Construction and characterization of plasmid vectors for cloning in Staphylococcus aureus and Staphylococcus carnosus

Several plasmid vectors for cloning in Staphylococcus aureus and S. carnosus have been constructed and characterized. The chimeric plasmids are composed of parts of the following parental plasmids: The chloramphenicol-resistance plasmid, pC194, the tetracycline-resistance plasmid, pMK148, and the erythromycin-resistance plasmid, pE12. All the chimeric plasmids confer two selectable antibiotic-resistance markers on host cells. Insertional inactivation of the various antibiotic-resistance markers occurred at the BclI site of pE12, and the Sau96- or AvaII-site of pMK148; only a slight inactivation of the chloramphenicol-resistance marker occurred at the HaeIII-site of pC194. The chimeric plasmids pCT20 and pCE10 are both stable in S. aureus and S. carnosus. In addition, the hybrid plasmids of pCT20 and pCE10, containing lambda-DNA fragments in various restriction sites between 0.4 and 1.2 kb, are stably maintained. The inserted lambda-DNA fragments appear unchanged.