugger ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Carbon Source ◽  
1H Nmr ◽  
31P Nmr ◽  
Capsular Polysaccharide ◽  
Defined Medium ◽  
Flow Cytometric ◽  
Unequivocal Identification ◽  
Pneumococcal Serotype ◽  
Polysaccharide Composition

The structure of the exopolysaccharide capsule of Streptococcus pneumoniae is defined by the genetic arrangement of the capsule operon allowing the unequivocal identification of the pneumococcal serotype. Here, we investigated the environment-dependent composition of the polysaccharide structure of S. pneumoniae serotype 6F. When grown in a chemically defined medium (CDM) with glucose versus galactose, the exopolysaccharide capsule of the serotype 6F strains reveals a ratio of 1/0.6 or 1/0.3 for galactose/glucose in the capsule by 1H-NMR analyses, respectively. Increased production of the capsule precursor UDP-glucose has been identified by 31P-NMR in CDM with glucose. Flow cytometric experiments using monoclonal antibodies showed decreased labelling of Hyp6AG4 (specific for serotype 6A) antibodies when 6F is grown in glucose as compared to galactose, which mirrors the 1H-NMR results. Whole-genome sequencing analyses of serotype 6F isolates suggested that the isolates evolved during two different events from serotype 6A during the time when the 13-valent pneumococcal conjugate vaccine (PCV-13) was introduced. In conclusion, this study shows differences in the capsular structure of serotype 6F strains using glucose as compared to galactose as the carbon source. Therefore, 6F strains may show slightly different polysaccharide composition while colonizing the human nasopharynx (galactose rich) as compared to invasive locations such as the blood (glucose rich).

scholarly journals A Latex Bead-Based Flow Cytometric Immunoassay Capable of Simultaneous Typing of Multiple Pneumococcal Serotypes (Multibead Assay)

2000 ◽  
Vol 7 (3) ◽  
pp. 486-489 ◽  
Author(s):  
M. K. Park ◽  
D. E. Briles ◽  
M. H. Nahm
Keyword(s):  
Streptococcus Pneumoniae ◽  
Rapid Method ◽  
Capsular Polysaccharide ◽  
Pneumococcal Serotypes ◽  
Rabbit Antibody ◽  
Green Fluorescence ◽  
Red Fluorescence ◽  
Flow Cytometric ◽  
Latex Beads ◽  
Single Flow

ABSTRACT A simple and rapid method of simultaneously determining 15Streptococcus pneumoniae serotypes was developed. Fifteen latex beads of different sizes and different red fluorescence levels were coated with 1 of 15 serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9N, 9V, 14, 18C, 19A, 19F, 22F, and 23F) of pneumococcal capsular polysaccharide (PS). The bead mixture was incubated with individual pneumococcal lysate, a pool of rabbit antisera capable of binding the 15 serotypes, and fluorescein (green fluorescence)-conjugated anti-rabbit antibody. Bead size, red fluorescence, and green fluorescence were measured in a single flow cytometer run. The green fluorescence of the beads was inhibited only when there was a serotypic match between PS on the bead and PS in the pneumococcal lysate. This method distinguished cross-reactive serotypes and correctly identified the serotypes in 100% of 86 pneumococcal isolates tested.

scholarly journals Carbon source regulates polysaccharide capsule biosynthesis in Streptococcus pneumoniae

2019 ◽  
Vol 294 (46) ◽  
pp. 17224-17238 ◽  
Author(s):  
Lukas J. Troxler ◽  
Joel P. Werren ◽  
Thierry O. Schaffner ◽  
Nadezda Mostacci ◽  
Peter Vermathen ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Carbon Source ◽  
Capsular Polysaccharide ◽  
Carbon Sources ◽  
Cell Extract ◽  
Therapeutic Approaches ◽  
Capsule Production ◽  
Important Virulence Factor ◽  
Capsule Thickness ◽  
Whole Cell Extract

