Bioterrorism Agents — MCQs

Q: The virulence of Bacillus anthracis is mediated by two key plasmid-encoded factors. Which of the following is the correct biochemical composition?

pXO1 poly-D-glutamate capsule. ***pXO2–encoded poly-D-glutamate capsule and pXO1-encoded anthrax toxin*** - The virulence of *Bacillus anthracis* depends on two main plasmids: **pXO1**, which encodes the **three-part exotoxin** (lethal factor, edema factor, and protective antigen), and **pXO2**, which encodes the **poly-D-glutamate capsule**. - The **poly-D-glutamate capsule** is unique among bacteria because it is polypeptide-based rather than polysaccharide-based, which helps the organism evade **phagocytosis**. *pXO1 polysaccharide capsule* - The **capsule** of *Bacillus anthracis* is encoded by the **pXO2 plasmid**, not pXO1. - The capsule is biochemically composed of **poly-D-glutamic acid** (a polypeptide), not carbohydrates or polysaccharides. *pXO2 polysaccharide capsule* - While the **pXO2 plasmid** is correctly identified as the carrier for the capsule genes, the biochemical composition is incorrect. - The capsule is a **polypeptide** (poly-D-glutamate), providing protection against host immune surveillance. *pXO2 poly-D-glutamate capsule and pXO1 exotoxin* - Note: The option provided in the list (pXO2 poly-D-glutamate capsule) is biologically accurate in its description of the capsule, but the question asks for the complete biochemical composition implied by the plasmids listed. - This choice is an incorrect distracter based on the specific mapping of plasmid functions; **pXO1 carries toxins** (lethal factor, edema factor, and protective antigen) while **pXO2 carries the capsule** genes.

Practice by Chapter

Classification of Bioterrorism Agents

Practice Questions

Anthrax as a Bioweapon

Practice Questions

Smallpox and Other Viral Agents

Practice Questions

Botulinum Toxin

Practice Questions

Plague as a Bioweapon

Practice Questions

Tularemia

Practice Questions

Viral Hemorrhagic Fevers

Practice Questions

Laboratory Diagnosis of Bioterrorism Agents

Practice Questions

Public Health Response to Bioterrorism

Practice Questions

Biosafety and Biosecurity

Practice Questions

Medical Management of Bioterrorism Victims

Practice Questions

Bioterrorism Preparedness

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Scan to download app