Iranian Biomedical Journal

en In silico and in vivo Investigations of the Immunoreactivity of Klebsiella pneumoniae OmpA Protein as a Vaccine Candidate Molecular Microbiology Molecular Microbiology مقاله کامل Full Length/Original Article <div style="text-align: justify;">Background: The growing threat of antibiotic resistance and Klebsiella pneumoniae infection in healthcare settings highlights the urgent need for innovative solutions, such as vaccines, to address these challenges. This study sought to assess the potential of using K. pneumoniae outer membrane protein A (OmpA) as a vaccine candidate through both in silico and in vivo analyses. Methods: The study examined the OmpA protein sequence for subcellular localization, antigenicity, allergenicity, similarity to the human proteome, physicochemical properties, B-cell epitopes, MHC binding sites, tertiary structure predictions, molecular docking, and immune response simulations. The ompA gene was cloned into the pET-28a (+) vector, expressed, purified and confirmed using Western blotting analysis. IgG levels in the serum of the immunized mice were measured using ELISA with dilutions ranging from 1:100 to 1:6400, targeting recombinant outer membrane protein A (rOmpA) and K. pneumoniae ATCC 13883. The sensitivity and specificity of the ELISA method were also assessed. Results: The bioinformatics analysis identified rOmpA as a promising vaccine candidate. The immunized group demonstrated significant production of specific total IgG antibodies against rOmpA and K. pneumoniae ATCC1 13883, as compared to the control group (p < 0.0001). The titers of antibodies produced in response to bacterial exposure did not show any significant difference when compared to the anti-rOmpA antibodies (p > 0.05). The ELISA test sensitivity was 1:3200, and the antibodies in the serum could accurately recognize K. pneumoniae cells. Conclusion: This study is a significant advancement in the development of a potential vaccine against K. pneumoniae that relies on OmpA. Nevertheless, additional experimental analyses are required. </div> Klebsiella pneumoniae, Outer membrane protein, Vaccine 156 167 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-5562-1&slc_lang=en&sid=1 shahla shahbazi shahbazi.shahla@yahoo.com 0000-0001-6325-1075 No Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran Farzad Badmasti fbadmasti2008@gmail.com 0000-0003-3502-147X No Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran Mehri Habibi m_habibi1362@yahoo.com 0000-0003-2191-7873 No Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran Samira Sabzi samira6913@yahoo.com 0000-0002-4462-5083 No Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran Narjes Noori Goodarzi noorinarjes93@gmail.com 0000-0001-9786-6182 No Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Mehdi Farokhi mehdifarokhi83@gmail.com 0000-0001-7023-2905 Yes National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran Mohammad Reza Asadi Karam* m_asadi12@yahoo.com 0000-0003-1000-9116 No Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran