Analysis of Susceptibility to Selected Antibiotics in Klebsiella pneumoniae, Escherichia coli, Enterococcus faecalis and Enterococcus faecium Causing Urinary Tract Infections in Kidney Transplant Recipients over 8 Years: Single-Center Study

Background: Urinary tract infections (UTIs) are the most common bacterial infections among kidney transplant (KTX) recipients. The purpose of this study was to analyze antimicrobial resistance (AMR) in four most common pathogens responsible for UTIs in KTX recipients and determine risk factors (RF) for resistance in the same group. Methods: Analyzed antibiograms were based on urine samples positive for bacterial growth of 10(5) colony-forming units (CFU)/mL obtained from hospitalized adult KTX recipients presenting with UTI symptoms upon admission to the center in years 2011–2018. Results: In total, 783 antibiograms were analyzed for Klebsiella pneumoniae (258 samples, 33.0%), Escherichia coli (212, 27.0%), Enterococcus faecalis (128, 24.0%), and Enterococcus faecium (125, 16.0%). The decrease in susceptibility of E. coli to amoxicillin/clavulanic acid (62.9% vs. 40.0%) and ciprofloxacin (100% to 40.0%) was observed. Susceptibility to gentamicin increased from 33.3% to 92.9% in E. faecium. Susceptibility to tigecycline remained 100% through all years in case of E. faecalis and E. faecium. Male gender was a RF for resistance to amoxicillin/clavulanic acid (p = 0.008), ciprofloxacin (p = 0.0003), trimethoprim/sulfamethoxazole (p = 0.00009), ceftriaxone (p = 0.0001), and cefuroxime axetil (p = 0.00038) in K. pneumoniae and against gentamicin in E. faecalis (p = 0.015). Higher resistance to ampicillin in E. faecalis (p = 0.012) and to ciprofloxacin (p = 0.0003), trimethoprim/sulfamethoxazole (p = 0.007), piperacillin/tazobactam (p = 0.003), ceftriaxone (p = 0.001), and cefuroxime axetil (p = 0.013) in K. pneumoniae was observed in higher age groups of patients. Diabetes as a cause of kidney insufficiency (p = 0.026) and kidney-pancreas transplantation (p = 0.014) was RF for resistance to ceftriaxone in K. pneumoniae. Conclusions: AMR in uropathogens from KTX recipients fluctuated. There were identifiable RFs for resistance in the examined bacteria–antibiotic combinations. We recommend continuous mapping of site-specific microorganisms as etiology and susceptibility may vary between institutions and over time.