FMGE 2025 - Microbiology Practice Questions

Q: A 3-month-old child was admitted with pneumonia. The microscopy shows the following image. Choose the correct organism.

Influenza. ***Influenza*** - The image displays a virus with two key surface glycoproteins: **Hemagglutinin (HA)** and **Neuraminidase (NA)**. These proteins are the defining structural features of the Influenza virus and are crucial for its entry into and exit from host cells. - Influenza virus is a well-known cause of respiratory illnesses, including severe **pneumonia**, particularly in high-risk groups such as infants, the elderly, and immunocompromised individuals. *Rotavirus* - Rotavirus is the leading cause of severe **gastroenteritis** (diarrhea and vomiting) in infants and young children; it is not a primary cause of pneumonia. - It is a **non-enveloped** virus with a distinct wheel-like appearance (hence the name "rota"), which is structurally different from the enveloped virus shown in the diagram. *Hepatitis virus* - Hepatitis viruses (A, B, C, etc.) are hepatotropic, meaning they primarily infect and cause inflammation of the **liver (hepatitis)**, and are not associated with respiratory infections like pneumonia. - Their viral structures and surface antigens are different; for example, Hepatitis B virus has **HBsAg** on its surface, not HA and NA. *Respiratory syncytial virus* - While RSV is a very common cause of **pneumonia** and **bronchiolitis** in infants, its viral structure differs from the one depicted. - RSV belongs to the *Paramyxoviridae* family and has **Fusion (F)** and **Attachment (G)** proteins on its surface, not Hemagglutinin and Neuraminidase.

Q: Identify the microorganism shown in the image.

Entamoeba histolytica. ***Entamoeba histolytica*** - The image displays the **trophozoite** stage, characterized by a single nucleus with a central, dot-like **karyosome**. - A key diagnostic feature seen here is the presence of ingested **red blood cells** within the cytoplasm, a phenomenon known as **erythrophagocytosis**, which indicates invasive disease. *Giardia lamblia* - *Giardia* trophozoites are pear-shaped and **binucleated**, often described as having a face-like appearance, which is distinct from the single nucleus seen in the image. - They are flagellated protozoa and do not phagocytose red blood cells. *Shigella dysenteriae* - *Shigella* is a **bacterium**, not a protozoan, and would appear as a small, rod-shaped organism under a microscope. - It lacks the complex eukaryotic structures, such as a distinct nucleus and cytoplasmic inclusions, that are visible in the provided image. *Campylobacter jejuni* - This is a **bacterium** known for its characteristic curved, S-shaped, or "gull-wing" morphology. - As a prokaryote, it is much smaller and structurally simpler than the large amoeboid parasite shown.

Question 1

A 3-month-old child was admitted with pneumonia. The microscopy shows the following image. Choose the correct organism.

Accepted Answer

Influenza

Answer

Rotavirus

Answer

Hepatitis virus

Answer

Respiratory syncytial virus

Question 2

Identify the microorganism shown in the image.

Accepted Answer

Entamoeba histolytica

Answer

Giardia lamblia

Answer

Campylobacter jejuni

Answer

Shigella dysenteriae

FMGE 2025 — Microbiology