FMGE 2019 - Microbiology PYQs Practice Questions

Q: A bacterium that can thrive at temperatures around 60-70 degrees Celsius is classified as

Thermophilic. ***Thermophilic*** - **Thermophilic** bacteria are heat-loving organisms that thrive at high temperatures, typically in the range of **45°C to 80°C**, with optimal growth around 50-70°C - These organisms are commonly found in hot springs, compost heaps, and industrial processes - **Note**: Extreme thermophiles (hyperthermophiles) can grow at temperatures exceeding 80-100°C, found in hydrothermal vents and geothermal environments *Mesophilic* - **Mesophilic** bacteria grow best at moderate temperatures, typically between **20°C and 45°C** - This includes most human pathogens and bacteria found in normal body temperature environments - These organisms cannot survive the high temperatures characteristic of thermophiles *Cryophilic* - **Cryophilic** (or psychrophilic) bacteria are cold-loving organisms that thrive at low temperatures, typically **below 20°C** - These organisms are adapted to cold environments like polar regions, deep oceans, and refrigerated foods - They would be rapidly killed at thermophilic temperature ranges *Halophilic* - **Halophilic** bacteria require high concentrations of salt (NaCl) for growth - This classification is based on **salt tolerance**, not temperature preference - Halophiles can be mesophilic, thermophilic, or psychrophilic depending on their temperature requirements [Practice more Microbiology PYQs on OnCourse]

Q: Which of the following viruses is from the Herpes virus family?

EBV. ***EBV*** - **Epstein-Barr Virus (EBV)** is a member of the **Herpesviridae** family, specifically **Human Herpesvirus 4 (HHV-4)**. - It is a **DNA virus** (double-stranded DNA), which is characteristic of all herpesviruses. - It is known to cause **infectious mononucleosis** and is associated with various malignancies. *Rubella* - **Rubella virus** belongs to the family **Togaviridae** and is the causative agent of **German measles**. - It is an **RNA virus** and is not classified within the Herpesviridae family. *Rabies* - **Rabies virus** is a member of the **Rhabdoviridae** family, specifically the genus **Lyssavirus**. - It is a neurotropic **RNA virus** causing a rapidly progressive, fatal encephalitis. *Measles* - **Measles virus**, also known as **Rubeola**, belongs to the family **Paramyxoviridae**. - It is an **RNA virus** responsible for a highly contagious airborne disease. [Practice more Microbiology PYQs on OnCourse]

Q: Increased susceptibility to N. meningitidis infections is associated with deficiency of which complement component:

C5-C9 deficiency. ***C5-C9 deficiency*** - Deficiencies in **C5-C9 components** impair the formation of the **Membrane Attack Complex (MAC)**, which is crucial for lysing Gram-negative bacteria like **N. meningitidis**. - Patients with MAC deficiencies are at significantly higher risk for recurrent invasive **N. meningitidis** infections. *C1-C4 deficiency* - Deficiencies in **C1-C4 components** primarily affect the **classical complement pathway** and are associated with increased susceptibility to **bacterial infections** and **immune complex diseases** (e.g., SLE). - While these deficiencies compromise opsonization and inflammation, they are not specifically linked to recurrent **N. meningitidis** infections. *C3 deficiency* - **C3 deficiency** is a severe primary immunodeficiency leading to profound defects in complement activation via all pathways, affecting **opsonization** and the formation of the MAC. - This deficiency causes severe recurrent **pyogenic infections** due to encapsulated bacteria but is not as specifically or commonly linked to **N. meningitidis** as deficiencies in the terminal pathway. *C2 deficiency* - **C2 deficiency** is the most common complement deficiency and primarily impacts the **classical pathway**, leading to impaired opsonization and immune complex clearance. - It is often associated with recurrent infections (especially with encapsulated bacteria) and **lupus-like syndromes**, but not specifically increased susceptibility to **N. meningitidis** infections. [Practice more Microbiology PYQs on OnCourse]

Q: Molluscum contagiosum is caused by a:

