title: Translocation of antibiotic resistance markers of a plasmid-free Streptococcus pyogenes (group A) strain into different streptococcal hemolysin plasmids.
abstract: Wild-type strain A454 (Streptococcus pyogenes) transferred en bloc its erythromycin (Em) and tetracycline (Tc) resistance markers into several plasmid-free streptococcal recipients. No plasmid DNA was detected in either the wild-type or the transconjugant strains. Crosses were performed between A454 and S. faecalis Rec+ or Rec- recipients carrying hemolysin-bacteriocin plasmids, pIP964 or pAD1 . The Em Tc-resistant transconjugants obtained harbored either the parental plasmid or an Em Tc resistance plasmid derived from pIP964 or pAD1 . The restriction endonuclease analysis of 12 derivative plasmids showed insertions of various sizes into different fragments of pIP964 or pAD1 . A454 and the Em Tc-resistant plasmid-free transconjugants were found to contain two EcoRI DNA fragments, that shared homology with 32P-labeled pIP1077 , one of the Em Tc resistance derivative plasmids, but not with 32P-labeled pIP964 . No homology was detected between pIP1077 and the cellular DNA of the antibiotic-susceptible recipients.
mesh_terms: D003227:Conjugation, Genetic; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial / Q000235:genetics; D004352:Drug Resistance, Microbial; D004917:Erythromycin / Q000494:pharmacology; D006459:Hemolysin Factors; D010957:Plasmids; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000235:genetics*; D013752:Tetracycline / Q000494:pharmacology
chemical_list: D004269:DNA, Bacterial; D004917:Erythromycin; D004262:DNA Restriction Enzymes; D013752:Tetracycline