Antimicrobial Resistance in Gram-negative Bacilli Isolated from Urinary Tracts Infections

From Mar 2000 to Nov 2001 the prevalence of resistance to ampicillin, sulfomethaxazol-trimetoprim, (SXT) nitrofurantoin, nalidixic acid, ciprofloxacin, cephalothin, and gentamicin in 740 gram-negative bacilli isolated from outpatients with acute urinary tract infections (UTIs) at Kashan Central Laboratory was prospectively evaluated. Eschericia coli (Eco/i) (75%) was the most common causing UTIs, followed by Klebsiella spp. (17%) and Proteus spp. (2.1 %). Arnong them 80% more isolates were resistance to ampicillin and 47% more isolates to SXT. Cephalothin resistance among Ecoli isolates was >28%, Klebsiella spp 32.1 % and Proteus spp. 40%. Overall, the rate of ciprofloxacin resistance among them was 7.8 to 18.2%. Nalidixic acid resistance among Ecoli isolates was 6.5%, Klebsiella spp 9.7% and Proteus spp 15%. Arnong the isolates, 15% less isolates were resistance to gentamicin. Nitrofurantoin showed the lowest resistance rates «4.5%) with exception of the Proteus spp. (10%). The high prevalence ofresistance is surprising, it may reflect the widespread use of antibiotics in Kashan continued regional, and national surveillance is warranted.