From the FDA Drug Label
Daptomycin for injection is indicated for the treatment of adult and pediatric patients (1 to 17 years of age) with complicated skin and skin structure infections (cSSSI) caused by susceptible isolates of the following Gram-positive bacteria: Staphylococcus aureus (including methicillin-resistant isolates), Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus dysgalactiae subsp. equisimilis, and Enterococcus faecalis (vancomycin-susceptible isolates only). Complicated skin and skin structure infections, including diabetic foot infections, without concomitant osteomyelitis, caused by Staphylococcus aureus (methicillin-susceptible and -resistant strains), Streptococcus pyogenes, or Streptococcus agalactiae.
Daptomycin (IV) 1 and linezolid (PO) 2 are both indicated for the treatment of complicated skin and skin structure infections caused by Streptococcus agalactiae.
- Daptomycin (IV) is indicated for the treatment of adult and pediatric patients with complicated skin and skin structure infections (cSSSI) caused by susceptible isolates of Streptococcus agalactiae.
- Linezolid (PO) is indicated for the treatment of complicated skin and skin structure infections, including diabetic foot infections, without concomitant osteomyelitis, caused by Streptococcus agalactiae.
From the Research
For Streptococcus agalactiae complicated cellulitis, the recommended treatment is intravenous penicillin G at 2-4 million units every 4-6 hours or ampicillin 1-2g every 4-6 hours, as supported by the most recent study 3 which identified penicillin G as a protective factor against mortality. For patients with penicillin allergy, clindamycin 600-900mg IV every 8 hours or vancomycin 15-20mg/kg IV every 12 hours are appropriate alternatives, considering the antimicrobial susceptibility profiles determined by studies such as 4 which found all GBS strains to be sensitive to Penicillin, Ampicilin, and Vancomycin. Treatment should typically continue for 7-14 days, with longer durations for more severe infections or those with complicating factors like immunosuppression or diabetes. Transition to oral therapy (amoxicillin 500mg three times daily, or clindamycin 300-450mg four times daily for penicillin-allergic patients) can occur once clinical improvement is evident, usually after 2-3 days of IV therapy. Complicated cellulitis may require surgical debridement if abscesses are present. Elevation of the affected limb, pain management, and monitoring for systemic spread are essential components of care. Group B Streptococcus is naturally sensitive to beta-lactam antibiotics, which inhibit cell wall synthesis, making penicillins highly effective first-line agents, as discussed in 5. Regular wound care and assessment for improvement within 48-72 hours should guide ongoing management decisions, taking into account the clinical manifestations and prognostic factors for Streptococcus agalactiae bacteremia among nonpregnant adults, as described in 3. Some key points to consider in the management of Streptococcus agalactiae complicated cellulitis include:
- The increasing trend of S. agalactiae infections in nonpregnant adults, as observed in 3
- The high mortality rate associated with S. agalactiae infections, particularly in certain serotypes like serotype III, as reported in 6
- The importance of antimicrobial susceptibility testing, given the increasing frequency of resistance to non-beta-lactam antibiotics, as noted in 4 and 5
- The need for early identification of specific strains, risk factors, or genetic mechanisms that may cause complicated GBS sepsis, as highlighted in 7