Resistome clustering in sewage samples across regions. a Principal coordinate analysis (PCoA) performed on the resistome Bray–Curtis dissimilarity matrix. The amount of variation explained by coordinates 1 and 2 is included in the axis labels. b Antimicrobial resistance class-level heat map. Relative abundances of genes (fragments per kilo base per million fragments (FPKM)) were summed to drug classes (AmGlyc aminoglycoside, Mac macrolide, Oxa oxazolidinone, Phen phenicol, Quin quinolone). Colors represent log (ln) transformed relative abundances (FPKM). Complete-linkage clustering of Pearson correlation coefficients was used to hierarchically cluster both samples and drug classes. Nature Communications 10, Article number: 1124 (2019).