Urinary tract infection (urinarytractinfection, UTI) refers to the growth and reproduction of the pathogen in the urinary tract, urinary tract and invading the mucosa or tissue caused by inflammation, is one of the most common infection of bacterial infection. Infection of upper urinary tract infection and urinary tract infection, urinary tract infection refers to pyelonephritis urethritis and cystitis, including urinary tract infection, urinary tract infection more than 95% are caused by single bacteria. The pathogenic Escherichia coli, the bacterium serotype is 140 kinds, one is caused by the bacterium Escherichia coli isolated from urine and feces of patients with type of Escherichia coli, found in the asymptomatic bacteriuria or urinary tract infection. No complications of Proteus, gas bacillus coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Streptococcus in re infection, indwelling catheter, complication of urinary tract infection. Candida albicans, model Cryptococcal infection found in diabetes and use of corticosteroids and immunosuppressive drugs and patients after renal transplantation. Staphylococcus aureus in skin trauma and drug addicts due to bacteremia or sepsis. Virus, mycoplasma infection is rare in recent years has gradually increased trend. A variety of bacterial infection in indwelling catheter, neurogenic bladder stones, congenital malformation and intestinal tract, vagina, urethral fistula.