Figure 7.

DNA damages and cell death in response to K. pneumoniae 1084S meningitis. (A–C) DNA damages. Brain sections of the 1084-inoculated mice which developed meningitis at 24 h post-intravenous-inoculation (A) and sections of the control (B), and ΔClbA-inoculated mice (C) were stained for γ-H2AX. (D–I) Cell death. Brain sections retrieved from the 1084S-inoculated mice which developed meningitis at 24 h post-intravenous-inoculation (IV) (D), at the 5th day post-intranasal-inoculation (IN) (G), and at the 7th day post-orogastric-inoculation (OG) (H), and the corresponding control (E) and the ΔClbA-inoculated mice (F) were subjected to TUNEL assay (D–H) and the detection of cleaved caspase 3 (I). Representative images are shown. Brown staining indicates a positive reaction with the respective antibody. Scale bar: 50 μm. (J–N) Nuclear alterations of the brain cells in response to K. pneumoniae 1084S meningitis. Karyorrhexis (nuclear fragmentation), pyknosis (nuclear shrinkage), and karyolysis (nuclear fading) are presented in (J–N), respectively. Scale bar: 5 μm. (O) Positive cells for respective antibodies in brain sections were quantified using the HistoQuest software of TissueFAXS plus system (TissueGnostics GmbH). Data represent means ± SEM from three mice per group. An asterisk (^*) represents statistical significance, p < 0.05 (one-tailed) determined by Student's t-test, between 1084S and ΔClbA.