scholarly journals Cross‐Protection between Group A and Group B Streptococci Due to Cross‐Reacting Surface Proteins

2000 ◽  
Vol 182 (1) ◽  
pp. 142-149 ◽  
Author(s):  
Margaretha Stålhammar‐Carlemalm ◽  
Thomas Areschoug ◽  
Charlotte Larsson ◽  
Gunnar Lindahl
Keyword(s):  
Cross Protection ◽  
Surface Proteins ◽  
Group B Streptococci ◽  
Group A ◽  
Group B

scholarly journals Doubly Branched Hexasaccharide Epitope on the Cell Wall Polysaccharide of Group A Streptococci Recognized by Human and Rabbit Antisera

2005 ◽  
Vol 73 (10) ◽  
pp. 6383-6389 ◽  
Author(s):  
Francis Michon ◽  
Samuel L. Moore ◽  
John Kim ◽  
Milan S. Blake ◽  
France-Isabelle Auzanneau ◽  
...  
Keyword(s):  
Cell Wall ◽  
Rabbit Antiserum ◽  
Cell Wall Polysaccharide ◽  
Group A Streptococci ◽  
Group B Streptococci ◽  
Group A ◽  
Streptococcal Polysaccharide ◽  
Synthetic Oligosaccharides ◽  
Group B ◽  
Dominant Epitope

ABSTRACT A number of epitope specificities associated with the cell wall polysaccharide antigen of group A streptococci were identified in a polyclonal rabbit antiserum induced in rabbits by whole group A streptococci and in polyclonal convalescent human antisera from children that had recovered from streptococcal A infections. The identification was achieved by using a series of synthetic oligosaccharides, glycoconjugates, and bacterial polysaccharide inhibitors to inhibit the binding of the group A helical polysaccharide to the polyclonal antisera. The exclusively dominant epitope expressed in the convalescent human antisera was the doubly branched extended helical hexasaccharide with the structure α-l-Rhap(1→2)[β-d-GlcpNAc(1→3)]α-l-Rhap(1→3)α-l-Rhap(1→2)[β-d-GlcpNAc(1→3)]α-l-Rhap. The hexasaccharide epitope also bound with the highest immunoreactivity to the rabbit antiserum. In contrast, the human antisera did not show significant binding to the singly branched pentasaccharide with the structure α-l-Rhap(1→2)α-l-Rhap(1→3)α-l-Rhap(1→2)[β-d-GlcpNAc(1→3)]α-l-Rhap or the branched trisaccharide α-l-Rhap(1→2)[β-d-GlcpNAc(1→3)]α-l-Rhap, although both these haptens bound significantly to the same rabbit antiserum, albeit with less immunoreactivity than the hexasaccharide. Inhibition studies using streptococcal group A and B rabbit antisera and the inhibitors indicated above also suggested that the group A carbohydrate, unlike the group B streptococcal polysaccharide, does not contain the disaccharide α-l-Rhap(1→2)α-l-Rhap motif at its nonreducing chain terminus, stressing the importance of mapping the determinant specificities of these two important streptococcal subcapsular group polysaccharides to fully understand the serological relationships between group A and group B streptococci.

TRANSFERABLE DRUG RESISTANCE TO GROUP A AND GROUP B STREPTOCOCCI

The Lancet ◽  
1978 ◽  
Vol 311 (8065) ◽  
pp. 655-656 ◽  
Author(s):  
J.D.A. Van Embden ◽  
N. Soedirman ◽  
H.W.B. Engel
Keyword(s):  
Drug Resistance ◽  
Group B Streptococci ◽  
Group A ◽  
Group B

scholarly journals Genotypic versus phenotypic methods in the detection of Listeria monocytogenes prosthetic joint infection

