Successful Treatment of Extended-Spectrum β-Lactamase-Producing Klebsiella pneumoniae Recurrent Urinary Tract Infection with High Doses of Amoxicillin with Clavulanic Acid in a Kidney Transplant Recipients: A Case Report

Introduction: An increase in the number of infections with Klebsiella pneumoniae producing Extended-Spectrum beta-Lactamase (ESBL+) is a clinical issue, because there are no guidelines regarding the correct choice of an antibiotic and duration of treatment in kidney transplant recipients. The bacterial capacity to degrade almost all beta-lactam antibiotics, except carbapenems, causes resistance to standard treatment and makes long-term intravenous antibiotic therapy necessary. Case Presentation: This report describes the case of a 44-year-old patient after kidney transplantation, who developed recurrent urinary tract infections (UTIs) caused by ESBL-producing K. pneumoniae despite prolonged antibiotic targeted treatments with imipenem/cilastatin, meropenem, imipenem/cilastatin with amikacin and oral phosphomycin for UTI prophylaxis. Ineffectiveness of previous treatments caused the necessity to use a non-standard therapy of the consecutive UTI episode with high doses of amoxicillin combined with standard doses of clavulanic acid to break the bacteria's resistance. There was no recurrence of UTI and control urine cultures were sterile over the entire course of treatment, lasting 165 days, and throughout the follow-up period of more than 1 year. Conclusions: It has been shown in this case that UTI with the aetiology of K. pneumoniae could be treated on an outpatient basis with high doses of amoxicillin in combination with standard doses of clavulanic acid followed by prolonged antibiotic prophylaxis.