Antimicrobial resistance pattern in Escherichia coli causing urinary tract infection among inpatients

BACKGROUND & OBJECTIVES: Recent studies suggest an increasing antimicrobial resistance among Escherichia coli causing urinary tract infection (UTI). We undertook this study to know the resistance pattern of E. coli causing UTI in patients admitted to a tertiary care hospital in north India, and to know the treatment given and response of the patients. METHODS: The details of E. coli grown from urine samples and their antibiotic sensitivity pattern were collected from the laboratory registers and the patient details were collected from the case records. The urine samples received were processed using standard methods and antibiotic susceptibility was done by Kirby-Bauer disk diffusion test. RESULTS: Of the total 311 E. coli isolates, 119 (38.2%) were isolated from in-patients, which were considered for the study. Of these 119 E. coli isolates, 91 (76.51%) were multi drug resistant (MDR). The isolates showed high levels of resistance to ampicillin (88.4%), amoxicillin-clavulanic acid (74.4%), norfloxacin (74.2%), cefuroxime (72.2%), ceftriaxone (71.4%) and co-trimoxazole (64.2%). The isolates were sensitive to amikacin (82.6%), piperacillin-tazobactum (78.2%), nitrofurantoin (82.1%) and imipenem (98.9%). Ceftriaxone was most commonly used for empirical therapy for UTI among inpatients in our hospital. Of the 93 cases of UTI due to MDR E. coli, 73 improved on treatment and 12 worsened, which were referred to higher centres. INTERPRETATION & CONCLUSIONS: Our study showed that 76.5 per cent of E. coli isolates from urine samples of inpatients were MDR. Diabetes, chronic renal disease and catherization were some of the risk factors associated. The high rate of resistance could be because only inpatients were included and the increased usage of cephalosporins in our hospital for empirical therapy.