2.2 Bacterial strains,animals and materials
Experiments were performed with the strains listed in Table S2 (Supplementary materials). Materials for DNA manipulation were purchased from Takara Bio (China). Other chemicals were of analytical grade supplied by Sinopharm Chemical Reagent (China). Mice (Balb/C, male, 6-weeks old) were purchased from the Laboratory animal center in our University, Wuhan, China.