Seven isolates were identified as Pseduomonas aeruginosa from clinical samples. Antibiotic sensitivity test were done to determine their sensitivity to number of antibiotics, the results illustrated all that isolates were resistant to most used antibiotics. The ability of Pseduomonas isolates to produce haemolysin, protease and pyocyanin were detected in this study, all isolates had the ability to produce pyocyanin pigment, hemolysis and protease. The antimicrobial activity of the ethanolic extracts of Thuja orientalis and green tea against P.aeruginosa were investigated. The results showed that both these plant extracts have inhibitory effect against Pseduomonas isolates and it was shown that ethanolic extract of green tea was more efficient against P. aeruginosa isolated from eye infection while ethanolic extracts of Thuja orientalis was more effective against P. aeruginosa isolated from wound infection. Minimum inhibitory concentration (MIC) of ethanolic extract of Thuja orientalis be resoluted, it was 10 mg/ml. The effect of ethanolic extract of Thuja orientalis on the production of haemolysin, protease and pyocyanin was detected, the ethanolic extract of Thuja orientalis at MIC (10 mg/ml) completely inhibited Pseudomonas growth and haemolysis on blood agar, also inhibited protease and pyocyanin production. The ethanolic extracts of Thuja orientalis at sub MIC (5 mg/ml) had the ability to inhibit haemolysin production on blood agar. It also inhibited production of pyocyanin on nutrients agar and had effect on protease production. The minimum inhibitory concentration (MIC) of ethanolic extracts of the green tea was 100mg/ml and there was a significant induction of Protease IV expression in the groups treated with ethanolic extracts of the green tea in comparison with gentamicin and the highest induction in expression of Protease IV gene was at Sub MIC of gentamicin.
