Insertional inactivation of streptolysin S expression in Streptococcus pyogenes.

摘要: The inactivation of a genetic determinant critical for streptolysin S production was accomplished by transfer and insertion the transposon Tn916 into DNA group A streptococcal strain. D strain CG110 able to efficiently CS91 when donor recipient cells were concentrated incubated together on membrane filters. Among tetracycline-resistant transconjugants, nonhemolytic mutants that no longer produced retained capacity produce O discovered. Hemolytic revertants from these regained tetracycline sensitivity; other still resistance phenotype. Hybridization studies employing located sequences in EcoRI HindIII fragments devoid S; one carried single copy Tn916, two multiple copies transposon. Images