Continued Efficacy Of Nitrofurantoin And Co-Trimoxazole For Community-Acquired Urinary Tract Infections Amid Rising Antimicrobial Resistance In Southern India

Abstract

Background: Urinary tract infections (UTIs) impose a substantial global burden, contributing to significant morbidity and accelerating antimicrobial resistance (AMR), particularly in regions like Southern India where resistance patterns are evolving rapidly.

 Objectives: This study aimed to elucidate long-term trends in the microbiological etiology and antimicrobial susceptibility of community-acquired UTIs (CA-UTIs) among outpatients in Southern India from 2014 to 2022, thereby informing evidence-based empirical treatment guidelines and enhancing antibiotic stewardship efforts.

Methods: A retrospective observational analysis was conducted on 5,550 unique outpatient urine cultures positive for CA-UTI at a tertiary care hospital in Secunderabad, Southern India. Pathogens were identified and susceptibility tested using the Vitek 2 Compact system, interpreted per CLSI guidelines.

Results: Escherichia coli dominated (64.2%), followed by Klebsiella pneumoniae (19.5%). E. coli susceptibility to nitrofurantoin remained consistently high at ~80%, and to co-trimoxazole increased to 52% by 2022. In contrast, third-generation cephalosporin susceptibility (e.g., cefotaxime, ceftriaxone) declined from 44% (2014) to 30% (2022), and ciprofloxacin susceptibility fell from 33% to 18%. K. pneumoniae showed low nitrofurantoin susceptibility (~30%) but improved co-trimoxazole susceptibility to 56% by 2022. Extended-spectrum beta-lactamase (ESBL) rates were 30% in E. coli and 40% in K. pneumoniae, with carbapenem and amikacin susceptibility >85% for E. coli.

Conclusion: Nitrofurantoin and co-trimoxazole retain efficacy as first-line empirical therapies for uncomplicated CA-UTIs in this region. Ongoing local surveillance is imperative to combat escalating AMR.