From the Guidelines
Amoxicillin-clavulanate is generally considered the most effective oral agent for treating Aerococcus urinae urinary tract infections, with a typical dosage of 875/125 mg twice daily for 7-10 days. The choice of antibiotic should be guided by local resistance patterns and susceptibility testing, if possible. According to the European Association of Urology guidelines 1, the treatment of complicated UTIs should be based on local resistance patterns, and amoxicillin-clavulanate is a recommended option. The Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases also recommend amoxicillin-clavulanate as an alternative for the treatment of acute uncomplicated cystitis and pyelonephritis in women 1.
Some key points to consider when treating Aerococcus urinae UTIs include:
- Obtaining urine cultures before starting antibiotics to ensure accurate identification of the causative organism
- Completing the full course of antibiotics, even if symptoms resolve quickly
- Increasing fluid intake to help flush the urinary system
- Considering follow-up cultures to ensure complete eradication, particularly in complicated cases or recurrent infections
- Being aware of local resistance patterns and adjusting treatment accordingly, as recommended by the European Association of Urology guidelines 1 and the Infectious Diseases Society of America and the European Society for Microbiology and Infectious Diseases 1.
Alternatives to amoxicillin-clavulanate may include nitrofurantoin (100 mg twice daily for 5-7 days) or trimethoprim-sulfamethoxazole (160/800 mg twice daily for 7-10 days) if susceptibility is confirmed, as noted in the guidelines 1. However, the most recent and highest quality study, the 2024 European Association of Urology guidelines 1, supports the use of amoxicillin-clavulanate as a first-line treatment option.
From the Research
Effective Oral Agents for Treating Aerococcus urinae UTIs
The most effective oral agent for treating Aerococcus urinae urinary tract infections (UTIs) can be determined by examining the susceptibility of A. urinae to various antibiotics.
- Nitrofurantoin is a commonly prescribed antibiotic for A. urinae UTIs, achieving clinical and microbiological success in 71/76% of cases 2.
- Pivmecillinam is also effective in treating A. urinae cystitis, while ciprofloxacin is effective in treating pyelonephritis caused by A. urinae 2.
- Penicillin, amoxicillin, and nitrofurantoin are recommended for treating A. urinae infections, especially in older adults with multimorbidity and urologic cancer 3.
- Nitroxoline, an approved antimicrobial for UTI, has shown high activity against A. urinae isolates, with low minimum inhibitory concentrations (MICs) 4.
- A. urinae isolates have also shown high susceptibility to ampicillin, meropenem, rifampicin, vancomycin, and fosfomycin, with susceptibility rates ranging from 91.7% to 100% 5.
- Penicillins, such as penicillin and amoxicillin, are effective treatment options for less severe A. urinae cases, while combination therapy with gentamicin may be beneficial for severe cases, such as endocarditis 6.
Antibiotic Susceptibility Patterns
A. urinae isolates have shown varying susceptibility patterns to different antibiotics, including:
- High susceptibility to penicillin, amoxicillin, meropenem, rifampicin, vancomycin, and fosfomycin 5
- Moderate to good activity against quinolones, erythromycin, and tetracycline 6
- Resistance to ciprofloxacin, with a resistance rate of 10.9% 4
- High-level aminoglycoside resistance not found in any isolates 6