Genomic Profiling of Evolving Daptomycin Resistance in a Patient with Recurrent Staphylococcus argenteus Sepsis

Area of Science:

• Microbiology
• Genomics
• Infectious Diseases

Background:

• Staphylococcus argenteus is a recently identified species linked to invasive infections.
• Antimicrobial resistance is a growing global health concern, particularly in staphylococcal species.

Observation:

• A patient with a complex vascular graft infection was initially diagnosed with Staphylococcus aureus.
• The patient underwent repeated treatment with daptomycin, a lipopeptide antibiotic.

Findings:

• Longitudinal isolates revealed the emergence of daptomycin and vancomycin resistance in Staphylococcus argenteus.
• Whole-genome sequencing identified the acquisition of the MprF S337L mutation.
• This mutation is predicted to alter cell surface charge, potentially conferring resistance to cationic antimicrobial agents.

Implications:

• This case highlights the potential for Staphylococcus argenteus to develop antimicrobial resistance.
• Understanding resistance mechanisms like MprF S337L is crucial for managing complex infections.
• The findings underscore the importance of accurate species identification and antimicrobial stewardship.