Proteus (bacterium)

Proteus is a genus of Gram-negative Proteobacteria, which includes pathogens responsible for many human urinary tract infections. Proteus species do not usually ferment lactose, but have shown to be capable lactose fermenters depending on the species in a TSI test, Triple Sugar Iron. Since it belongs to the family of Enterobacteriaceae, general characters are applied on this genus: It is oxidase-negative, but catalase- and nitrase-positive. Specific tests include positive urease (which is the fundamental test to differentiate Proteus from Salmonella) and phenylalanine deaminase tests. On the species level, indol is considered reliable, as it is positive for Proteus vulgaris but negative for Proteus mirabilis. Some species are motile.

Pathogenesis