Bioterrorism Agents — MCQs

Bioterrorism Agents Indian Medical PG Practice Questions and MCQs

Question 21: Capsule of Bacillus anthracis is formed of:

A. Polysaccharide
B. Lipopolysaccharide
C. Long chain fatty acids
D. Polypeptide (Correct Answer)

Explanation: ***Polypeptide*** - The capsule of *Bacillus anthracis* is unique among bacteria as it is composed of **poly-D-glutamic acid**, a polypeptide. - This polypeptide capsule is a major **virulence factor**, protecting the bacterium from phagocytosis by host immune cells. *Polysaccharide* - Most bacterial capsules are composed of **polysaccharides**, which are long chains of sugar molecules. - While common in other bacteria, this is not the composition of the *Bacillus anthracis* capsule. *Lipopolysaccharide* - **Lipopolysaccharide (LPS)** is a major component of the outer membrane of **Gram-negative bacteria** and acts as an endotoxin. - *Bacillus anthracis* is a **Gram-positive bacterium** and does not possess LPS in its capsule or cell wall. *Long chain fatty acids* - **Fatty acids** are primarily components of lipids and membranes, not typically the main structural component of an entire bacterial capsule. - While lipids are part of bacterial cell structures, they do not form the protective capsule of *Bacillus anthracis*.

Question 22: Wool-sorter's disease is caused by which of the following?

A. Vibrio cholerae
B. Pseudomonas aeruginosa
C. Coxiella burnetii
D. Bacillus anthracis (Correct Answer)

Explanation: **Bacillus anthracis** - **Wool-sorter's disease** is the historical name for the **inhalational form of anthrax**, caused by inhaling spores of *Bacillus anthracis*. - This form of anthrax primarily affects the lungs and can lead to severe, often fatal, pneumonia. - The disease was named after workers in the wool industry who developed anthrax from handling contaminated animal hides and wool. *Pseudomonas aeruginosa* - *Pseudomonas aeruginosa* is a common opportunistic pathogen associated with **hospital-acquired infections**, especially in immunocompromised individuals. - It causes a wide range of infections, including pneumonia, but is not linked to wool-sorter's disease. *Vibrio cholerae* - *Vibrio cholerae* is the bacterium responsible for **cholera**, an acute diarrheal illness. - It is transmitted through **contaminated water or food** and causes severe dehydration, not respiratory disease. *Coxiella burnetii* - *Coxiella burnetii* causes **Q fever**, which is primarily transmitted through inhalation of aerosols from infected animals. - While it can cause pneumonia, it is a distinct disease from anthrax and is not referred to as wool-sorter's disease.

Question 23: What organism is associated with the Fadyean reaction?

A. Clostridium perfringens
B. Clostridium botulinum
C. Bacillus cereus
D. Bacillus anthracis (Correct Answer)

Explanation: ***Bacillus anthracis*** - The **Fadyean reaction** (also called **M'Fadyean reaction**) is a specific diagnostic test used to identify **Bacillus anthracis** in blood or tissue smears. - It involves staining with **polychrome methylene blue** (Loeffler's methylene blue), which reveals *B. anthracis* bacilli surrounded by a **pink/purple capsule** against a blue background. - This capsule demonstration is characteristic of *B. anthracis* and is particularly useful for diagnosing **anthrax** in animals. - Note: This is different from the "string of pearls" test, which uses penicillin to induce characteristic morphological changes. *Clostridium perfringens* - This organism is known for causing **gas gangrene** and **food poisoning**, often identified by its characteristic **double zone of hemolysis** on blood agar (also called Nagler's reaction). - It does not exhibit capsule formation demonstrable by the Fadyean reaction. *Clostridium botulinum* - This bacterium is primarily associated with **botulism**, a severe neuroparalytic disease caused by its potent neurotoxins. - Identification typically involves **toxin detection assays** (mouse bioassay) rather than capsule staining techniques. *Bacillus cereus* - **Bacillus cereus** is a common cause of **food poisoning**, producing toxins that lead to emetic or diarrheal syndromes. - While it is a *Bacillus* species, it **does not produce a capsule** and therefore cannot be identified using the Fadyean reaction.

Practice by Chapter

Classification of Bioterrorism Agents

Practice Questions

Anthrax as a Bioweapon

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Smallpox and Other Viral Agents

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Botulinum Toxin

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Plague as a Bioweapon

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Tularemia

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Viral Hemorrhagic Fevers

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Laboratory Diagnosis of Bioterrorism Agents

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Public Health Response to Bioterrorism

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Biosafety and Biosecurity

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Medical Management of Bioterrorism Victims

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Bioterrorism Preparedness

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