Staphylococcus aureus endocarditis. Combined therapy with vancomycin and rifampin

Area of Science:

• Infectious Diseases
• Pharmacology
• Pediatrics

Background:

• Staphylococcus aureus infections, including bacteremia and endocarditis, pose significant clinical challenges.
• Vancomycin is a primary antibiotic for treating serious Gram-positive bacterial infections.

Observation:

• Two pediatric patients with persistent Staphylococcus aureus bacteremia and endocarditis did not respond to vancomycin therapy.
• Elevated vancomycin serum levels did not achieve therapeutic efficacy in these cases.
• One isolate was methicillin-resistant Staphylococcus aureus (MRSA), and the other patient had penicillin hypersensitivity.

Findings:

• A significant difference was observed between vancomycin's minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).
• The addition of rifampin to vancomycin therapy resulted in marked clinical and laboratory improvements in both patients.
• Rifampin demonstrated synergistic or additive effects when combined with vancomycin.

Implications:

• Rifampin may be a valuable adjunctive therapy for severe Staphylococcus aureus infections refractory to vancomycin.
• This case highlights the importance of considering alternative or combination therapies when standard treatments fail.
• Further research is warranted to explore the role of rifampin in treating challenging Staphylococcus aureus endocarditis and bacteremia.