Fig 8. Histopathological analysis of vaccinated animals at 4 weeks post challenge.

(a) The figure depicts representative 40x magnification photomicrographs of formalin fixed, paraffin embedded and haematoxylin-eosin (H&E) stained 5 μm sections of lung tissue of guinea pigs (n = 6) vaccinated with BCG, MtbΔbioA, two doses of MtbΔbioA (ΔbioA/ΔbioA) or saline and euthanized at 4 weeks post challenge. The scale bars depict 200 μm. AS and G denote alveolar spaces and granuloma, respectively. (b) The graphical representation of the total granuloma score of the lung sections is shown by box plot of 6 animals per group (the mean is represented by ‘+’, median value is denoted by horizontal line, box represents the inter quartile range and the minimum and maximum value is denoted by whiskers). *p <0.05 and **p <0.01 (Mann-Whitney test, two tailed). (c) The figure depicts the graphical representation of the number of granulomas that were scored in lung section from each animal in a group. The black region depicts the number of necrotic granulomas out of the total number of granulomas seen in lung section from each animal. (d) The graphical representation of the total granuloma score of the liver sections of 6 animals per group is shown by box plot (the mean is represented by ‘+’, median value is denoted by horizontal line, box represents the inter quartile range and the minimum and maximum value is denoted by whiskers). **p <0.01 (Mann-Whitney test, two tailed).