Yersinia pestis -animated quick review
Yersinia pestis is a gram negative coccobacillus that can cause pneumonia, septicemia, and the bubonic plague. This organism is widely believed to be responsible for the death of approximately one third of the European population between 1347 and 1353. Today, the reservoir for this organism is several species of rodents including the black-tailed prairie dog, commonly found in the Southwest region, and transmitted via the flea vector. There have been several incidents of human transmission in people exposed to these animals. Pathogenesis includes several factors that allow the bacteria to suppress and avoid the normal immune response including an anti-phagocytic polysaccharide capsule and anti-phagocytic F1 and VW antigens that inhibit macrophages. Yersinia pestis is known to proliferate inside lymph nodes, causing lymphadenopathy and buboes, most frequently involving the inguinal lymph nodes.
The term buboes gave rise to the name the bubonic plague. The organism could also get into the lungs causing a severe pneumonia with symptoms of chest pain, dyspnea, and hemoptysis. If the organism gets into the bloodstream, it can cause septicemic plague with complications of disseminated intravascular coagulation (DIC). Widespread DIC causes destruction of the blood vessels and results in black cutaneous hemorrhagic lesions on the skin. Many historians believe these lesions gave rise to the name “Black Death.”.
Yersinia pestis is a gram negative coccobacillus that can cause pneumonia, septicemia, and the bubonic plague. This organism is widely believed to be responsible for the death of approximately…By: Rewise MD