Pseudomonas are ubiquitous and are found worldwide. They arefound in soil, vegetations, water, plants, and animals with a predilection to moist environments. They are also commonly found in hospital environment. They are opportunistic patho-gens often causing hospital or nosocomial infections. These organisms are notorious because of the potency to develop innate resistance to many antibiotics.
P. aeruginosa is the most important species associated withhuman infection. It is a most common human saprophyte, but it rarely causes disease in healthy individuals. P. aeruginosa causes most of human infections in immunocompromised human host.