Can beta-hemolytic Streptococcus (Strep) group C be treated with amoxicillin (Amoxicillin)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: March 15, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Yes, beta-hemolytic Group C Streptococcus can be effectively treated with amoxicillin. The typical adult dosage is 500 mg orally three times daily for 10 days, or alternatively, 875 mg twice daily for 10 days [ 1 ]. For children, the recommended dose is 45-50 mg/kg/day divided into two doses for 10 days. Amoxicillin is considered a first-line treatment because Group C streptococci remain highly susceptible to penicillins [ 1 ]. The medication works by inhibiting bacterial cell wall synthesis, leading to cell death.

Key Considerations

  • For patients with penicillin allergy, alternatives include clindamycin (300-450 mg orally three times daily for adults) or azithromycin (500 mg on day 1, then 250 mg daily for 4 more days) [ 1 ].
  • It's essential to complete the full course of antibiotics even if symptoms improve before completion to ensure complete eradication of the bacteria and prevent complications or recurrence.
  • Adequate hydration and rest are also recommended during treatment.

Treatment Approach

  • The choice of treatment should be based on the severity of the infection, patient's medical history, and susceptibility of the bacteria to antibiotics.
  • In general, strains of group B, C, F, and G streptococci are slightly more resistant to penicillin than are strains of group A streptococci [ 1 ].
  • The addition of gentamicin to penicillin or to ceftriaxone for at least the first 2 weeks of a 4- to 6-week course of antimicrobial therapy for group B, C, and G streptococcal IE may be considered [ 1 ].

From the FDA Drug Label

Amoxicillin for oral suspension is indicated in the treatment of infections due to susceptible (ONLY β-lactamase–negative) isolates of Streptococcusspecies. (α-and β-hemolytic isolates only)

The FDA drug label does not specifically mention Streptococcus group C. It mentions Streptococcus species with α-and β-hemolytic isolates only, but it does not provide information on specific groups, such as group C. Therefore, no conclusion can be drawn about the effectiveness of amoxicillin against beta-hemolytic Streptococcus (Strep) group C 2.

From the Research

Treatment of Beta-Hemolytic Streptococcus Group C

  • Beta-hemolytic Streptococcus group C can be treated with various antibiotics, including beta-lactam antibiotics 3.
  • According to a study, all group C streptococcal isolates were susceptible to third and fourth-generation cephalosporins, imipenem, chloramphenicol, rifampin, teicoplanin, and vancomycin 3.
  • The study also found that 2 group C strains were resistant to oxacillin and showed intermediate susceptibility to penicillin G 3.
  • Another study found that all beta-hemolytic streptococci, including group C, were susceptible to penicillin, amoxycillin, cephalosporins, and linezolid 4.
  • Amoxicillin is a beta-lactam antibiotic that can be used to treat beta-hemolytic Streptococcus group C infections, as it is susceptible to this type of antibiotic 3, 4.

Comparison of Antibiotics

  • A study compared the clinical and bacteriologic efficacy and tolerability of oral clindamycin with those of oral amoxicillin/clavulanic acid in the outpatient treatment of acute recurrent group A beta-hemolytic streptococcal pharyngotonsillitis 5.
  • The study found that both treatments achieved comparable rates of bacteriologic eradication at 12 days and 3 months and comparable clinical cure rates at 3 months 5.
  • Patients who received clindamycin had significantly greater clinical cure rates at 12 days 5.
  • Another study found that resistance to erythromycin, tetracycline, clindamycin, chloramphenicol, and quinolones is emerging among beta-hemolytic streptococci 4.

Route of Antibiotic Administration

  • A study compared oral and intravenous definitive antibiotic therapy for beta-hemolytic streptococcal bloodstream infections from soft tissue sources 6.
  • The study found that patients who transitioned to oral antibiotics by day 7 showed higher rates of 30-day treatment failure than propensity-matched patients who continued intravenous therapy 6.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.