scholarly journals Acquisition of factor H by a novel surface protein on group B Streptococcus promotes complement degradation

2009 ◽  
Vol 23 (11) ◽  
pp. 3967-3977 ◽  
Author(s):  
Ravi Maruvada ◽  
Nemani V. Prasadarao ◽  
C. E. Rubens
Keyword(s):  
Group B Streptococcus ◽  
Surface Protein ◽  
Factor H ◽  
Group B

scholarly journals Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of glyceraldehyde-3-phosphate dehydrogenase fromStreptococcus agalactiaeNEM316

2014 ◽  
Vol 70 (7) ◽  
pp. 938-941 ◽  
Author(s):  
Revathi Nagarajan ◽  
Karthe Ponnuraj
Keyword(s):  
Signal Sequence ◽  
Structure Refinement ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Diffusion Method ◽  
Space Groups ◽  
Essential Enzyme ◽  
Bacteria And Fungi ◽  
Group B ◽  
Surface Adhesins

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an essential enzyme involved in glycolysis. Despite lacking the secretory signal sequence, this cytosolic enzyme has been found localized at the surface of several bacteria and fungi. As a surface protein, GAPDH exhibits various adhesive functions, thereby facilitating colonization and invasion of host tissues.Streptococcus agalactiae, also known as group B streptococcus (GBS), binds onto the host using its surface adhesins and causes sepsis and pneumonia in neonates. GAPDH is one of the surface adhesins of GBS binding to human plasminogen and is a virulent factor associated with host colonization. Although the surface-associated GAPDH has been shown to bind to a variety of host extracellular matrix (ECM) molecules in various bacteria, the molecular mechanism underlying their interaction is not fully understood. To investigate this, structural studies on GAPDH ofS. agalactiaewere initiated. ThegapCgene ofS. agalactiaeNEM316 encoding GAPDH protein was cloned into pET-28a vector, overexpressed inEscherichia coliBL21(DE3) cells and purified to homogeneity. The purified protein was crystallized using the hanging-drop vapour-diffusion method. The GAPDH crystals obtained in two different crystallization conditions diffracted to 2.8 and 2.6 Å resolution, belonging to two different space groupsP21andP212121, respectively. The structure was solved by molecular replacement and structure refinement is now in progress.

scholarly journals Reduced trans-placental transfer of group B Streptococcus surface protein antibodies in HIV-infected mother-newborn dyads

2016 ◽  
pp. jiw566
Author(s):  
Sonwabile Dzanibe ◽  
Peter V. Adrian ◽  
Sheila Z. Kimaro Mlacha ◽  
Ziyaad Dangor ◽  
Gaurav Kwatra ◽  
...  
Keyword(s):  
Placental Transfer ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Infected Mother ◽  
Group B

Association between maternal Group B Streptococcus surface-protein antibody concentrations and invasive disease in their infants

2015 ◽  
Vol 14 (12) ◽  
pp. 1651-1660 ◽  
Author(s):  
Ziyaad Dangor ◽  
Gaurav Kwatra ◽  
Alane Izu ◽  
Peter Adrian ◽  
Clare L Cutland ◽  
...  
Keyword(s):  
Group B Streptococcus ◽  
Surface Protein ◽  
Invasive Disease ◽  
Group B

scholarly journals Protein rib: a novel group B streptococcal cell surface protein that confers protective immunity and is expressed by most strains causing invasive infections.

1993 ◽  
Vol 177 (6) ◽  
pp. 1593-1603 ◽  
Author(s):  
M Stålhammar-Carlemalm ◽  
L Stenberg ◽  
G Lindahl
Keyword(s):  
Cell Surface ◽  
Protective Immunity ◽  
Group B Streptococcus ◽  
Rabbit Antiserum ◽  
Surface Protein ◽  
Amino Acid Sequences ◽  
Cell Surface Protein ◽  
Type Iii ◽  
Invasive Infections ◽  
Group B

The group B Streptococcus, an important cause of invasive infections in the neonate, is classified into four major serotypes (Ia, Ib, II, and III) based on the structure of the polysaccharide capsule. Since the capsule is a known virulence factor, it has been extensively studied, in particular in type III strains, which cause the majority of invasive infections. Two cell surface proteins, alpha and beta, have also been studied in detail since they confer protective immunity, but these proteins are usually not expressed by type III strains. We describe here a cell surface protein, designated protein Rib (resistance to proteases, immunity, group B), that confers protective immunity and is expressed by most strains of type III. Protein Rib was first identified as a distinct 95-kD protein in extracts of a type III strain, and was purified to homogeneity from that strain. Rabbit antiserum to protein Rib was used to demonstrate that it is expressed on the cell surface of 31 out of 33 type III strains, but only on 1 out of 25 strains representing the other three serotypes. Mouse protection tests showed that antiserum to protein Rib protects against lethal infection with three different strains expressing this antigen, including a strain representing a recently identified high virulence type III clone. Protein Rib is immunologically unrelated to the alpha and beta proteins, but shares several features with the alpha protein. Most importantly, the NH2-terminal amino acid sequences of the Rib and alpha proteins are identical at 6 out of 12 positions. In addition, both protein Rib and the alpha protein are relatively resistant to trypsin (and Rib is also resistant to pepsin) and both proteins vary greatly in size between different clinical isolates. Finally, both protein Rib and the alpha protein exhibit a regular ladderlike pattern in immunoblotting experiments, which may reflect a repetitive structure. Taken together, these data suggest that the Rib and alpha proteins are members of a family of proteins with related structure and function. Since protein Rib confers protective immunity, it may be valuable for the development of a protein vaccine against the group B Streptococcus, an encapsulated bacterium.

