Natural acquired group B Streptococcus capsular polysaccharide and surface protein antibodies in HIV-infected and HIV-uninfected children

Vaccine ◽  
2016 ◽  
Vol 34 (44) ◽  
pp. 5217-5224 ◽  
Author(s):  
Sonwabile Dzanibe ◽  
Peter V. Adrian ◽  
Sheila Z. Kimaro Mlacha ◽  
Shabir A. Madhi
Keyword(s):  
Capsular Polysaccharide ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
Group B

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.

scholarly journals Identification of novel cps locus polymorphisms in nontypable group B Streptococcus

2006 ◽  
Vol 55 (6) ◽  
pp. 775-783 ◽  
Author(s):  
Srinivas V. Ramaswamy ◽  
Patricia Ferrieri ◽  
Lawrence C. Madoff ◽  
Aurea E. Flores ◽  
Nikhil Kumar ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Group B Streptococcus ◽  
Surface Protein ◽  
The Elderly ◽  
Surface Proteins ◽  
Pcr Analysis ◽  
Genetic Profile ◽  
Gene Encoding ◽  
Group B ◽  
Type V

Group B Streptococcus (GBS) is an important pathogen responsible for a variety of diseases in newborns and the elderly. A clinical GBS isolate is considered nontypable (NT) when serological methods fail to identify it as one of nine known GBS serotypes. Eight clinical isolates (designated A1–A4, B1–B4) showed PFGE profiles similar to that of a GBS serotype V strain expressing R1, R4 surface proteins. These unique isolates were further characterized by immunologic and genetic methods. Rabbit sera to isolates A1 and A2 reacted weakly with concentrated HCl extracts of A1–A4 isolates, but not with those of B1–B4 isolates. In addition, a type V capsular polysaccharide (CPS) inhibition ELISA revealed that cell wall extracts from isolates A1–A4, but not from B1–B4, expressed low but measurable amounts of type V CPS. Molecular serotyping with PCR analysis showed that all eight isolates contained a type V-specific CPS gene (cpsO) and harboured the gene encoding the surface protein Alp3. Multilocus sequence typing identified isolate A1 as belonging to a new sequence type (ST) designated ST-173, whereas the other seven isolates keyed to ST-1. Sequencing of the 18 genes (17 736 bp) in the cps locus showed that each NT isolate harboured one to three unique polymorphisms, and also identified an IS1381 element in cpsE of the B4 isolate. Collectively, genetic and immunologic analyses revealed that these NT isolates expressing R1, R4 proteins have a genetic profile consistent with that of type V, an emergent, antigenically diverse and increasingly prevalent GBS serotype.

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

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

Synthesis of a disialylated hexasaccharide of Type VIII Group B Streptococcus capsular polysaccharide

1999 ◽  
Vol 319 (1-4) ◽  
pp. 1-16 ◽  
Author(s):  
Eva Eichler ◽  
Harold J. Jennings ◽  
Michel Gilbert ◽  
Dennis M. Whitfield
Keyword(s):  
Capsular Polysaccharide ◽  
Group B Streptococcus ◽  
Type Viii ◽  
Group B

scholarly journals NeuA Sialic Acid O-Acetylesterase Activity Modulates O-Acetylation of Capsular Polysaccharide in Group B Streptococcus

2007 ◽  
Vol 282 (38) ◽  
pp. 27562-27571 ◽  
Author(s):  
Amanda L. Lewis ◽  
Hongzhi Cao ◽  
Silpa K. Patel ◽  
Sandra Diaz ◽  
Wesley Ryan ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Capsular Polysaccharide ◽  
Group B Streptococcus ◽  
Site Directed Mutagenesis ◽  
Synthetase Activity ◽  
Bacterial Surface ◽  
Acetylneuraminic Acid ◽  
Single Polypeptide ◽  
Group B

Group B Streptococcus (GBS) is a common cause of neonatal sepsis and meningitis. A major GBS virulence determinant is its sialic acid (Sia)-capped capsular polysaccharide. Recently, we discovered the presence and genetic basis of capsular Sia O-acetylation in GBS. We now characterize a GBS Sia O-acetylesterase that modulates the degree of GBS surface O-acetylation. The GBS Sia O-acetylesterase operates cooperatively with the GBS CMP-Sia synthetase, both part of a single polypeptide encoded by the neuA gene. NeuA de-O-acetylation of free 9-O-acetyl-N-acetylneuraminic acid (Neu5,9Ac2) was enhanced by CTP and Mg2+, the substrate and co-factor, respectively, of the N-terminal GBS CMP-Sia synthetase domain. In contrast, the homologous bifunctional NeuA esterase from Escherichia coli K1 did not display cofactor dependence. Further analyses showed that in vitro, GBS NeuA can operate via two alternate enzymatic pathways: de-O-acetylation of Neu5,9Ac2 followed by CMP activation of Neu5Ac or activation of Neu5,9Ac2 followed by de-O-acetylation of CMP-Neu5,9Ac2. Consistent with in vitro esterase assays, genetic deletion of GBS neuA led to accumulation of intracellular O-acetylated Sias, and overexpression of GBS NeuA reduced O-acetylation of Sias on the bacterial surface. Site-directed mutagenesis of conserved asparagine residue 301 abolished esterase activity but preserved CMP-Sia synthetase activity, as evidenced by hyper-O-acetylation of capsular polysaccharide Sias on GBS expressing only the N301A NeuA allele. These studies demonstrate a novel mechanism regulating the extent of capsular Sia O-acetylation in intact bacteria and provide a genetic strategy for manipulating GBS O-acetylation in order to explore the role of this modification in GBS pathogenesis and immunogenicity.

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