FMGE 2017 - Microbiology PYQs Practice Questions

Q: Which of the following is anaerobic non-acid fast bacilli:

Actinomyces. ***Actinomyces*** - *Actinomyces* species are **obligate anaerobes** to **facultative anaerobes** that appear as **Gram-positive, non-acid-fast, filamentous rods** (bacilli). - They are classically described as **anaerobic bacteria** and are the prototypical example of anaerobic non-acid-fast bacilli. - They cause chronic infections (actinomycosis) often involving abscess formation with sulfur granules and sinus tracts. *Mycobacterium tuberculosis* - *Mycobacterium tuberculosis* is an **obligate aerobe**, not anaerobic. - It is characterized by its **acid-fastness** due to high mycolic acid content in its cell wall. - Requires oxygen for growth and is the causative agent of tuberculosis. *Listeria* - *Listeria monocytogenes* is a **facultative anaerobe**, meaning it preferentially grows in **aerobic conditions** but can survive anaerobically. - While it is a non-acid-fast Gram-positive bacillus, it is **not classified as an anaerobic organism** in standard microbiology terminology. - *Actinomyces* is the classic answer for anaerobic non-acid-fast bacilli. *Nocardia* - *Nocardia* species are **strict aerobes**, not anaerobic. - They are **weakly acid-fast** filamentous bacteria, distinguishing them from the non-acid-fast *Actinomyces*. - Require oxygen for growth and are found in soil. [Practice more Microbiology PYQs on OnCourse]

Q: Vertical transmission of resistance to ciprofloxacin occurs :-

Mutation. ***Mutation*** - Vertical transmission of resistance occurs when a bacterium with a **resistance gene**, such as one conferring resistance to **ciprofloxacin**, replicates and passes that gene to its progeny. - This typically happens through **spontaneous mutations** in the bacterial genome that alter the drug's target or uptake, and these mutations are then inherited by subsequent generations. *Transduction* - **Transduction** involves the transfer of genetic material, including resistance genes, via **bacteriophages** (viruses that infect bacteria). - This is a **horizontal gene transfer** mechanism, not a vertical one. *Conjugation* - **Conjugation** is the direct transfer of genetic material, often in the form of **plasmids**, from one bacterium to another through direct cell-to-cell contact. - This is a form of **horizontal gene transfer**, not vertical transmission. *Transformation* - **Transformation** is the uptake of **free DNA** from the environment by a bacterium, which can then integrate this DNA into its own genome. - This mechanism is also a type of **horizontal gene transfer**, not vertical transmission of resistance to daughter cells during replication. [Practice more Microbiology PYQs on OnCourse]

Q: Tropical pulmonary eosinophilia is most characteristically seen due to which of the following infections?

Filaria. *Filaria* - **Tropical pulmonary eosinophilia (TPE)** is a hypersensitivity reaction to microfilariae from filarial nematodes like *Wuchereria bancrofti* and *Brugia malayi* [1]. - It is characterized by cough, dyspnea, wheezing, and marked **peripheral eosinophilia**, with interstitial infiltrates on chest X-ray [1]. *Roundworm* - **Ascaris lumbricoides** can cause **Loeffler's syndrome**, a transient pulmonary infiltration with eosinophilia during larval migration, but not chronic TPE [2]. - Symptoms are usually less severe and self-limiting compared to TPE [2]. *Trichinella* - **Trichinella spiralis** causes **trichinellosis**, presenting with muscle pain, fever, and periorbital edema, possibly with eosinophilia, but typically does not manifest as TPE. - Pulmonary involvement is rare and not the characteristic feature. *Ancylostoma* - **Hookworm (Ancylostoma duodenale, Necator americanus)** larvae can cause mild pulmonary symptoms and eosinophilia during migration through the lungs [3]. - However, they also do not typically lead to the severe and chronic pulmonary symptoms seen in TPE [3]. [Practice more Microbiology PYQs on OnCourse]

Q: Microsporum involves:

Skin and hair. ***Skin and hair*** - *Microsporum* species are **dermatophytes** that commonly cause superficial fungal infections - They have a particular predilection for keratinized tissues like **skin and hair**, leading to conditions such as **tinea capitis** (scalp ringworm) and **tinea corporis** (body ringworm) - This is the characteristic pattern for *Microsporum* species including *M. canis*, *M. audouinii*, and *M. gypseum* *Skin and nails* - While *Microsporum* can affect the skin, its involvement with **nails (onychomycosis)** is extremely rare - Nail infections are typically associated with **Trichophyton rubrum** or **T. mentagrophytes**, not *Microsporum* *Hair and nails* - **Nail involvement** is not a characteristic of *Microsporum* infections - The main sites of infection are hair and smooth skin, not nails *Skin, hair and nails* - Including **nails** as a site for *Microsporum* is inaccurate; its primary targets are skin and hair only - While some dermatophytes (like *Trichophyton*) can affect all three tissues, *Microsporum* has specific tropism for skin and hair [Practice more Microbiology PYQs on OnCourse]

Question 1

Which of the following is anaerobic non-acid fast bacilli:

Accepted Answer

Actinomyces

Answer

Mycobacterium tuberculosis

Answer

Listeria

Answer

Nocardia

Question 2

Vertical transmission of resistance to ciprofloxacin occurs :-

Accepted Answer

Mutation

Answer

Transduction

Answer

Conjugation

Answer

Transformation

Question 3

Tropical pulmonary eosinophilia is most characteristically seen due to which of the following infections?

Accepted Answer

Filaria

Answer

Roundworm

Answer

Trichinella

Answer

Ancylostoma

Question 4

Microsporum involves:

Accepted Answer

Skin and hair

Answer

Skin and nails

Answer

Hair and nails

Answer

Skin, hair and nails

FMGE 2017 — Microbiology