Fig 1.
Graphic design of the workflow for urines preparation and 1H-NMR spectra processing.
Urine samples were centrifuged and 700 μl of the supernatant were added to 0.2 mL of 3-(trimethylsilyl)-propionic-2,2,3,3-d4 acid (TSP) sodium salt 10 mM in deuterated water. The pH values of the solutions were adjusted to 7.0 by means of NaOH 1M and the samples were subjected to 1H-NMR spectroscopy. The spectra obtained by 1H-NMR were aligned and baseline-adjusted (normalization) and the signals were assigned to a specific metabolite by comparing their chemical shift and multiplicity with dedicated databases and libraries. Quantification of the molecules was achieved after the calculation of the area under each peak by means of a rectangular integration. The added TSP, at a known concentration, was employed as internal standard.
Table 1.
Demographic, behavioural and clinic characteristics of the women enrolled for the study.
Table 2.
Molecules whose concentration (mM, mean ± SD) showed significant differences (P<0.05) in relation to Chlamydia trachomatis positivity.
CT-: C. trachomatis-negative; CT+: C. trachomatis-positive.
Fig 2.
rPCA model calculated on the space constituted by the concentration of the molecules listed in Table 1.
In the scoreplot (A), CT-negative (CT-) and CT-positive (CT+) subjects are represented in black and gray respectively, with lines connecting each subject to the median of its group. In the barplot (B), describing the correlation between the concentration of each molecule and its importance over PC 1, dark gray bars highlight statistically significant correlations (P<0.05).