ABSTRACT
Pseudomonas aeruginosa and Staphylococcus aureus are important pathogens that produce wide spread infections. Purpose of this study was to evaluate the antimicrobial effect of ultrasonic irradiation [US] alone and in combination with antibiotic on antibiotic resistance Pseudomonas aeruginosa and Staphylococcus aureus. In this study ultrasonic irradiation [US] in a laboratory-scale batch sonoreactor with low frequency [42 kHz] plate type transducer at 170W of acoustic power was used. The Water samples, were taken from different wards of the 3 teaching hospitals which were affiliated to the Kurdistan University of Medical Sciences to isolate Pseudomonas aeruginosa and Staphylococcus aureus and also to determine their antimicrobial susceptibility pattern. Our results showed that Pseudomonas aeruginosa and Staphylococcus aureus were affected by the ultrasound and the bactericidal effect increased with time. It was found that P. aeruginosa was more susceptible to the ultrasonic treatment than S. aureus. The combination of US with an antibiotic [amoxicillin] enhanced killing of both bacteria over the use of US alone. There were no differences in resistance to ultrasound between isolated strains and standard strains from Persian type culture collection