Clinical presentation and antibiotic resistance trends of Escherichia coli isolated from clinical samples in South India: A two-year study (2022-2023).

Abstract

Background: Escherichia coli (E. coli) is a common pathogen responsible for various infections, particularly in healthcare settings. Its antibiotic resistance and susceptibility patterns are crucial for effective treatment. This study aims to assess the prevalence of E. coli in clinical samples and evaluate its antibiotic resistance patterns at SRM Medical Hospital and Research Center from 2022 to 2023.

Methods: A retrospective study was conducted using microbiological records from 30,838 clinical samples collected over two years. Positive E. coli isolates were identified and subjected to antimicrobial susceptibility testing. Demographic data, including age and sex, were analysed. Resistance patterns were assessed using the Vitek 2 system and disc diffusion methods as per CLSI guidelines.

Results: Out of 30,838 samples, 8694 yielded positive cultures, with 2597 E. coli isolates. Most isolates (69.6 %) were from urine, followed by exudate (20.4 %) and blood (6.8 %). E. coli infection was more prevalent in females (60.92 %) and individuals aged 41-70 years (48.97 %) (p < 0.001). High resistance was observed for amoxicillin-clavulanate (32 %) and ciprofloxacin (17.98 %), with high susceptibility to colistin (90.98 %) and piperacillin-tazobactam (90 %).

Conclusion: This study highlights the prevalence of E. coli, especially in urine samples and among females and older adults. High resistance to commonly used antibiotics emphasizes the need for regular susceptibility testing and antimicrobial stewardship.

Clinical implication: This study emphasizes the need for ongoing antibiotic resistance monitoring and customized treatment strategies to combat E. coli infections. Future efforts should focus on enhancing antimicrobial stewardship programs to reduce the spread of resistant strains.