ABSTRACT

Pseudomonas aeruginosa is a nonfermenting Gram-negative bacterium that has minimal nutritional requirements and can survive on a wide variety of surfaces and in aqueous environments. Pseudomonas has numerous reservoirs in the hospital, including sinks, respiratory equipment, cleaning solutions, flowers, and uncooked vegetables, and it occasionally may be recovered from the hands of medical personnel. The pathogenesis of P. aeruginosa may be divided into three stages: bacterial attachment and colonization, local invasion and dissemination, and systemic disease; although disease progression can stop at any stage. The P. aeruginosa isolated from the sputum of patients with cystic fibrosis are commonly mucoid variants that produce the exopolysaccharide alginate. Antibiotic resistance in P. aeruginosa is an increasing problem, posing many therapeutic challenges. Many strains of P. aeruginosa exhibiting beta-lactam resistance reflect a prior exposure of the patients to broad-spectrum beta-lactams. P. aeruginosa is often resistant to a variety of broad-spectrum antimicrobial agents, making it a formidable pathogen.