The disease is caused by a microorganism and several bacteria have been suspected of being responsible.
Staphylococcus pyogenes aureus—a microorganism producing yellow pus.
Staphylococcus pyogenes citreus—a microorganism producing lemon-colored pus.
Staphylococcus pyogenes albus—a microorganism producing white pus.
This disease is caused by a microorganism known as the spirochaeta pallida or treponema pallidum of Schaudinn and Hoffmann.
A microorganism which apparently has a specific relationship to Rocky Mountain spotted fever.