Color enhanced Scanning Elctron Micrograph (SEM) of Pseudomonas aeruginosa, a versatile gram-negative bacterium that grows in soil, marshes, and coastal marine habitats, as well as on plant and animal tissues. Pseudomonas aeruginosa is rod-shaped bacterium that can cause disease in plants and animals, including humans. A species of considerable medical importance, P. aeruginosa is a multidrug resistant pathogen recognised for its ubiquity, its intrinsically advanced antibiotic resistance mechanisms, and its association with serious illnesses, hospital-acquired infections such as ventilator-associated pneumonia and various sepsis syndromes. The organism is considered opportunistic insofar as serious infection often occurs during existing diseases or conditions. Magnification: unknown.