Introduction: Patients hospitalized in the intensive care units (ICUs) are 5 to 10 times more likely to acquire nosocomial infections than other patients admitted in the hospital. The frequency of infections at different anatomic sites and the risk of infection vary by the type of ICU, and the frequency of specific pathogens varies by infection site. Contributing to the seriousness of nosocomial infections, especially in ICUs, is the increasing incidence of infections caused by antibiotic-resistant pathogens.

Aims and objectives: To evaluate the bacteriological profile and their antibiotic sensitivity pattern in intensive care unit (ICU) settings of a tertiary care institute.

Material and methods: It is a6-yearretrospective study conducted in the Department of Microbiology, Jawaharlal Nehru Institute of Medical Sciences from 2017 January to 2023 January. The bacterial isolates from the clinical samples were identified and antibiotic susceptibility testing were done by Kirby Bauer disc diffusion method and VITEK 2 automated system. Data were recorded as numbers and proportions.

Result: Of the total 1547 samples received in 6 years, 508 were bacterial culture positive.  Majority of the bacterial isolates were from urine followed by blood, sputum, surgical wounds, stool, CSF, etc. In our study, most of the bacterial isolates were found to be Gram-negative bacilli while the remaining were Gram-positive cocci. Out of the 508 bacterial isolates, the highest culture positivity was from Surgery ICU. The most frequently identified isolates were Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumanii, CoNS, Enterococcus faecalis, Proteus mirabilis, Salmonella typhi, etc.

Conclusion: Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Proteus mirabilis, Pseudomonas aeruginosa, etc were thecommon isolates from our study. The study alsoshows that the susceptibility of the first line drugs and second line drugs are low. Nosocomial infections, especially those caused by antibiotic-resistant pathogens, represent an important source of morbidity and mortality for the patients hospitalized in an ICU setting.