The prevalence of antimicrobial resistance (AMR) is increasing rapidly worldwide, including in
bacteria colonizing healthy human and animal populations. The recent reports of plasmid
mediated colistin resistance, potentially associated with colistin usage in agriculture, further
raise fears of infections that have become untreatable due to AMR. The commensal flora of
humans and animals is a reservoir of AMR encoding genes and Escherichia coli in particular
can carry multiple AMR determinants. Antimicrobial resistance transmission within E. coli
appears dominated by certain lineages. To what extent these are restricted to certain host
species is unknown. Such host restriction may be an important determinant of the likelihood
of transmission of resistant E. coli between different reservoirs, such as between animal and
human hosts. The identification of determinants that allow disentanglement of the different
modes of resistance transmission (i.e. bacteria vs mobile genetic elements such as plasmids)
is crucial for a more targeted design of interventions to prevent and reduce transmission of
resistance. The proposed research aims to identify determinants of host restriction of E. coli
and their potential association with antimicrobial resistance transmission and prevalence. We
propose a One Health approach using mixed methods, including whole genome sequencing
of a large collection of E. coli isolates from human, animal and environmental sources in
different geographic areas across Europe and in Vietnam, experimental models to study the
role of host restriction determinants in transmission and bacterial fitness, and mathematical
modelling. The research should result in a risk-assessment, estimating the contribution of
different transmission routes and predicting the effect of interventions on a single route on the
overall prevalence in the different compartments. Less...