Proteus (bacterium) - Clinical Significance

Clinical Significance

Three species — P. vulgaris, P. mirabilis, and P. penneri — are opportunistic human pathogens. Proteus includes pathogens responsible for many human urinary tract infections. 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. 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 spp.