Infection with non-adherent mutants of <i>N. meningitidis</i>.

<p>(A) Bacterial CFU counts from the blood of mice infected with wild type <i>N. meningitidis</i> (WT), an isogenic non-piliated <i>pilD</i> mutant strain (<i>pilD</i>), and a piliated but non-adherent <i>pilC1</i> mutant strain (<i>pilC1</i>). (B) Bacterial counts of biopsies from grafted human skin and contralateral mouse skin of mice infected for 24 h as in (A). (C) 3D reconstruction of human vessel from a grafted mouse infected with the <i>pilD</i> mutant strain (UEA lectin, red). Small amounts of tissue auto-fluorescence and collagen can be seen in the green channel. (D) H&E staining of grafted human skin in a mouse infected with the <i>pilD</i> mutant strain. Arrow highlights very mild inflammation around a vessel. (E) H&E staining of grafted human skin in a mouse infected with the <i>pilC1</i> mutant strain. Arrow highlights signs of congestion in a vessel. (F) Cytokine analysis of human IL-6 in serum of mice grafted with human skin and infected with the WT or mutant strains. (G) Cytokine analysis of human IL-8 in the same mice as (F).