From the Guidelines
Proteus bacteria in urine are generally sensitive to Clavulin (amoxicillin-clavulanate), but resistance patterns can vary by region and individual patient factors, so urine culture and sensitivity testing is recommended to confirm susceptibility. According to the international clinical practice guidelines for the treatment of acute uncomplicated cystitis and pyelonephritis in women, beta-lactam agents, including amoxicillin-clavulanate, are appropriate choices for therapy when other recommended agents cannot be used 1. The guidelines also note that the resistance rates for amoxicillin-clavulanic acid show regional variability, but are generally <10% 1.
For uncomplicated urinary tract infections caused by Proteus, a typical adult dosage of amoxicillin-clavulanate would be 875mg amoxicillin/125mg clavulanate twice daily for 7-10 days, or 500mg/125mg three times daily. However, it is essential to consider local antimicrobial susceptibility patterns and individual patient factors when selecting empirical antimicrobial therapy 1. Patients should complete the full course of antibiotics even if symptoms improve quickly, drink plenty of fluids, and contact their healthcare provider if symptoms worsen or don't improve within 48-72 hours of starting treatment.
Key considerations for treatment include:
- Urine culture and sensitivity testing to confirm susceptibility to amoxicillin-clavulanate
- Local antimicrobial susceptibility patterns and individual patient factors
- Completion of the full course of antibiotics
- Monitoring for symptoms and potential side effects
- Adjustment of treatment as needed based on culture and sensitivity results or clinical response 1.
From the FDA Drug Label
To reduce the development of drug-resistant bacteria and maintain the effectiveness of amoxicillin and clavulanate potassium tablets USP, and other antibacterial drugs, amoxicillin and clavulanate potassium should be used only to treat infections that are proven or strongly suspected to be caused by susceptible bacteria 1.5 Urinary Tract Infections – caused by beta-lactamase–producing isolates of E. coli, Klebsiella species, and Enterobacter species.
The FDA drug label does not specifically mention Proteus bacteria. However, based on the information provided, amoxicillin and clavulanate potassium is indicated for the treatment of Urinary Tract Infections caused by beta-lactamase–producing isolates of E. coli, Klebsiella species, and Enterobacter species.
- Proteus is not listed as a susceptible bacteria in the provided drug labels 2 2. Therefore, it cannot be concluded that Proteus bacteria in urine is sensitive to Clavulin (amoxicillin-clavulanate).
From the Research
Antibiotic Sensitivity of Proteus Bacteria
- The sensitivity of Proteus bacteria to Clavulin (amoxicillin-clavulanate) is reported in several studies 3, 4, 5.
- According to a 2022 study, the all-pathogen susceptibility to amoxicillin/clavulanate was 79.6% 3.
- A 2024 study evaluated the use of oral amoxicillin/clavulanate for urinary tract infections caused by ceftriaxone non-susceptible Enterobacterales and found that amoxicillin-clavulanate recipients did not have higher failure rates compared to standard of care recipients 5.
- However, a 2025 study reported high resistance rates (>20%) for amoxicillin-clavulanate among urinary tract infection pathogens in a low-resource/high-resistance area of Latin America 4.
Specific Findings for Proteus mirabilis
- A 2015 review discussed the virulence factors and pathogenesis of Proteus mirabilis in urinary tract infections, but did not provide specific information on antibiotic sensitivity 6.
- A 2012 study investigated the risk factors and clinical presentation of Proteus mirabilis urinary tract infections, but did not report on antibiotic sensitivity 7.
- The 2022 study mentioned earlier reported that Proteus mirabilis was one of the most prevalent pathogens in urinary tract infections, but did not provide specific susceptibility data for this species 3.