Unveiling a Rarity: First Instance of Urinary Tract Infection Caused by Corynebacterium tuberculostearicum in India.

Introduction: Corynebacterium species other than C. diphtheriae are being continuously reported as pathogens.

Case presentation: A patient visited the Urology Outpatient Department of a tertiary care centre in India reporting lower abdominal pain, urinary incontinence, and intermittent weak urine flow persisting for 12 years, intensifying over the last 15 days. She also experienced urgency, straining, weak stream, and incomplete voiding, along with a previous fever episode. The patient had a medical record of multiple urethral dilations and surgeries since 2014, with the most recent urethral dilatation in July 2023. Diagnostic tests revealed a thickened bladder with notable post-void residual urine. Uroflowmetry indicated obstructive uropathy. Urine analysis exhibited elevated leucocytes, epithelial cells, red blood cells, and abundant bacilli. Corynebacterium tuberculostearicum was identified through matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) following three pure growths of Gram-positive bacilli in urine cultures. The organism showed sensitivity to cotrimoxazole and tetracyclines. Treatment with doxycycline significantly improved the symptoms.

Conclusion: The organism Corynebacterium tuberculostearicum is a very rare cause of UTI and the patient responded well to treatment.