Monitoring microbial communities in intensive care units over one year in China

Healthcare-associated infections (HAIs) seriously threaten patient health in intensive care units (ICUs). Profiling the microbial composition and diversity in ICU is important to prevent HAI-related spreading. Given that microbial communities vary across different environments, the time-scale characteristics of pathogens in ICUs have not been explored in China. In our study, to study the bacterial communities of two different ICUs in China, we proceeded dynamic monitoring using 16S rRNA sequencing for a whole year among the bed sheets, bed rails, shared pulse oximeters, bedside lockers, nurses' hands, floor, and carts. Our results showed that the microbial composition significantly changed within months. Significant differences in alpha and beta diversities were also observed among the 12 sampling months in each ICU. Additionally, we found the persistence of several HAI-related bacteria, including Acinetobacter, Pseudomonas, Staphylococcus, Escherichia, and Enterococcus. Source tracking analysis showed that most bacteria in both ICUs came from buildings or human skin. With deep investigations of hospital microbial surveillance on a long-term time-scale, we hope that these results will provide constructive guidelines to prevent the spread of HAIs in ICUs.