Pseudomonas aeruginosa is a Gram-negative bacterium commonly found in soil and ground water. It rarely affects healthy people and most community-acquired infections are associated with prolonged contact with contaminated water.
Photo: Janice Carr/CDC
P. aeruginosa is increasingly important clinically as it is a major cause of both healthcare-associated infections and chronic lung infections in people with cystic fibrosis.
Although P. aeruginosa is an opportunistic pathogen (i.e. more likely to infect those patients who are already very sick as opposed to healthy patients), it can cause a wide range of infections, particularly among immunocompromised people (HIV or cancer patients) and persons with severe burns, diabetes mellitus or cystic fibrosis.
P. aeruginosa is one of the more common causes of healthcare-associated infections and is increasingly resistant to many antibiotics. In hospitals the organism contaminates moist/wet reservoirs such as respiratory equipment and indwelling catheters and infections can occur in almost every body site but are particularly serious in the bloodstream (bacteraemia).
Most infections are susceptible to third generation cephalosporins (ceftazidime), carbapenems (imipenem and meropenem), aminoglycosides (gentamicin and tobramycin) and colistin. Serious infections are usually treated with ticarcillin or piperacillin (both broad-spectrum penicillins), often in combination with an aminoglycoside. Experimental vaccines currently undergoing clinical testing may be particularly helpful for patients with cystic fibrosis.
DH guidance from Chief Medical Officer [external PDF] issued February 2012
DH Advice for healthcare settings [external link] issued March 2013