Fig. 4

Oxygen in CSF is not decreased during early phase of S. suis meningitis in pigs. a In three of six infected pigs, bacteria were detectable inside the CSF and blood, reflecting the onset of meningitis. The CFU/mL increased over time inside the CSF. b-c) By flow cytometry, cells/mL inside the CSF were measured and granulocyte-specific cells are presented. b Sixteen h post infection, significantly more granulocytes were detected inside the CSF of infected pigs with bacteria inside the CSF compared to uninfected pigs (unpaired, one-tailed Student’s t-Test, n_uninfected = 6, n_infected = 3 in each group). c During all analyzed time-points, significant or remarkably higher amounts of granulocytes were detected inside the CSF of infected pigs, with bacteria inside the CSF compared to infected pigs without bacteria inside the CSF (unpaired, one-tailed Student’s t-Test, n = 3 in each group). d The amount of oxygen measured inside the CSF-compartment showed no significant differences between the three groups at all time-points (ANOVA table was calculated for each time point). e During the onset of meningitis, no correlation between oxygen and granulocytes (r and P values left side) or bacteria (r and P values right side) was identified in CSF of infected animals. Calculation is based on all parameters from all animals and time-points with a two-tailed nonparametric Spearman r correlation calculation (n = 16). In all graphs, error bars are presented with ± SD. In b–d, each dot reflects one animal (*P < 0.05)