Aetes) dominated get 76932-56-4 samples regardless of the lysis method and analysis pipeline used. The phyla Synergistetes, Tenericutes, and SR1 had a relative abundance ,1 in all samples (Figure 1 and Table S2).Abundance of TaxaAssessment of the salivary samples using two extraction procedures revealed a high degree of congruence in terms of the composition and abundance of species in the microbiota. From the phylum level down to the OTU level, all of the taxa with an average proportion .0.12 in samples processed using one extraction method were also detected with the other method, when applying the same bioinformatics analysis pipeline (Figure 1). The most frequent taxa tended to be the most abundant, and the same taxa tended to be abundant and frequent for both extraction methods. These trends, at the OTU level, are exemplified for Pipelines 1 and 6 in Figure 2. The correlation between the extraction methods in terms of OTU abundance and prevalence reached the highest values in Pipeline 6 (Table 1). Only very low-abundance (average proportion ,0.08 ) OTUs were present in all six samples derived from one extraction method but absent in all samples obtained with the other method. Two OTUs assigned to the genus Treponema (Spirochaetes), along withDNA Extraction from Salivary MicrobiotaFigure 1. Microbial community profiles for saliva samples at the phylum (A) and genus (B) level. Only taxa found at an average frequency .0.25 by at least one extraction method in at least one analysis pipeline are presented. The Iloprost chemical information indicator values .0.5, determined by indicator species analysis, associated with the Benjamini-Hochberg corrected P values,0.05, were used to define indicators. Symbols “.” and “,” correspond 1315463 to such indicator taxa and denote increasing and decreasing trends in the relative abundance for enzymatic vs. mechanical lysis. Blank cells without borders correspond to taxa names absent from a given taxonomy. E, enzymatic lysis; M, mechanical lysis; P_1 _6, bioinformatics pipelines 1?. doi:10.1371/journal.pone.0067699.gDNA Extraction from Salivary MicrobiotaFigure 2. Average relative abundance and prevalence of OTUs determined using Pipelines 1 (A) and 6 (B). The top panel (of each figure) shows the relative abundance of each OTU averaged for the six samples processed with the same extraction method. Individual OTUs are ranked on the x-axis according to their average relative abundance in all (12) samples from high (left) to low (right). E, enzymatic lysis; M, mechanical lysis. Bottom panel indicates the number of samples (0?) in which the corresponding OTU was found (prevalence). Green bars, enzymatic lysis; blue bars, mechanical lysis. doi:10.1371/journal.pone.0067699.gShared OTUs and Diversity EstimatesPipeline 2 generated the highest total number of OTUs, as well as the highest average number of OTUs per sample (Table 1). The proportion of chimeras detected using Chimera Slayer (Pipeline 2) was lower than that obtained with UCHIME (Pipeline 1) or a BLASTN-based method (Pipeline 3) (Table 1). When the samples derived from the mechanical disruption were compared with thoseobtained by enzymatic lysis, the following trends 23977191 were observed across all analysis pipelines: (i) lower average fraction of detected chimeras; (ii) higher average number of OTUs per sample; and (iii) greater average fraction of OTUs shared among samples. The Chao 1 richness estimator predicted a higher number of OTUs for mechanically-lysed samples in all pipelines except Pipel.Aetes) dominated samples regardless of the lysis method and analysis pipeline used. The phyla Synergistetes, Tenericutes, and SR1 had a relative abundance ,1 in all samples (Figure 1 and Table S2).Abundance of TaxaAssessment of the salivary samples using two extraction procedures revealed a high degree of congruence in terms of the composition and abundance of species in the microbiota. From the phylum level down to the OTU level, all of the taxa with an average proportion .0.12 in samples processed using one extraction method were also detected with the other method, when applying the same bioinformatics analysis pipeline (Figure 1). The most frequent taxa tended to be the most abundant, and the same taxa tended to be abundant and frequent for both extraction methods. These trends, at the OTU level, are exemplified for Pipelines 1 and 6 in Figure 2. The correlation between the extraction methods in terms of OTU abundance and prevalence reached the highest values in Pipeline 6 (Table 1). Only very low-abundance (average proportion ,0.08 ) OTUs were present in all six samples derived from one extraction method but absent in all samples obtained with the other method. Two OTUs assigned to the genus Treponema (Spirochaetes), along withDNA Extraction from Salivary MicrobiotaFigure 1. Microbial community profiles for saliva samples at the phylum (A) and genus (B) level. Only taxa found at an average frequency .0.25 by at least one extraction method in at least one analysis pipeline are presented. The indicator values .0.5, determined by indicator species analysis, associated with the Benjamini-Hochberg corrected P values,0.05, were used to define indicators. Symbols “.” and “,” correspond 1315463 to such indicator taxa and denote increasing and decreasing trends in the relative abundance for enzymatic vs. mechanical lysis. Blank cells without borders correspond to taxa names absent from a given taxonomy. E, enzymatic lysis; M, mechanical lysis; P_1 _6, bioinformatics pipelines 1?. doi:10.1371/journal.pone.0067699.gDNA Extraction from Salivary MicrobiotaFigure 2. Average relative abundance and prevalence of OTUs determined using Pipelines 1 (A) and 6 (B). The top panel (of each figure) shows the relative abundance of each OTU averaged for the six samples processed with the same extraction method. Individual OTUs are ranked on the x-axis according to their average relative abundance in all (12) samples from high (left) to low (right). E, enzymatic lysis; M, mechanical lysis. Bottom panel indicates the number of samples (0?) in which the corresponding OTU was found (prevalence). Green bars, enzymatic lysis; blue bars, mechanical lysis. doi:10.1371/journal.pone.0067699.gShared OTUs and Diversity EstimatesPipeline 2 generated the highest total number of OTUs, as well as the highest average number of OTUs per sample (Table 1). The proportion of chimeras detected using Chimera Slayer (Pipeline 2) was lower than that obtained with UCHIME (Pipeline 1) or a BLASTN-based method (Pipeline 3) (Table 1). When the samples derived from the mechanical disruption were compared with thoseobtained by enzymatic lysis, the following trends 23977191 were observed across all analysis pipelines: (i) lower average fraction of detected chimeras; (ii) higher average number of OTUs per sample; and (iii) greater average fraction of OTUs shared among samples. The Chao 1 richness estimator predicted a higher number of OTUs for mechanically-lysed samples in all pipelines except Pipel.
