author(s)
Buthina Abulhameed Abdullah, Husamuldeen Salim Mohammed Saeed and Noor A Al-Taii

abstract
Effective control of pathogenic bacteria key to the prevention and treatment of disease, therefore many plants are used in traditional medicine as treatment for bacterial infections. In the present study (7) microbial pathogens as (Staphylococcus aureus, Salmonella typhimurium, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Listeria monocytogenes and Streptococcus mutans) isolated in the laboratory of veterinary medicine collage of Baghdad university. The present results show that aqueous olive leaves extract have potential antibacterial activities against some of bacterial strains, then select Staphylococcus aureus and Streptococcus mutans which are more sensitive to different concentrations (0.5, 1, 3, 6%) than other bacterial strain for the ability of hot aqueous extract of olive leaves. Plasmid profiling is among the methods used to determine and characterize aqueous olive leaves extract traits in bacteria. To induce the cleavage in cells, DNA fragmentation of microorganisms used. In addition to those treated with antibiotic (kanamycin and ampicillin) for comparing the results, the DNA fragments were observed using agarose gel electrophoresis. This phenomenon was tested for the ability of extract of olive leafs to induce the cleavage in cells (DNA fragmentation). Pathogenic bacteria Staphylococcus aureus and Streptococcus mutans were exposed to at (0.5, 1, 3 and 6%) concentration and incubated for 24 hours. Staphylococcus aureus and Streptococcus mutans when applied with the extracts olive leaves showed a marked DNA fragmentation, and no fragmentation was observed in untreated cells. The results confirmed that the extracts of olive leaves can interact with DNA of the bacteria. This may explain the inhibitory action on DNA synthesis. Hence, the hot aqueous extract of olive leaves possessed antibacterial potential against these microorganisms. While kanamycin and ampicillin not posses such activity.