what type of bacteria cause yersinia pestis
Yersinia pestis bacteria can cause three different types of plague: bubonic, septicemic, or pneumonic. In bubonic plague, the most common form, bacteria infect the lymph system and causes it to become inflamed.(The lymph or lymphatic system is a major component of your body's immune system. The organs within the lymphatic system are the tonsils, adenoids, spleen, and thymus.).neumonic Plague. This is the most serious form of plague and occurs when Y. pestis bacteria infect the lungs and cause pneumonia. 1  You get primary pneumonic plague when you inhale plague bacteria from an infected person or animal.