Bioterrorism Agents Practice Questions

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.

Q: All of the following statements about Glanders are false except?

Belongs to class B bioterrorism agents according to CDC.. **Explanation:** **Glanders** is a serious zoonotic disease caused by the Gram-negative bacterium ***Burkholderia mallei***. It primarily affects horses, mules, and donkeys. **Why Option D is Correct:** The CDC categorizes bioterrorism agents into three classes (A, B, and C) based on their potential for dissemination and severity. **Class B agents** are the second highest priority; they are moderately easy to disseminate, result in moderate morbidity rates, and low mortality rates. *Burkholderia mallei* (Glanders) and *Burkholderia pseudomallei* (Melioidosis) are both classified as **Category B** agents. **Why the other options are Incorrect:** * **Option A:** Glanders is **not** a mild, self-limited illness. It is a severe, often fatal disease characterized by pneumonia, bloodstream infections (sepsis), and chronic localized infections in the skin and muscle. * **Option B:** Glanders is caused by ***Burkholderia mallei***, not *Brucella*. *Brucella* causes Brucellosis (undulant fever). * **Option C:** Human infection **can** be acquired from infected animals. It is a zoonosis transmitted through direct contact with infected animal tissues, secretions, or inhalation of infectious aerosols. **High-Yield NEET-PG Pearls:** * **Causative Agent:** *Burkholderia mallei* (Non-motile, unlike *B. pseudomallei* which is motile). * **Strauss Reaction:** A classic diagnostic test where intraperitoneal inoculation of infected material into male guinea pigs causes severe orchitis (scrotal swelling). * **Mallein Test:** A skin test used in veterinary medicine to detect Glanders in horses. * **Category A Agents (The "Big Six"):** Anthrax, Botulism, Plague, Smallpox, Tularemia, and Viral Hemorrhagic Fevers (Ebola/Marburg). Remember these for contrast!

Q: Tularemia belongs to which category of bioterrorism agents?

Category A. **Explanation:** The Centers for Disease Control and Prevention (CDC) classifies bioterrorism agents into three categories (A, B, and C) based on their potential for public health impact, ease of dissemination, and requirement for special public health preparedness. **1. Why Category A is Correct:** **Tularemia** (caused by *Francisella tularensis*) is classified as a **Category A** agent. These are high-priority agents because they: * Can be easily disseminated or transmitted from person to person (though Tularemia is primarily highly infectious via aerosol). * Result in high mortality rates and have the potential for major public health impact. * Might cause public panic and social disruption. * Require special action for public health preparedness. **2. Why other options are incorrect:** * **Category B:** These are second-highest priority agents. They are moderately easy to disseminate, result in moderate morbidity rates, and low mortality rates (e.g., *Coxiella burnetii* (Q fever), *Brucella* species, *Staphylococcal* enterotoxin B, and food safety threats like *Salmonella*). * **Category C:** These are third-priority agents and include emerging pathogens that could be engineered for mass dissemination in the future because of availability and ease of production (e.g., Nipah virus, Hantavirus, and Multi-drug resistant TB). * **Category D:** There is no official "Category D" in the CDC bioterrorism classification system. **Clinical Pearls for NEET-PG:** * **Infectivity:** *Francisella tularensis* is extremely virulent; as few as **10–50 organisms** can cause disease. * **Vector:** Often transmitted by ticks, deer flies, or contact with infected rabbits ("Rabbit Fever"). * **Clinical Forms:** Ulceroglandular (most common) and Pneumonic (most lethal, the form used in bioterrorism). * **Diagnosis:** Requires Biosafety Level 3 (BSL-3) labs. * **Treatment:** Streptomycin or Gentamicin are the drugs of choice.

Q: Which of the following is not a Group A bioterrorism agent?

Salmonella. **Explanation:** The CDC categorizes bioterrorism agents into three groups (A, B, and C) based on their potential for mass dissemination, mortality rates, and public health impact. **Why Salmonella is the correct answer:** *Salmonella* species (specifically food safety threats) are classified as **Category B** agents. Category B agents are the second highest priority; they are moderately easy to disseminate, result in moderate morbidity rates, and low mortality rates. While they still pose a threat, they do not have the same catastrophic potential as Category A agents. **Why the other options are incorrect:** Category A agents are high-priority pathogens that pose the highest risk to national security because they can be easily transmitted from person to person, result in high mortality rates, and might cause public panic. * **Smallpox (*Variola major*):** A classic Category A agent due to its high infectivity and historical severity. * **Hemorrhagic fever viruses:** This includes Ebola, Marburg, Lassa, and Machupo. These are Category A due to high fatality rates and specialized laboratory requirements. * **Botulism (*Clostridium botulinum* toxin):** Though not contagious, the extreme potency of the toxin makes it a Category A threat. **High-Yield NEET-PG Pearls:** * **Mnemonic for Category A Agents:** "**ABC** **S**ure **P**ay" * **A**nthrax (*Bacillus anthracis*) * **B**otulism (*Clostridium botulinum*) * **C**holera is NOT here (Note: *Vibrio* is Category B) — The 'C' stands for **C**yclical/Viral Hemorrhagic Fevers. * **S**mallpox * **P**lague (*Yersinia pestis*) * **T**ularemia (*Francisella tularensis*) * **Category C:** Emerging pathogens that could be engineered for mass dissemination (e.g., Nipah virus, Hantavirus, MDR-TB).

