Pseudomonas aeruginosa: Résistance et options thérapeutiques à l'aube du deuxième millénaire

Objectives. To present to the clinician an overview of the pathologies caused by P. aeruginosa (clinical manifestations, antibiotic resistance, diagnostic, present and future therapeutic options) based on an analysis of the recent literature and on the opinions of specialists. Main Points. Pseudomonas aeruginosa can cause a variety of nosocomial infections and can invade almost all anatomical sites (with a preference for the respiratory tract, especially in cystic fibrosis patients). Resistance is frequent and can be native (constitutive expression of β-lactamases and/or efflux pumps; low permeability of the outer membrane), but also acquired (genes coding for antibiotic-degrading enzymes, overexpression of efflux pumps, decreased permeability of porins, target mutations). These mechanisms often confer upon the organism a multiresistance phenotype, making susceptibility testing essential. The initial empiric treatment will most often be a combined therapy, based on local epidemiology (typically a β-lactam plus an aminoglycoside or a fluoroquinolone). This treatment will need to be readjusted as soon as possible based on susceptibility determinations, optimized use of the antibiotics selected, and clinical outcome. Colistin is useful when dealing with multiresistant isolates. Therapeutic innovations remain scarce. Conclusions. Infections caused by P. aeruginosa are potentially frightening. Treatment requires a correct diagnostic and rests upon a rational selection of antibiotics, the sue for which must be optimized on pharmacodynamic basis. © 2007. Elsevier Masson SAS