Plasmid-encoded resistance to macrolides and lincosamides in Staphylococcus hyicus

Area of Science:

• Microbiology
• Molecular Biology
• Veterinary Science

Background:

• Antibiotic resistance in bacteria is a growing global health concern.
• Plasmids are common vehicles for the spread of antibiotic resistance genes.
• Staphylococcus hyicus is a bacterium that can infect livestock, potentially harboring resistance mechanisms.

Purpose of the Study:

• To isolate and characterize a plasmid responsible for antibiotic resistance in a porcine Staphylococcus hyicus strain.
• To determine if this resistance mechanism is transferable and to compare it with known resistance plasmids.
• To identify potential protein products encoded by the resistance plasmid.

Main Methods:

• Isolation and purification of a 2.35 kb plasmid (pSE2) from Staphylococcus hyicus.
• Interspecific transformation experiments to confirm plasmid-encoded resistance.
• Restriction mapping to compare pSE2 with other macrolide/lincosamide resistance plasmids.
• Analysis of proteins encoded by the pSE2 plasmid.

Main Results:

• A 2.35 kb plasmid, designated pSE2, was identified as conferring constitutive resistance to macrolide/lincosamide antibiotics.
• The resistance trait was transferable via interspecific transformation.
• Restriction mapping indicated that pSE2 differs from MLR-plasmids found in human-associated staphylococcal infections.
• The pSE2 plasmid was found to encode two proteins of approximately 20.5 and 30 kDa.

Conclusions:

• The porcine Staphylococcus hyicus plasmid pSE2 is a novel genetic element conferring macrolide/lincosamide resistance.
• The distinct genetic makeup of pSE2 suggests unique evolutionary pathways for antibiotic resistance in animal reservoirs.
• Understanding such animal-borne resistance plasmids is crucial for monitoring and combating the spread of antimicrobial resistance.