Therapeutic guidelines for Pseudomonas aeruginosa infections.

Pseudomonas aeruginosa nowadays is encountered among the leading pathogen in (i) ICU pneumonia; (ii) nosocomial bacteremia and AIDS primary bacteremia; (iii) iv drug users endocarditis; (iv) exacerbations of cystis fibrosis; (v) malignant external otitis and 'swimmers's ear', and (vi) contact lenses keratitis and traumatic endophthalmitis. The most vulnerable nosocomial hosts are the neutropenics and the mechanically ventilated patients in whom mortality rate exceeds 30%. Virulence of P. aeruginosa is attributed to the elaboration of various enzymes and toxins. There is also worldwide emergence of multiresistant phenotypes to antipseudomonal antibiotics. Therapeutic guidelines should therefore be based on (i) continuous resistance surveillance; (ii) in vitro synergistic interactions of antibacterial agents; (iii) pharmacodynamic properties of antibiotics interpreted by optimal dosing and appropriate frequency of administration; and (iv) current information on the necessity for combination therapy using an aminoglycoside.