DISTRIBUTION OF PRESUMPTIVE PATHOGENICITY FACTORS AMONG BETA-HEMOLYTIC STREPTOCOCCI ISOLATED FROM ETHIOPIA

Beta-hemolytic streptococci are known to bind several mammalian protei ns, which are presumed to be important in pathogenicity. The distribut ion of such binding structures was examined for mouse albumin, human s erum IgA, human IgG, human fibrinogen, and human plasminogen. A total of 218 group A beta-hemolytic streptococci (GAS) were studied: 5 isola tes from children with acute rheumatic fever (ARF), 18 from acute post -streptococcal glomerulonephritis (APSGN), 57 from tonsillitis, 52 fro m skin infections, and 86 from healthy carriers. Sixty-eight Streptoco ccus equisimilis and 20 group G streptococci were also included. Most of the S. equisimilis (60/68) and group G (14/20) were obtained from a pparently healthy carriers. The results were evaluated with respect to T type, serum opacity reaction (SOR), site of isolation, and disease type. No direct correlation was detected between the protein-binding s tructures studied. There was no apparent correlation between any parti cular protein-binding structure and specific T type. Albumin-binding a nd IgA-binding activities were inversely correlated among skin and nep hritis GAS isolates. A strong correlation was demonstrated between IgA -binding activity and SOR production, while albumin-binding activity c orrelated with SOR-negative strains. Albumin-binding levels in isolate s from ARF, APSGN and tonsillitis were significantly higher than in is olates from healthy carriers (P<0.001). A higher albumin-binding capac ity was shown in skin isolates from APSGN than in isolates from impeti go (P < 0.001).