Figure 6.

Morphological variation in bacterial extracellular matrix apparently specific to biofilm microcolonies in mice gavaged with a small, TnSeq-derived mutant pool of 11 E. faecalis. (A) E. faecalis microcolonies attached to murine colonic epithelium. Under higher magnification, the foreground cluster (white filled squares; higher magnification in B) appears to have a rougher, less voluminous extracellular matrix compared to the background microcolony ECM (white open diamonds; higher magnification in C). Additional examples of other areas of the colon exhibit the same duality (D, E). Murine colon colonized by the parental OG1RF E. faecalis strain only appears to form the classic ECM form predominantly seen in (C) – compare with Figure 4E. Bars: A - C = 5 µm; D, E = 30 µm.