Variation in <i>Mmm</i> colony opacity associated to antigenic variation of the glucose PTS permease.

<p><b>A: </b><i>Mmm</i> strain Afadé colonies on PPLO supplemented agar observed under stereomicroscope with indirect light. <b>B:</b> Colony-blotting performed from the same plate using the 3F3 monoclonal antibody. (Magnification: x10).</p

Exopolysaccharide (EPS) secretion by <i>Mmm</i> strain Afadé in supplemented PPLO broth and CMRL-1066 medium.

<p>EPS extracted either from <i>Mmm</i> culture (Afadé) or from unseeded medium used as negative control (Neg) were spotted onto a nylon membrane and either stained with a glycoprotein detection reagent (<b>A</b>) or immunodetected using a serum from a CBPP-positive bovine (<b>B</b>).</p

PG1^T colony opacity is related to the presence of capsular material.

<p><b>A:</b> Colony morphology of PG1^T opaque (OP) and translucent (TR) colony variants grown on PPLO supplemented agar with (right) or without (left) Congo red. Magnification: x30. <b>B:</b> Electron microscopy of Ruthenium red-stained PG1^T OP and TR colonies. CM: cytoplasmic membrane.</p

Kinetics of exopolysaccharides secretion and viability of <b><i>Mmm</i></b><b> strain Afadé following transfer into CMRL-1066 medium with (red) or without (blue) glucose supplementation.</b>

<p>Glucose (1 g/L) was added at 24, 48 and 72 h (arrows).</p

NMR spectra of EPS produced by <i>Mmm</i>.

<p><b>A: ¹H NMR spectrum, B: 2D COSY NMR spectrum and C: 2D HSQC NMR spectrum.</b></p

Growth, pH and exopolysaccharide (EPS) secretion of translucent (blue) and opaque (red) colony variants in CMRL-1066 medium.

<p>50 ml of CMRL-1066 medium were inoculated with 10⁸–10⁹ CFU/mL and incubated for 96 hours. Viable titer, pH and EPS production were determined every 24 h.</p