sentences:  Bacterial small RNAs play critical roles in virulence and stress/adaptation responses.Although their specific functions have not been discovered in "Rickettsia", few studies showed the expression of novel sRNA in human microvascular endothelial cells (HMEC) infected with "Rickettsia".The genus "Rickettsia" is named after Howard Taylor Ricketts (1871–1910), who studied Rocky Mountain spotted fever in the Bitterroot Valley of Montana, and eventually died of typhus after studying that disease in Mexico City.