Microbiological Profile of Organisms Causing Bloodstream Infection in Critically Ill Patients

Abstract

Background: Bloodstream infection (BSI) is the most frequent infection in critically ill patients. As BSI's among patients in inten-sive care units (ICU's) are usually secondary to intravascular cath-eters, they can be caused by both Gram-positive and Gram-negative microorganisms as well as fungi. Infection with multidrug-resistant (MDR) organisms is becoming more common, making the choice of empirical antimicrobial therapy challenging. The objective of this study is to evaluate the spectrum of microorganisms causing BSI's in a Medical-Surgical Intensive Care Unit (MSICU) and their antimicrobial resistance patterns. Methods: A prospective observational study among all adult pa-tients with clinical signs of sepsis was conducted in a MSICU of an inner-city hospital in New York City between May 1, 2010 and May 30, 2011. Results: A total of 722 adult patients with clinical signs of systemic inflammatory response syndrome (SIRS) and/or sepsis were admit-ted to the MSICU between May 1, 2010 and May 30, 2011. From those patients, 91 (12.6%) had one or more positive blood culture. A 122 isolates were identified: 72 (59%) were Gram-positive bac-teria, 38 (31.1%) were Gram-negative organisms, and 12 (9.8%) were fungi. Thirteen (34.2%) Gram-negative organisms and 14 (19.4%) Gram-positive bacteria were classified as MDR. Conclusions: Antimicrobial resistance, particularly among Gram-negative organisms, continues to increase at a rapid rate, especially in the ICU's. Coordinated infection control interventions and anti-microbial stewardship policies are warranted in order to slow the emergence of resistance.