Summary

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 antibiotic-use patterns 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 nitrofurantoin and TMP-SMX[1] 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.