2009 ◽  
Vol 58 (6) ◽  
pp. 829-831 ◽  
Author(s):  
Barbora Žaloudíková ◽  
Martin Kelbl ◽  
Libor Paša ◽  
Tomáš Freiberger
Keyword(s):  
Listeria Monocytogenes ◽  
Prosthetic Joint Infection ◽  
Pathogen Detection ◽  
Joint Infection ◽  
Group B Streptococci ◽  
Prosthetic Joint ◽  
Routine Clinical Setting ◽  
Group A ◽  
Phenotypic Methods ◽  
Group B

A rare case of a severe prosthetic joint infection in a 71-year-old immunocompetent woman is presented. Listeria monocytogenes was identified in two consecutive samples using broad-range PCR and sequencing, whereas cultivation remained negative for the first sample and streptococci of a non-group A streptococci, non-group B streptococci type were detected for the second one. This report demonstrates that the phenotypic approach may lead to misidentification of L. monocytogenes in a routine clinical setting. Molecular methods of pathogen detection might be useful when a rare and/or unexpected micro-organism is present or the sample is collected during antibiotic treatment.

scholarly journals Synergistic hemolysis phenomenon shown by an alpha-toxin-producing Clostridium perfingens and streptococcal CAMP factor in presumptive streptococcal grouping

1978 ◽  
Vol 8 (5) ◽  
pp. 480-488
Author(s):  
S M Gubash
Keyword(s):  
Human Blood ◽  
Test Group ◽  
Blood Agar ◽  
Group A Streptococci ◽  
Alpha Toxin ◽  
Group B Streptococci ◽  
Camp Factor ◽  
Group A ◽  
Camp Test ◽  
Group B

A new phenomenon of synergistic hemolysis by Clostridium perfringens alpha-toxin and the streptococcal CAMP factor on human and guinea pig erythrocytes is described. A possible mode of action of the CAMP factors is suggested. On human blood agar all of the tested isolates of group B streptococci gave an arrowhead-shaped zone of hemolysis; 74% of group A gave a crescent-shaped lytic zone, whereas all isolates of groups C and G and the remaining 26% of group A streptococci gave a bullet-shaped lytic zone. By comparison, in the CAMP test incubated aerobically and anaerobically, 70 and 91%, respectively, of streptococci other than group B gave positive, arrowhead-shaped lytic zones. If all intermediate positive reactions in the CAMP tests were read as negative after aerobic incubation, only 89% of group B streptococci would be properly identified. The synergistic hemolysis phenomenon, using an alpha-toxin-producing C. perfringens and human blood agar, provided a reliable test for presumptive identification of group B streptococci, with promising potential to differentiate in the same test group A streptococci from other groups.

The human IgA-Fc α receptor interaction and its blockade by streptococcal IgA-binding proteins

2002 ◽  
Vol 30 (4) ◽  
pp. 491-494 ◽  
Author(s):  
J. M. Woof
Keyword(s):  
Pathogenic Bacteria ◽  
Surface Proteins ◽  
Receptor Interaction ◽  
Group B Streptococci ◽  
Domain Swap ◽  
Mucosal Surfaces ◽  
Β Protein ◽  
Group B ◽  
A Site ◽  
Streptococcal Proteins

IgA plays a key role in immune defence of the mucosal surfaces. IgA can trigger elimination mechanisms against pathogens through the interaction of its Fc region with FcαRs (receptors specific for the Fc region of IgA) present on neutrophils, macrophages, monocytes and eosinophils. The human FcαR (CD89) shares homology with receptors specific for the Fc region of IgG (FcαRs) and IgE (FcαRIs), but is a more distantly related member of the receptor family. CD89 interacts with residues lying at the interface of the two domains of IgA Fc, a site quite distinct from the homologous regions at the top of IgG and IgE Fc recognized by FcαR and FcαRI respectively. Certain pathogenic bacteria express surface proteins that bind to human IgA Fc. Experiments with domain-swap antibodies and mutant IgAs indicate that binding of three such proteins (Sir22 and Arp4 of Streptococcus pyogenes and β protein of group B streptococci) depend on sites in the Fc interdomain region of IgA, the binding region also used by CD89. Further, we have found that the streptococcal proteins can inhibit interaction of IgA with CD89, and have thereby identified a mechanism by which a bacterial IgA-binding protein may modulate IgA effector function.

