Emerging Carriage of NDM-5 and MCR-1 in Escherichia coli From Healthy People in Multiple Regions in China: A Cross Sectional Observational Study

Abstract

Background Carriage of carbapenem-resistant Enterobacteriaceae (CRE) in humans may contribute to the dissemination of CRE and impact on communities and healthcare facilities. Carbapenem-resistant Escherichia coli (CREC) is one of the major type of CRE in the human gut. Here, we describe a cross-sectional study to investigate the prevalence of CREC, and in particular the mcr-1 carrying CREC, in health volunteers in China. Methods During September to December 2016, 3859 non-duplicated stool specimens were collected from healthy volunteers who received regular physical examinees in healthcare centers located in 19 provinces across China. Enrichment culture supplemented meropenem was used to isolate CREC. Carbapenemase producing determinants and the mcr-1 gene were determined by PCR amplification and sequencing. Isolates were further analyzed by antibiotic susceptibility test, genotyping, and whole genome analysis. Findings A total of 92 non-duplicated CREC were isolated from 3859 stool specimens, among which 43 CREC are carbapenemase positive. In addition, the co-existence of bla NDM and mcr-1 was found in 14 CREC, which also showed resistance to the majority of all antimicrobial agents analyzed. The genetic background of these CREC isolates are highly diversified based on molecular typing. Furthermore, whole genome sequence indicated that NDM-5 is the predominant determinant conferring carbapenem resistance in CREC, and that NDM-5 carrying plasmids (IncX3) are very similar. Interpretation The incidence of CREC carriage in healthy people in China was small; however, the co-existence of CREC with mcr-1 is disconcerting. Therefore, pre-screening prior to admission and monitoring of patients on high-dependency wards is highly recommended to control and prevent the dissemination of CRE in hospitals. Outstanding Question The high prevalence of CREC in the healthy people should not be underestimated, as it may increase the risk of infection. This knowledge could have impact on the pre-screening and monitoring of CRE before patient administration.

Rapid Increase in Carbapenemase-Producing Enterobacteriaceae in Retail Meat Driven by the Spread of the bla NDM-5 -Carrying IncX3 Plasmid in China from 2016 to 2018

“…The ϳ50-kb plasmids carrying bla NDM were confirmed to be IncX3 type by using primers covering both the backbone of IncX3 plasmid and bla NDM genes. Totally, among the 110 NDM producers, 87 (79.1%) bla NDM genes were carried by IncX3 plasmids (Table S2), which was consistent with previous reports that the IncX3 plasmid was a major vector driving the transmission of bla NDM (7,12,13,18). IncX3 plasmid was first associated with the dissemination of bla NDM-1 among clinical CRE strains (19).…”

Increasing Prevalence of ESBL-Producing Multidrug Resistance Escherichia coli From Diseased Pets in Beijing, China From 2012 to 2017

“…Carbapenem-resistant Enterobacteriaceae is mediated largely by the production of carbapenemase especially for NDM isolates. NDM-5, an NDM-1 variant, exhibited increased enzyme activity to carbapenems (Rogers et al, 2013) and its gene bla NDM-5 has been reported worldwide (Khan et al, 2017) and is the most prevalent variant in China (Shen et al, 2018). In support of this, 84 (52%) NDM-5-producing E. coli were collected from 161 bla NDM carrying CRE in chickens (Wang et al, 2017).…”

Colistin-resistance gene mcr in clinical carbapenem-resistant Enterobacteriaceae strains in China, 2014–2019

“…In this study, mcr-1 and bla NDM-5 are the most dominant (78.6%, 11/14) combination among MCR-CREC strains. Escherichia coli isolates carrying both mcr-1 and bla NDM-5 also have disseminated among healthy people in various regions of China [48]. The pattern of transmission of resistance genes between patients and healthy individuals should also be carefully monitored.…”