Q: Which of the following is classified as a Category A bioterrorism agent?

Plague. ### Explanation The Centers for Disease Control and Prevention (CDC) classifies bioterrorism agents into three categories (A, B, and C) based on their risk to national security, ease of dissemination, and potential for public health impact. **1. Why Plague is Correct:** **Plague (*Yersinia pestis*)** is classified as a **Category A** agent. These are high-priority agents because they: * Can be easily disseminated or transmitted from person to person. * Result in high mortality rates. * Have the potential for major public health impact (causing panic and social disruption). * Require special action for public health preparedness. * *Other Category A agents include:* Anthrax (*B. anthracis*), Smallpox (*Variola major*), Botulism (*C. botulinum* toxin), Tularemia (*F. tularensis*), and Viral Hemorrhagic Fevers (e.g., Ebola, Marburg). **2. Why the Other Options are Incorrect:** * **Brucella (Option B):** Classified as **Category B**. These agents are moderately easy to disseminate, result in moderate morbidity, and low mortality rates. * **E. coli O157:H7 (Option D):** Also a **Category B** agent (specifically under food safety threats). * **SARS (Option C):** Classified as **Category C**. These are emerging pathogens that could be engineered for mass dissemination in the future because of availability and ease of production (e.g., Hantavirus, Nipah virus). **3. High-Yield Clinical Pearls for NEET-PG:** * **Pneumonic Plague:** The most likely form used in bioterrorism due to aerosol transmission; it is nearly 100% fatal if untreated. * **Safety Lab Level:** Most Category A agents require Biosafety Level 3 (BSL-3) or BSL-4 containment. * **Mnemonic for Category A:** "**ABC** **P**ast **T**ime" (**A**nthrax, **B**otulism, **C**holera/Viral Hemorrhagic Fevers, **P**lague, **T**ularemia, **S**mallpox).

Q: Which of the following agents is NOT considered a targeted critical agent for bioterrorism?

Bacillus cereus. The CDC classifies bioterrorism agents into three categories (A, B, and C) based on their potential for mass dissemination, mortality rates, and public health impact. **Explanation of the Correct Answer:** **C. Bacillus cereus** is the correct answer because it is a common cause of food poisoning (emetic and diarrheal types) and is not classified as a bioterrorism agent. While it is closely related to *Bacillus anthracis*, it lacks the specific virulence plasmids ($pXO1$ and $pXO2$) required to cause anthrax, which is a Category A "Tier 1" select agent. **Analysis of Incorrect Options:** * **A. Junin virus:** This is the causative agent of Argentine Hemorrhagic Fever. It is classified as a **Category A** agent because it causes high mortality and poses a severe threat to public health. * **B. Ricinus communis:** This plant is the source of **Ricin toxin**. Ricin is classified as a **Category B** agent. It is considered a significant threat because it is relatively easy to produce and can be aerosolized or used to contaminate food/water. * **D. Coxiella burnetii:** The causative agent of Q fever. It is classified as a **Category B** agent due to its low infectious dose (a single organism can cause disease) and its ability to resist environmental desiccation. **High-Yield Clinical Pearls for NEET-PG:** * **Category A (Highest Priority):** Think "6-Pack": Anthrax (*B. anthracis*), Botulism (*C. botulinum*), Plague (*Y. pestis*), Smallpox (*Variola major*), Tularemia (*F. tularensis*), and Viral Hemorrhagic Fevers (Ebola, Marburg, Lassa, Junin). * **Category B (Second Priority):** Includes Ricin, Q fever, Brucellosis, Glanders, and food/water safety threats like *Salmonella* or *Vibrio cholerae*. * **Category C (Emerging Pathogens):** Includes Nipah virus, Hantavirus, and Multi-drug resistant TB.

Q: Which of the following is NOT a category A bioterrorism agent?

