From the Research
Staphylococcus aureus is the most clinically significant gram-positive bacteria that appears in clusters under microscopic examination, and when treating suspected S. aureus infections, empiric therapy should include antibiotics effective against methicillin-resistant strains (MRSA) until susceptibilities are known, as recommended by the most recent study 1. When considering treatment options, it's essential to distinguish between methicillin-susceptible S. aureus (MSSA) and MRSA, as treatment differs significantly between these two types.
- For mild skin and soft tissue infections, oral options include trimethoprim-sulfamethoxazole (1-2 DS tablets twice daily), doxycycline (100mg twice daily), or clindamycin (300-450mg four times daily) for 7-10 days, as suggested by 2.
- For severe infections or bacteremia, intravenous vancomycin (15-20mg/kg every 8-12 hours), daptomycin (6-10mg/kg daily), or linezolid (600mg twice daily) is recommended, according to 1. It's also important to note that vancomycin has been associated with poor outcomes such as nephrotoxicity, persistent bacteremia, and treatment failure, as reported by 3. Therefore, switching from vancomycin to nafcillin or cefazolin may be beneficial in patients with MSSA bacteremia, as it has been shown to reduce mortality hazards, as demonstrated by 3. Proper identification of the causative organism is crucial for appropriate antibiotic selection, and the clustering pattern of S. aureus under microscopic examination is a key diagnostic feature that distinguishes staphylococci from streptococci, which typically form chains, as described by 4.