Establishment of levofloxacin resistant mouse model

  Objective: To detect the effect of low concentration of levofloxacin on the pneumonia model of Pseudomonas aeruginosa (PA) infection in mice, and to explore the method of levofloxacin resistance. Methods: A model of pneumonia caused by PA-infected mice was used. In each experiment, mice were randomly grouped according to body weight, with different bacterial concentration, number of infections, and administration methods, and the law of changes in mouse body weight and mouse lung index were used as evaluation indicators to analyze The therapeutic effect of levofloxacin and the feasibility of establishing the model were explored. Results Low-concentration levofloxacin had a single infection of PA (1×109cfu/mL) in mice. The lung index of model group 1 and model group 2 were significantly different from the normal group ( P<0.01); There is no significant difference between levofloxacin group 2 and model group 2. Low-concentration levofloxacin has a single infection of PA (1×1010cfu/mL) mice. Compared with the normal group, model group 1 and model group 2 have both Significant difference (P<0.01). There is no significant difference between levofloxacin group 3 and model group 2, and there is no significant difference. Levofloxacin group 1 and 2 can significantly reduce the lung index of the model group; in the experiment of PA repeated infection mice, model group 1 Compared with the model group 2 and the normal group, there is a significant difference (P<0.01). There is no significant difference between the levofloxacin group 2 and the model group 2. In each experiment, the mice weighed more than the normal group on the second day after infection Decrease, the results are not significantly different. Conclusion: Under the experimental conditions, low-concentration levofloxacin single-infected mice with PA (1×1010cfu/mL), and low-concentration levofloxacin repeatedly infected mice with PA, the animal model can simulate the phenomenon of clinical drug resistance to a certain extent 。