Associated factors for bacterial colonization in patients admitted to the intensive care unit of the Clinical Hospital of Infectious Diseases.

Introduction: This study aimed to identify isolates from colonization and assess the risk factors for bacterial colonization and the risk of death in patients admitted to the intensive care unit (ICU) of the Constanţa County Infectious Diseases Hospital between September 2017 and September 2019.

Methods: This was a retrospective case-control study in a single center that included all patients admitted to the ICU in Constanţa, Romania, who underwent bacteriological screening upon admission and 7 days after admission, between September 2017 and September 2019. In total, 253 patients were included in this study. The nasal exudate, pharyngeal exudate, and rectal swab samples were screened.

Results: In this study, 253 patients were screened bacteriologically, of which 53 had bacterial colonization and 200 did not. Among the bacterial strains, Klebsiella spp. (43.39%) was the most frequently isolated. The predominant resistance mechanism detected in the bacterial isolates was extended-spectrum β-lactamase (ESBL). Multivariate analysis identified a Carmeli score of 3 as an independent risk factor for acquiring bacterial colonization in the ICU. The mortality rate of patients with bacterial colonization was 11.32% and 6% for the patients without colonization (p>0.05).

Conclusions: Our study revealed an increased prevalence of Enterobacterales colonization in the ICU. Risk factors for acquiring bacterial colonization differed depending on the type of bacterial colonization, such as ESBL, carbapenemases, methicillin-resistant Staphylococcus aureus (MRSA), and vancomycin-resistant enterococci (VRE). An independent risk factor for acquiring bacterial colonization was the Carmeli score of 3.