In the USA, PM accounts for about 3% of all hospital infections and 44% of CAUTI. PM is a common cause of complicated UTI in patients with anatomical or functional abnormalities of the urinary tract, particularly in patients with long-term indwelling catheters, who may develop catheter-associated UTI (CAUTI).
It is an opportunistic pathogen that accounts for <0.005% of the human intestinal flora in healthy subjects. PM is widely distributed in the environment, mainly in water, soil, and human and animal gastrointestinal tracts. PM, originally discovered in 1885 by Hauser, is a kind of motile Gram-negative bacteria in the Enterobacteriaceae family due to the growth of a solid surface and its shape which can show a sharp change from short rod “swimming” cell differentiation for the expression of thousands of flagella and highly elongated cell “group”, it was named after a Greek god. However, complicated UTIs, especially those caused by Proteus mirabilis (PM), pose increasing medical challenges. UTI caused by Escherichia coli and others has been extensively studied. Uncomplicated UTI usually affects other aspects of patients without urinary tract structural or neurological abnormalities complicated UTI is defined as an infection associated with hazards to the urinary tract or host immune factors, including urinary obstruction, urinary retention due to neurological diseases, immunosuppression, renal failure, kidney transplantation, pregnancy, and presence of foreign bodies such as stones, indwelling catheters, or other drainage devices. UTI is divided clinically into uncomplicated and complicated UTI. Urinary tract infection (UTI) is one of the most common bacterial infections, and in the world, each year about 150 million people are affected by this it is an important cause of infection in male infants of all ages and elderly men and women and can cause serious complications, including frequent recurrence of infection, pyelonephritis with sepsis, infant kidney injury, premature delivery, and complications from frequent use of antibiotic drugs (such as severe antibiotic resistance and Clostridium difficile infection). In this review, we discuss how PM is mediated by a catheter into the urethra, bladder, and then rose to the kidney causing UTI and the main virulence factors associated with different stages of infection, including flagella, pili or adhesins, urease, hemolysin, metal intake, and immune escape, encompassing both historical perspectives and current advances. This leads to catheter encrustation and blockage and, in most cases, is accompanied by urine retention and ascending UTI, causing cystitis, pyelonephritis, and the development of bladder or kidney stones, or even fatal complications such as septicemia and endotoxic shock. Clinically, PM can form a crystalline biofilm on the outer surface and inner cavity of the urethral indwelling catheter owing to its ureolytic biomineralization.
PM is the main pathogen causing complicated urinary tract infections (UTIs), especially catheter-associated urinary tract infections.
Proteus mirabilis (PM) is a Gram-negative rod-shaped bacterium and widely exists in the natural environment, and it is most noted for its swarming motility and urease activity.