Rickettsia. The CDC classifies bioterrorism agents into three categories (A, B, and C) based on their risk to national security, ease of dissemination, and potential for public health impact. **Explanation of the Correct Answer:** **C. Rickettsia** is the correct answer because it is classified as a **Category B** agent. Category B agents are the second-highest priority; they are moderately easy to disseminate, result in moderate morbidity rates, and low mortality rates. Specifically, *Rickettsia prowazekii* (Typhus fever) and *Coxiella burnetii* (Q fever) fall into this group. **Explanation of Incorrect Options (Category A Agents):** Category A agents are high-priority pathogens that pose the highest risk because they are easily transmitted from person to person, result in high mortality rates, and require special action for public health preparedness. * **A. Ebola:** A Viral Hemorrhagic Fever (VHF). All VHFs (Ebola, Marburg, Lassa, Machupo) are Category A. * **B. Botulism:** Caused by the *Clostridium botulinum* toxin; it is Category A due to its extreme potency and lethality. * **D. Yersinia:** *Yersinia pestis* (Plague) is Category A because it can be aerosolized and has a high fatality rate if untreated. **High-Yield Clinical Pearls for NEET-PG:** * **Mnemonic for Category A:** "**ABC** **P**list **S**urely" (**A**nthrax, **B**otulism, **C**holera/Smallpox—actually **S**mallpox, **P**lague, **T**ularemia, **V**iral Hemorrhagic Fevers). * **Category C:** Emerging pathogens that could be engineered for mass dissemination (e.g., Hantavirus, Nipah virus, Multi-drug resistant TB). * **Variola major** (Smallpox) is the only Category A agent that has been globally eradicated but remains a bioterrorism threat.

Q: Which of the following is a Category A Bioterrorism agent?

Ebola virus. **Explanation:** The Centers for Disease Control and Prevention (CDC) classifies bioterrorism agents into three categories (A, B, and C) based on their risk to national security, ease of dissemination, and potential for public health impact. **Correct Answer: D. Ebola virus** Category A agents are the highest priority because they are easily transmitted from person to person, result in high mortality rates, and have the potential for major public health impact. The "Big Six" Category A agents are: 1. **Anthrax** (*Bacillus anthracis*) 2. **Botulism** (*Clostridium botulinum* toxin) 3. **Plague** (*Yersinia pestis*) 4. **Smallpox** (*Variola major*) 5. **Tularemia** (*Francisella tularensis*) 6. **Viral Hemorrhagic Fevers** (including **Ebola**, Marburg, Lassa, and Machupo). **Analysis of Incorrect Options:** * **A. Brucella:** Classified as a **Category B** agent. These are moderately easy to disseminate, result in moderate morbidity, and low mortality rates. * **B. Melioidosis (*Burkholderia pseudomallei*):** Also a **Category B** agent. (Note: Glanders is also in this category). * **C. Hanta virus:** Classified as a **Category C** agent. These are emerging pathogens that could be engineered for mass dissemination in the future because of availability and ease of production. **High-Yield Clinical Pearls for NEET-PG:** * **Category A Mnemonic:** "**B**-**A**-**P**-**T**-**S**-**V**" (**B**otulism, **A**nthrax, **P**lague, **T**ularemia, **S**mallpox, **V**iral Hemorrhagic Fevers). * **Coxiella burnetii (Q fever)** is a common "trap" option; it is Category B, not A. * **Category C** includes Nipah virus, Yellow fever, and Multidrug-resistant TB.

Question 1

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

Accepted Answer

pXO1 poly-D-glutamate capsule

Answer

pXO1 polysaccharide capsule

Answer

pXO2 polysaccharide capsule

Answer

pXO2 poly-D-glutamate capsule

Question 2

All of the following statements about Glanders are false except?

Accepted Answer

Belongs to class B bioterrorism agents according to CDC.

Answer

It is an acute illness which presents with mild upper respiratory tract symptoms, usually self-limited.

Answer

Glanders is caused by Brucella.

Answer

Human infection cannot be acquired from infected animals.

Question 3

Tularemia belongs to which category of bioterrorism agents?

Accepted Answer

Category A

Answer

Category B

Answer

Category C

Answer

Category D

Question 4

Which of the following is not a Group A bioterrorism agent?

Accepted Answer

Salmonella

Answer

Smallpox

Answer

Hemorrhagic fever

Answer

Botulism

Question 5

Which of the following is classified as a Category A bioterrorism agent?

Accepted Answer

Plague

Answer

Brucella

Answer

SARS

Answer

E. coli O157:H7

Question 6

Which of the following agents is NOT considered a targeted critical agent for bioterrorism?

Accepted Answer

Bacillus cereus

Answer

Junin virus

Answer

Ricinus communis

Answer

Coxiella burnetii

Question 7

Which of the following is NOT a category A bioterrorism agent?

Accepted Answer

Rickettsia

Answer

Ebola

Answer

Botulism

Answer

Yersinia

Question 8

Which of the following is a Category A Bioterrorism agent?

Accepted Answer

Ebola virus

Answer

Brucella

Answer

Malioidosis

Answer

Hanta virus

Question 9

Which of the following is true about Bacillus anthracis?

Accepted Answer

It is an agent used in bioterrorism.

Answer

It causes a zoonotic disease.

Answer

Human-to-human transmission is possible.

Answer

Antibiotics have no role in its treatment.

Question 10

Sentinel laboratories are mainly involved in:

Accepted Answer

Control of Bioterrorism

Answer

External Quality Assessment of laboratories

Answer

Diagnosis of HIV infection

Answer

Diagnosis of Tuberculosis

Bioterrorism Agents — MCQs

Bioterrorism Agents — MCQs

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