Association of Length of Stay With Contamination of Multidrug-Resistant Organisms in the Environment and Colonization in the Rectum of Intensive Care Unit Patients in China.

To the Editor—Multidrug-resistant organisms (MDROs) have recently caused infection outbreaks with increased morbidity and mortality. Colonization of the inanimate hospital environment and intestines may contribute to the increased prevalence of MDROs. To prevent the spread of MDROs in the intensive care unit (ICU), the correlation between colonization of MDROs and the length of patient hospitalization is important to consider. However, there are few reports in the literature on the epidemiology of MDROs in China that highlight the change in trends of their colonization rate. Here, we studied the contamination of the surrounding environment (eg, telemetry units, blood pressure cuffs, flashlights, stethoscopes, bedside tables, and bed frames, controllers, and mattresses) and rectal colonization of ICU patients at a tertiary teaching hospital in China with 5 types of MDROs (ie, multidrug-resistant [MDR] Acinetobacter baumannii [AB], methicillin-resistant Staphylococcus aureus, MDR-Pseudomonas aeruginosa, MDR-Escherichia coli, and MDR-Klebsiella pneumoniae). Samples were collected using cotton swabs. Methicillin-resistant S. aureus was isolated by CHROMagar MRSA plates (CHROMagar) and identified using Staphytect Plus kits (Oxoid). Gram-negative MDROs were isolated by ChromID Extended-Spectrum Beta-Lactamase plates (bioMeriéux) and identified using the analytical profile index system (bioMeriéux). AB and P. aeruginosa isolates that were resistant to ceftazidime were considered MDROs. The overall MDRO contamination rate of ICU patients’ surrounding environment was 26.4%. The MDR-AB contamination rate was 18.9%, and its proportion versus all MDROs was 71.6%. The contamination rates of methicillinresistant S. aureus, MDR-K. pneumonia, MDR-E. coli, and MDR-P. aeruginosa were 3.4%, 3.0%, 1.6%, and 1.1%, respectively. Furthermore, the MDRO contamination rate was 10.0% on day 1, and it increased to 35.4% by day 3, 35.8% by day 7, and 46.6% by day 14 or longer. The MDR-AB contamination rate and the proportion of MDR-AB versus all MDROs increased with the length of stay in ICU (Table 1).