PREVALENCE AND ANTIMICROBIAL SUSCEPTIBILITY OF E. COLI IN CLINICAL SAMPLES FROM SUNCITY - RAJASTHAN

Background: The prevalence and antimicrobial susceptibility of Escherichia coli (E. coli) are critical for managing infections and guiding treatment strategies. This study assesses these factors in clinical samples from a tertiary care center in Suncity, Rajasthan. This retrospective observational study was conducted at MGH Hospital, Methods: affiliated with Dr. SN Medical College (SNMC), from March, 2023, to June, 2023. A total of 2,250 clinical samples, including urine, blood, sputum, wound swabs, and other relevant specimens, were processed. E. coli isolates were identified using colony morphology, Gram staining, and biochemical tests. Antimicrobial susceptibility was determined via the KirbyBauer disk diffusion method, with results interpreted according to CLSI guidelines. E. coli was isol Results: ated from 179 samples, yielding an overall prevalence of 7.9%. The majority of isolates were from inpatient department (IPD) samples (76.5%), with urine samples being the most frequent source (41%). Other sources included pus (38%), sputum (8%), tracheal aspirates (7%), Foley's catheters (3%), stool (2%), and central lines (0.5%). Ward-wise, the medicine ward had the highest incidence (36.5%), followed by the ICU (24%), orthopedic ward (20%), surgery ward (19%), and burns ward (0.5%). Antimicrobial susceptibility testing revealed high sensitivity to imipenem (88.6%), meropenem (80.4%), and piperacillin-tazobactam (80%). Susceptibility was also notable for cefepime (76.3%), amikacin (69%), and gentamicin (65.4%). For urine isolates specifically, fosfomycin (95.8%) and nitrofurantoin (94.5%) showed the highest susceptibility. Conversely, the lowest susceptibility was observed for ampicillin (5%), amoxiclav (9.9%), and ciprofloxacin (33%). Resistance to ceftazidime and ceftriaxone was also significant, with susceptibility rates of 35% and 44%, respectively. Conclusions: The study identifies a substantial prevalence of E. coli infections with a notable proportion exhibiting multidrug resistance. High susceptibility to carbapenems and piperacillin-tazobactam is encouraging, but the low susceptibility to commonly used antibiotics like ampicillin and ciprofloxacin highlights a critical need for revised local treatment guidelines. These findings support the implementation of targeted antimicrobial stewardship programs and contribute to regional and national surveillance efforts.