Journal: Infection and Immunity
Article Title: Reduced Virulence of Group A Streptococcal Tn916 Mutants That Do Not Produce Streptolysin S
Figure Lengend Snippet: Southern hybridization analysis of Hin dIII restriction digests of genomic DNA probed with tetM . (A) Hemolytic wild-type T18P (lane 1) does not hybridize with the tetM probe. Nonhemolytic transconjugants SB1-4, SB2-9, SB30-2, SB1-9, SB5-9, SB6-9, SB7-9, SB1-1, and SB8-2 (lanes 2 to 10, respectively) all contain at least one copy of Tn 916 and hybridize with the tetM probe. Isolates in lanes 2, 7, and 9 possess more than one Tn 916 insertion. All lanes possess two bands hybridizing with the tetM probe corresponding to approximately 6.5 and 14 kb. The Tn 916 donor strain CG110 (lane 11) contains several copies of Tn 916 . (B) Hemolytic wild-type MGAS166s (lane 1) does not hybridize with the tetM probe. The nonhemolytic transconjugants SBNH1, SBNH3, SBNH4, SBNH5, SBNH6, SBNH7, and SBNH8 (lanes 2 to 8, respectively) all possess at least one copy of Tn 916 . Isolates in lanes 3, 4, 7, and 8 possess more than one Tn 916 insertion. Isolates in all lanes possess two bands of similar size, approximately 14 and 7.5 kb. The migration of molecular size standards (1-kb ladder) is indicated on the left.
Article Snippet: M typing of nonhemolytic transconjugants confirmed that M protein was produced, and both SB30-2 and SBNH5 had the same M-protein phenotypes as their M18 and M1 parent strains, respectively.
Techniques: Hybridization, Migration