A Cross- Sectional Study of Antimicrobial Resistance Patterns of Klebsiella pneumoniae and Escherichia coli isolates at a Tertiary Care Hospital in Gujarat, India

BACKGROUND:: Antimicrobial resistance (AMR) is a growing global threat, with Escherichia coli and Klebsiella pneumoniae recognized as major pathogens causing urinary, respiratory, bloodstream, and wound infections. The increasing prevalence of extended-spectrum beta-lactamase (ESBL) producers and carbapenem-resistant Enterobacteriaceae has severely limited therapeutic options, especially in tertiary care hospitals. Continuous local surveillance is essential to guide empirical therapy and strengthen antibiotic stewardship. OBJECTIVES: To determine the antimicrobial resistance patterns of E. coli and K. pneumoniae isolates from clinical specimens in a tertiary care hospital, and to estimate the prevalence of ESBL and carbapenemase production. METHODOLOGY : This hospital-based cross-sectional study was conducted in the Department of Microbiology, GMERS Medical College, Gandhinagar, from January 2023 to January 2024. A total of 300 consecutive non-duplicate isolates, including 180 E. coli and 120 K. pneumoniae, were obtained from urine, blood, pus, respiratory samples, and body fluids. Identification was carried out by standard biochemical tests and confirmed by automated systems where required. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disk diffusion method on Mueller–Hinton agar as per CLSI 2023 guidelines. ESBL production was confirmed by the combined disk method, and carbapenemase production was detected using the Modified Hodge Test and Carbapenem Inactivation Method. Data were analyzed using descriptive statistics and chi-square test. RESULTS: E. coli was the predominant isolate from urine specimens (61.1%), while K. pneumoniae was more common in respiratory (18.3%) and blood samples (26.7%). High resistance was observed to third-generation cephalosporins in both organisms (>70%), and fluoroquinolone resistance exceeded 65%. Carbapenem resistance was noted in 22% of E. coli and 31% of K. pneumoniae isolates. ESBL production was detected in 57.8% of E. coli and 64.2% of K. pneumoniae, while carbapenemase production was found in 16.1% and 24.2% respectively. Multidrug resistance was identified in 48.3% of E. coli and 55.8% of K. pneumoniae isolates. CONCLUSION: The study revealed a high prevalence of ESBL-producing and carbapenem-resistant E. coli and K. pneumoniae, with a significant burden of multidrug resistance. These findings highlight the urgent need for robust antibiotic stewardship, strict infection control measures, and continuous AMR surveillance to prevent further escalation of resistance in tertiary care hospitals.