Plague Bacterium

Plague is an infectious disease caused by the Gram-negative, bipolar-staining bacterium called Yersinia pestis. Naturally occurring plague is most often acquired by the bite of a flea that had previously fed on infected rodents. In such cases, plague classically presents as a localized abscess with secon dary formation of very large, fluctuant regional lymph nodes known as buboes (bubonic plague).

Plague may also be transmitted via aerosol and by inhalation of sputum droplets from...