Figure 6.

Commensal bacteria populations and inflammatory response in the nose and auditory bulla of EDA pathway deleted mice. (A) Leukocyte numbers in the nasal wash of Edar^dlJ/dlJ and Eda^Ta mice are significantly elevated (see text for details) compared to FVB, Edar^dlJ/+and Junbo mice. (B) Total bacterial load (CFU) in nasal samples are significantly elevated (see text for details) in Edar^dlJ/dlJ (predominately E. coli) and Eda^Ta (predominately Staphylococcus aureus) mice than FVB, Edar^dlJ/+and Junbo mice. (C) Cocci colonies (c) associated with plant foreign body (fb) in the nasopharynx (nd) at the opening of the auditory tube (at) of a 43-week-old Eda^Ta mouse. (D) Total bacterial load in bulla samples was highest in Edar^dlJ/dlJ (predominately E. coli) and Junbo (mixed bacterial isolates, see Supplementary material, Table S1 for bacterial isolate list). (E) Giemsa stained cytology of bulla exudate from an E. coli culture positive 11-week-old Edar^dlJ/dlJmouse shows a foamy macrophage with bacilli (ba); (F) a histology section shows the Gram-negative bacilli (ba) are intracytoplasmic; F4/80 IHC (Vector SG detection kit has a blue-grey chromogen) and Neutral Red counterstain. (G) Bulla foamy macrophages from a 13-week-old Eda^Ta mouse contain lipid bodies; formalin fixed cytology preparation stained with Oil Red O. (A,B,D) The graphs represent data points, the median (that incudes zero values) as a bar, and the ratio above each represents the number of positive samples divided by the total number sampled. Scale bars: 100 µm (C); 20 µm (E,F); 50 µm (G).