Fig. 3

Distribution of operational taxonomic units (OTUs) in procedural controls and PCR water samples. An OTU belonging to the genera Ralstonia dominated the procedural control samples with an average relative abundance of 51.81% in scope rinse (n = 10), 54.33% in catheter rinse (n = 10), 55.36% in cryotube (n = 9), 52.82% in protected specimen brushes (n = 10) and 54.93% in phosphate buffered saline (n = 10). The same Ralstonia OTU also dominated the molecular grade water samples (n = 3) at an average relative abundance of 29.42%. The PCR water control sample was dominated by Rhizobium (38.11%), Anaerobacillus New Reference OTU 110 (20.69%) and Delftia (10.65%) in run A and Anaerobacillus New Reference OTU 110 (32.93%), Anaerobacillus OTU 622288 (24.04%) and Delftia (10.68%) in run B. Taxonomic rank is described using prefixes (o__: order, f__: family, g__: genus). Data unrarefied