Treatment of Staphylococcus aureus and Streptococcus Infections
For staff infections caused by Staphylococcus aureus or Streptococcus, treatment should be based on whether the infection is methicillin-resistant or methicillin-susceptible, with appropriate antibiotic selection guided by the type of infection and local resistance patterns. 1
Classification of Skin and Soft Tissue Infections (SSTIs)
- Purulent SSTIs: Characterized by presence of pus, abscess, or purulent drainage 1
- Non-purulent SSTIs: Characterized by cellulitis without purulent drainage 1
Initial Management
Purulent SSTIs
- Primary treatment: Incision and drainage for abscesses and boils 1
- Antibiotic therapy indications: 1
- Severe or extensive disease involving multiple sites
- Rapid progression with associated cellulitis
- Signs of systemic illness
- Comorbidities or immunosuppression
- Extremes of age
- Abscess in difficult-to-drain area (face, hand, genitalia)
- Associated septic phlebitis
- Lack of response to incision and drainage alone
Non-purulent SSTIs
- Primary treatment: Empiric therapy targeting β-hemolytic streptococci 1
- Consider MRSA coverage: For patients who don't respond to β-lactam therapy or have systemic toxicity 1
Antibiotic Selection
For Outpatient Treatment of MSSA Infections
- First-line options: 1
- Semi-synthetic penicillins (dicloxacillin, flucloxacillin)
- First-generation cephalosporins (cephalexin, cefazolin)
- Clindamycin (if local resistance <10%)
For Outpatient Treatment of MRSA Infections
Recommended oral options: 1
- Clindamycin (if susceptible)
- Trimethoprim-sulfamethoxazole (TMP-SMX)
- Tetracyclines (doxycycline or minocycline) - not for children <8 years
- Linezolid
For dual coverage of MRSA and Streptococci: 1
- Clindamycin alone
- TMP-SMX or tetracycline plus β-lactam (e.g., amoxicillin)
- Linezolid alone
For Inpatient Treatment of Complicated SSTIs
Recommended IV options for MRSA: 1
- Vancomycin
- Linezolid (600 mg IV/PO twice daily)
- Daptomycin (4 mg/kg IV once daily)
- Telavancin (10 mg/kg IV once daily)
- Clindamycin (600 mg IV/PO three times daily)
For MSSA hospitalized patients: 1
- β-lactam antibiotics (e.g., cefazolin)
- Modify to MRSA-active therapy if no clinical response
Duration of Therapy
- Outpatient SSTIs: 5-10 days, based on clinical response 1
- Inpatient complicated SSTIs: 7-14 days, based on clinical response 1
Special Considerations
Pediatric Patients
- For minor skin infections: Mupirocin 2% topical ointment 1
- For complicated infections: 1
- Vancomycin (first choice)
- Clindamycin 10-13 mg/kg/dose IV every 6-8 hours (if local resistance <10%)
- Linezolid for children >12 years: 600 mg PO/IV twice daily; for children <12 years: 10 mg/kg/dose PO/IV every 8 hours
Antibiotic Resistance Concerns
- MRSA resistance rates: Up to 50% of MRSA strains have inducible or constitutive clindamycin resistance 1
- Treatment failures: Reported in 21% of cases with doxycycline or minocycline 1
- Streptococcal resistance: Increasing macrolide resistance in S. pyogenes (from 4-5% to 8-9%) 1
Monitoring and Follow-up
- Re-evaluation: Patients sent home on empiric therapy should be reevaluated in 24-48 hours to verify clinical response 1
- Culture: Obtain cultures from abscesses and purulent SSTIs for patients: 1
- Receiving antibiotic therapy
- With severe local infection or signs of systemic illness
- Who have not responded adequately to initial treatment
- When there is concern for a cluster or outbreak
Common Pitfalls to Avoid
- Inadequate drainage: Relying solely on antibiotics for abscess treatment without proper incision and drainage 1
- Inappropriate empiric therapy: Not considering local resistance patterns when selecting empiric antibiotics 1
- Insufficient follow-up: Failing to reassess patients on empiric therapy within 24-48 hours 1
- Monotherapy for severe infections: Using single agents for severe or complicated infections when combination therapy may be needed 1