From the Guidelines
Penicillin or Ceftriaxone are the recommended antibiotics for Streptococcus bacteremia, as they are effective against most streptococcal species, including penicillin-susceptible oral streptococci and group D streptococci 1.
Recommended Regimens
- For penicillin-susceptible streptococci, penicillin or ceftriaxone can be administered for 4 weeks, with vancomycin as an alternative for patients allergic to beta-lactams 1.
- For uncomplicated cases, short-term 2-week therapy can be administered by combining penicillin or ceftriaxone with gentamicin or netilmicin 1.
- Ceftriaxone alone or combined with gentamicin or netilmicin given once a day is convenient for outpatient therapy 1.
Important Considerations
- Aminoglycosides should be given for at least 2 weeks in cases of penicillin-resistant streptococci 1.
- Vancomycin may be preferred in cases of highly resistant isolates (MIC ≥4 mg/L) 1.
- Teicoplanin has been proposed as an alternative, but requires loading doses and has limited experience in streptococcal IE 1.
Key Points
- The cure rate is expected to be >95% with recommended regimens 1.
- Gentamicin and netilmicin can be given once daily in patients with normal renal function 1.
- Ceftriaxone is a convenient option for outpatient therapy 1.
From the Research
Antibiotic Recommendations for Streptococcus Bacteremia
The recommended antibiotic for Streptococcus bacteremia is a beta-lactam antibiotic, such as penicillin 2, 3, 4.
- Penicillin is the drug of choice for infections caused by streptococci of the anginosus group 2.
- Beta-lactam antibiotics, such as cefaclor, are also effective in treating group A beta-hemolytic streptococcal pharyngitis 3.
- The use of oral step-down therapy with beta-lactam antibiotics is common and has similar readmission and mortality rates compared to definitive intravenous therapy 4.
Alternative Antibiotic Options
In cases where beta-lactam antibiotics are not suitable, alternative options include:
- Macrolides, such as erythromycin, which may be effective against group A Streptococcus 5.
- Vancomycin, which is effective against alpha- and nonhemolytic streptococci 6.
- Clindamycin, which is effective against streptococci of the anginosus group 2.
Considerations for Antibiotic Selection
When selecting an antibiotic for Streptococcus bacteremia, consider the following:
- The presence of beta-lactamase-producing organisms in the pharynx, which may affect the efficacy of penicillin 3.
- The susceptibility of the streptococcal isolate to different antibiotics, which may vary depending on the species and strain 2, 6.
- The severity of the infection and the patient's clinical condition, which may influence the choice of antibiotic and duration of therapy 4.