Proteus (bacterium)
Proteus is a genus of Gram-negative bacteria. It is a rod shaped, aerobic and motile bacteria, which is able to migrate across surfaces due its “swarming†characteristic in temperatures between 20 and 37 °C.[1] Their size generally ranges from 0.4 to 0.8 μm in diameter and 1.0–3.0 μm in length. They tend to have an ammonia smell.[2] Proteus bacilli are widely distributed in nature as saprophytes, being found in decomposing animal matter, sewage, manure soil, the mammalian intestine, and human and animal feces. They are opportunistic pathogens, commonly responsible for urinary and septic infections, often nosocomial.
For other uses, see Proteus (disambiguation).The term Proteus signifies changeability of form, as personified in the Homeric poems in Proteus, "the old man of the sea", who tends the sealflocks of Poseidon and has the gift of endless transformation. The first use of the term “Proteus†in bacteriological nomenclature was made by Hauser (1885), who described under this term three types of organisms which he isolated from putrefied meat.
Clinical significance[edit]
Three species—P. vulgaris, P. mirabilis, and P. penneri—are opportunistic human pathogens. Proteus includes pathogens responsible for many human urinary tract infections.[3] P. mirabilis causes wound and urinary tract infections. Most strains of P. mirabilis are sensitive to ampicillin and cephalosporins. P. vulgaris is not sensitive to these antibiotics but ticarcillin. However, this organism is isolated less often in the laboratory and usually only targets immunosuppressed individuals. P. vulgaris occurs naturally in the intestines of humans and a wide variety of animals, and in manure, soil, and polluted waters. P. mirabilis, once attached to the urinary tract, infects the kidney more commonly than E. coli. P. mirabilis is often found as a free-living organism in soil and water.
About 10–15% of kidney stones are struvite stones, caused by alkalinization of the urine by the action of the urease enzyme (which splits urea into ammonia and carbon dioxide) of Proteus (and other) bacterial species.
Cheese makers have found Proteus bacterium's species Proteus vulgaris, growing on cheese rinds in purple color, making the cheese inedible. It is successful in implanting itself in a complex cheese ecosystem and substantially contributed to the organoleptic properties of cheese during ripening. It does not interact well with other bacteria in the same ecosystem.[12]
See also