【Animal modeling】-Escherichia coli-induced bacterial prostatitis animal model

  [Modeling mechanism] The main way for bacteria to enter the prostate is inflammation, edema or obstruction of the lower urethra, which will increase the pressure of the urethra and make the urine containing bacteria return to the ducts and acinars of the prostate. Alternatively, bacteria in the rectum can spread to the prostate through the lymphatic vessels, or reach the prostate through the bloodstream.

  [Modeling method] Rabbit, mouse, rat. Standard E. coli strain (ATCC25922). A set of conventional surgical instruments.

  1. After the animals are anesthetized with ether through the prostate injection, under aseptic conditions, cut the lower abdominal wall along the midline of the abdomen and bladder, and gently lift the two seminal vesicles with forceps and place them in the seminal vesicles. It exposes the dorsal lobe of the attached prostate (equivalent to the outer edge of a person). Human prostatitis mainly occurs in the surrounding area), inject 0.1 ml of each E. coli solution on both sides, suture the abdominal muscle skin, wrap it with sterile gauze, and return to the cage. You can eat and drink freely. The acute prostatitis caused by this model becomes most obvious within 1-3 days.

  2. Urethral perfusion: single and repeated perfusion: the standard pathogenic Escherichia coli is cultured in an incubator at 37°C for 18 hours before use, and a bacterial solution of 150 x 100 million CFU/ml is prepared in sterile saline. Fix the back of the experimental animal, raise the buttocks, insert a 10 Fr (human) 3 compartment 2 cystic ureter into the bladder under aseptic conditions, inject 5 ml of water into the bladder balloon after emptying, and pull the balloon outward The urethral balloon is infused into the bladder by injecting 2 ml of water, and 2.5 ml of bacterial solution is injected into it. 72 hours after the rabbit was infected, a model of acute bacterial prostatitis was formed. If the perfusion is repeated, it will be perfused once a day 3 days before the experiment, then 10, 20, 30, 40, 55 days. Animals were sacrificed 72 hours after the last perfusion to identify bacterial cultures and pathological observations.

  3. Observation indicators include whether there is hyperemia, edema, bleeding or adhesion in the prostate tissue, the number of white blood cells and lecithin bodies in the prostate fluid, and the pathological observation of the prostate. [Characteristics of the model] Injection of a single bacterial solution will cause acute inflammation in the first 3 days, and in the following 7 weeks, about 50% of the rats will spontaneously eliminate prostate bacteria without developing CBP. Do it. The prostate showed acute inflammation within 2 weeks in the solution, while the prostate showed chronic inflammatory lesions after 8 weeks. Acute inflammation is manifested by hyperemia and edema of the prostate. In the chronic stage, pathological observations show that the glandular epithelium is flat, cubic and highly cylindrical, glandular secretion is reduced, interstitial lymphocyte infiltration and fibroblast proliferation. The white blood cell count and lecithin count in the prostate fluid were both higher than the normal range. [Model Evaluation and Application] Both models can establish bacterial prostatitis models. The latter has a nearly clinical cause, with obvious hyperemia and edema of the prostate tissue, and pus-like viscous prostate fluid. A large number of neutrophils and monocytes were found in the matrix. Since this model is caused by bacterial infection, it can be used for antibacterial testing and pharmacodynamic verification, as well as anti-infection and analgesic testing.