ABSTRACT
Objective At present, the traditional model of urinary tract infection is not only complex in operation process but also easy to be infected, and the model with simple transurethral bacterial injection is not stable enough. This study established a rat model of foreign body-associated urinary tract infection. A spiral polyethylene tube (PT) was placed transurethrally into the bladder by transurethral inoculation with extended-spectrum β-lactamases-producing Escherichia coli (ESBLs E.coli).Methods SD female rats were randomly divided into blank control group, no foreign body groups at 7d and 14d, foreign body groups at 7d and 14d. ESBLs E.coli was injected transurethrally by foreign body into the bladder in foreign body groups. The same volumes of ESBLs E.coli and sterile saline were injected respectively in no foreign body and blank groups. Examination was made on bilateral renal gravity index, the numbers of white blood cells and neutrophils, the bacteriological and pathological changes in urine and kidney.Results The bilateral renal gravity index, the percentage of neutrophils and and the positive rates of renal and urine bacteria culture in foreign body groups at 7d and 14d were significantly higher than those in blank control group and no foreign body groups(P＜0.05). The number of white blood cells in foreign body group at 7d was significantly higher than those of blank control and no foreign body group(P＜0.05). The positive rates of renal and urine bacteria culture were 100% in the foreign body groups at 7d and 14d. The positive rate of urine bacteria culture in no foreign body at 7d was 33.3%. Under the light microscope, there were inflammatory changes in the kidney and bladder tissues of the rats in foreign body groups, and a few fibrous tissues were formed around glomeruli in foreign body group at 14d.Conclusion The establishment of a highly successful and stable rat model of urinary tract infection can be successfully achieved by injection of ESBLS E.coli through transurethral foreign body placed in bladder.