In addition, the B9H01_03990-deficient strain (ΔB9H01_03990) alleviated ZO-1 degradation in hCMEC/D3 cells and BBB disruption in the mouse brain and transwell infection models, whereas the complementary strain CΔB9H01_03990 reversed this reduction in BBB disruption. Here, TJP1 is linked to infection.