Figure 2.

Relative abundance [copies of antimicrobial resistance genes (ARG)/copies of 16S-rRNA] of tetracycline resistance genes. a) tet(A), b) tet(B), c) tet(M), d) tet(O), e) tet(Q), and f) tet(W). Error bars represent standard deviation of the mean. A — feedlot A, B — feedlot B, C — feedlot C, DC — feedlot D (conventional production), DN — feedlot D (natural production), CB — catch basin, Influent — sewage influent, Effluent — sewage effluent, and Creek — Ephemeral creek.

^{a,b,c,d,e,f,g} Different letters represent significant difference (P ≤ 0.05).

* Unable to be detected/outside of standard curve.