[In vitro activity of fosfomycin trometamol in the treatment of Escherichia coli related uncomplicated urinary tract infections]

Although in certain countries in Europe fosfomycin trometamol (FT) has been used for many years, in Turkey FT has become available in recent years. FT has a broad-spectrum activity against most of gram-positive and gram-negative bacteria. In this study, we aimed to evaluate the effect of FT, a new alternative antimicrobial agent in the treatment of patients with Escherichia coli related uncomplicated lower urinary tract infection (UTI). For this purpose, between May 2007-July 2008, FT susceptibility of 771 nonduplicate E. coli strains, isolated from urine samples of patients with uncomplicated lower UTI (bacteria > or = 10(5) cfu/mL), was determined by disk diffusion method according to Clinical and Laboratory Standarts Institute (CLSI) criteria. Simultaneously, extended-spectrum beta-lactamase (ESBL) detection was performed by double disk synergy test in all isolates. Among all E. coli isolates, FT resistance rate was 0.4% (3/771) and ESBL positivity was 19.5% (150/771). The rates of ESBL producing strains isolated from inpatients and outpatients were 34.1% (70/205) and 14.1% (80/566), respectively, and the difference was found statistically significant (p = 0.0001). Although resistance to FT was not detected in non-ESBL producing E. coli isolates (n = 621), FT resistance rate was 2% (3/150) in ESBL producers. As far as the current literature was concerned this was the largest scale study investigating the activity of FT in Turkey. Resistance to antimicrobials that had been used frequently as therapeutic options for the treatment of E. coli related UTIs, has been increasing. In the present study high susceptibility rates to FT was determined for urinary E. coli isolates. In conclusion, these data suggest that FT may be a good alternative for the treatment of uncomplicated UTIs as a first line antimicrobial agent.

[Antimicrobial resistance profiles of community-acquired uropathogenic Escherichia coli isolates during 2004-2006 in a training hospital in Istanbul]

In order to reveal the antimicrobial resistance profiles against first-line antimicrobial agents in community-acquired acute uncomplicated urinary tract infections (UTIs), resistance patterns were determined for 1664 Escherichia coli strains collected between 2004 and 2006 in GATA Haydarpasa Training Hospital, Istanbul, Turkey. Of the isolates 38.2% were found to be susceptible to all of the tested antimicrobial agents, while the resistance rate to single antibiotic was 13.5%. Highest prevalence of antimicrobial resistance was observed for ampicillin (AMP) (49%), followed by amoxycillin-clavulanic acid (AMC) (34%), sulphamethoxazole/trimethoprim (SXT) (34%) and ciprofloxacin (CIP) (18%). The rate of multidrug resistant isolates was 33.5% and 48.4% of them were co-resistant. Resistance against two antimicrobials was identified in 244, against three antimicrobials in 205, against four antimicrobials in 160, against five antimicrobials in 63 and against six antimicrobials in 23 strains. Most frequent phenotypes indicating resistance against two, three and four antimicrobial agents were AMP/AMC (5.7%), AMP/AMC/SXT (5.4%) and AMP/AMC/cephazolin/SXT (2.6%), respectively. Extended spectrum beta-lactamase (ESBL) activity was detected in 40 (2.4%) of the isolates. Most prominent increases in resistance prevalence during the study period were observed for AMP (from 52% to 63%), AMC (from 33% to 45%) and CIP (from 15% to 22%). These results show that resistance to AMP, AMC and SXT are frequent in community-acquired E. coli strains and empirical initial treatment with these agents will most probably be inappropriate in our region.