Which organism causes anthrax?

Which organism causes anthrax?

• A. Bacillus anthracis
• B. Clostridium botulinum
• C. Yersinia pestis
• D. Staphylococcus aureus

Answer: (A)

Anthrax is caused by Bacillus anthracis, a spore-forming, gram-positive bacillus that persists in soil and can infect animals and humans. The spores enable the bacteria to survive harsh conditions, and infection occurs when they enter the body through skin breaks, inhalation, or ingestion. Inside the host, the bacteria release a tripartite toxin—protective antigen, edema factor, and lethal factor—that disrupts cellular signaling, causes edema, tissue necrosis, and can lead to shock. Clinically, this can present as cutaneous, inhalational, or gastrointestinal disease, with inhalational anthrax being the most severe. This combination of durable spores and a distinctive toxin profile sets Bacillus anthracis apart from other organisms. For contrast, Clostridium botulinum causes botulism via a neurotoxin, Yersinia pestis causes plague, and Staphylococcus aureus leads to various skin, foodborne, and systemic infections, not anthrax.

Anthrax is caused by Bacillus anthracis, a spore-forming, gram-positive bacillus that persists in soil and can infect animals and humans. The spores enable the bacteria to survive harsh conditions, and infection occurs when they enter the body through skin breaks, inhalation, or ingestion. Inside the host, the bacteria release a tripartite toxin—protective antigen, edema factor, and lethal factor—that disrupts cellular signaling, causes edema, tissue necrosis, and can lead to shock. Clinically, this can present as cutaneous, inhalational, or gastrointestinal disease, with inhalational anthrax being the most severe. This combination of durable spores and a distinctive toxin profile sets Bacillus anthracis apart from other organisms. For contrast, Clostridium botulinum causes botulism via a neurotoxin, Yersinia pestis causes plague, and Staphylococcus aureus leads to various skin, foodborne, and systemic infections, not anthrax.