Structural determination and serology of the native polysaccharide antigen of type-III group B Streptococcus

1980 ◽  
Vol 58 (2) ◽  
pp. 112-120 ◽  
Author(s):  
Harold J. Jennings ◽  
Karl-Gunnar Rosell ◽  
Dennis L. Kasper

The native polysaccharide antigen isolated from type-III group B Streptococcus contains D-galactose (Gal), D-glucose (Glc), 2-acetamido-2-deoxy-D-glucose (GlcNAc), and sialic acid (NeuNAc) in the molar ratio of 2:1:1:1 and its structure can be represented by the following repeating unit:[Formula: see text]By cleavage of all the labile sialic acid end groups the incomplete type-III antigen is obtained which is structurally identical to the S. pneumoniae type-14 polysaccharide. Thus, the native type-III polysaccharide is serologically distinct from the incomplete type-III antigen by virtue of the former having determinants terminating in sialic acid and the latter in β-D-galactopyranose units. None of these latter determinants could be detected in streptococcal organisms grown under pH-controlled conditions (pH 7.0) or in rabbit antiserum made to these pH-controlled organisms. However, in antisera produced in rabbits to the same organisms grown without pH control (Lancefield procedures), antibodies to both types of determinant could be detected. This can be attributed to the removal of some of the masking sialic acid residues from the cell-associated native polysaccharide by degradative procedures which occur during these latter conditions.

1989 ◽  
Vol 67 (5) ◽  
pp. 877-882 ◽  
Author(s):  
Jose L. Di Fabio ◽  
Francis Michon ◽  
Jean-Robert Brisson ◽  
Harold J. Jennings ◽  
Michael R. Wessels ◽  
...  

The native polysaccharide antigen isolated from type IV group B Streptococcus contains D-galactose, D-glucose, 2-acetamido-2-deoxy-D-glucose, and sialic acid in the molar ratio 2:2:1:1 and is composed of the following repeating unit:[Formula: see text]The structural analysis of this antigen was based on results obtained from methylation analysis, partial hydrolysis, nitrous acid deamination, and nuclear magnetic resonance spectroscopic techniques. Keywords: capsular polysaccharide, high resolution NMR spectroscopy, group B Streptococcus, polysaccharide structure, polysaccharide degradation.


1979 ◽  
Vol 149 (1) ◽  
pp. 58-66 ◽  
Author(s):  
J Y Tai ◽  
E C Gotschlich ◽  
R C Lancefield

Group B streptococcus type Ib (strain H36B) was subjected to digestion with extracellular muralytic enzymes prepared from Streptomyces albus. Type Ib-specific polysaccharide antigen was isolated from the lysate by alcohol precipitation and Sepharose 6B chromatography. The purified type Ib antigen has a Kd value of 0.31 on a Sepharose 4B column and contains four sugars, galactose, glucose, N-acetyl glucosamine, and sialic acid in a molar ratio of 2.05:0.86:1.00:0.90. Acid treatment (pH 2.0) of this polysaccharide results in partial degradation of the antigen (Kd = 0.41 on Sepharose 4B) with the loss of 93% of the sialic acid. The molar ratio of the remaining sugars in the polysaccharide remains identical to that in the native one. This suggests that the sialic acid is at the terminal position in the molecule. Both intact and acid-treated antigen cross-react with some type Ia and type Ic antisera as a result of the common Iabc determinant, but not with type II and type III antisera. Absorption studies indicate that Ib-specific determinant and Iabc determinant are on the same molecule and that sialic acid is not the cross-reactive determinant.


PEDIATRICS ◽  
1978 ◽  
Vol 62 (4) ◽  
pp. 620-621
Author(s):  
Gerald W. Fischer ◽  
James W. Bass ◽  
George H. Lowell ◽  
Martin H. Crumrine

The article by Bortolussi et al. on pneumococcal septicemia and meningitis in the neonat (Pediatrics 60:352, September 1977) was of great interest to us, since we have been analyzing the effect of antibody directed against Streptococcus pneumoniae on group B Streptococcus type III. We have recently shown (unpublished data) that antibody directed against S. pneumoniae type 14 precipitates the hot hydrochloric acid-extracted polysaccharide antigen of group B Streptococcus type III. Further studies have shown that this antibody is opsonic for group B Streptococcus type III in an in vitro bactericidal assay and protective in a suckling rat model of group B Streptococcus type III sepsis.1


