Antimicrobial resistance (AMR) is a serious threat to global public health, but obtaining
representative data on AMR for healthy human populations is difficult. Here, we use
metagenomic analysis of untreated sewage to characterize the bacterial resistome from
79 sites in 60 countries. We find systematic differences in abundance and diversity
of AMR genes between Europe/North-America/Oceania and Africa/Asia/South-America. Antimicrobial
use data and bacterial taxonomy only explains a minor part of the AMR variation that
we observe. We find no evidence for cross-selection between antimicrobial classes,
or for effect of air travel between sites. However, AMR gene abundance strongly correlates
with socio-economic, health and environmental factors, which we use to predict AMR
gene abundances in all countries in the world. Our findings suggest that global AMR
gene diversity and abundance vary by region, and that improving sanitation and health
could potentially limit the global burden of AMR. We propose metagenomic analysis
of sewage as an ethically acceptable and economically feasible approach for continuous
global surveillance and prediction of AMR.