The exopolysaccharide capsule of Streptococcus pneumoniae is an important virulence factor, but the mechanisms that regulate capsule thickness are not fully understood. Here, we investigated the effects of various exogenously supplied carbohydrates on capsule production and gene expression in several pneumococcal serotypes. Microscopy analyses indicated a near absence of the capsular polysaccharide (CPS) when S. pneumoniae was grown on fructose. Moreover, serotype 7F pneumococci produced much less CPS than strains of other serotypes (6B, 6C, 9V, 15, and 23F) when grown on glucose or sucrose. RNA-sequencing revealed carbon source-dependent regulation of distinct genes of WT strains and capsule-switch mutants of serotypes 6B and 7F, but could not explain the mechanism of capsule thickness regulation. In contrast, 31P NMR of whole-cell extract from capsule-knockout strains (Δcps) clearly revealed the accumulation or absence of capsule precursor metabolites when cells were grown on glucose or fructose, respectively. This finding suggests that fructose uptake mainly results in intracellular fructose 1-phosphate, which is not converted to CPS precursors. In addition, serotype 7F strains accumulated more precursors than did 6B strains, indicating less efficient conversion of precursor metabolites into the CPS in 7F, in line with its thinner capsule. Finally, isotopologue sucrose labeling and NMR analyses revealed that the uptake of the labeled fructose subunit into the capsule is <10% that of glucose. Our findings on the effects of carbon sources on CPS production in different S. pneumoniae serotypes may contribute to a better understanding of pneumococcal diseases and could inform future therapeutic approaches.

scholarly journals Metabolism of Lactobacillus sakei Chr82 in the Presence of Different Amounts of Fermentable Sugars

Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 720
Author(s):  
Federica Barbieri ◽  
Luca Laghi ◽  
Fausto Gardini ◽  
Chiara Montanari ◽  
Giulia Tabanelli
Keyword(s):  
Amino Acid ◽  
Carbon Source ◽  
1H Nmr ◽  
Starter Culture ◽  
Growth Conditions ◽  
Defined Medium ◽  
Lactobacillus Sakei ◽  
Commercial Strain ◽  
Fermented Sausages ◽  
Growth Performances

Lactobacillus sakei is widely used as a starter culture in fermented sausages since it is well adapted to meat environments and able to maintain high viability thanks to secondary pathways activated when hexoses are depleted (i.e., metabolism of pentoses and amino acids). In this study, a commercial strain of L. sakei was inoculated in a defined medium with ribose or glucose as the carbon source, at optimal or reduced concentrations, to evaluate its different physiological and metabolic responses in relation to different growth conditions. The results obtained with different approaches (HPLC, 1H-NMR, flow cytometry) evidenced different growth performances, amino acid consumptions and physiological states of cells in relation to the carbon source as an active response to harsh conditions. As expected, higher concentrations of sugars induced higher growth performances and the accumulation of organic acids. The low sugars amount induced the presence of dead cells, while injured cells increased with ribose. Arginine was the main amino acid depleted, especially in the presence of higher ribose, and resulted in the production of ornithine. Moreover, the 1H-NMR analysis evidenced a higher consumption of serine at the optimal sugars concentration (pyruvate production). This information can be helpful to optimize the use of these species in the industrial production of fermented sausages.

scholarly journals Antibodies to Streptococcus pneumoniae Capsular Polysaccharide Enhance Pneumococcal Quorum Sensing

mBio ◽  
2011 ◽  
Vol 2 (5) ◽  
Author(s):  
Masahide Yano ◽  
Shruti Gohil ◽  
J. Robert Coleman ◽  
Catherine Manix ◽  
Liise-anne Pirofski
Keyword(s):  
Monoclonal Antibodies ◽  
Streptococcus Pneumoniae ◽  
Quorum Sensing ◽  
Direct Effect ◽  
Pneumococcal Disease ◽  
Effector Cell ◽  
Capsular Polysaccharide ◽  
Genetic Exchange ◽  
Content Type ◽  
Specific Antibodies

