Rapid Increase in Prevalence of Carbapenem-Resistant Enterobacteriaceae (CRE) and Emergence of Colistin Resistance Gene mcr-1 in CRE in a Hospital in Henan, China

The global spread of carbapenem-resistantEnterobacteriaceae (CRE) is one of the most severe threats to human health in a clinical setting. The recent emergence of plasmid-mediated colistin resistance genemcr-1 among CRE strains greatly compromises the use of colistin as a last resort for the treatment of infections caused by CRE. This study aimed to understand the current epidemiological trends and characteristics of CRE from a large hospital in Henan, the most populous province in China. From 2014 to 2016, a total of 7,249Enterobacteriaceae isolates were collected from clinical samples, among which 18.1% (1,311/7,249) were carbapenem resistant. Carbapenem-resistantKlebsiella pneumoniae and carbapenem-resistantEscherichia coli were the two most common CRE species, withKlebsiella pneumoniae carbapenemases (KPC) and New Delhi metallo-β-lactamases (NDM), respectively, responsible for the carbapenem resistance of the two species. Notably, >57.0% (n = 589) of theK. pneumoniae isolates from the intensive care unit were carbapenem resistant. Furthermore,bla NDM-5 andmcr-1 were found to coexist in oneE. coli isolate, which exhibited resistance to almost all tested antibiotics. Overall, we observed a significant increase in the prevalence of CRE isolates during the study period and suggest that carbapenems may no longer be considered to be an effective treatment for infections caused byK. pneumoniae in the studied hospital.