MCR-1-positve Escherichia coli (MCRPEC) have been reported in humans worldwide; however, thus far, their prevalence is low and potential sources for human mcr-1 carriage have not yet been identified. Here, we analyse a nationwide epidemiological dataset on MCRPEC in humans throughout China and assess the factors associated with MCRPEC carriage using natural and national anthropogenic data. We identified 774 non-duplicate MCRPEC isolates from 774 stool samples collected from 5,159 healthy individuals in 30 provinces and municipalities in 2016, with a prevalence of MCRPEC ranging from 3.7 to 32.7% (average: 15.0%)-substantially higher than previously reported. MCRPEC carriage was associated with provincial regions, the production of sheep and freshwater aquaculture, annual consumption of total meat, pork and mutton, and daily intake of aquaculture products. MCRPEC was significantly more prevalent in provinces with higher aquaculture industries. Whole-genome sequencing analysis revealed that the MCRPEC isolates were clustered into four distinct lineages, two of which were dominant and harboured most of the MCRPEC isolates. The high prevalence of MCRPEC in the community poses a substantial risk for colistin usage in clinical practice and suggests the need for intestinal screening of mcr-1 carriers in intensive care units in Chinese hospitals. Furthermore, our data suggest that aquaculture is a significant reservoir of mcr-1.
The mobile colistin resistance gene is globally disseminated in both and species, with the latter potentially serving as a reservoir for this gene. Here, we investigated the prevalence of in rectal swabs from humans, in food-producing animals and their products, and in the aquatic environment, and we investigated the genetic relationships between the -positive isolates. An enriched broth screening method was used to detect in samples, and species identification of isolates from positive samples was carried out by matrix-assisted laser desorption ionization-time of flight mass spectrometry and shotgun sequencing. All -positive isolates were subjected to antimicrobial susceptibility testing, conjugation, and whole-genome sequencing. Ten isolates, including 2 from human rectal swabs, 1 from pork, 3 from chicken meat, and 4 from the aquatic environment, were positive for , but only 2 showed resistance to colistin. In addition to the variants identified previously (the novel variants were termed to), all isolates harbored -like genes downstream of the variants. The MCR-3.13 to MCR-3.18 proteins exhibited only 89.2% to 96.1% amino acid identity to the original MCR-3 protein. Whole-genome sequence analysis indicated diversity within the genetic environments of -positive isolates and possible transmission between different sources in China and even worldwide. Close relationships between -positive and-negative isolates suggested that might be common in species, which are not inherent hosts of but may act as an important reservoir of this mobile colistin resistance gene.
To investigate the prevalence of the recently emerging colistin resistance gene mcr-1 in Enterobacteriaceae among companion animals, we examined 566 isolates collected from cats and dogs in Beijing, China, during 2012–2016. Of these isolates, 49 (8.7%) were mcr-1–positive.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.