Fig. 1

Principal component analysis of the abundance of A latent and B established ARGs. Aquatic includes samples from fresh, lentic, and marine water; Plants includes rhizosphere samples; Infants include samples from their digestive system; Wastewater includes activated sludge, water and sludge, fecal source, and raw wastewater; Terrestrial includes soil samples; Human includes samples from the skin, digestive and respiratory systems; Birds includes samples from their digestive system; and Mammals includes samples from the digestive systems of bovines, mice, and pigs. The analysis was based on log-transformed ARG abundance using all metagenomic samples but a maximum of 400 per environment are shown. The ellipses are calculated based on a multivariate t-distribution at a 75% confidence level. Latent ARGs were in general more diverse than established ARGs and showed less overlap especially for the aquatic, terrestrial, and plant environments