Antimicrobial Resistance Profile in ICU Patients Across India: A Multicenter, Retrospective, Observational Study

Area of Science:

• Microbiology
• Infectious Diseases
• Clinical Pharmacy

Background:

• Antimicrobial resistance (AMR) patterns are dynamic and geographically variable, necessitating regional data for effective empirical treatment selection.
• Multidrug-resistant (MDR) strains, including methicillin-resistant Staphylococcus aureus (MRSA), are significant causes of nosocomial infections, leading to increased morbidity and mortality.

Purpose of the Study:

• To evaluate the antimicrobial resistance (AMR) profile of bacterial isolates from intensive care unit (ICU) patients across multiple tertiary care centers in India.
• To provide data on regional resistance patterns to guide empirical antibiotic therapy in critical care settings.

Main Methods:

• A multicenter, retrospective study utilizing electronic laboratory records from microbiology labs in Indian hospitals.
• Data from 21,556 invasive sample records collected between December 2010 and January 2021.
• Antibiotic susceptibility testing performed using Kirby-Baur disk diffusion and automated Vitek 2 compact system, adhering to CLSI-2014 guidelines.

Main Results:

• Gram-negative bacteria (4,183 isolates) were more common than gram-positive bacteria (815 isolates).
• Key gram-negative pathogens included Klebsiella pneumoniae (36.6%), Escherichia coli (30.34%), and Acinetobacter spp. (14.08%), showing high resistance to fluoroquinolones and cephalosporins (e.g., Acinetobacter spp. 89.13% resistance to ceftazidime).
• Common gram-positive bacteria were S. aureus (67.73%) and Enterococcus spp. (12.88%), with significant resistance to penicillin, erythromycin, and ciprofloxacin.

Conclusions:

• Gram-negative bacteria are the predominant cause of antibiotic-resistant infections in Indian ICUs.
• High resistance rates were observed for beta-lactams, fluoroquinolones, and macrolides against both gram-negative and gram-positive isolates.
• Continuous monitoring of MDR and antibiotic consumption patterns is crucial for effective infection control and treatment strategies.