Vaccine candidates for cellulitis from Staphylococcus aureus and Streptococcus pyogenes - In silico approach

Staphylococcus aureus and Streptococcus pyogenes are the causative agents of cellulitis, a bacterial skin infection. Cellulitis primarily affects the skin, and it later spreads to the other parts of the body, especially through the lymph nodes and bloodstream. Without proper medication, it becomes life-threatening. The main symptoms include inflammation, tenderness, tight and swollen skin, and fever. Vaccines using epitopes as antigens trigger quick immune responses; in addition, they are cost effective. These antigens are derived from bacterial proteins. In this study, virulence factors from membrane proteins such as sak, tst, isdA, clfB, and can fromS. aureus (Fig. 1) and SPy, scpA, and hylp1 from S. pyogenes (Fig. 2) were selected for predicting the vaccine epitopes. VaxiJen server was used to evaluate the antigenicity of the selected proteins; BCPred, AAPPred, and ABCpred were used for B-cell epitope prediction, while ProPred and ProPred I were used for T-cell epitope prediction. MHCPred was used for the selected alleles, DRB1*0101 and DRB1*0401. Pepitope server was used for epitope mapping of the selected peptides. Epitopes that are common among those from BCPred, AAPPred, and ABCpred were selected: LKYGPKFDK (tst) and MTFDDKNGK (cna) from S. aureus and YTNSDKGGS (SPy), FKIEPDTTV (SPy), MTPSERLDL (scpA), VKTDDQQDK (scpA), and LKFKPAATV (hylp1) from S. pyogenes. Among them, YTNSDKGGS, MTPSERLDL, and MTFDDKNGK, were identified as suitable vaccine candidates for eliciting immune responses. These results of this study can be used to create a peptide-based vaccine for preventing cellulitis.(c) 2023 The Authors. Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).