Importance of identification of lactose nonfermenting Escherichia coli and their prevalence in urinary isolates

Abstract

Introduction: Escherichia coli is one of the most common bacteria causing urinary tract infection. Accurate identification of urinary isolates is highly desirable and frequently challenging. Our study aims at identifying the “atypical” phenotype of E. coli by conventional, automated, and molecular methods and studying its prevalence among all the urinary isolates of E. coli. Materials and Methods: The present prospective study was conducted in the Department of Microbiology of a teaching tertiary care hospital of Central India for 6 months during the year 2014–2015. A total of 592 urine samples were processed. Identification of different urinary isolates was done by conventional and automated methods and by molecular method in special cases. Results: Two hundred and sixty-one uropathogens were isolated during the study. Among these, 110 (42.1%) isolates were E. coli, of which 4 (3.6%) isolates were confirmed as “atypical” E. coli by automated and molecular method. Conclusions: Our study highlights the challenges in the identification of atypical urinary isolates of E. coli. Accurate identification is essential for implicating proper antibiotic treatment.

Keywords

• 16S ribosomal RNA sequencing
• atypical Escherichia coli
• VITEK-2 Compact