Type-Specific Antigens of Group B Type Ic Streptococci

Wilkinson, Hazel W.; Eagon, R. G.

doi:10.1128/iai.4.5.596-604.1971

Cited by 154 publications

(102 citation statements)

References 26 publications

(25 reference statements)

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“…In the present investigation protein antigen c could be detected in combination with polysaccharide antigen Ib. This corresponded to the observations of Wilkinson and Eagon [25] and Jensen [26]. According to Brady et al [27] this protein antigen c consists of four independently expressed components called cK, cL, cQ and cN.…”

Section: Resultssupporting

confidence: 87%

Determination of epidemiological relationships ofStreptococcus agalactiaeisolated from bovine mastitis

Merl¹,

Abdulmawjood²,

Lämmler³

et al. 2003

FEMS Microbiology Letters

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In the present study 79 streptococcal cultures isolated from subclinical mastitis of 54 cows from seven dairy farms (A^G) in Hesse, Germany, were comparatively investigated using conventional and molecular methods. The isolates could be identified as Streptococcus agalactiae, belonging to Lancefield's serological group B by determination of cultural, biochemical and serological properties and by polymerase chain reaction (PCR)-mediated amplification of species-specific parts of the 16S ribosomal DNA, the 16S^23S rDNA intergenic spacer region and the CAMP factor gene cfb. The investigated group B streptococci were further characterized serologically for specific polysaccharide and protein antigens. Serotyping the isolates revealed a predominance of surface protein antigen X, either alone or in combination with polysaccharide antigen Ia. This could be observed for 39 isolates of farms A, B and C. Six group B streptococci from farm E displayed the serotype pattern III/Rib, two isolates from farm G showed the serotype pattern Ib/cK. The remaining cultures from farms D and F (n = 32) were non-typable. The occurrence of protein Rib could be confirmed by PCR amplification of the gene rib. The two isolates with serotype pattern Ib/cK also reacted positively for the cL-encoding gene bag. Additional properties which allowed a phenotypic characterization of the S. agalactiae were the degree of pigmentation, growth properties in fluid media and soft agar, the surface hydrophobicity, the ability to hemagglutinate rabbit erythrocytes and their resistance reactions to tetracycline and minocycline. The isolates of the seven farms showed identical or almost identical characteristics. The 79 group B streptococci were additionally investigated by macrorestriction analysis of their chromosomal DNA using the restriction endonucleases SmaI, ApaI and SalI. The restriction patterns obtained by pulsed-field gel electrophoresis displayed identical or closely related patterns for the cultures of the various farms. The pheno-and genotypic characteristics of the 79 group B streptococci of the present study revealed that a single S. agalactiae strain or at least closely related subtypes of this strain were responsible for the mastitis situation of the seven farms.

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Section: Resultssupporting

confidence: 87%

Determination of epidemiological relationships ofStreptococcus agalactiaeisolated from bovine mastitis

Merl¹,

Abdulmawjood²,

Lämmler³

et al. 2003

FEMS Microbiology Letters

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“…Group B streptococci may also produce the protein antigen originally called the Ic protein by Wilkirison & Eugon (6) and later designated the Ibc protein antigen by Wilkinson (5). The antigen was prepared by extraction of whole cells of the bacteria with hot HC1, and separated from the polysaccharides present in the extract by precipitation with cold trichloroacetic acid (6). On immunodiffusion the Ibc protein preparation produced two precipitation lines against antisera (6).…”

Section: Division Of Group B Streptococci Into Serotypesmentioning

confidence: 99%

“…The antigen was prepared by extraction of whole cells of the bacteria with hot HC1, and separated from the polysaccharides present in the extract by precipitation with cold trichloroacetic acid (6). On immunodiffusion the Ibc protein preparation produced two precipitation lines against antisera (6). Probably all type Ib strains and some type I1 and type 111 strains possess the protein antigen (2, 4, 7,8).…”

