Fig 3. Responses of neutrophils and macrophages to blocked flea bites without transmission of Y. pestis.

(A and B) two representative examples of confocal images of Lys-eGFP mouse ears after being fed upon for 50 min by Y. pestis pMcherry blocked fleas (left = 2 fleas, right = 4 fleas). Mice were injected with Sytox Blue i.p. prior to flea feeding. Upper panels show t = 0 h and lower panels show t = 4 h. The full time series can be seen in S2 and S3 Videos. Sytox Blue staining was used to identify the flea bite sites (blue, shown in upper panels only). GFP^dim cells are macrophages, GFP^bright cells are neutrophils, the red channel would have shown Y. pestis pMcherry if they were present. The red seen in these images is autofluorescent background of the hair and hair follicles. Scale bar represents 100 μm.