Intra-laboratory reproducibility expressed as the ratio of correctly analysed clinical sample pairs over the total number of pairs versus workload expressed as number of clinical samples processed in 2008 (A) and in 2010 (B).

<p>A linear regression analysis indicated that the slope of both graphs does not significantly deviate from zero (A: p = 0,3183; B: p = 0,5623).</p

Participating laboratories in the two rounds of clinical and environmental EQAP.

<p>Participating laboratories in the two rounds of clinical and environmental EQAP.</p

Panel composition of the two rounds of environmental EQAP and concordant results per sample (inter-laboratory reproducibility).

a<p>All samples consisted of a mixture of soil, leaf litter, detritus, animal faeces.</p>b<p>Mean Ct value of duplicate IS2404 real-time PCR before samples were shipped to participants and after all participants had returned results.</p>c<p>One laboratory was missing a sample in round 1.</p

Qualitative results per laboratory of the two rounds of environmental EQAP.

a<p>The total n° of suspensions analyzed varies per laboratory because some laboratories reported inconclusive results. ^b This laboratory did not formally submit results, but used the program to troubleshoot its DNA extraction and PCR protocols with the assistance of the coordinating laboratory (see results for details). ER: enoyl reductase domain; KR: ketoreductase B domain.</p

Qualitative results per laboratory of the two rounds of clinical EQAP.

a<p>The total n° of suspensions analyzed varies per laboratory because some laboratories reported inconclusive results. ^b The number of concordant pairs divided by the total number of pairs. ^c Delay between the date of shipment of the panel and the reported date of analysis. NT: not tested; ER: enoyl reductase domain; KR: ketoreductase B domain.</p

Panel composition of the two rounds of clinical EQAP and concordant qualitative results per sample (inter-laboratory reproducibility).

a<p>No sample was inhibited. ^b The total number of respondent laboratories varies because inconclusive results were removed from the analysis as well as a missing suspension in one laboratory in round 1.</p

Concordance expressed as proportion of concordant results of participating laboratories vs. workload expressed as number of clinical samples processed in 2008 (A) and in 2010 (B).

<p>A linear regression analysis identified a non-significant trend towards better performance by laboratories handling high sample volumes (A: p = 0,0830; B: p = 0,1618).</p

Sample information.

<p>Sample information.</p

Phylum taxonomy level classifications.

<p>Bar plot showing the relative proportions of the phyla within all the samples.</p

PCoA plot representing the distances between samples, expressed by the Bray-Curtis metric.

<p>Each point represents a different sample, while the colored circles, triangles, and squares represent BU, non-BU, and Healthy, respectively.</p