FIG. 1.

Second-derivative FTIR spectra in the polysaccharide absorption region (900 to 1,200 cm⁻¹). The polysaccharide region, characterizing essentially cell wall structure and composition, is a primary feature for strain delineation. For each of the two patients considered here (grey lines and black lines), second-derivative spectra of samples isolated from different body sites and on different sampling days are shown.