Antibacterial Activity Of Isolated Immunodominant Proteins Of Naja Naja (Oxiana) Venom

The aim of this study is to investigate antibacterial effects of immunodominant proteins isolated from the venom of Naja Naja Oxiana snake against Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa.
The innate immune system is an important line of defense against bacterial diseases. Antibacterial proteins produced by snake venoms have recently attracted significant attention due to their relevance to bacterial diseases and the potential of being converted into new therapeutic agents.
Identification of immunodominant proteins of the venom of N. Oxiana snake was performed by SDS-PAGE and western blot analysis.Identified proteins were isolated directly from preparative gel electrophoresis by Electro-elution. In the next step, antibacterial effects of immunodominant proteins were tested against several strains of clinical isolates, including S.aureus, B.subtilis and P.aeruginosa, E.coli using broth microdilution and disc-diffusion assays. In order to compare the results of the disc-diffusion assay, antibacterial effects of several antibiotics (Gentamicin, Ampicillin, Penicillin, Amoxicillin and Ciprofloxacin) were also examined using the same conditions.
Results showed immunodominant proteins of 14, and 65kDa with high immunogenicity were very effective in inhibiting the growth of (S.aureus, B.sub) that were tested. However, they were only moderately effective in inhibiting the growth of(P.aeruginosa and E.coli). However, immunodominant proteins of 22 and 32kDa with high mmunogenicity, showed slight effectiveness in inhibiting the growth of two the Gram-positive and Gram-negative bacteria that were tested.
To the best of our knowledge, these immunodominant proteins are novel antigens for potent antimicrobial effects against (S.aureus, B.subtilis ) and less antimicrobial effect against (E.coli, P.aeruginosa).