scholarly journals Protection from Group B Streptococcal Infection in Neonatal Mice by Maternal Immunization with Recombinant Sip Protein

2002 ◽  
Vol 70 (9) ◽  
pp. 4897-4901 ◽  
Author(s):  
Denis Martin ◽  
Stéphane Rioux ◽  
Edith Gagnon ◽  
Martine Boyer ◽  
Josée Hamel ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Neonatal Infection ◽  
Active Immunization ◽  
Infection Model ◽  
Lethal Challenge ◽  
Specific Antibodies ◽  
Pregnant Mice ◽  
Group B

ABSTRACT The protective potential of antibodies directed against group B streptococcus (GBS) Sip surface protein was determined by using the mouse neonatal infection model. Rabbit Sip-specific antibodies administered passively to pregnant mice protected their pups against a GBS lethal challenge. In addition, active immunization with purified recombinant Sip protein of female CD-1 mice induced the production of specific antibodies that also confer protection to the newborn pups against GBS strains of serotypes Ia/c, Ib, II, III, and V. These data confirm that Sip-specific antibodies can cross the placenta and conferred protective immunity against GBS infections.

scholarly journals Genetic diversity of the C protein β-antigen gene and its upstream regions within clonally related groups of type Ia and Ib group B streptococci

Microbiology ◽  
2006 ◽  
Vol 152 (3) ◽  
pp. 771-778 ◽  
Author(s):  
Noriyuki Nagano ◽  
Yukiko Nagano ◽  
Ryuichi Nakano ◽  
Ryoichi Okamoto ◽  
Matsuhisa Inoue
Keyword(s):  
Genetic Diversity ◽  
Response Regulator ◽  
Surface Protein ◽  
Premature Termination Codon ◽  
Factor H ◽  
Binding Region ◽  
Group B Streptococci ◽  
C Protein ◽  
Expression Levels ◽  
Group B

C protein β antigen (Bac), a surface protein of group B streptococci (GBS), is known to concurrently bind the Fc portion of IgA and factor H (FH). The authors' previous work has demonstrated that mRNA expression levels show diversity among clonally related strains containing genes (bac) encoding Bac, with high expression noted in invasive strains. In this study, the bac gene and upstream regions containing putative promoters, three ORFs and an IS1381 insertion sequence were characterized. Three invasive strains showed high bac expression levels and did not show any notable mutations except one strain producing Bac that was able to bind FH but not IgA. A deletion of 51 amino acid residues, including part of the Bac IgA-binding region, was identified and hypothesized to contribute to the loss of the IgA-binding ability of this strain. A vaginal strain that showed somewhat higher bac expression levels and produced Bac lacking immunoreactivity contained an 11 bp deletion, which generated a premature termination codon, in the region preceding the IgA-binding region. In another vaginal strain that did not express bac, disruption of the upstream ORFs of the sensor histidine kinase and DNA-binding response regulator, due to frameshift mutations, was noted although it is not known whether these proteins directly affect bac expression levels. An IS1381 insertion into the promoter region was found in another vaginal strain that showed low expression levels and produced Bac with a significantly larger proline-rich repeat region. These results demonstrate considerable genetic diversity of the bac and upstream regions of invasive and noninvasive GBS, which may contribute to the variability of bac expression levels among those strains.

scholarly journals Perinatal hormones favor CC17 group B Streptococcus intestinal translocation through M cells and hypervirulence in neonates

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Constantin Hays ◽  
Gérald Touak ◽  
Abdelouhab Bouaboud ◽  
Agnès Fouet ◽  
Julie Guignot ◽  
...  
Keyword(s):  
Late Onset ◽  
Group B Streptococcus ◽  
Intestinal Barrier ◽  
Surface Protein ◽  
Neonatal Infection ◽  
M Cells ◽  
M Cell ◽  
Hormonal Exposure ◽  
Group B ◽  
The Impact

