Stability and expression of the staphylococcal constitutive macrolide-lincosamide-streptogramin B resistance plasmid pE3692 in Staphylococcus aureus and Bacillus subtilis.

The constitutive MLS resistance plasmid pE3692 (2.4 kb) from S. aureus and pE3692-9 plasmid derived from pE3692 by in vitro deletion of the small HindIII-HindIII fragment Sta (0.3 kb) were introduced into S. aureus RN450 and B. subtilis UOT0277 strains. The pE3692 plasmid was completly stable in S. aureus RN450, however, in B. subtilis UOT0277 this plasmid was segregationally unstable. Deletion of the Sta t fragment from the pE3692 reduced plasmid stability considerably both in S. aureus and B. subtilis host strains. The lower expression of tylosin-resistance of the erm gene of the pE3692-9 plasmid in B. subtilis UOT0277 strain was also observed.