الفهرس 
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Abstract
SUMMARY
Antibacterial activity of venom extracted from the oriental hornet Vespa orientalis L. was tested against different bacterial pathogens. The selected bacterial strains were MRSA, B.subtilis and S.muans as Gram-positive bacteria; E.coli, K.pneumonia and S. typhimurium as Gram-negative bacteria.
To identify the proteins responsible for the antibacterial activity of wasp venom an electrophoretic study was carried out.
Mode of action of wasp venom against the tested bacterial strains was studied by transmission electron microscopy.
The results of the study can be summarized as follows:
1. Wasp venom activity against Gram+ve bacteria:
In measuring the antimicrobial properties of Vespa orientalis L. venom (conc.0.2mg/ml) activity against Gram positive bacteria, it was found that Vespa orientalis L. crude venom represented a significant effect against MRSA،B.subtilis and S.mutans. The measured inhibition zones were 19.2 mm for MRSA, 18.3 mm for B.subtilis and 10.2mm for S.mutans. Comparing with the tetracycline antibiotic the measured inhibition zones were 9.9mm for MRSA, 13.6 mm for B. subtilis and 16.5mm for S.mutans.
2. Wasp venom activity against Gram -ve bacteria:
In measuring the antimicrobial activity of Vespa orientalis L. venom (conc.0.2mg/ml) activity against Gram negative bacteria, it was found that Vespa orientalis L. crude
SUMMARY
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venom represented a significant effect against E.coli،
K.pneumonia and S. typhimurium. The measured inhibition zones were 17.8 mm for E.coli, 16.6mm for K.pneumonia and 9.2mm for S.typhimurium. Comparing with the tetracycline antibiotic the measured inhibition zones were 9.9mm for E.coli, 13.6 mm for K.pneumonia and 16.5mm for S.typhimurium.
3. Determination of Minimum inhibitory concentration (MIC) of Vespa orientalis L. venom against bacteria:
The corresponding MICs of the Vespa orientalis L. venom were ranged between 2×10-2 and 2×10-8mg/ml, while, MICs of tetracycline antibiotic were ranged between 2×10-3 and 2×10-7 mg/ml. All tested bacterial strains were found to be susceptible to the venom and among them, MRSA was the most sensitive.
4. The mode of action of Vespa orientalis L. venom against tested bacteria:)Ultra structural changes(:
The results proved that, wasp venom at its minimum inhibitory concentrations caused cell membrane disruption exhibited by extensive membrane blebbing, ruffling and detachment. Furthermore, reduced electron density was demonstrated in bacterial cultures treated with wasp venom in comparison to the control, loss in cytoplasmic contents , ruptured membrane and expelled cellular contents cumulatively, these data strongly suggested that wasp venom could cause extensive membrane permeability and utilize a cell membrane interaction as its mechanism of action is bactericidal Compared with tetracycline effect; at its minimum inhibitory concentrations the cell of MRSA، B.subtilis and E. coli cells were slightly affected with moderate membrane blebbing, loss of cytoplasmic electron density and membrane detachment.
5. Protein characterization:
The results revealed that the total number of protein bands resolved in 15%SDS polyacrylamide gel were seven polypeptide bands with molecular masses of these protein bands were“310 ،
227.89، 186.84 ، 116.58،73.144 ،68.938 and 60.931KDa”.