Does Corynebacterium aurimucosum Urinary Tract Infection (UTI) require treatment?

Treatment of Corynebacterium aurimucosum Urinary Tract Infection

Corynebacterium aurimucosum urinary tract infections require antibiotic treatment, with amoxicillin being the preferred first-line agent based on susceptibility data. 1

Clinical Significance and Diagnosis

Corynebacterium aurimucosum is an emerging opportunistic pathogen that has been underrecognized due to previous limitations in identification methods. Recent evidence shows it can cause genuine urinary tract infections:

• C. aurimucosum has been confirmed as a causative agent in urinary tract infections (21% of confirmed infections in a multicenter study) 1
• When isolated from urine in significant quantities with associated leukocyturia, it should be considered clinically relevant rather than a contaminant 2
• The presence of symptoms along with repeated isolation from multiple urine samples supports its pathogenic role 2

Treatment Recommendations

First-line Treatment:

• Amoxicillin is the preferred first-line treatment with >80% of isolates showing susceptibility (MIC90 of 2 μg/ml) 1

Alternative Options:

• Vancomycin or linezolid (100% susceptibility) for patients with beta-lactam allergies or treatment failures 1
• Gentamicin or tetracycline (>80% susceptibility) may be considered in appropriate clinical scenarios 1

Medications to Avoid:

• Penicillin G and clindamycin (>90% resistance) 1
• Ciprofloxacin and cefotaxime have limited activity (only ~50% susceptibility) 1

Treatment Duration

While specific duration guidelines for C. aurimucosum UTI are not established, following general UTI treatment principles is appropriate:

• For uncomplicated UTI: 7-14 days of therapy is recommended 3
• For complicated UTI: 7-14 days (extending to 14 days for men when prostatitis cannot be excluded) 3
• When the patient is hemodynamically stable and has been afebrile for at least 48 hours, a shorter treatment duration (7 days) may be considered 3

Special Considerations

Complicated UTI Factors

Treatment should be more aggressive if any of these complicating factors are present:

• Obstruction at any site in the urinary tract
• Foreign body presence
• Incomplete voiding
• Immunosuppression
• Diabetes mellitus
• Male gender
• Recent history of instrumentation 3

Catheter-Associated UTI

If the infection is catheter-associated:

• Remove the catheter as soon as possible 3
• Obtain urine culture and susceptibility testing to guide therapy 3
• Treat for 7-14 days regardless of whether the patient remains catheterized 3

Monitoring and Follow-up

• Urine culture should be obtained before initiating treatment
• Follow-up cultures may be necessary to confirm eradication, especially in complicated cases
• Monitor for clinical improvement within 72 hours; if no improvement occurs, consider urologic evaluation and treatment adjustment 3

Conclusion

C. aurimucosum should be considered a genuine pathogen when isolated from urine with appropriate clinical context. Treatment with amoxicillin is recommended as first-line therapy based on susceptibility data, with vancomycin or linezolid as alternatives for patients with allergies or treatment failures.