scholarly journals Rapid recognition of group B streptococci by pigment production and counterimmunoelectrophoresis

1976 ◽  
Vol 3 (3) ◽  
pp. 287-290
Author(s):  
K Merritt ◽  
T L Treadwell ◽  
N J Jacobs
Keyword(s):  
The Other ◽  
Clinical Isolates ◽  
Simple Test ◽  
Serological Testing ◽  
Group B Streptococci ◽  
Columbia Agar ◽  
Group A ◽  
Group B ◽  
Group D ◽  
Sensitive Method

Streptococci from clinical isolates were studied for their ability to produce pigment in stab cultures in Columbia agar. Serological grouping of these organisms was done by counterimmunoelectrophoresis using Burroughs-Wellcome antisera. In this group of isolates, 66 of the 68 organisms grouped as B by serological testing produced pigment in the Columbia agar stab cultures. Pigment was not produced by any of the other 36 streptococci studied (11 group A, 9 group C, 4 group D, and 12 nongroupable). The use of the Columbia agar stab culture is recommended as a rapid and simple test for recognition of group B streptococci. The counterimmunoelectrophoresis test is also suggested as a convenient, rapid, and sensitive method for grouping the streptococci.

scholarly journals Molecular Epidemiology and Distribution of Serotypes, Surface Proteins, and Antibiotic Resistance among Group B Streptococci in Italy

2007 ◽  
Vol 45 (9) ◽  
pp. 2909-2916 ◽  
Author(s):  
G. Gherardi ◽  
M. Imperi ◽  
L. Baldassarri ◽  
M. Pataracchia ◽  
G. Alfarone ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Molecular Epidemiology ◽  
Surface Proteins ◽  
Group B Streptococci ◽  
Group B

scholarly journals Identification of Group B Streptococcal Sip Protein, Which Elicits Cross-Protective Immunity

2000 ◽  
Vol 68 (10) ◽  
pp. 5610-5618 ◽  
Author(s):  
Bernard R. Brodeur ◽  
Martine Boyer ◽  
Isabelle Charlebois ◽  
Josée Hamel ◽  
France Couture ◽  
...  
Keyword(s):  
Amino Acid ◽  
Molecular Mass ◽  
Protective Immunity ◽  
Genomic Library ◽  
Protein Band ◽  
Surface Proteins ◽  
Group B Streptococci ◽  
Universal Vaccine ◽  
Reading Frame ◽  
Group B

ABSTRACT A protein of group B streptococci (GBS), named Sip for surface immunogenic protein, which is distinct from previously described surface proteins, was identified after immunological screening of a genomic library. Immunoblots using a Sip-specific monoclonal antibody indicated that a protein band with an approximate molecular mass of 53 kDa which did not vary in size was present in every GBS strain tested. Representatives of all nine GBS serotypes were included in the panel of strains. Cloning and sequencing of the sip gene revealed an open reading frame of 1,305 nucleotides coding for a polypeptide of 434 amino acid residues, with a calculated pI of 6.84 and molecular mass of 45.5 kDa. Comparison of the nucleotide sequences from six different strains confirmed with 98% identity that the sip gene is highly conserved among GBS isolates. N-terminal amino acid sequencing also indicated the presence of a 25-amino-acid signal peptide which is cleaved in the mature protein. More importantly, immunization with the recombinant Sip protein efficiently protected CD-1 mice against deadly challenges with six GBS strains of serotypes Ia/c, Ib, II/R, III, V, and VI. The data presented in this study suggest that this highly conserved protein induces cross-protective immunity against GBS infections and emphasize its potential as a universal vaccine candidate.

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