Figure 1.

Workflow of identification of the biomarkers for rickettsial infection and the severity of infection. The biomarker development workflow has three steps, each indicated in the arrows. In step 1, the potential protein markers for Rickettsia conorii infection were identified via proteomics profiling of the secretome of human umbilical vein endothelial cells (HUVECs) infected with R. conorii. In step 2, the presence of the secretome markers in the plasma was verified using a mouse model of rickettsial infection, and the potential markers for the severity of rickettsia infection were identified via proteomics profiling of the plasma from the animals with different doses of R. conorii. In step 3, the protein markers identified in steps 1 and 2 were verified using the plasma from patients with rickettsia infection. LD, lethal dose; SLD, sublethal dose. RC0497, putative N-acetylmuramoyl-L-alanine amidase RC0497.