Mycoplasma suis loads and MIA (microbead immunoassay) results of Mycoplasma suis-infected and sham-inoculated pigs. A The copy number of M. suis strain Illinois organisms was detected by qPCR  on blood samples of M. suis-infected pigs (pig#5, pig#6 and pig#7) along the course of the experiment. Sham-inoculated pigs (pig #1, pig #2 and pig #3) were consistently negative on qPCR for the extent of the experiment. B Serum antibodies were measured using recombinant GrpE (rGrpE) protein in a microbead immunoassay (MIA) . + = positive, − = negative, based on established MFI (median fluorescence intensity) cut-off. ND: not determined. ☨pigs have already been euthanized. Serum MFI values above the established cut-off values were considered positive, while serum MFI values below the established cut-off values were considered negative. MFI cut-off for all pigs was 74.07. It is important to note that a high cut-off may have been encountered due to the low number of animals to determine a cut-off, which increases the standard deviation. M. suis-infected group: pig #1, pig #2 and pig #3. Sham-inoculated group: pig #5, pig #6, pig #7. Day 0 corresponds to inoculation day. At day 0, blood was collected prior to M. suis or sham-inoculation. Black arrows indicate the days chosen for RNA-Seq analysis for each pig.