Comparative Analysis of Antimicrobial Resistance Patterns in ICU and Non-ICU Isolates from a Gujarat Surveillance Network, India: A Semi-annual Antibiogram Study

Abstract

Aims: To compare antimicrobial resistance patterns between intensive care unit (ICU) and non-intensive care unit (non-ICU) isolates in hospitals participating in the Gujarat State surveillance network. Study Design: Retrospective analytical surveillance study. Place and Duration of Study: Hospitals enrolled in the Gujarat State Antimicrobial Resistance Surveillance Network, India, using semi-annual antibiogram data from July to December 2024. Methodology: Aggregate antibiogram data were obtained from the Gujarat State Antimicrobial Resistance Surveillance Network. Three bacterial pathogens- Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus were included. Resistance proportions for clinically relevant antibiotics were compared between intensive care unit and non-intensive care unit inpatient isolates. Statistical analysis was performed using chi-square test. Odds ratios (OR) with 95% confidence intervals were calculated to assess the association between intensive care unit admission and antimicrobial resistance. Interpretation of findings is limited by the use of aggregated surveillance data without patient-level variables, isolate de-duplication or inter-hospital standardization adjustment. Results: A total of 837 isolates were analyzed, including 300 intensive care unit and 537 non-intensive care unit isolates. Escherichia coli from intensive care units showed higher carbapenem resistance (41.0% vs 27.9%; OR = 1.79; P = 0.026). Klebsiella pneumoniae exhibited significantly greater resistance in ICU to piperacillin-tazobactam (69.0% vs 52.0%; OR = 2.06; P = 0.006) and carbapenems (imipenem: 48.0% vs 23.5%, OR = 3.01; P < 0.001). Methicillin resistance in Staphylococcus aureus was higher in ICU isolates (48.0% vs 34.6%; OR = 1.74; P = 0.029). Conclusion: ICU isolates demonstrated significantly higher resistance to key antibiotics compared with non-ICU isolates, highlighting intensive care units as focal points for antimicrobial resistance and priority targets for stewardship and infection control interventions.