Section: Division Of Group B Streptococci Into Serotypesmentioning

confidence: 99%

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Complete And Incomplete Ibc Protein Fraction in Group B Streptococci

Bevanger¹,

Mæeland²

1979

Acta Pathologica Microbiologica Scandinavica Section B Microbio

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The Ibc protein fraction of group B streptococci was isolated from the type Ib strain H36B, the type Ic strain A909, and the type Ic strain 335, and examined against antisera by immunodiffusion and immunoelectrophoresis. The fraction from the Ib strain and one of the Ic strains (A909) contained two antigens or groups of antigens, called the α and β antigens, respectively. Strain 335 produced the a but not the β antigen. This was also the case with three other group B isolates previously classified as type Ic. One type II and one type III strain produced both antigens. The results suggest that group B streptococci producing the Ibc fraction can be subdivided further on the basis of the antigens that are present in that fraction.

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“…It is also used together with capsular polysaccharide in serotyping of GBS. Initially the C protein was shown to consist of two antigens, K and L [9]. The K antigen consists of large, identical, tandem repeat units [10].…”

Section: Introductionmentioning

confidence: 99%

An Escherichia coli-Enterococcus faecalis shuttle vector as a tool for the construction of a group B Streptococcus heterologous mutant expressing the β antigen (Bac) of the C protein complex

Kreikemeyer¹

1999

FEMS Microbiology Letters

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Group B streptococci (GBS) represent a very important group of human pathogens. So far little is known about the mechanisms by which these bacteria can cause disease and the bacterial factors involved. One putative virulence factor is the L antigen of the C protein complex (Bac), which can bind to the Fc region of human IgA. Its binding function might represent an important virulence mechanism. However, the genetic manipulation of this group of bacteria, necessary to prove involvement of bacterial factors in pathogenesis, is still in its infancy. We therefore tested the pAM401 vector system for its suitability in the construction of a heterologous expression mutant using the Bac protein as a model antigen. The bac gene, including its own promoter, was cloned into the Escherichia coli-Enterococcus faecalis shuttle vector pAM401 and was stably maintained extrachromosomally in the bac-deficient GBS strain 335. Expression of Bac was assessed by extracting the protein from transformed 335(pPJTU1) cells, negative controls (335 wild-type, 335(pAM401)) and other Bac-expressing GBS strains (A909, LA239). Blots of the extracted proteins probed with IgA, polyclonal sera and a monoclonal antibody raised against Bac clearly revealed expression of the 130-kDa protein in the transformed GBS 335(pPJTU1) cells. The correct processing and surface anchoring of the expressed Bac was demonstrated by binding of 125 I-labelled IgA to whole cells. Strain 335(pPJTU1) bound 12 times as much IgA compared to the parental strain LA239 and the GBS 335 negative controls, and a total of 25% compared to the high-level-expressing strain A909. Our studies show that the pAM401 shuttle vector can be used for stable heterologous expression of surface proteins in GBS. Our strategy is also of major importance for the complementation of deletion mutants in GBS and other Gram-positive human pathogens to fulfill Koch's postulates. The Bac mutant constructed in this study, 335(pPJTU1), can be used in animal models to assess the importance of Bac in GBS pathogenesis. ß 1999 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.Abbreviations: GBS, group B streptococci; Bac, L antigen of the C protein complex; IgA, immunoglobulin A; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis FEMS Microbiology Letters 180 (1999) 255^262

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Type-Specific Antigens of Group B Type Ic Streptococci

Cited by 154 publications

References 26 publications

Determination of epidemiological relationships ofStreptococcus agalactiaeisolated from bovine mastitis

Determination of epidemiological relationships ofStreptococcus agalactiaeisolated from bovine mastitis

Complete And Incomplete Ibc Protein Fraction in Group B Streptococci

An Escherichia coli-Enterococcus faecalis shuttle vector as a tool for the construction of a group B Streptococcus heterologous mutant expressing the β antigen (Bac) of the C protein complex

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