CFU burden of the recombinant <i>E. coli</i> in tissue cage fluid (TCF) and secreted Gluc activity in TCF correlate to a high degree for the established tissue cage infection.

<p>Mouse tissue cages were inoculated with 10⁵ CFU of the recombinant <i>E .coli</i> strain ML6189 expressing Gluc or the parental <i>E. coli</i> strain ATCC25922. TCF was collected at different time points and analyzed by both CFU plating and measurement of secreted Gluc activity (details seen Experimental Procedures). CPS: photon counts per second. For all panels, the mean value for each group of samples is represented by a black bar. Data from two independent experiments were pooled. (A) CFU burden of ML6189 in TCF at different time points during 18 days of tissue cage infection. (B) CFU burden of ATCC25922 in TCF at different time points along 18 days of tissue cage infection. (C) Secreted Gluc activity in TCF at different time points of ML6189 infection. The red bars represent mean value of the background Gluc signal calculated from data in panel D. Note: for ML6189 infection, 4 mice (day 11) and 5 mice (day 18) were removed from the group for imaging experiments and were excluded from quantification of Gluc activity in TCF (panel C). (D) Secreted Gluc activity in TCF at different time points of ATCC25922 infection.