Which organism is the causative agent of plague?

Which organism is the causative agent of plague?

• A. Brucella spp
• B. Yersinia pestis
• C. Coxiella burnetii
• D. Bacillus anthracis

Answer: (B)

Plague is caused by Yersinia pestis, a Gram-negative bacterium carried by fleas that feed on infected rodents. It can cause bubonic, septicemic, or pneumonic forms in humans, with virulence factors like the F1 capsule and plasmid-encoded toxins helping the bacterium evade the immune response and spread. The other organisms are associated with different diseases: Brucella species cause brucellosis, Coxiella burnetii causes Q fever, and Bacillus anthracis causes anthrax.

Plague is caused by Yersinia pestis, a Gram-negative bacterium carried by fleas that feed on infected rodents. It can cause bubonic, septicemic, or pneumonic forms in humans, with virulence factors like the F1 capsule and plasmid-encoded toxins helping the bacterium evade the immune response and spread. The other organisms are associated with different diseases: Brucella species cause brucellosis, Coxiella burnetii causes Q fever, and Bacillus anthracis causes anthrax.