Group B Streptococcus (GBS) is the leading cause of invasive bacterial neonatal infections. Late-onset diseases (LOD) occur between 7 and 89 days of life and are largely due to the CC17 GBS hypervirulent clone. We studied the impact of estradiol (E2) and progesterone (P4), which impregnate the fetus during pregnancy, on GBS neonatal infection in cellular and mouse models of hormonal exposure corresponding to concentrations found at birth (E2-P4 C0) and over 7 days old (E2-P4 C7). Using representative GBS isolates, we show that E2-P4 C7 concentrations specifically favor CC17 GBS meningitis following mice oral infection. CC17 GBS crosses the intestinal barrier through M cells. This process mediated by the CC17-specific surface protein Srr2 is enhanced by E2-P4 C7 concentrations which promote M cell differentiation and CC17 GBS invasiveness. Our findings provide an explanation for CC17 GBS responsibility in LOD in link with neonatal gastrointestinal tract maturation and hormonal imprint.

scholarly journals Reverse Line Blot Assay for Direct Identification of Seven Streptococcus agalactiae Major Surface Protein Antigen Genes

2006 ◽  
Vol 13 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Zuotao Zhao ◽  
Fanrong Kong ◽  
Gwendolyn L. Gilbert
Keyword(s):  
Streptococcus Agalactiae ◽  
Blot Hybridization ◽  
Group B Streptococcus ◽  
Immunoglobulin A ◽  
Surface Protein ◽  
Epidemiological Studies ◽  
Reverse Line Blot ◽  
Variable Surface ◽  
Group B ◽  
Major Surface

ABSTRACT We developed a multiplex PCR-based reverse line blot hybridization assay (mPCR/RLB) to detect the genes encoding members of the family of variable surface-localized proteins of Streptococcus agalactiae (group B streptococcus [GBS]), namely, Bca (Cα), Rib, Epsilon (Epsilon/Alp1/Alp5), Alp2, Alp3, and Alp4, and the immunoglobulin A binding protein, Bac (Cβ). We used the assay to identify these genes in a collection of well-characterized GBS isolates and reference strains. The results showed that mPCR/RLB avoids the common problems of cross-reaction and nontypability associated with protein typing using antisera. It is as sensitive as, but more practical than, separate gene-specific PCRs and would be suitable for large molecular epidemiological studies of GBS.

scholarly journals Intranasal Immunization of Mice with Group B Streptococcal Protein Rib and Cholera Toxin B Subunit Confers Protection against Lethal Infection

2004 ◽  
Vol 72 (2) ◽  
pp. 1184-1187 ◽  
Author(s):  
Charlotte Larsson ◽  
Jan Holmgren ◽  
Gunnar Lindahl ◽  
Charlotta Bergquist
Keyword(s):  
Cholera Toxin ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Cholera Toxin B Subunit ◽  
Toxin B ◽  
Intranasal Immunization ◽  
Cholera Toxin B ◽  
B Subunit ◽  
A Cell ◽  
Group B

ABSTRACT Intranasal immunization of mice with Rib, a cell surface protein of group B streptococcus (GBS), conjugated to or simply coadministered with the recombinant cholera toxin B subunit, induces systemic immunoglobulin G (IgG) and local IgA antibody responses and confers protection against lethal GBS infection. These findings have implications for the development of a human GBS vaccine.

scholarly journals Towards a genotyping system for Streptococcus agalactiae (group B streptococcus): use of mobile genetic elements in Australasian invasive isolates

2003 ◽  
Vol 52 (4) ◽  
pp. 337-344 ◽  
Author(s):  
Fanrong Kong ◽  
Diana Martin ◽  
Gregory James ◽  
Gwendolyn L. Gilbert
Keyword(s):  
Streptococcus Agalactiae ◽  
Capsular Polysaccharide ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Mobile Genetic Elements ◽  
Genetic Elements ◽  
Gene Profiles ◽  
Polysaccharide Synthesis ◽  
Genetic Clusters ◽  
Group B

This study forms part of the development of an integrated genotyping system for Streptococcus agalactiae (group B streptococcus, GBS) that can be used to study the population genetics of the organism and the pathogenesis and epidemiology of GBS disease. In recent previous studies, two sets of markers, the capsular polysaccharide synthesis (cps) gene cluster and surface protein antigen genes, have been used to assign molecular serotypes (MS) and protein-gene profiles (PGP) to more than 200 isolates. In the present study, five mobile genetic elements (MGE) have been used as a third set of markers, to characterize further 194 invasive isolates, recovered from blood or cerebrospinal fluid (CSF). Of these, 97 % contained one or more of the five MGE, the distribution of which was related to MS and PGP, as illustrated by MS III, which is divisible into four serosubtypes with different combinations of the MGE (or none). Fifty-six different genotypes and eight genetic clusters were identified, each with different combinations of the three sets of molecular markers. Five predominant genotypes (Ia-1, Ib-1, III-1, III-2 and V-1) contained 62 % of the isolates and five of the eight genetic clusters contained 92 % of the isolates. The 17 CSF isolates were relatively widely distributed between 10 genotypes and across seven of the eight clusters. Further study is needed to determine whether these genotypes or clusters share common markers of increased virulence. In future, comparison of invasive with colonizing strains of GBS may elucidate the significance of these findings.

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