Regional variations in antimicrobial susceptibility of community-acquired uropathogenic Escherichia coli in India: Findings of a multicentric study highlighting the importance of local antibiograms

Abstract

Objectives: Evidence-based prescribing is essential to optimize patient outcomes in cystitis. This requires knowledge of local antibiotic resistance rates. Diagnostic and Antimicrobial Stewardship (DASH) to Protect Antibiotics (https://dashuti.com/) is a multicentric mentorship program guiding centers in preparing, analyzing and disseminating local antibiograms to promote antimicrobial stewardship in community urinary tract infection. Here, we mapped the susceptibility profile of Escherichia coli from 22 Indian centers.

Methods: These centers spanned 10 Indian states and three union territories. Antibiograms for urinary E. coli from the outpatient departments were collated. Standardization was achieved by regional online training; anomalies were resolved via consultation with study experts. Data were collated and analyzed.

Results: Nationally, fosfomycin, with 94% susceptibility (inter-center range 83-97%), and nitrofurantoin, with 85% susceptibility (61-97%), retained the widest activity. The susceptibility rates were lower for co-trimoxazole (49%), fluoroquinolones (31%), and oral cephalosporins (26%). The rates for third- and fourth-generation cephalosporins were 46% and 52%, respectively, with 54% (33-58%) extended-spectrum β-lactamase prevalence. Piperacillin-tazobactam (81%), amikacin (88%), and meropenem (88%) retained better activity; however, one center in Delhi recorded only 42% meropenem susceptibility. Susceptibility rates were mostly higher in South, West, and Northeast India; centers in the heavily populated Gangetic plains, across north and northwest India, had greater resistance. These findings highlight the importance of local antibiograms in guiding appropriate antimicrobial choices.

Conclusions: Fosfomycin and nitrofurantoin are the preferred oral empirical choices for uncomplicated E. coli cystitis in India, although elevated resistance in some areas is concerning. Empiric use of fluoroquinolones and third-generation cephalosporins is discouraged, whereas piperacillin/tazobactam and aminoglycosides remain carbapenem-sparing parenteral agents.

Keywords: Antimicrobial resistance; Community-acquired UTIs; Escherichia coli; India.

Figure 1

Participating states and centers.

Figure 2

Antimicrobial Susceptibility profile of Escherichia coli to the major antibiotic groups. Number of strains tested for each group were as follows: nitrofurantoin (7790), fosfomycin (4165), trimethoprim-sulphamethoxazole (6639), amoxicillin-clavulanic acid (4307), ceftriaxone/cefotaxime (6014), ciprofloxacin (6712).

Figure 3

Average susceptibility of Escherichia coli to five major antimicrobial groups. Third-generation cephalosporins: average of ceftazidime, cefotaxime, ceftriaxone, and cefixime. β-Lactam-β-lactamase inhibitors: average of piperacillin-tazobactam and cefoperazone/sulbactam. Carbapenems: average of imipenem and meropenem. Number of strains tested were as follows: Third-generation cephalosporins: ceftazidime (3871), cefotaxime (3369), ceftriaxone (2645), and cefixime (530). Beta-Lactam-beta-lactamase inhibitors: piperacillin-tazobactam (5242) and cefoperazone/sulbactam (4094). Aminoglycosides: gentamicin (6834), amikacin (6945) Carbapenems: imipenem (6203) and meropenem (7064).