Comprehensive genome based analysis of Vibrio parahaemolyticus for identifying novel drug and vaccine molecules: Subtractive proteomics and vaccinomics approach

Multidrug-resistant Vibrio parahaemolyticus has become a significant threat to human health as well as aquaculture, prioritizing the development of effective drug and vaccine candidates. Hence, the study was designed to identify novel therapeutics using a comprehensive genome-based analysis of V. parahaemolyticus. From V. parahaemolyticus proteome, a total of 4822 proteins were investigated in order to find out effective drug and vaccine targets. A range of diverse subtractive proteomics approaches – namely, identification of human non-homologous and pathogen-specific essential proteins, druggability and ‘anti-target’ analysis, prediction of subcellular localization, human microbiome non-homology screening, analysis of virulence factors, protein-protein interactions studies. Among 16 novel cytoplasmic proteins, ‘VIBPA Type II secretion system protein L’ and ‘VIBPA Putative fimbrial protein Z’ were allowed to molecular docking with 350 human metabolites, which revealed that Eliglustat, Simvastatin and Hydroxocobalamin were the top drug molecules considering free binding energy. On the contrary, ‘Sensor histidine protein kinase UhpB’ and ‘Flagellar hook-associated protein of 25 novel membrane proteins were subjected to T and B cell epitope prediction, antigenicity testing, transmembrane topology screening, allergenicity and toxicity assessment, population coverage analysis and molecular docking were adopted to generate the most immunogenic epitopes. Three subunit vaccines were constructed by the combination of highly antigenic epitopes along with suitable adjuvant, PADRE sequence and linkers. The designed vaccine constructs (V1, V2, V3) were analyzed by their physiochemical properties and molecular docking with MHC molecules that suggested the superiority of construct V1. Besides, the binding affinity of human TLR1/2 heterodimer and construct V1 was also biologically significant. The vaccine-receptor complex exhibited deformability at a minimum level that also strengthened our prediction. The optimized codons of the designed construct was cloned into pET28a(+) vector of E. coli strain K12. However, the predicted drug molecules and vaccine constructs could be further studied to combat V. parahaemolyticus associated infections.