Epitope Based Vaccine Peptide Predictions for fimH gene of Acinetobacter baumannii

Background: Acinetobacter baumannii is an opportunistic bacterial pathogen that is primarily associated with hospital-acquired infections. Recently, there is a dramatic increase in the incidence of multidrug-resistant (MDR) strains, which has significantly raised the profile of this emerging opportunistic pathogen. MDR is often associated with the formation of biofilms and various other virulence factors. Amidst all the genes, fimH gene is our area of interest in this research, because it is an important virulence factor in A. baumannii which encodes the Type 1 fimbriae, that helps bacteria bind to the surface of host cells initiating further infection.

Aim: The aim of this study was to assess the epitope based vaccine epitope peptide predictions for the fimH protein of A. baumannii.

Materials and Methods: The fimH gene for epitope prediction was selected. Druggability and physico-chemical properties were analysed. Antigenicity was predicted. Epitope mapping of T-cell MHC class 1, Class 1 immunogenicity, conservancy and toxicity analysis was done. T-cell class II epitopes were further mapped together with the immuno-dominant B-cell epitopes.

Results: From the selected 20 epitopes, 2 best epitopes (AALVASVCL and YSSGANAFT) were selected after analysing their antigenicity and allergenicity. The epitope YSSGANAFT showed better values in association with HLA alleles - HLA-DP, HLA-DQ, HLA-DR and TLR-2.

Conclusion: The finding of the study documents a single immunodominant peptide (sequence) as a promising vaccine candidate to treat infections caused by A. baumannii. However further experimental analysis must be performed to assess the immunological memory and response of the peptide in both in-vitro and in-vivo studies.