Skip to main content
. 2023 Sep 5;169(9):001391. doi: 10.1099/mic.0.001391

Fig. 3.

Fig. 3.

S. aureus does not recruit C4BP when incubated in human serum. (a) C4BP recruitment to the bacterial surface was analysed following incubation of bacteria [ S. aureus (JE2), M. catarrhalis (RH4), S. pyogenes (AP1) and L. lactis MG1363 with pKS80 empty control or pKS80 expressing SdrE] in either 10 % or 40% normal human serum (NHS). (b) Ten different S. aureus reference strains [LAC (clonal complex, CC))8; MW2 (CC1); N315 (CC5); SH1000 (CC8); Newman (CC8); TW20 (CC239); EMRSA15 (CC22); MRSA252 (CC30); Mu3 (CC5); Mu50 (CC5)] were examined for serum C4BP binding in 10 % NHS. All strains tested except SH1000 carry the sdrE gene. S. pyogenes strain AP1 is shown as a reference for a known C4BP binder. (c) C4BP recruitment was assessed using IgM/IgG depleted serum and compared to no serum and secondary antibody only controls. (a–c) Bound C4BP was detected using F(ab’)2 murine anti-human C4BP MK104 and goat anti-mouse AF-488 secondary antibody. The geometric mean fluorescence intensity (gMFI) was measured using a BD FACS Canto flow cytometer. Bars indicate the mean; data points represent three biological replicates and error bars inform the standard deviation.