Prevalence of extended-spectrum β-lactamases producing escherichia coli in urinary specimens and their phenotypic detection by modified three-dimensional enzyme extract test: Comparison with the Phenotypic confirmatory disc diffusion test

Escherichia coli is the most common cause of UTI in community as well as in hospitalised patients. Detection of ESBLs producing organisms from samples such as urine may be important because this represents an epidemiologic marker of colonization, and therefore there is potential for transfer of such organisms to others.

The purpose of this study was to know prevalence of extended spectrum β-lactamases (ESBLs) in strains of Escherichia coli isolated from urine specimens and comparison of PCDDT and IMTDT of ESBL detection.

Department of Microbiology, MGM Medical College, Indore. Cross sectional study.

A total of 200 Escherichia coli strains isolated from 1500 consecutive non repeating urine specimens selected for the study. They studied for ESBL production phenotypic confirmatory disc diffusion test (PCDDT) and indirect modified three-dimensional enzyme extract test (IMTDT).

Kappa statistics.

86% (171) of the isolates found to be resistant to atleast one of the 3^rd generation cephalosporines tested (cefpodoxime, cefotaxime, ceftazidime and ceftriaxone). ESBL detected in 99 (58%) of the Escherichia coli by PCDDT and in 76% (130) by IMTDT.

Our study shows prevalence of ESBL producing Escherichia coli in urinary isolates. IMTDT found to be better than PCDDT for the detection of ESBL. The overall prevalence of ESBL producing uropathogenic Escherichia coli found to be 49.5% for our institute.