Conjugative transfer of high-level mupirocin resistance and the mobilization of non-conjugative plasmids in Staphylococcus aureus

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• Antibiotic resistance in Staphylococcus aureus is a growing public health concern.
• Mupirocin resistance is often mediated by plasmid-borne genes like mupA.
• Conjugative plasmids play a significant role in the dissemination of antibiotic resistance.

Purpose of the Study:

• To characterize a novel conjugative plasmid, pXU12, encoding mupirocin resistance.
• To investigate the mobilization capabilities of pXU12 for other plasmids.
• To evaluate the utility of pXU12 for transferring non-conjugative plasmids in laboratory settings.

Main Methods:

• Isolation and characterization of the conjugative plasmid pXU12 from Staphylococcus aureus MB494.
• Conjugation experiments to assess plasmid transfer frequency and kinetics.
• Mobilization assays to determine pXU12's ability to transfer other plasmids, including pXU13.

Main Results:

• The 31-kb conjugative plasmid pXU12 confers high-level mupirocin resistance via the mupA gene.
• pXU12 demonstrated rapid transfer in conjugation experiments (transconjugants within 15 min).
• pXU12 efficiently mobilized the erythromycin resistance plasmid pXU13 and 11 other nonconjugative plasmids.

Conclusions:

• pXU12 is a highly efficient conjugative plasmid capable of mobilizing various non-conjugative plasmids.
• The findings suggest pXU12 can be a valuable tool for transferring and isolating non-conjugative plasmids from resistant Staphylococcus aureus strains.
• This research contributes to understanding plasmid-mediated antibiotic resistance and provides a potential laboratory method for plasmid manipulation.