Pseudomonas aeruginosa is a member of the family Pseudomonadaceae . The family includes the Pseudomonas species along with the Xanthomonas which together embody the informal group of bacteria known as the Pseudomonads . These are Gram-negative rods that are motile by way of a single polar flagella.
Pseudomonads are oxidase and catalase positive.
Pseudomonads have very diverse metabolic capabilities and can grow on a wide range of carbon sources. However, they are very susceptible to drying, making airborne spread less likely. Pseudomonads are ubiquitous and typically free-living in environmental habitats such as water, soil, and vegetation. Pseudomonads are generally known as plant pathogens as demonstrated by Pseudomonas solanacearum , which infects over 200 different plants worldwide, including many important crops. However, four species of Pseudomonas are pathogens of humans.