Treatment Strategy for a Multidrug-Resistant Klebsiella UTI

Objective: To describe the management strategy for a multidrug-resistant (MDR) Klebsiella urinary tract infection (UTI). Case Summary: A 69-year-old Caucasian woman with a past medical history of recurrent UTIs and a right-lung transplant presented with fever to 101.4°F, chills, malaise, and cloudy, foul-smelling urine for approximately 1 week. She was found to have a MDR Klebsiella UTI that was sensitive to tigecycline and cefepime. To further evaluate the degree of resistance Etest minimum inhibitory concentrations were requested for cefepime, amikacin, meropenem, and ertapenem. The patient received a 14-day course of amikacin, which resulted in resolution of her symptoms. One month later, the patient’s UTI symptoms returned. The urine culture again grew MDR Klebsiella, sensitive only to tigecycline. Fosfomycin was initiated and resulted in limited resolution of her symptoms. Colistin was started, however, therapy was discontinued on day 5 secondary to the development of acute kidney injury. Despite the short course of therapy, the patient’s symptoms resolved. Discussion: The case presented lends itself well to numerous discussion items that are important to consider when determining optimal treatment for MDR Gram-negative bacilli (GNBs). Susceptibility testing is an important tool for optimizing antibiotic therapy, however, automated systems may overestimate the susceptibility profile for a MDR GNB. Treatment strategies evaluated to treat MDR GNB, include combination therapy with a carbepenem and synergy using polymyxin. Conclusion: We have described the management strategy for a MDR Klebsiella UTI, the consequences of the initial management strategy, and potential strategies to manage these types of infections in future patients.