Multidrug-Resistant Gram-Negative Bacteria in ICU Patients: Prevalence, Species-Wise Resistance Profiles, Risk Factors, and Clinical Outcomes in a Tertiary Care Hospital

Abstract

Background: Multidrug-resistant (MDR) Gram-negative bacteria are the predominant cause of healthcare-associated infections in intensive care units (ICUs), with limited therapeutic options. Comprehensive surveillance of species-specific resistance profiles and risk factors is critical for antimicrobial stewardship.

Objective: To determine MDR prevalence with species-wise antimicrobial susceptibility profiles, identify host and clinical risk factors for MDR acquisition, and evaluate clinical outcomes.

Methods: Prospective observational study; n=150 ICU patients. Disk diffusion AST (CLSI). MDR defined as resistance to ≥3 antimicrobial classes. Species-wise resistance to 13 antibiotics quantified. Chi-square test and descriptive statistics used. p<0.05 was significant.

Results: MDR prevalence: 74.0% (111/150). Highest in Klebsiella pneumoniae. ESBL: 51.3%; carbapenem resistance: 50.0%. Mean ICU stay: 13.97±6.63 days; mortality: 48.7%. No statistically significant association found between MDR and clinical outcomes (ICU stay p=0.156; mortality p=0.089). All six resistance genes detected in 46–52% of isolates.

Conclusion: A critical MDR burden exists in ICU settings in central India. Targeted infection control, antimicrobial stewardship, and molecular surveillance are urgently required. Clinical outcomes are multifactorially determined, with AMR as one of several contributing variables.