MOLECULAR CHARACTERIZATION OF THE ERYTHROMYCIN RESISTANCE PLASMID PPV142 FROM STAPHYLOCOCCUS SIMULANS

The 2.5-kb erythromycin resistance (Em(R)) plasmid pPV142 of Staphyloc occus simulans 13044 was isolated and characterized. Sequence analysis identified ORF1 and ORF2 encoding a 158-residue replication protein ( Rep142) and a 244-residue erythromycin resistance protein (Erm, rRNA a denine N-6-methyltransferase), respectively. Structural analysis and S outhern hybridization showed that the rep and ermM genes in pPV142 sha red homology with the EmR plasmid pPV 141 (2.4 kb) of S. chromogenes 3 688 and other EmR plasmids known to exist in staphylococci and bacilli . Based on the presence of a 61-bp repeat upstream of the ermM gene, p PV142 is apparently a unique member of the pSN2 family of EmR plasmids able to express erythromycin resistance constitutively. (C) 1998 Fede ration of European Microbiological Societies. Published by Elsevier Sc ience B.V. All rights reserved.