Staphylococcus aureus that produced biofilm is the most important pathogenic agent of different diseases and it is difficult to be treated due to the product of the biofilms that caused resistances against antibiotics. The biofilm acts as a barrier to create a stable internal environment for bacterial cell activity and protects bacterial cells from adverse conditions including extreme temperature and antibacterial drugs. The aim of the current study is to evaluate the effect of purified acidocin (alone) that produced by Lactobacillus acidophilus isolates or with biofilm extract produced by Staphylococcus aureus, on cell permeability and mode of action on cell structure under scanning electron microscope. Forty eight Staphylococcus aureus isolates were diagnosed from the total 142 cows milk samples collected from different areas.These isolates were produced biofilm with different thickness. Six Staphylococcus aureus isolates out of forty-eight shown higher thickness (3mm) of biofilm with protein concentration 62, 66,70,72,80 and 85 mg /ml. Twenty-five Lactobacillus acidophilus isolates were diagnosed from samples of healthy cow’s milk and chicken crops. Extraction and gel filtration chromoatography by sepharose 6B for acidocin purification was carried out. The effectiveness of pure acidocin was tested against culture of Staphylococcus aureus that produced biofilm of 3 mm. The study included the use of the Electron microscope to investigate the mode of acidocin and biofilm action on the bacterial cell membrane. The acidocin product indicated that pore formation important for bactericidal activity against cell membrane with highly potent for the treatment against Staphylococcus aureus infection. In addition, the treatment with combination between acidocin and biofilm lead to lysis of cytoplasm, nucleic acid destruction, disappearance and vacuolization in Staphylococcus aureus cells. The treatment with combination between acidocin and biofilm lead to lysis of cytoplasm, nucleic acid destruction, disappearance and vacuolization in Staphylococcus aureus cells.
Keywords | S. aureus , L. acidophilus, Acidocin, Biofilm Cell membrane