Fosfomycine tromethamine as second agent for the treatment of acute uncomplicated urinary tract infections in all age groups in the Netherlands?

Abstract number: R2327

Nys S., Knottnerus B., ter Riet G., Donker G., Geerlings S., Stobberingh E.

Background: Uncomplicated urinary tract infections (UTIs) are common among female patients. According to the national guidelines of the Dutch College (NHG) for General Practitioners (GPs) the drugs of first and second choice as therapy for UTIs are nitrofurantoin and trimethoprim with resistance percentages of 2% and 23% respectively. The third choice is fosfomycine tromethamine (FT) for which unfortunately no current resistance data from the Netherlands are available. The aim of this study was to determine these resistance percentages.

Material and Methods: During a 2-year period urine samples were collected from a representative sample of 21 general practices spread over the Netherlands, the Sentinel Stations of the Netherlands Institute for Health Services Research (NIVEL).

Escherichia coli isolated from female patients visiting their GP with symptoms of an acute uncomplicated UTI were used. FT susceptibility was determined with E-tests. An MIC for FT of 64 mg/L or lower was considered susceptible, MIC-values of 96 mg/L or higher resistant. E. coli ATCC25922 was used as a reference strain.

Results: In total, 1705 E. coli strains were tested of which 11 (0.64%) were FT resistant. The MIC50 and MIC90 values in this population were 1 and 4 mg/L respectively. Within the inhibition zone of 162 susceptible E. coli strains, resistant mutant colonies were observed of which after repetition of the susceptibility testing 68 were resistant. In total, 79 (5%) strains were FT resistant. There was no cross-resistance observed between FT and other antimicrobial agents tested previously.

Discussion: The high in vitro susceptibility to fosfomycine tromethamine in this population and the lack of cross-resistance between fosfomycine tromethamine and other agents together with the extensive global clinical experience support the choice of the NHG-guidelines to include fosfomycine tromethamine as a second – instead of third – therapeutic option in general practice for uncomplicated UTIs.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
Back to top