Anatomical dissemination of bTB-lesions and infection burden in asymptomatic cattle naturally infected with <i>M. bovis.</i>

<p>(<b>A</b>) Frequency of animals categorized according to their anatomical dissemination of bTB-lesions into five levels: I, lesions of bTB in the head lymph nodes, including retropharyngeal, mandibular, and parotid lymph nodes; II, presence of lesions of bTB in thoracic lymph nodes, including the mediastinal, bronchial, tracheobronchial lymph nodes, <i>or</i> in abdominal lymph nodes, including mesenteric, inguinal, gastric, hepatic, splenic, renal, sub-iliac, medial and lateral iliac lymph nodes; III, simultaneous presence of lesions suggestive of bTB in thoracic <i>and</i> abdominal lymph nodes; IV, presence of lesions of bTB in organs of the thoracic <i>or</i> abdominal cavity; and V, simultaneous presence of lesions of bTB in organs of thoracic <i>and</i> abdominal cavities. Schematic cartoon of the scoring system is represented. Continuous line represents both cavities affected (thoracic and abdominal); dotted line represents only one cavity affected. Green balloons indicate affected organs and blue balloons indicate affected lymph nodes. Correlation between levels of lesion dissemination and pathology severity (<b>B</b>) or mycobacterial loads (<b>C</b>) in cattle naturally infected with <i>M. bovis</i>. In (<b>B</b>), the results are expressed applying the gross pathology severity semi-quantitative scoring per animal previously described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053884#pone.0053884-Vordermeier1" target="_blank">[26]</a>, and (<b>C</b>) as number of CFU.mL⁻¹ (colony-forming units per mL of granulomatous tissue homogenate). Spearman’s correlation indexes (Spearman’s r and p values) are shown in the graphs.