Study of catheter associated urinary tract infection and biofilm production by Escherichia coli

Abstract

Introduction: Catheter associated urinary tract infection (CAUTI) is most common nosocomial infection accounting for 40% of all institutionally acquired infections and is significantly associated with increased morbidity and health care costs. The study was undertaken to identify the incidence of CAUTI, the causative organisms and their antibiotic sensitivity and biofilm production by Escherichia coli in patients with urinary catheter for more than 24 hours. Materials and Methods: The study included 250 hospitalized patients who catheterized for more than 24 hours. The urine sample aspirated from the port of catheter and subjected to wet mount and Gram staining and inoculated on blood agar, MacConkey agar and CLED media by standard loop method. The isolates with significant counts (?102CFU/ml) were identified and antibiotic susceptibility testing was done by Kirby Bauer disc diffusion methods as per CLSI guidelines. Escherichia coli isolates were tested for biofilm production qualitatively by Tube method and Congo Red Agar method. Results: The present study showed CAUTI in 27.2% of the catheterized patients. Escherichia coli was the most common organism isolated (33.8%).The most effective antibiotics against Gram negative isolates were Imipenem (95.23%) and against Gram positive isolates were Vancomycin and Linezolid (100% each). 91.6% Escherichia coli isolates were biofilm producers. Conclusion: The Study showed that the duration of catheterization (?6 days) is the most important predisposing factor for developing CAUTI. Escherichia coli is the most common organism causing CAUTI. The high incidence of resistance to conventional antibiotic such as Ampicillin, Co-trimoxazole and Ciprofloxacin among the pathogens causing CAUTI. Keywords: CAUTI, Escherichia coli, Biofilm.