Study of Colistin Resistant Gram Negative Organism in Hospitalized Patients: A Retrospective Study

Abstract

Background Intensive care units have become hotspots for antimicrobial resistance, particularly concerning colistin resistance, posing a threat of untreatable infections. Aim This study aims to analyze the epidemiological and clinical aspects of patients carrying colistin-resistant organisms. It focuses on identifying risk factors, the microbiological profile, susceptibility patterns, and treatment outcomes. Materials and methods Isolates with colistin MIC >2 µg/mL, identified via BD PHOENIX, were subjected to colistin broth disc elution testing (as per CLSI guidelines) in our Microbiology Department between January and December 2022. Results Among the 30 patients, colistin-resistant gram-negative isolates were found predominantly in blood cultures (50%), followed by ET/TT cultures (23.3%), urine cultures (10%), and other sites (16.7%). Klebsiella pneumoniae was the most common organism (80%), showing the highest sensitivity to Ceftazidime-avibactam + Aztreonam (CAZ-AVI + ATM) (76.7%). Of these patients, 66.7% recovered and were discharged, while 33.3% succumbed during hospitalization despite treatment. Conclusion The study underscores a notable presence of colistin-resistant gram-negative isolates, predominantly in blood cultures, with K. pneumoniae being predominant. The combination of CAZ-AVI + ATM exhibited the highest sensitivity. However, the mortality rate of 33.3% despite sensitive antibiotic treatment highlights the urgency for ongoing vigilance and research to combat colistin-resistant infections and improve patient outcomes. How to cite this article Diwane D, Rajhans PA, Jog SA, Dalvi M. Study of Colistin Resistant Gram Negative Organism in Hospitalized Patients: A Retrospective Study. Indian J Crit Care Med 2024;28(3):286–289.