Comparative analysis of PIA and rSesC mixture, as vaccine candidate against the biofilm forming Staphylococcus aureus.

Background: Staphylococcus aureus as a causative agent of hospital-acquired infections, has been considered as the primary concern in biomaterial-related infections (BAIs).

Methods: Following the purification of polysaccharide intercellular adhesion (PIA) as an efficient macromolecule in biofilm formation in the native condition, recombinant S. epidermidis surface exposed rSesC protein, with the most homology to clumping factor A (ClfA) in S. aureus was cloned and expressed in a prokaryotic host as well. Fourier transform infrared spectrometry (FTIR) and Western blotting procedure analyzed purified PIA and protein, respectively. Then, the immune response was evaluated by measuring total IgG titers. Moreover, the capacity of Anti-biofilm forming activity of arisen antibodies to a biofilm forming S. aureus strains was assessed by semi-quantitative micro-plate procedure.

Results: Data showed that the total IgGs was boosted in mice immunized sera. By performing inhibition assay, biofilm inhibitory effect of secreted antibodies to test strain was observed. Arisen antibodies against the mixture significantly were more potent than PIA and rSesC, when comparing them in a biofilm inhibition assay.