Epidemiology and Genetic Characteristics of Carbapenem-resistant Escherichia coli in Chinese Intensive Care Units Analyzed by Whole-genome Sequencing: A Prospective Observational Study

CREC represents a public health threat worldwide, and its colonization precedes or occurs simultaneously with infection; once the colonization rate increases, its infection rate rises sharply. In our observation hospital, the colonization rate of CREC remained low, and almost all of the CREC isolates detected were ICU-acquired. Contamination of the surrounding environment by CREC-carrier patients shows a very limited spatiotemporal distribution. As the dominant ST of the CSEC isolates found, ST1193 might be considered a strain of notable concern with potential to cause a future outbreak. ST1656 and ST131 also deserve attention as they comprised the majority of the CREC isolates found, while NDM-5 gene screening should play an important role in medication guidance as the main carbapenem-resistant gene identified. The disinfectant chlorhexidine that is used commonly in clinic is effective for CREC rather than CRKP, possibly explaining the lower positive rate of CREC compared to CRKP.