THE ANTIBIOTIC RESISTANCE PATTERN OF GRAM-NEGATIVE BACILLI ISOLATED FROM URINE CULTURES OF ADULT OUTPATIENTS ADMITTED TO VALI ASR HOSPITAL OF FASA CLINICAL LABORATORY IN 2012-13

Introduction : Urinary tract infections are among the most common infections in human beings. The inappropriate prescription of antibiotics for treating these infections increases resistance of pathogens to them. The purpose of the present study is to determine the frequency and antibiotic resistance pattern of gram-negative bacilli in adult patients with urinary tract infection admitted to Vali Asr Hospital of Fasa Clinical Laboratory in 2012-13. This is a cross-sectional study conducted on 1108 adult outpatients with a positive urine culture admitted to Vali Asr Hospital of Fasa Clinical Laboratory. Urine samples were cultured on blood agar and MacConkey's agar media. The bacteria grown on the plates were then identified by conventional biochemical methods. The disc diffusion antibiotic sensitivity test was then conducted according to CLSI standards. In 92.12% of the cases, urinary tract infection was caused by gram-negative bacilli. The isolated bacteria showed the highest resistance to the antibiotics cotrimoxazole (54.7%), cephalothin (55.6%), cefixime (45%) and nalidixic acid (43.6%). The bacteria showed the highest sensitivity to the antibiotics ciprofloxacin (74%), gentamicin (56%), nitrofurantoin (64.9%) and ceftriaxone (58.2%) . Conclusion: The present study showed that gram-negative bacilli, particularly Escherichia coli, are the most common bacteria causing urinary tract infections and the majority of strains were resistant to the antibiotics commonly used in treatments.