【Animal Model】-Establishment and Evaluation of Rat Vaginitis Model

  Objective: To establish a rat model of vaginitis and provide a new model for the development and evaluation of therapeutic agents for vaginitis.

  Method: Separate and purify vaginal samples from clinical patients with Gardnerella vaginalis, Streptococcus albicans and Group B Streptococcus. Gardnerella vaginalis, Streptococcus albicans and Group B Streptococcus strains. 26 female rats were pretreated with estradiol benzoate (20 mg/kg) and streptomycin (10μg each) in the morning, and they were inoculated vaginally in the afternoon, and then another 10 female rats Rats were injected subcutaneously. The normal group of estradiol benzoate (20 mg/kg) was used once a day for 3 days. Before grouping, leucorrhea was collected and vaginal irrigation was performed, and the vaginal mixed bacterial infection of rats was observed. According to body weight and bacterial load (complex metronidazole vaginal suppository 54 mg, once every 5 days), 20 successfully infected rats were randomly divided into model group and drug verification group, with 10 rats in each group. The same amount of 0.9% sodium chloride was injected vaginally into the normal group and the model group. After the last dose, collect vaginal lavage to detect strain load, and collect vaginal discharge for vaginal smear, cleanliness and pH check. Remove the vaginal tissue, and observe the histopathological changes by HE staining.

  Result: The vaginal wall of the model group became thicker, and the stratified squamous epithelial cells showed degeneration, necrosis, and lamina propria hyperemia and edema. Neutrophils are the main cells, lymphocytes and monocytes infiltrate inflammatory cells. In addition, scattered spots are seen in the papillary area, fibroblasts proliferate, and reticular fibers proliferate slightly. The mixed bacterial count, pH value and cleanliness score of the vaginal lavage fluid of the model group were significantly higher than those of the normal group (P\u003c0.01), and the negative conversion rate was significantly reduced (P\u003c0.01). The complex metronidazole vaginal suppository group can significantly reduce the vagina, increase the number of mixed bacteria in the lavage fluid, the pH value and cleanliness score, and the vaginal conversion rate, significantly increase the degree of vaginal tissue lesions, and can be improved.

  Conclusion: After pretreatment of rats with estrogen and streptomycin sulfate injection, mixed bacterial inoculation can establish a rat mixed vaginitis model.