THE EFFECT OF MUTAGENS AGENT ETHIDIUM BROMIDE ON SOME THERAPEUTIC PROPERTIES FOR LOCAL IRAQI ISOLATE Saccharomyces boulardii

Objective: This study includes the using Ethidium bromide as as chemical mutagenic agent To Mutagenesis of local isolates Saccharomyces boulardii and tested the changes that happen in therapeutic and Physiological Characteristics. Methods: local isolates of S. boulardiihas have been exposed to (5, 10, 15, 20, and 25) µg/ml of Ethidium bromide, mutants were isolated and tested against Escherichia coli O157:H7. Mutant Isolate gave highest antimicrobial activity was compared with wild type isolate physiology characteristics, Autoaggregation ability and cholesterol reducing. Results: Results were as following : decreasing of survival rate by increasing of Ethidium bromide concentration , where the survival was 11.8% at exposure to dose15µg/ml overnight,the highest percentage of mutants were induced as a result of that concentration and they gave the highest mutants 11.53%, six mutants were isolated, S. boulardii M6 culture filtrates extract where gave the highest antimicrobial activity where diameter of inhibition zone was 12 mm,Compared with the culture filtrates extract of wild type S. boulardii W.T which was 10 mm diameter. no difference between S. boulardii W.T and S. boulardii M6 in physiology characteristics where both of isolates appeared tolerance to low pH and high concentrations of bile salts .also there was an improvement in Autoaggregation ability (significant difference P<0.05) , it reached 69.72 % for S. boulardii M6 Compared with 65.37 % for S. boulardii W.T. in addition to that an improvement in the ability to reduce cholesterol level. the percentage of cholesterol reducing after incubation 24 and 48 hrs. was 29.78% and 57.26 % respectively, Comparison with the ability to reduce cholesterol for wild type S. boulardii W.T, which reached 25.59 and 53.90% respectively. Conclusion: mutant local Iraqi isolate Saccharomyces boulardii by chemical agent Ethidium bromide was appeared an improvement in antimicrobial activity against Escherichia coli O157:H7and in some therapeutic characteristics Autoaggregation ability and cholesterol level lowering.