beta 2-microglobulin (beta 2m) was found to interact with many group A streptococcal strains. The interaction appeared to require multipoint attachment, since monomeric beta 2m in solution showed no binding, whereas both beta 2m monomers bound to liposomes, and beta 2m in aggregates showed affinity for the bacteria. Aggregated HLA antigens (-A, -B and -C) and aggregated beta 2m exhibited the same binding patterns when tested in binding experiments with various group A streptococcal strains. Furthermore, beta 2m aggregates in excess completely blocked the binding of aggregated HLA antigens, thereby demonstrating that beta 2m is able to interact with streptococcal surface structures also when it is part of the HLA antigen complex. M protein-positive group A streptococcal strains bound significantly more beta 2m than M protein-negative variants of these strains. Purified M 12 protein partly inhibited the binding of radiolabelled beta 2m aggregates to whole streptococci, and in gel filtration and affinity chromatography experiments, the M 12 protein interacted with beta 2m. These various data suggest that the interaction between beta 2m and group A streptococci could be mediated by M protein. Lipoteichoic acid (LTA) is a constituent of the streptococcal cell wall that has been reported to form complexes with M protein at the bacterial cell surface. However, LTA did not influence the interaction between beta 2m and streptococci, suggesting that the binding of beta 2m to streptococcal M protein represents a pure protein-protein interaction. In vivo such an interaction could be established between infecting streptococci and host cells. Among 45 strains of different M types large differences in beta 2m binding were recorded, whereas among 60 strains of the classical nephritogenic M types 12 and 49, all were highly beta 2m-reactive, which points towards a role for beta 2m in streptococcal pathogenicity.

The currently available vaccine is without major side-effects and effective in producing a significant immune response. Antibody levels should be monitored in vaccinated patients with chronic renal diseases considering the rapid decline as early as 6 months after vaccination. Evaluation of the efficacy of revaccination in these patients requires further investigations.

No abstract

The currently available vaccine is without major side-effects and effective in producing a significant immune response. Antibody levels should be monitored in vaccinated patients with chronic renal diseases considering the rapid decline as early as 6 months after vaccination. Evaluation of the efficacy of revaccination in these patients requires further investigations.

An oligonucleotide probe of 30 nucleotides length has been constructed, spanning the codons of amino acids 2 to 11 of the mature M1 protein of group A streptococci (Streptococcus pyogenes). It was labeled with digoxigenin-dUTP and visualized after hybridization with an anti-digoxigenin-antibody/alkaline phosphatase conjugate. It definitely detected the emm1 gene in dot-blotted 20-micrograms amounts of total nucleoid acid extracts. When tested with 27 type M1 group A streptococci of several epidemiologically unrelated outbreaks and 24 non-M1 strains, its sensitivity and specificity of detection reached 100% even at a hybridization temperature 35 degrees C below the calculated Tm. A detailed protocol for the construction and use of this oligonucleotide probe is given.