همایش ملی بیوانفورماتیک ایران

صفحه اصلی / 4th international edition and 13th Iranian Conference on Bioinformatics

In Silico Design and Evaluation of a Multi-Epitope Vaccine Candidate Against Escherichia coli and Staphylococcus aureus Involved in Bovine Clinical Mastitis

نویسندگان :

Aryan Ghorbani¹ Negin Khalili-samani² Maryam Amirinia³ Faezeh Jazayeri-soreshjani⁴ Faranak Ravanan⁵ Mohammad Oveysi-rastabi⁶ Abbas Doosti⁷

1- دانشگاه شهرکرد 2- دانشگاه آزاد اسلامی واحد شهرکرد 3- دانشگاه آزاد اسلامی واحد شهرکرد 4- دانشگاه آزاد اسلامی واحد شهرکرد 5- دانشگاه آزاد اسلامی واحد شهرکرد 6- دانشگاه آزاد اسلامی واحد شهرکرد 7- دانشگاه آزاد اسلامی واحد شهرکرد

کلمات کلیدی :

Multi-epitope vaccine،E. coli،S. aureus،Mastitis،immunoinformatics

چکیده :

Bovine mastitis caused by Escherichia coli and Staphylococcus aureus is a significant economic and health burden in the dairy industry[Hoogeveen et al., 2019; Heikkilä et al., 2018]. This study aimed to design and evaluate a computationally optimized multi-epitope vaccine using in silico approaches to combat these pathogens. The Vaxign database screened 79 E. coli and 38 S. aureus proteins based on transmembrane helices, antigenicity, and non-homology to host proteins. Antigenicity analysis shortlisted 10 proteins, from which two highly antigenic candidates—PhoE and ferric enterobactin outer membrane transporter (FEOMT) for E. coli and MS7_2175 and SasA for S. aureus—were selected. CTL, HTL, and linear B-cell epitopes were predicted using IEDB tools with strict selection criteria, resulting in 37 CTL, 31 HTL, and multiple B-cell epitopes. The multi-epitope vaccine construct was designed using GGGS and HEYGAEALERAG linkers to ensure flexibility and immunogenicity. Physicochemical analysis revealed favorable characteristics, including a molecular weight of 40.64 kDa, an instability index of 41.11, and hydrophilic properties (GRAVY score: -0.921). Structural validation using Ramachandran plot showed 93.33% of residues in the favored region, indicating a stable 3D conformation. Molecular docking against TLR11 receptor demonstrated strong binding affinity (-1028.2 kcal/mol), suggesting efficient immune activation. Codon optimization for E. coli expression achieved a CAI of 0.98 and GC content of 71%, enabling successful in silico cloning into the pcDNA3.1(+) vector. This study introduces a novel and promising multi-epitope vaccine candidate designed through integrated immunoinformatics approaches. The vaccine’s strong immunogenic potential and stability highlight its suitability for further experimental validation, paving the way for effective control of bovine mastitis caused by E. coli and S. aureus.