ABSTRACTThe use of pneumococcal capsular polysaccharide (PPS)-based vaccines has resulted in a substantial reduction in invasive pneumococcal disease. However, much remains to be learned about vaccine-mediated immunity, as seven-valent PPS-protein conjugate vaccine use in children has been associated with nonvaccine serotype replacement and 23-valent vaccine use in adults has not prevented pneumococcal pneumonia. In this report, we demonstrate that certain PPS-specific monoclonal antibodies (MAbs) enhance the transformation frequency of two differentStreptococcus pneumoniaeserotypes. This phenomenon was mediated by PPS-specific MAbs that agglutinate but do not promote opsonic effector cell killing of the homologous serotypeinvitro. Compared to the autoinducer, competence-stimulating peptide (CSP) alone, transcriptional profiling of pneumococcal gene expression after incubation with CSP and one such MAb to the PPS of serotype 3 revealed changes in the expression of competence (com)-related and bacteriocin-like peptide (blp) genes involved in pneumococcal quorum sensing. This MAb was also found to induce a nearly 2-fold increase in CSP2-mediated bacterial killing or fratricide. These observations reveal a novel, direct effect of PPS-binding MAbs on pneumococcal biology that has important implications for antibody immunity to pneumococcus in the pneumococcal vaccine era. Taken together, our data suggest heretofore unsuspected mechanisms by which PPS-specific antibodies could affect genetic exchange and bacterial viability in the absence of host cells.IMPORTANCECurrent thought holds that pneumococcal capsular polysaccharide (PPS)-binding antibodies protect against pneumococcus by inducing effector cell opsonic killing of the homologous serotype. While such antibodies are an important part of how pneumococcal vaccines protect against pneumococcal disease, PPS-specific antibodies that do not exhibit this activity but are highly protective against pneumococcus in mice have been identified. This article examines the effect of nonopsonic PPS-specific monoclonal antibodies (MAbs) on the biology ofStreptococcus pneumoniae. The results showed that in the presence of a competence-stimulating peptide (CSP), such MAbs increase the frequency of pneumococcal transformation. Further studies with one such MAb showed that it altered the expression of genes involved in quorum sensing and increased competence-induced killing or fratricide. These findings reveal a novel, previously unsuspected mechanism by which certain PPS-specific antibodies exert a direct effect on pneumococcal biology that has broad implications for bacterial clearance, genetic exchange, and antibody immunity to pneumococcus.

scholarly journals Genetic Relatedness of the Streptococcus pneumoniae Capsular Biosynthetic Loci

2007 ◽  
Vol 189 (21) ◽  
pp. 7841-7855 ◽  
Author(s):  
Angeliki Mavroidi ◽  
David M. Aanensen ◽  
Daniel Godoy ◽  
Ian C. Skovsted ◽  
Margit S. Kaltoft ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Genetic Relatedness ◽  
Pneumococcal Serotypes ◽  
Major Cluster ◽  
Genes Encoding ◽  
Pneumococcal Serotype ◽  
Streptococcal Polysaccharide ◽  
Single Cluster ◽  
Dependent Pathway ◽  
Sequence Similarities

ABSTRACT Streptococcus pneumoniae (the pneumococcus) produces 1 of 91 capsular polysaccharides (CPS) that define the serotype. The cps loci of 88 pneumococcal serotypes whose CPS is synthesized by the Wzy-dependent pathway were compared with each other and with additional streptococcal polysaccharide biosynthetic loci and were clustered according to the proportion of shared homology groups (HGs), weighted for the sequence similarities between the genes encoding the shared HGs. The cps loci of the 88 pneumococcal serotypes were distributed into eight major clusters and 21 subclusters. All serotypes within the same serogroup fell into the same major cluster, but in six cases, serotypes within the same serogroup were in different subclusters and, conversely, nine subclusters included completely different serotypes. The closely related cps loci within a subcluster were compared to the known CPS structures to relate gene content to structure. The Streptococcus oralis and Streptococcus mitis polysaccharide biosynthetic loci clustered within the pneumococcal cps loci and were in a subcluster that also included the cps locus of pneumococcal serotype 21, whereas the Streptococcus agalactiae cps loci formed a single cluster that was not closely related to any of the pneumococcal cps clusters.

Structural studies of the capsular polysaccharide from Streptococcus pneumoniae Type 12F

1981 ◽  
Vol 59 (14) ◽  
pp. 2081-2085 ◽  
Author(s):  
Karin Leontein ◽  
Bengt Lindberg ◽  
Jörgen Lönngren
Keyword(s):  
Streptococcus Pneumoniae ◽  
Nmr Spectroscopy ◽  
Capsular Polysaccharide ◽  
Structural Studies ◽  
Methylation Analysis ◽  
Mannuronic Acid ◽  
Structure Formula

The capsular polysaccharide from Streptococcus pneumoniae type 12F is composed of D-glucosyl, D-galactosyl, 2-acetamido-2-deoxy-D-galactosyl, 2-acetamido-2,6-dideoxy-L-galactosyl, and 2-acetamido-2-deoxy-D-mannuronic acid residues in the proportions 2:1:1:1:1. The main structural evidence was adduced from nmr spectroscopy, methylation analysis, and specific degradations whereby it could be concluded that the polysaccharide is composed of hexasaccharide repeating-units having the structure:[Formula: see text]

Sign in / Sign up

Export Citation Format

Share Document