1976 ◽  
Vol 143 (2) ◽  
pp. 258-270 ◽  
Author(s):  
C J Baker ◽  
D L Kasper ◽  
C E Davis

The type III polysaccharide of -roup B Streptococcus has been isolated and purified by a method that employs washing of intact cells at neutral pH. That the polysaccharide prepared by this procedure is the "native" type III antigen is suggested by its molecular size in excess of 10(6) daltons, its degradation by acid and heat treatment to a fragment with immunologic characteristics of the classical HCl antigen, and its type-specific serologic activity. The type III polysaccharide in native form contains sialic acid, galactose, glucose, glucosamine, heptose, and mannose. It is acidic in nature, is resistant to neuramindiase degradation, contains no O-acetyl groups, and does not share antigenic determinants with capsular type K1 antigen of Escherichia coli or Group B polysaccharide antigen of Neiserria meningitidis.


1993 ◽  
Vol 177 (6) ◽  
pp. 1593-1603 ◽  
Author(s):  
M Stålhammar-Carlemalm ◽  
L Stenberg ◽  
G Lindahl

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.


1999 ◽  
Vol 67 (4) ◽  
pp. 1866-1870 ◽  
Author(s):  
Shinji Takahashi ◽  
Youko Aoyagi ◽  
Elisabeth E. Adderson ◽  
Yoshiyuki Okuwaki ◽  
John F. Bohnsack

ABSTRACT The majority of type III group B streptococcus (GBS) human neonatal infections are caused by a genetically related subgroup called III-3. We have proposed that a bacterial enzyme, C5a-ase, contributes to the pathogenesis of neonatal infections with GBS by rapidly inactivating C5a, a potent pro-inflammatory molecule, but many III-3 strains do not express C5a-ase. The amount of C5a produced in serum following incubation with representative type III strains was quantitated in order to better understand the relationship between C5a production and C5a-ase expression. C5a production following incubation of bacteria with serum depleted of antibody to the bacterial surface was inversely proportional to the sialic acid content of the bacterial capsule, with the more heavily sialylated III-3 strains generating less C5a than the less-virulent, less-sialylated III-2 strains. The amount of C5a produced correlated significantly with C3 deposition on each bacterial strain. Repletion with type-specific antibody caused increased C3b deposition and C5a production through alternative pathway activation, but C5a was functionally inactivated by strains that expressed C5a-ase. The increased virulence of III-3 strains compared to that of III-2 strains results at least partially from the higher sialic acid content of III-3 strains, which inhibits both opsonophagocytic killing and C5a production in the absence of type-specific antibody. We propose that C5a-ase is not necessary for III-3 strains to cause invasive disease because the high sialic acid content of III-3 strains inhibits C5a production.


1979 ◽  
Vol 149 (2) ◽  
pp. 327-339 ◽  
Author(s):  
D L Kasper ◽  
C J Baker ◽  
R S Baltimore ◽  
J H Crabb ◽  
G Schiffman ◽  
...  

The type III polysaccharides of group B Streptococcus in its native state chemically consists of glucose, galactose, glucosamine, and sialic acid. The core of this polysaccharide lacks sialic acid and precipitates with type III antiserum to give a partial identity with the precipitate between the native antigen and this serum. The core determinant is immunochemically similar to the capsular polysaccharide of type XIV Streptococcus pneumoniae, while the native type III group B streptococcal polysaccharide does not cross-react with type XIV pneumococcal antiserum. In human sera, it is antibody directed to the native antigen which correlates very highly with opsonic immunity (r = 0.94) while a poorer correlation exists between antibody to the core antigen and opsonins (r = 0.51 P less than 0.001). In natural infections, as association exists between low levels of maternal antibody to the native antigen and risk of disease in the infant. This association is not true for antibody to the core structure, where both infected infants and their mothers have much higher levels of antibody to the core than the native antigens. Infected infants are also more likely to respond to infection by developing antibody to the native antigen. Immunization of 12 adults with multivalent pneumococcal polysaccharide induced significantly better antibody response to the core antigen than to the native, and this vaccine induced opsonic activity in only one recipient. Immunization of adults with type III group B streptococcal antigens induced antibody to the native determinant which correlated with opsonic activity. Therefore, it would appear that native group B streptococcal polysaccharides will provide the best candidate antigens for immunization.


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