Incidence of multidrug-resistant bacteria in tracheal secretions from critically ill patients in the intensive care unit

Abstract

Ventilator-associated pneumonia is a severe nosocomial infection that affects the disease course of critically ill patients. Awareness of potential pathogens is essential for prevention, early detection, and proper treatment, as well. In this retrospective cross-sectional study, we investigated the tracheal secretions collected from critically ill patients with the aim to detect the occurrence of multidrug-resistant bacteria. We examined the bacteriological culture results of the tracheal secretions of the patients hospitalized at the Intensive Care Unit of Tîrgu Mureș Emergency Clinical County Hospital between 1st November 2017 and 31st January 2018. Admission diagnoses and comorbidities were recorded, and white blood cell counts were monitored. We determined the quality of the lower respiratory samples by microscopic examination and the results of the microbiological tests, taking into account the germ count of pathogens and the antibiotic-resistance pheno-type. During the three months, 194 samples were received from 107 patients for bacteriological examination. After the first sample collection 34 (31.77%) tracheal secretions were positive for pathogens, while in the remaining samples normal upper respiratory bacterial flora was found. From the 34 positive samples, 22 were colonizing pathogens and 30 were isolated in a clinically significant amount. Predominantly Staphylococcus aureus (n=14; 26.9%), Klebsiella pneumoniae (n=9; 17.3%), Escherichia coli (n=8.1%) and other Gram-negative bacteria (n=21; 40.4%) were identified. Among these strains 38 (73.07%) were not multidrug-resistant. The rate of positivity of individual sampling showed a positive correlation with the average duration of hospital stay (p=0.0016; r=0.8740). A total of 26 patients developed early-onset or late-onset ventilator-associated pneumonia. Potential risk factors for infection with multidrug-resistant bacteria were found. We can conclude that recently admitted patients in the intensive care unit are rarely carriers of multidrug-resistant bacteria, but become colonized or infected with multidrug-resistant strains during long-term intensive care.