Fig. 5

Hierarchical cluster analyses of FTIR spectroscopic data from CEs of the A. pleuropneumoniae serotype 2. Hierarchical cluster analysis was performed using recorded FTIR spectra from the CEs of the infection strain grown in vitro and after re-isolation from different organs of the infected pigs 1–4 and 6 (I1-4 and I6): isolates from the lung of I1-4 and 6 as well as the inoculation strain (Cluster b), isolates from the left and right tonsil of I4 (Cluster a). For calculation of the dendrogram the Ward’s algorithm and the FTIR spectral regions of 1200–900 cm⁻¹ and 1800–1500 cm⁻¹ were used