Salmonella species are non-spore-forming, predominantly motile enterobacteria with cell diameters between about 0. 7 and 1. 5 µm, lengths from 2 to 5 µm, and peritrichous flagella (all around the cell body). They are chemotrophs, obtaining their energy from oxidation and reduction reactions using organic sources. They are also facultative anaerobes, capable of generating ATP with oxygen ("aerobically") when it is available, or when oxygen is not available, using other electron acceptors or fermentation ("anaerobically"). S. enterica subspecies are found worldwide in all warm-blooded animals and in the environment. S. bongori is restricted to cold-blooded animals, particularly reptiles.