Nosocomial infections-related antimicrobial resistance in a multidisciplinary intensive care unit

Abstract

Background: Intensive care units (ICUs) have become hubs of nosocomial infections worldwide. There has been a continuous rise in the development of antimicrobial resistance among ICU-acquired infections. Particularly, the Gram-negative bacteria implicated in ICU-acquired infections have become resistant to the majority of the antibiotics leading to a critical therapeutic problem. The present study was conducted to determine the antimicrobial resistance pattern of microorganisms causing nosocomial infections (ventilator-associated pneumonia [VAP], central line-associated bloodstream infection [CLABSI], and catheter-associated urinary tract infection [CAUTI]) in a multidisciplinary ICU. Materials and Methods: This prospective observational cohort study included the patients with ICU stay ≥ 48 h and any of the ICU-acquired infections: VAP, CLABSI, or CAUTI. The appropriate specimen was collected as per the standard procedure and cultured. The antimicrobial susceptibility of all the bacterial isolates recovered from the samples was performed according to the Clinical and Laboratory Standards Institute (CLSI) recommendations. The antimicrobial resistance data were analyzed using WHONET Microbiology Laboratory Database software 5.6 (WHONET 5.6). Results: Gram-negative microorganisms were the principal pathogens causing various infections in the ICU, out of which Pseudomonas aeruginosa and Klebsiella pneumonia were the commonest. Most of the Gram-negative bacteria showed a high degree of resistance to the majority of the antibiotics. Colistin was observed to be the most effective antimicrobial for Gram-negative pathogens followed by doripenem, meropenem, and tigecycline. The majority of Staphylococcus aureus isolates (71.4%) were methicillin-resistant S. aureus; however, all were sensitive to vancomycin and linezolid. Vancomycin-resistant Enterococci constituted 43% of Enterococcus isolates and were sensitive to linezolid and tigecycline. Conclusion: Antimicrobial resistance was very high among the pathogens causing nosocomial infections in the ICU, especially Gram-negative bacteria demonstrated a substantially high degree of resistance to the majority of the antibiotics. Antibiotic stewardship will help control the emergence of multidrug-resistant microbes.

Keywords

• antibiotic resistance
• gram-negative bacteria
• intensive care unit
• nosocomial infections