*Purpose: Urease-producing bacteria release significant amounts of ammonia. Donor-derived Ureaplasma infections in lung transplant recipients have been implicated in the pathogenesis of hyperammonemia syndrome (HS). In such cases, clinicians often opt for long courses of ≥2 antibiotics, but antimicrobial resistance (R) is rarely documented and its frequency is unknown.

*Methods: We present the first, to our knowledge, case of HS caused by levofloxacin (lvq)-R U. urealyticum infection in a kidney transplant (KT) recipient.

*Results: A 16-year-old female with end-stage renal disease from systemic lupus erythematosus underwent deceased donor KT. For 10 months, serum creatinine (Cr) was <1 mg/dL. She then developed sterile pyuria and renal dysfunction (Cr 1.6-4.4). Two renal biopsies showed interstitial inflammation, one also granulomas. Infectious disease work-up, including next-generation DNA sequencing of allograft tissue for bacterial pathogens, was unrevealing. When she developed polyarthritis and fever, blood and urine Ureaplasma-Mycoplasma PCR were sent. Urine PCR was positive for U. urealyticum. After 3 days of doxycycline (doxy), ammonia level was checked and was 498 (normal <50) µmol/L, despite no encephalopathy. Renally-dosed lvq (q.o.d.) was administered for 3 weeks with resolution of pyuria and negative repeat urine PCR. Ammonia levels initially decreased, but increased again while on lvq (Fig. 1: *). Two months later, she was admitted with worse polyarthritis, confusion, asterixis and ammonia >600. Blood PCR, urine PCR, left knee synovial fluid PCR and culture were now positive. She was started on daily lvq+doxy. Ammonia levels normalized and all symptoms improved. Susceptibility testing (ST) showed lvq-R (MIC 32 mg/L), therefore lvq was changed to azithromycin, with ongoing clinical improvement.

*Conclusions: The frequency of Ureaplasma infections is likely underestimated. ST should be performed in Ureaplasma strains isolated from extragenital specimens. In transplant recipients with HS, empiric treatment with ≥2 antibiotics may be indicated.

« Back to 2020 American Transplant Congress