Abstract
Background: Mostly intensive care unit (ICU) patients are more susceptible to nosocomial infections caused by hospital-based various strains of bacteria and other opportunistic pathogens. Due to the widespread use of broad-spectrum antibiotics, these strains of pathogens are often multi-drug resistant. To prevent resistance against the antimicrobial agent various departments of the health care system have to work together, so we can use the antimicrobial agents as effectively as we can to treat illnesses.

Aim and Objectives: The objective of this study was to know the prevalence of different micro-organisms causing infections in ICU and their sensitivity and resistance pattern and to determine the overall microbiological and resistance profile which helps formulate therapeutic guidelines in ICU.

Materials and Methods: A cross-sectional study was conducted at a tertiary care teaching hospital in Ahmedabad to assess the culture and sensitivity pattern of clinical samples such as blood, urine, sputum, wound, and endotracheal aspiration for a 1-year duration (August 2019 - August 2020).

Results: A total of 941 samples were received for microbiological investigation from ICU, out of which 322 were positive. The Utmost isolated organism was - Klebsiella (37.26%) followed by Escherichia coli (16.45%), Pseudomonas (12.42%), and Staphylococcus aureus (7.45%). The Gram-negative bacteria (GNB) were most sensitive to drugs like colistin (96.26% %) and tigecycline (83.40%) followed by carbapenems (71.79%), aminoglycosides (71.36%), and fluoroquinolones (67.21%). More sensitive drugs for isolated Gram-positive organisms were linezolid (100%) followed by teicoplanin (98.41%) and vancomycin (98.41%).

Conclusion: High prevalence of multidrug-resistant organisms such as methicillin-resistant S. aureus, vancomycin-resistant enterococci and GNB producing Extended-spectrum Beta-lactamase, AmpC, or carbapenem-resistant GNB in our study, raise serious concerns about antibiotic resistance. The main reason for increasing antimicrobial-resistant bacteria is poor infection control practices and inappropriate use of antibiotics. Hence, research regarding antibiotic sensitivity and resistance will be very helpful for doctors to initiate appropriate empirical antibiotics in treating critical illnesses.

Key words: Antimicrobial Susceptibility Pattern; Nosocomial Infection; Clinical Isolates