Plasmid-specified FemABX-like immunity factor in Staphylococcus sciuri DD 4747.

Area of Science:

• Microbiology
• Molecular Biology
• Bacterial Genetics

Background:

• Plasmids in Staphylococcus species carry genes conferring various traits.
• Lysostaphin endopeptidase is a key enzyme used against Staphylococcus aureus infections.
• Understanding resistance mechanisms is crucial for developing effective antimicrobial strategies.

Purpose of the Study:

• To characterize a novel gene from Staphylococcus sciuri DD 4747 with potential antimicrobial resistance functions.
• To investigate the role of an epr-like gene in lysostaphin endopeptidase resistance in Staphylococcus aureus.

Main Methods:

• Plasmid isolation and sequencing from Staphylococcus sciuri DD 4747.
• Genetic manipulation of Staphylococcus aureus RN4220 by introducing the epr-like gene.
• Assessment of lysostaphin endopeptidase resistance in recombinant strains.
• Analysis of cell wall peptidoglycan composition using biochemical methods.

Main Results:

• A plasmid from S. sciuri DD 4747 contained replication, amidase-like, and epr-like genes.
• Introduction of the epr-like gene into S. aureus RN4220 increased resistance to lysostaphin endopeptidase.
• Recombinant strains exhibited altered peptidoglycan composition with increased serine and decreased glycine content.
• The epr-like gene was identified as a member of the femABX-like immunity gene family.

Conclusions:

• The identified epr-like gene confers resistance to lysostaphin endopeptidase in Staphylococcus species.
• This gene functions by modifying cell wall peptidoglycan structure.
• This represents the first instance of a femABX-like immunity gene not physically linked to the gene for the bacteriolytic enzyme it protects against.