Carbohydrate antigen of serotype g “ Streptococcus milleri ”: immunochemical characterization

Oral Microbiology and Immunology

1996

Carbohydrate antigens of the serotype k/Lancefield group G "Streptococcus milleri" were extracted by autoclaving whole cells of the type k reference strain Streptococcus anginosus K214-2K. The type k and group G antigen molecules are separated from each other and partially purified by a DEAE-Sephadex A25 column chromatography followed by a Sephadex G-100 gel filtration. In the double diffusion and the immunoelectrophoresis, the type k and group G antigen preparations obtained yielded single bands with their homologous antisera respectively. The type k antigen preparation contained principally glycerol, rhamnose, ribitol, galactose and glucose in a molar ratio of 0.54:1.20:0.43:0.33:1.00. The quantitative precipitin inhibition test indicated that beta(1-6)glucosyl-glucose (gentiobiose) sequence played a major role in immunodeterminant structure. Thus, the type k antigen of "S. milleri" appears to be a new carbohydrate type antigen that is chemically different from any Ottens type antigen. In contrast, the group G antigen preparation contained high proportion of rhamnose in addition to glucose, N-acetylglucosamine and N-acetylgalactosamine in a molar ratio of 6.45:1.00:0.24:1.15, and the rhamnose residue was involved in the immunodominant epitope, being in good agreement with the previously proposed chemical structure of the group antigen.

Section: Discussionmentioning

confidence: 95%

“…Immunoelectrophoresis was performed at 10 mA for 70 min in the gel in 0.025 M barbital buffer, pH 8.6. Quantitative precipitin reaction and its inhibition by haptens were done as described previously (13).…”

Section: Immunological Methodsmentioning

confidence: 99%

Immunochemical characterization of the carbohydrate antigens of serotype k and Lancefield group G “Streptococcus milleri”

Kitada

Oral Microbiology and Immunology

1996

Serotype variation in Streptococcus anginosus, S. constellatus and S. intermedius

Journal of Medical Microbiology

Eifuku-Koreeda²,

Kitada³

et al. 1998

Various serotypes reported in three serotyping systems for the 'Streptococcus milleri' group, i.e., Ottens I-IV, Osano I-IV and serotypes a-k, were compared with each other in a capillary precipitation test and by the double immunodiffusion test. Only two of the 19 serotypes, f and Ottens-111, were identical, and the other 17 serotypes were independent. Thus, 18 serotypes and another three candidates (a-, b-and g-crossreactive) were found in the 'S. milleri' group. Of the 248 strains tested, 197 were serotypable, and 23 strains carried two type antigens. Generally, the Ottens I, 11, 111 (serotype j ) , IV and Osano IV antigens, often together with the Lancefield group F antigen, were found in S. anginosus and S. constellatus. In addition, the serotype a, c, d, e and k antigens with the group A, C or G antigen were distributed in S. anginosus, the serotype b antigen in S. constellatus and the g, h, i, j , Osano I, I1 and I11 antigens in S. intermedius. Twenty-five of the untypable strains were Lancefield groupable (mostly F).

Immunochemical characterization of the carbohydrate antigens of serotype c/Lancefield group C “Streptococcus milleri”

Kitada

Yakushiji

Oral Microbiology and Immunology

1993

Carbohydrate antigens of the serotype c/Lancefield group C "Streptococcus milleri" were extracted by autoclaving whole cells of the type c reference strain K51Y. The type c and group C antigen molecules were separated and partially purified by a DEAE-Sephadex A-25 column chromatography followed by Sephadex G-100 gel filtration. The purified type c antigen and group C antigen were homogeneous in the double diffusion and in the immunoelectrophoresis. The type c antigen was composed principally of glycerol, rhamnose, glucose and N-acetylglucosamine in a molar ratio of 0.22:0.27:1.00:0.48. The quantitative precipitin inhibition test indicated that N-acetylglucosamine played a major role in immunodeterminant structure. Thus, the type c antigen of "S. milleri" is a new carbohydrate type antigen and is immunochemically different from the Ottens-type antigen III found occasionally in group C streptococci. In contrast, the group C antigen preparation contained a high proportion of N-acetylgalactosamine in addition to glycerol, rhamnose, glucose and N-acetylglucosamine, and the N-acetylgalactosamine residue was involved in the immunodominant epitope, being in good agreement with the previously proposed chemical structure of the group antigen. N-acetylgalactosamine was detected in the autoclaved extracts of a nontypeable/group C strain but not of a type c/ungroupable strain.