Fig. 1: Surface localization of potential vaccine candidates on GAS M49 surface.

a Surface exposure analysis of 18 selected candidates. GAS M49 cells were incubated with protein-specific polyclonal antibodies and surface localization was analyzed by flow cytometry using FITC-conjugated secondary goat anti-mouse IgG. Mean fluorescence intensity (MFI) obtained for each immunized serum (I) was normalized with the MFI of preimmunized sera (PI) to measure the fold difference. Serum candidates showing >2.4-fold difference in MFI (represented by red dotted line) were considered significant. b Histogram depicting SPy_2191 surface exposure. In the overlay diagram, purple line represents control M49 GAS cells without antisera, blue line represents cells with preimmunized antisera and red line represents cells incubated with SPy_2191 antisera. Experiment was repeated two times and data shown here are a representative experiment.