Emergence of antibiotic resistance amongst hospital-acquired urinary tract infections and pharmacokinetic/pharmacodynamic considerations.

Bacterial urinary tract infections (UTIs) are frequent infections in the nosocomial setting. Nosocomial UTIs are almost exclusively complicated UTIs, although the complicating factors may be very heterogenous. The bacterial spectrum of nosocomial UTIs is broad and antibiotic resistance is common. The results of international and national surveillance studies on the bacterial spectrum and antibiotic resistance of nosocomial uropathogens are provided. The treatment of nosocomial UTIs encompasses treatment of the complicating factors as well as antimicrobial chemotherapy. At least in serious UTIs, adequate initial antibiotic therapy results in lower mortality. Therefore, the initial antibiotic regimen must provide sufficient antibiotic cover. However, this can only be achieved if the bacterial spectrum and antibiotic resistance patterns of uropathogens in the institution are followed continuously. Provisional microbiological findings, such as reports on Gram stain or certain biochemical results, can lead to early stratification of pathogens and allow more tailored empiric antibiotic therapy. Antibiotic therapy of nosocomial UTIs has to consider two different aspects: (1) therapeutic success in the individual patient; and (2) prevention of emergence of antibiotic-resistant mutants. The emergence of resistance can possibly be lowered by adequate drug selection and dosing. Increasing antibiotic resistance requires more prudent use of antimicrobial drugs.