Studies on Resistance of some bacteria to the Effect of antibiotics

Radiation has many application in the feild of medicine and pharmaceutical industry. This may include sterilisation, therapy and valuable mutational purposes.Exposure of the microbial cultures to sub-lethal doses of c-irradiation induces the loss or gain of one1 or more properties of microorganisms due to .genetic changes. This effect is usually explored to improve the yields of many pharmacuetical products produced by fermentation. Similarly virulence and hence pathogenicity of microorganisms’ as well as other biologic properties could also be changed upon exposure to sublethal doses of 2-irratliation. Accordingly, in the; present study the effect of sublethal doses of irradiation on certain microbial culture was investigated. These microorganisms comprise three bacterial species namely one strain of Staphylococcus ’aureus, four strains of Pseudomonas aeruginosa and one strain of Proteus mirabilis as well as three fungal, species namely Cylindrocarpon radicicola, Fusarium solani and Aspergillus flavcus