Fig. 3

Relative abundance of predominant OTUs. OTUs with a mean relative abundance >1 % in either samples, negative extraction controls or NTC_W are presented. The proportion is indicated by the scale at the bottom of the plot. Dilutions of the master stock are indicated from 1E0 (no dilution) to 1E-8 (10⁻⁸). For EC, SA, NEC_B and NEC_W, the data obtained from DNA extractions performed on three occasions (Exp1–Exp3) are presented from left to right. NTC_W were performed in duplicate for each of the three series. EC, E. coli; SA, S. aureus. NEC_W, negative extraction controls obtained substituting culture for water; NEC_B, negative extraction controls obtained by substituting culture for lysis buffer; NTC_W, no-template PCR control