Spectrum and susceptibility of pathogens causing acute uncomplicated lower UTI in females and its correlation to bacteriologic outcome after single dose therapy with fosfomycin trometamol versus ofloxacin/co-trimoxazole.

In a multicentric study comparing oral single-dose therapy of fosfomycin trometamol (3 g as fosfomycin) versus co-trimoxazole (1.92 g) or ofloxacin (200 mg) as many as possible of the pathogens were sent to and analysed in a central laboratory. The pathogens were identified and minimal inhibitory concentrations (MIC) of fosfomycin, trimethoprim alone and in combination with sulfamethoxazole, ofloxacin, ampicillin, amoxicillin combined with clavulanic acid, and cephadroxil were determined. The eradication of pathogens (cfu < 10(3)/ml at one week after single-dose therapy) was analysed according to species and MIC of the antibiotic used. Urine cultures of 349 patients were analysed. Escherichia coli was the predominating species followed by staphylococci and Proteus mirabilis. Enterococci were mostly found in mixed culture. Baseline pathogens of monoinfections were eradicated in 87.1%, in 88.9% and in 86.4% of 284 patients treated with fosfomycin trometamol, co-trimoxazole and ofloxacin, respectively. The MICs of the five antibacterial agents and the two antibiotic combinations for 253 baseline pathogens showed that of the E. coli strains none was resistant to ofloxacin, three (MIC = 128 mg/l) were resistant to fosfomycin, 3.6% to co-trimoxazole, 6.2% to trimethoprim, 8.8% to ampicillin, and 5.7% to amoxicillin/clavulanic acid. The eradication rates according to the MICs of the corresponding drugs showed equally good eradication rates for fosfomycin up to an MIC of 64 mg/l. Above this level two out of three strains were also eradicated by fosfomycin trometamol. For co-trimoxazole and ofloxacin no intermediately sensitive or resistant strains were found. Within the range of MICs found there were equally good eradication rates for both antibacterial agents.(ABSTRACT TRUNCATED AT 250 WORDS)