Background: In an era of increasing antimicrobial resistance, knowledge of local antimicrobial susceptibility patterns of common uropathogens is essential for prudent empiric therapy of community-acquired urinary tract infections.
Objectives: To define antimicrobial susceptibility of Gram-negative uropathogens in northern Israel over a 10 year period and to compare it with patterns of antibiotic use in the same community.
Methods: We tested the susceptibility of all Gram-negative urinary isolates from outpatients at HaEmek Medical Center over the years 1995, 1999, 2002 and 2005 to common antimicrobial agents. MIC90 of Escherichia coli to some of these agents was determined and antibiotic consumption data over the years 2000-2005 (DDD/1000/day) were obtained.
Results: We observed a rise in susceptibility rates of E. coli to amoxicillin-clavulanate, trimethoprim-sulfamethoxazole and nitrofurantoin and of other Gram-negative isolates to amoxicillin-clavulanate, ceftriaxone and cephalothin. Susceptibility rates of all Gram-negative uropathogens to ciprofloxacin decreased significantly. MIC90 of E. coli for all drugs tested remained stable. There was a significant decrease in the use of nitrofurantoin and TMP-SMX and a significant increase in the use of ampicillin, cephalothin and ceftriaxone.
Conclusions: Antibiotic resistance patterns mostly remained unchanged or improved slightly. There was, however, a constant decrease in susceptibility of all Gram-negative uropathogens to ciprofloxacin. Antibiotic use patterns could not explain the changes seen in antibiotic susceptibility patterns.