One-Year Retrospective Study of ICU Isolates: Epidemiology and Antibiotic Resistance Patterns

Mohankumar  Appadurai; Alice Peace  Selvabai; Priyadarshini  Shanmugam

Mohankumar Appadurai Research scholar, Microbiology Department, Chettinad Hospital and Research Institute Chettinad Academy of Research and Education Care, Kelambakkam, Tamilnadu, India
Alice Peace Selvabai Professor, Department of Microbiology, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education Care, Kelambakkam, Tamil Nadu, India
Priyadarshini Shanmugam Professor and Head of Microbiology, Chettinad Hospital, and Research Institute, Chettinad Academy of Research and Education Care, Kelambakkam, Tamil Nadu, India

Keywords: ICU Infections, Antimicrobial Resistance, Retrospective Analysis, General ICU, Antibiotic Susceptibility.

Abstract

Background: Intensive Care Units (ICUs) are environments with high risk for nosocomial infections due to invasive procedures and critically ill patient populations. Understanding the distribution of pathogens and their antibiotic susceptibility patterns is vital for effective infection control and therapeutic strategies.
Aim: This study aimed to analyze the distribution of bacterial isolates across various ICUs and assess their antimicrobial resistance and susceptibility patterns.
Methods: This retrospective study was performed on 496 culture-positive clinical samples collected from six ICUs within the tertiary care hospital. The isolates were characterized and tested for antimicrobial susceptibility using standard conventional methods.
Results: The majority of culture-positive samples originated from the general ICU (83%), followed by the Cardio Thoracic ICU (8%) and CATH ICU (7%). Gram-negative bacilli (70%) were predominant, with Klebsiella spp. (22%) and Escherichia coli (18.5%) being the frequently isolated organisms. Among Gram-positives, Staphylococcus(13.3%) and Enterococcus spp. (8.1%) were common. Meropenem, imipenem, and piperacillin-tazobactam showed higher efficacy against Gram-negative bacterial isolates. Vancomycin, linezolid, and Teicoplanin demonstrated high efficacy against Gram-positive isolates. Alarmingly, high resistance was noted to ampicillin, polymyxins, and certain cephalosporins. Acinetobacter spp. in ET aspirates exhibited pan-resistance.
Conclusion: The predominance of multidrug-resistant Gram-negative organisms, particularly in the general ICU, underscores the need for stringent infection control measures and periodic surveillance of antimicrobial resistance. Tailored antibiotic policies and effective stewardship programs are crucial for curbing ICU-acquired infections.

How to cite this article:
Appadurai M, Selvabai A P, Shanmugam P. One-Year Retrospective Study of ICU Isolates: Epidemiology and Antibiotic Resistance Patterns. J Commun Dis. 2026;58(1):88-96.

DOI: https://doi.org/10.24321/0019.5138.202613

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