Pox virus. ***Pox virus*** - **Molluscum contagiosum** is a common **cutaneous viral infection** caused by the **Molluscum Contagiosum Virus (MCV)**. - MCV belongs to the **Poxviridae family**, which are known for causing characteristic skin lesions. *Flavi virus* - **Flaviviruses** are a genus of RNA viruses, which cause diseases like **Dengue fever**, **Yellow fever**, and **Zika virus infection**. - They typically cause **systemic illnesses** with fever and rash, rather than localized skin lesions like molluscum contagiosum. *Adenovirus* - **Adenoviruses** are DNA viruses primarily associated with **respiratory infections** (e.g., common cold, bronchitis) and **conjunctivitis**. - They are not known to cause the characteristic **umbilicated papules** seen in molluscum contagiosum. *Rubivirus* - **Rubivirus** is a genus that includes the **Rubella virus**, which causes **German measles** (Rubella). - Rubella is characterized by a **maculopapular rash** and **lymphadenopathy**, which is distinct from the **umbilicated papules** seen in molluscum contagiosum. [Practice more Microbiology PYQs on OnCourse]

Q: Antemortem diagnosis of rabies is made with:

Corneal impression smear. ***Corneal impression smear*** - A **corneal impression smear** can detect viral antigens in the cornea using fluorescent antibody staining, a method that can be performed on living patients. - This technique provides a relatively rapid and non-invasive way to diagnose rabies **antemortem**. *Inoculation in culture media* - Rabies virus is notoriously difficult to culture in standard cell culture media, making this method impractical and unreliable for **antemortem diagnosis**. - While viral isolation is possible in specialized research settings, it is not a routine diagnostic tool for rabies in living patients. *Negri bodies in hippocampus* - **Negri bodies** are eosinophilic inclusions found in the cytoplasm of neurons, particularly in the hippocampus, which are pathognomonic for rabies. - However, their detection requires **postmortem brain tissue biopsy**, making this a **postmortem diagnostic** method, not antemortem. *Rabies virus specific antibodies* - While the presence of **rabies virus-specific antibodies** (particularly in CSF) can indicate exposure and infection, they often appear late in the disease course. - The detection of antibodies may not be reliable for early **antemortem diagnosis**, especially in naive individuals whose immune response has not yet fully developed. [Practice more Microbiology PYQs on OnCourse]

Question 1

A bacterium that can thrive at temperatures around 60-70 degrees Celsius is classified as

Accepted Answer

Thermophilic

Answer

Mesophilic

Answer

Cryophilic

Answer

Halophilic

Question 2

Which of the following viruses is from the Herpes virus family?

Accepted Answer

EBV

Answer

Rubella

Answer

Rabies

Answer

Measles

Question 3

Increased susceptibility to N. meningitidis infections is associated with deficiency of which complement component:

Accepted Answer

C5-C9 deficiency

Answer

C1-C4 deficiency

Answer

C3 deficiency

Answer

C2 deficiency

Question 4

Molluscum contagiosum is caused by a:

Accepted Answer

Pox virus

Answer

Flavi virus

Answer

Adenovirus

Answer

Rubivirus

Question 5

Antemortem diagnosis of rabies is made with:

Accepted Answer

Corneal impression smear

Answer

Inoculation in culture media

Answer

Negri bodies in hippocampus

Answer

Rabies virus specific antibodies

Question 6

EBV is most strongly associated with which of the following?

Accepted Answer

Nasopharyngeal carcinoma

Answer

Gastric cancer

Answer

Esophageal cancer

Answer

Hepatocellular carcinoma

Question 7

What is the mode of transmission of genetic material to bacteria through bacteriophage?

Accepted Answer

Transduction

Answer

Transformation

Answer

Conjugation

Answer

Translation

Question 8

A patient presented with some unknown fungal infection. Microscopic examination revealed brown coloured spherical fungi with septate hyphae. Possible condition:

Accepted Answer

Chromoblastomycosis

Answer

Histoplasmosis

Answer

Candida albicans

Answer

Coccidioidomycosis

Question 9

The causative agent for duodenal ulcer is:

Accepted Answer

H. Pylori

Answer

Lactobacilli

Answer

E. coli

Answer

Shigella

Question 10

Bacillus anthracis is:

Accepted Answer

Gram positive rods with square ends

Answer

Gram negative cocci in cluster

Answer

Gram positive cocci in cluster

Answer

Gram positive bacilli with spherical ends

FMGE 2019 — Microbiology