[Animal modeling] - Comparison of the application of two mycobacterium tuberculosis culture methods in the infection model experiment of tuberculosis mice

  Objective: To simultaneously verify the therapeutic effect of rifampicin in the tuberculosis infected mouse model by using two mycobacterium tuberculosis culture methods, and to explore the application value of BACTEC MGIT960 culture system in the tuberculosis infected mouse model

  Methods: The experiment was divided into BACTEC MGIT 960 culture group and L-J culture group, and 1.0 × Thirty six C57BL/6 female mice were infected with 106CFU/mLH37Rv bacterial solution. One week after infection, 18 mice were treated with rifampicin for four weeks, and 18 mice were injected with the same amount of phosphate buffer solution (PBS) as the control. The lung, spleen and liver homogenate of 36 mice were cultured with BACTECMGIT960 rapid culture and Roche culture methods

  Results: With BACTE CMGIT 960 culture method, the positive reporting time of liver, lung and spleen tissue cultures in the RIF treatment group was (187.11 ± 10.20) h, (347.22 ± 12.70) h, (276.39 ± 13.09) h, and that in the control group was (142.50 ± 11.70) h, (251.67 ± 16.63) h, (230.28 ± 7.22) h, respectively, with significant difference (P<0.001); By Roche culture method, the bacterial load of liver, lung and spleen tissues in RIF treatment group was (5.15 ± 0.15) log10CFU, (3.30 ± 0.23) log10CFU, (3.40 ± 0.25) log10CFU respectively, and the bacterial load of control group was (5.90 ± 0.25) log10CFU, (3.88 ± 0.31) log10CFU, (4.15 ± 0.30) log10CFU respectively, with significant difference between groups (P<0.001)

  Conclusion: BACTEC MGIT 960 culture method and Roche culture method were used to detect the bacterial load, and the culture results were consistent, but the time of positive results detected by the former was shortened by half on average, and the differentiation was also high, indicating that BACTEC MGIT 960 culture method had more advantages in the detection of bacterial load in animal models, and could be applied to the detection of bacterial load in animal models of tuberculosis infection