Pseudomonas aeruginosa is the third cause of nosocomial infections after staphylococcus aureus and e. coli .one of the problems with pseudomonas aeruginosa-related infections is prevalence of multi-drug resistant isolates that is occurred by different mechanisms. bacterial efflux pumps are capable of a wide range of antibiotics and detergents to efflux out of the cell. the aim of study was determining phenotypic activity of efflux pumps in mdr strains of pseudomonas aeruginosa resistant to fluoroquinolones
Methods
50 strains of pseudomonas aeruginosa were isolated from clinical specimens of patients were admitted to milad hospital and diagnosed by biochemical tests. antibiotic susceptibility was determined by disc diffusion method according to clsi. after determining the mdr isolates, for evaluation of efflux pump activity the mic of ciprofloxacin, levofloxacin was determined before and after treatment by cccp inhibitor .
Results
17(34%) mdr strains of pseudomonas aeruginosa that were resistant to more than two classes of antibiotics were detected. among 17 mdr strains of pseudomonas aeruginosa 2( 11/8%) and 3(17/64%) had mic reduction of at least 4 times and more for ciprofloxacin and lovofloxacin after cccp effect,respectively.
Conclusion
: the results showed that frequency of mdr pseudomonas aeruginosa are low. for these isolates the efflux pump is not major mechanism for resistance to ciprofloxacin and lovofloxacin antibiotics and further sties about other resistance mechanism is recommended.
