INI-CET 2019 - Microbiology PYQs Practice Questions

Q: In a clinical scenario where a patient presents with flaccid paralysis, which of the following toxins is most likely responsible?

Botulism. ***Correct Option: Botulism*** - **Botulinum toxin** blocks the release of **acetylcholine** at the neuromuscular junction, leading to **flaccid paralysis**. - This paralysis typically progresses symmetrically and can affect ocular, bulbar, and peripheral muscles. *Incorrect Option: Tetanus* - **Tetanus toxin** inhibits the release of **inhibitory neurotransmitters** (**GABA** and **glycine**) in the central nervous system. - This leads to uncontrolled muscle contractions, presenting as **spastic paralysis** and **lockjaw**. *Incorrect Option: Diphtheria* - **Diphtheria toxin** causes local inflammation and can lead to systemic effects, including **myocarditis** and **neuropathy**. - The neuropathy can cause weakness, but it is typically a **delayed polyneuropathy** rather than acute flaccid paralysis. *Incorrect Option: Cholera* - **Cholera toxin** activates adenylyl cyclase in intestinal cells, leading to excessive fluid and electrolyte secretion. - The primary symptom is **severe watery diarrhea** and dehydration, not paralysis. [Practice more Microbiology PYQs on OnCourse]

Q: Slow growing alveolar like tumor in liver is caused by:

E. multilocularis. **Correct: E. multilocularis** - *Echinococcus multilocularis* causes **alveolar echinococcosis**, characterized by a slow-growing, infiltrative, and destructive lesion in the liver with a sponge-like, alveolar appearance - This parasite's larval stage forms multiple small cysts that are not encapsulated, leading to a tumor-like mass, often described as having an "alveolar" structure - The growth pattern mimics a malignant tumor, with irregular borders and infiltration into surrounding liver tissue *Incorrect: Amoebic liver abscess* - An amoebic liver abscess is caused by **Entamoeba histolytica** and typically presents as a single or multiple well-defined, encapsulated lesions filled with "anchovy paste-like" pus, which is distinct from an alveolar tumor - These abscesses usually develop relatively quickly (acute to subacute) and are often associated with fever and right upper quadrant pain, unlike the slow, asymptomatic growth of alveolar echinococcosis *Incorrect: E. granulosus* - *Echinococcus granulosus* causes **cystic echinococcosis** (hydatid disease), which typically presents as a single, large, unilocular cyst with a clear, laminated membrane, often surrounded by a fibrous capsule - Unlike *E. multilocularis*, *E. granulosus* cysts tend to be well-defined, spherical, and expansile rather than infiltrative and alveolar - The key distinguishing feature is the **cystic** (unilocular or with daughter cysts) versus **alveolar** (multiple small vesicles) morphology *Incorrect: Cysticercus cellulosae* - *Cysticercus cellulosae* is the larval form of **Taenia solium** and causes cysticercosis, which primarily affects muscles, subcutaneous tissue, brain, and eyes - While it forms cysts, these are typically small, solitary, and calcify in various tissues, not forming a large, infiltrative, alveolar tumor-like mass in the liver - Hepatic cysticercosis is extremely rare [Practice more Microbiology PYQs on OnCourse]

Question 1

In a clinical scenario where a patient presents with flaccid paralysis, which of the following toxins is most likely responsible?

Accepted Answer

Botulism

Answer

Tetanus

Answer

Diphtheria

Answer

Cholera

Question 2

Slow growing alveolar like tumor in liver is caused by:

Accepted Answer

E. multilocularis

Answer

Amoebic liver abscess

Answer

E. granulosus

Answer

Cysticercus cellulosae

INI-CET 2019 — Microbiology