INVESTIGATIONS TO EXPRESSION OF INDUCIBLE RESISTANCE TO CHLORAMPHENICOL-ACETYLTRANSFERASE-GENES IN STAPHYLOCOCCUS-INTERMEDIUS AND STAPHYLOCOCCUS-AUREUS

The two plasmids PSCS1 from Staphylococcus intermedius and pSCS6 from Staphylococcus aureus conferred inducible resistance to chloramphenico l (Cm(R)). These CM(R)-plasmids differed only slightly from one anothe r in the nucleotide sequences of their chloramphenicol acetyltransfera se structural genes (cat). However, the cat gene regulatory regions of both plasmids revealed distinct differences in the nucleotide sequenc es of their functionally important domains. In comparison to plasmid p SCS6, plasmid pSCS1 exhibited a weaker translation initiation signal a nd a stronger translation termination signal within this cat gene regu latory region. Consequently, pSCS1 demonstrated delayed cat gene induc tion and a lower level of maximum CAT expression.