Extended spectrum, AmpC & metallo β-lactamases producing Escherichia coli in urinary isolates: A prospective study in north India

Abstract

Background & objectives One of the most prevalent bacterial illnesses in humans is the urinary tract infection (UTI), which is frequently brought on by Escherichia coli. The purpose of this study was to assess the antibiotic sensitivity pattern of E. coli that causes UTIs and identify the presence of extended spectrum β-lactamases (ESBL), AmpC β-lactamases (AmpC), and metallo β-lactamases (MBL) using a variety of phenotypic techniques. Methods After urine samples were inoculated on cysteine lactose-deficient agar culture media, isolated colonies were identified using standard biochemical tests. These isolates were then screened using different phenotypic confirmatory methods for β-lactamase detection and the Clinical Laboratory and Standards Institute (CLSI) guidelines. Results Out of the total urine samples, 7.08 per cent (177/2500) were positive for the growth of E. coli, out of which 40.11 per cent (71/177) were multi-drug resistant. Among the 71 isolates, 31 per cent were ESBL producers, 62 per cent were AmpC producers, and 7.04 and 4.22 per cent were co-producers of ESBL and AmpC, and AmpC and MBL, respectively. The E. coli isolates were found to be highly resistant to ciprofloxacin (83.61%), amoxicillin/clavulanate (81.92%), and gentamicin (61%). However, these were sensitive to imipenem (98.3%), fosfomycin (97.17%), and nitrofurantoin (94.35%). Interpretation & conclusions Early detection of various resistance patterns as well as understanding of the local susceptibility patterns among E. coli strains causing UTIs, are imperative for accurate treatment modalities. This knowledge would subsequently contribute to the management of antibiotic resistance and surveillance.

Keywords: AmpC; E. coli; ESBL; MBL; resistance; urinary tract infection; β-lactamases.