Related Experiment Videos
Molecular characterization of the erythromycin resistance plasmid pPV142 from Staphylococcus simulans
G A Somkuti1, D K Solaiman, D H Steinberg
1U.S. Department of Agriculture, ARS, Eastern Regional Research Center, Wyndmoor, PA 19038, USA. gsomkuti@arserrc.gov
Abstract:
The 2.5-kb erythromycin resistance (EmR) plasmid pPV142 of Staphylococcus 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 adenine N-6-methyltransferase), respectively. Structural analysis and Southern hybridization showed that the rep and ermM genes in pPV142 shared homology with the EmR plasmid pPV141 (2.4 kb) of S. chromogenes 3688 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, pPV142 is apparently a unique member of the pSN2 family of EmR plasmid able to express erythromycin resistance constitutively.
Insights
The erythromycin resistance plasmid pPV142 from Staphylococcus simulans was identified. This plasmid, unique in the pSN2 family, constitutively expresses erythromycin resistance via the ermM gene.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Erythromycin resistance (EmR) is a significant concern in staphylococci.
- Plasmids are key vectors for antibiotic resistance gene dissemination.
Purpose of the Study:
- To isolate and characterize the EmR plasmid pPV142 from Staphylococcus simulans 13044.
- To elucidate the genetic basis of erythromycin resistance conferred by pPV142.
Main Methods:
- Plasmid isolation and characterization.
- DNA sequencing and sequence analysis.
- Southern hybridization.
Main Results:
- The 2.5-kb plasmid pPV142 was isolated and sequenced.
- Sequence analysis revealed two open reading frames (ORFs): ORF1 (Rep142 replication protein) and ORF2 (ErmM erythromycin resistance protein).
- The rep and ermM genes showed homology to other EmR plasmids; pPV142 belongs to the pSN2 family and constitutively expresses EmR due to a 61-bp repeat upstream of ermM.
Conclusions:
- The pPV142 plasmid confers constitutive erythromycin resistance in Staphylococcus simulans.
- pPV142 represents a unique EmR plasmid within the pSN2 family, contributing to understanding antibiotic resistance mechanisms in staphylococci.