ABSTRACT

in this study, the presence of staphylococcus aureus was investigated from many clinical samples, and then about 14 isolates were obtained, diagnosed with all different diagnostic methods. the bacterial isolates produced for SNase were detected by the DNase agar medium,that revealed only11(78.57%) s. aureus were able to produce the enzyme. the crude activity and specific activity of SNase was 42U/ml , 231U/mg respectively.The isolate was chosen for purification by means of Precipitation with ammonium sulphate 70% saturation and ion-exchange chromatography .the purified SNase activity and specific activity was 45 U/ml and 436U/mg respectively. The purified enzyme had high efficiency to inhibit biofilm formation significantly of p. aeruginosa

Keywords: staphylococcus aureus , p. aeruginosa , nuclease (SNase) , biofilm