From the Research
Nitrofurantoin is a valid option for the treatment of cystitis caused by Aerococcus urinae, with a clinical and microbiological success rate of 71/76%. For less severe cases of Aerococcus urinae infections, nitrofurantoin can be used, with typical dosing of 100mg orally twice daily for 5-7 days depending on infection severity 1. In more severe cases, such as bacteremia or endocarditis, combination therapy with a beta-lactam antibiotic, such as penicillin or ampicillin, and an aminoglycoside, such as gentamicin, may be beneficial 2, 3. Aerococcus urinae is generally susceptible to beta-lactams, but resistance can occur, and treatment should be guided by susceptibility testing when available 4. Patients should complete the full course of antibiotics even if symptoms improve quickly to prevent recurrence and potential complications like endocarditis, which is a known risk with this organism 3. It's also important to note that fluoroquinolones, such as ciprofloxacin, may not be the best option due to increasing resistance rates, with a susceptibility rate of only 83.3% in one study 4. In penicillin-allergic patients, vancomycin can be used as an alternative, with typical dosing of 15-20mg/kg IV every 8-12 hours 2, 5. Overall, the choice of antibiotic and duration of treatment should be individualized based on the severity of the infection, the patient's underlying health status, and the results of susceptibility testing.