Urinary pathogens and bacterial sensitivity in hospitalized urological patients based upon clinical aspects

For a total of 396 hospitalized urological patients with complicated and/or hospital-acquired urinary tract infections (UTI) urinary pathogens with colony counts of 10(5)/ml or more were determined, several species were then subclassified by epidemiological markers. The minimal inhibitory concentrations (MIC) were measured using the agar dilution method for seven penicillins and for four penicillin combinations, for six oral and 14 parenteral cefalosporins, for three older and five newer quinolones, for two aminoglycosides, for two monobactams, for trimethoprim alone and in combination with sulfamethoxazole, for fosfomycin and for imipenem. Sensitivity and resistance of the strains were defined using breakpoints according to DIN 58.940 or analogous concentrations. The bacterial spectrum and the rate of resistant strains were correlated to clinical aspects pertaining to sexual status, age and underlying abnormalities within the urinary tract. There was a statistical difference in the frequency of E. coli and enterococci between patients with (complicated UTI) and without (uncomplicated UTI) abnormalities. Within the group of complicated UTI Proteus spp. were found significantly more often in patients with urolithiasis, Klebsiella spp. and staphylococci in patients with prostatic tumours (benign and malignant), enterococci in patients with prostatic and other tumours and E. coli in patients with abnormalities other than urolithiasis or tumours. Almost all antibiotics tested could be used in patients with uncomplicated UTI for empiric or calculated therapy if a rate of resistance of up to 10% is acceptable. In patients with urolithiasis only the newer acylaminopenicillins, the newer (fluoro-)quinolones, trimethoprim in combination with sulfamethoxazole, fosfomycin and imipenem fulfill this criterion. In order to treat complicated UTI with underlying tumours within the urinary tract empirically only piperacillin, apalcillin, imipenem and some of the newer quinolones (ofloxacin, ciprofloxacin and pefloxacin) could be recommended. The same was true for patients with indwelling catheters still present or recently removed.