Supplementary material
Figure S1. Experimental variation of the inoculum size administered to each animal group.
The inoculum prepared for each independent animal experiment was diluted, plated on solid medium and subjected to viable counting. Differences were statistically analyzed using ANOVA followed by post-hoc tests. The different inocula used were statistically indistinguishable. The horizontal line within the boxes represents the median, whereas the lower part represents the 25th percentile, and the upper part represents the 75th percentiles. The whiskers represent the range of the values.
Figure S2. Kinetics of IL-6 and TNFαproduction in rabbit serum during the first 180 min post-challenge.
At the indicated time points post-challenge, blood samples were extracted, and IL-6 (panel A) and TNFα (panel B) were quantified in animal sera (n = 6 per group) by solid-phase sandwich ELISA. The assays were performed in triplicate, and the results were analyzed using ANOVA followed by post-hoc tests.
Figure S3. Variation in the glucose and lactate levels in rabbit serum during the first 180 min post-challenge.
At the indicated time points post-challenge, blood samples were extracted, and glucose and lactate (panels A and B, respectively) were quantified in animal sera (n = 6 per group) in an automatic analyzer. The dotted line indicates the normal physiological value (on average) of each parameter. Assays were performed in triplicate, and the results were analyzed using ANOVA followed by post-hoc tests. Differences between groups were not statistically significant.
Figure S4. Variation of hematological markers in rabbit serum during the first 180 min post-challenge.
At the indicated time points post-challenge, blood samples were extracted, and several hematological markers (white blood cell density (A), red blood cell density (B), and hemoglobin concentration (C)) were quantified in animal sera (n = 6 per group) using an automatic analyzer. Assays were performed in triplicate, and the results were analyzed using ANOVA followed by post-hoc tests. The dotted line in panel A indicates normal levels. Differences between groups were not statistically significant.
Figure S5.Histological analysis of the spleen
Post-mortem samples of the spleen were extracted, fixed and subsequently prepared for inclusion, cutting and hematoxylin-eosin staining. Upper left panel (untreated animal): bacterial forms are visible inside the infiltrate of heterophils (600×; scale bar length is 20 microns); upper right panel (ceftriaxone-treated animal): hemorrhagic area inside the spleen (100×; scale bar length is 120 microns); lower left panel (Pep19-2.5- and ceftriaxone-treated animal): red pulp around a lymphoid follicle with heterophil infiltration (200×; scale bar length is 60 microns). Lower right panel (Pep19-2.5- and ceftriaxone-treated animal): Detail of bacterial formations in the cytoplasm of phagocytes (600×; scale bar length is 20 microns).