These infections are common in long-term catheterized patients, such as those who reside in nursing homes and chronic care facilities, and may be of particular danger to spinal cord injury patients ( 10). While the bacterium is capable of causing a variety of human infections, including those of wounds, the eye, the gastrointestinal tract, and the urinary tract, it is most noted for infections of the catheterized urinary tract, known as catheter-associated urinary tract infections (CAUTI) ( 4– 9). mirabilis can be found in a wide variety of environments, including soil, water sources, and sewage, but it is predominantly a commensal of the gastrointestinal tracts of humans and animals ( 2, 3). However, one group recently created a reconstructed phylogenetic tree based on shared core proteins, ribosomal proteins, and four multilocus sequence analysis proteins, and has proposed that the order Enterobacteriales be reclassified, placing Proteus within a new Morganellaceae family ( 1). mirabilis belongs to the class Gammaproteobacteria, and has long been recognized as a member of the order Enterobacteriales, family Enterobacteriaceae. Proteus mirabilis, a Gram-negative rod-shaped bacterium, is well-known for its urease production and distinctive ability to differentiate into elongated swarm cells and characteristic bull’s-eye pattern of motility on agar plates. A comprehensive review of factors associated with urinary tract infection is presented, encompassing both historical perspectives and current advances. Vaccines, using MR/P fimbria and its adhesin, MrpH, have been shown to be efficacious in the murine model. Global gene expression studies carried out in culture and in the murine model have revealed the unique metabolism of this bacterium. The pathogenesis of infection, including assessment of individual genes or global screens for virulence or fitness factors has been assessed in murine models of ascending UTI or CAUTI using both single-species and polymicrobial models.
During infection, histological damage is caused by cytotoxins including hemolysin and a variety of proteases, some autotransported. When swarms from different strains meet, a line of demarcation, a “Dienes line”, develops due to the killing action of each strain’s type VI secretion system. mirabilis undergoes a morphological conversion to a filamentous swarmer cell expressing hundreds of flagella. Motility is mediated by flagella encoded on a single contiguous 54 kb chromosomal sequence. Repressors of motility are often encoded by these fimbrial operons. Adherence of the bacterium to epithelial and catheter surfaces is mediated by 17 different fimbriae, most notably MR/P fimbriae. These infections may be accompanied by urolithiasis, development of bladder or kidney stones due to alkalinization of urine from urease-catalyzed urea hydrolysis. Proteus mirabilis, a Gram-negative rod-shaped bacterium most noted for its swarming motility and urease activity, frequently causes catheter-associated urinary tract infections (CAUTI) that are often polymicrobial.