Case 142

1. Presented by Kevin Toomer, MD, PhD and reviewed by Nikki Parrish, PhD.

An adult patient with a past medical history significant for treated urothelial carcinoma of the bladder presented to the emergency department (ED) with a one-day history of worsening fever, chills, and malaise. Laboratory evaluation was notable for acute kidney injury (creatinine 1.6 mg/dL, Ref. range 0.6-1.3) and elevated transaminases (AST 191 U/L, ref range ≤37 U/L; ALT 191 U/L, ref range ≤40 U/L). Urinalysis demonstrated pyuria (WBC 14,000/microliter), hematuria (RBC 3600/microliter), and positive leukocyte esterase. Urine microscopy demonstrated numerous bacteria. Blood and urine cultures were initially negative, and CT imaging showed no evidence of malignancy.

The patient defervesced within 24 hours of admission, the acute kidney injury resolved with administration of intravenous fluids, and the transaminitis resolved without intervention. The patient was discharged home after 48 hours of observation. Approximately 1 month after discharge, the mycobacterial urine culture obtained from the patient’s clean catch specimen was found to be positive, with Mycobacterium tuberculosis complex DNA identified by nucleic acid hybridization. Subsequent antimicrobial susceptibility testing demonstrated mono-resistance to pyrazinamide (PZA). Which of the following statements is accurate with respect to these findings?