title: Allelic variation of the streptokinase gene in beta-hemolytic streptococci group C and G isolates of human origin.
abstract: Genetic diversity of the streptokinase gene (sk) from 36 strains of S. equisimilis and 54 strains of group G streptococci was examined. The strains were isolated from patients with various streptococcal disease manifestations and healthy carriers. The region of the gene that corresponds to amino acid residues 174-244, was PCR amplified. The amplified product was subjected to MluI, PvuII, DraI and DdeI digestion. Based on the restriction enzyme digestion patterns nine sk alleles were recognized. There was no correlation between the various sk gene alleles and streptococcal disease manifestations. Three of the nine sk gene alleles, sk4, sk7, and sk8, were detected earlier among group A streptococci. The other six alleles were unique to S. equisimilis and group G streptococci. The most common alleles were sk5, found in 21/90 (23%) and sk10 detected in 43/90 (47%) of the strains. Alleles sk1 and sk2, the most frequent among group A streptococci, were not found among the strains in the present investigation. Thus, it appears that the sk gene has been evolving in line with other species distinguishing features of the streptococci.
authors.affiliation: Department of Laboratory Medicine, Karolinska Hospital, Stockholm, Sweden.
authors.forename: W
authors.initials: W
authors.lastname: Tewodros
authors.forename: I
authors.initials: I
authors.lastname: Karlsson
authors.forename: G
authors.initials: G
authors.lastname: Kronvall
mesh_terms: D000483:Alleles; D005798:Genes, Bacterial / Q000276:immunology*; D006801:Humans; D016133:Polymerase Chain Reaction; D013290:Streptococcal Infections / Q000382:microbiology; D013291:Streptococcus / Q000235:genetics* / Q000302:isolation & purification; D018502:Streptococcus equi / Q000235:genetics; D013300:Streptokinase / Q000235:genetics*
chemical_list: D013300:Streptokinase