Proteus

Abstract

Bacteria of the genus Proteus commonly are encountered in nature and frequently are associated with humans where they act as opportunistic pathogens and cause a variety of infections. They belong to the tribe Proteeae (other genera include Morganella and Providencia) in the family Enterobacteriaceae. The genus Proteus has four species: Proteus mirabilis, Proteus vulgaris (formerly known together as Proteus hauseri), Proteus penneri, and Proteus myxofaciens. Certain members of Proteus spp. are pathogenic for humans and P. mirabilis is the most frequently encountered and responsible for 70–90% of human infections. The common site of Proteus infection in humans is the urinary tract and P. mirabilis frequently is implicated with urinary tract infections. Proteus urinary tract infections are common in young boys and the elderly. The presence of Proteus spp. in food suggests that it has been prepared or stored improperly or contaminated with fecal material after cooking. Cells of Proteus spp. are sensitive to heat and are killed readily by moist heat at 55 °C for 1 h, by common disinfectants such as halogens, ozone, and formaldehyde, and by ultraviolet and γ irradiation. This article outlines the role of Proteus and other related organisms in food and food spoilage and as enteropathogens. Furthermore, this chapter presents the methods to isolate, identify, and, if necessary, type Proteus isolates.