How do we know if a virus or bacteria causes a disease? Would the pneumonic plague be caused by a virus and the bubonic plague by bacteria?
A. The best way to determine whether a disease is caused by a bacterium or a virus is to memorize it from the notes. There is a clue about treatment that can help help remembering. Typically, antibiotics can be used only to treat diseases caused by bacteria. They are ineffective against viruses. With respect to plague, all forms of it are caused by a bacterium that goes by the name of Yersinia pestis.
