Les mécanismes d'efflux et la résistance chez Pseudomonas aeruginosa

Pseudomonas aeruginosa is a nosocomial and community-acquired pathogen associated with considerable patient morbidity and mortality. Multidrug resistance in P. aeruginosa is a concern owing to the limited therapeutic options available to treat infections due to this organism. The continuous dissemination of «multi-drug resistant» (MDR) bacteria drastically reduces the efficacy of our antibiotic “arsenal” and consequently increases the frequency of therapeutic failure. In Pseudomonas aeruginosa MDR bacteria the over-expression of efflux pumps, as MexAB-OprM, expel structurally-unrelated antibiotics decreasing their intracellular concentration. Several clinical data indicate an increasing contribution of efflux pumps in the emergence and dissemination of resistant Gram-negative bacteria. It is necessary to clearly define the molecular and genetic bases of the efflux pump in order to understand the translocation of antibiotic molecules through the efflux transporter and to combat this mechanism.