NEET-PG 2013 Practice Questions

Q: What is the treatment of choice for a post-operative abscess?

Image guided aspiration. ***Image-guided aspiration*** - This is often the **first-line treatment** for a post-operative abscess, especially if it is well-localized. - It involves **draining the pus** under imaging guidance, relieving pressure and removing the infectious material. *Hydration* - While important for overall patient management, especially in cases of infection or sepsis, **hydration alone does not treat an abscess**. - It is a supportive measure but does not address the **localized collection of pus**. *IV antibiotics* - Antibiotics are typically indicated as an **adjunct to drainage**, especially in cases of systemic infection or cellulitis. - However, **antibiotics alone are often insufficient** to resolve an abscess as they have difficulty penetrating the necrotic core and thick capsule. *Reexploration* - **Surgical reexploration** is a more invasive option usually reserved for abscesses that are **large, multiloculated, not amenable to percutaneous drainage**, or when initial drainage attempts fail. - It carries greater risks and is not the initial treatment of choice for every post-operative abscess.

Q: Which of the following stimulate adenylate cyclase with G-protein coupled action ?

Cholera toxin. ***Cholera toxin*** - Cholera toxin is a **G-protein-activating toxin** that irreversibly activates **adenylate cyclase**. - This leads to increased intracellular levels of **cAMP**, causing excessive fluid secretion into the intestinal lumen and severe diarrhea. *Shiga toxin* - Shiga toxin acts by inactivating the **60S ribosomal subunit**, thereby inhibiting protein synthesis in eukaryotic cells. - Its primary effect is **cytotoxicity**, not direct stimulation of adenylate cyclase. *Diphtheria toxin* - Diphtheria toxin inhibits **protein synthesis** by inactivating **elongation factor-2 (EF-2)** through ADP-ribosylation. - This toxin specifically targets host cells, leading to cellular death and tissue damage. *Pseudomonas toxin* - **Exotoxin A** produced by *Pseudomonas aeruginosa* also inhibits **protein synthesis** by ADP-ribosylating and inactivating **EF-2**, similar to diphtheria toxin. - It does not directly affect adenylate cyclase activity.

Q: Which MRSA strain type is most commonly associated with hospital-acquired infections?

Phage type 80/81. ***Phage type 80/81*** - This **phage type**, particularly **epidemic methicillin-resistant *Staphylococcus aureus* (EMRSA) 15 and 16**, is historically and currently the most common cause of **hospital-acquired MRSA infections** worldwide. - It rapidly diversified and spread globally, becoming a significant nosocomial pathogen. *Phage type 83A* - While this phage type has been associated with **MRSA outbreaks**, it is not the most common strain type globally for hospital-acquired infections. - Its prevalence is more regional and sporadic compared to the widespread dominance of EMRSA 15/16. *Phage type 84* - **Phage type 84** is not widely recognized as a predominant strain associated with the majority of **hospital-acquired MRSA infections**. - Other, more virulent and successful clonal types have outcompeted it to become the most prevalent. *Phage type 85* - Similar to other less common types, **phage type 85** does not represent the major lineage responsible for the bulk of **hospital-acquired MRSA cases**. - The landscape of MRSA epidemiology is dominated by a few highly successful clonal complexes, of which 80/81 is a prime example.

Q: Which is the most common bacterial organism causing bacterial upper respiratory tract infections (including sinusitis, otitis media, and pharyngitis) in adults?

Streptococcus pneumoniae. ***Streptococcus pneumoniae*** - *Streptococcus pneumoniae* is the **most common bacterial pathogen** causing upper respiratory tract infections overall, including **bacterial sinusitis**, **otitis media**, and **community-acquired pneumonia**. - It is a frequent colonizer of the nasopharynx and leads to infection when host immunity is compromised. - Accounts for the highest burden of bacterial URTIs when considering all anatomical sites. *Haemophilus influenzae* - *Haemophilus influenzae* (particularly non-typeable strains) is the **second most common** cause of bacterial sinusitis and otitis media in adults. - While significant, it is less prevalent overall than *S. pneumoniae* across all URTI types. *Staphylococcus aureus* - *Staphylococcus aureus* primarily causes **skin and soft tissue infections** and device-related infections. - It is **not a common primary pathogen** in typical acute bacterial URTIs, though it may cause secondary infections or colonize the anterior nares. *Streptococcus pyogenes* - *Streptococcus pyogenes* (Group A Streptococcus) is the **most common cause of bacterial pharyngitis** (strep throat) in adults. - However, when considering the **full spectrum of bacterial URTIs** (pharyngitis, sinusitis, otitis media), *S. pneumoniae* has a broader overall impact and higher prevalence across multiple sites.

Q: Which organism is responsible for producing Draughtsman (Concentric Rings) on culture?

Bacillus anthracis. ***Bacillus anthracis*** - *Bacillus anthracis* is the organism responsible for producing the characteristic **"Draughtsman" or "Concentric Rings"** pattern on culture media - On blood agar, colonies show a **"Medusa head"** appearance with **concentric rings** and **comma-shaped projections** radiating outward from the center - This distinctive morphology results from chains of bacilli growing in parallel alignment, creating the characteristic pattern - The colonies are typically **non-hemolytic, grey-white, and have irregular edges** *H. ducreyi* - *Haemophilus ducreyi* causes **chancroid** and is difficult to culture - Colonies appear as **small, grey-yellow, translucent** with a **cohesive ("school of fish")** appearance when pushed across the agar - Does not produce concentric rings *B. pertussis* - *Bordetella pertussis* grows on **Bordet-Gengou agar** or **Regan-Lowe medium** - Colonies have a characteristic **"mercury droplet"** or **"bisected pearl"** appearance due to their smooth, shiny, convex morphology - This is completely different from the Draughtsman pattern *Pneumococci* - *Streptococcus pneumoniae* produces **alpha-hemolytic colonies** on blood agar - Colonies are **small, dome-shaped, mucoid** with a **central umbilication** (draughtsman or checker-piece appearance refers to the depression, not concentric rings) - The "draughtsman" term when applied to pneumococci refers to the flattened checker-piece shape, not the concentric ring pattern of *B. anthracis*

Q: Birdshot retinopathy is characterized by all except?

Unilateral. ***Unilateral*** - **Birdshot retinopathy** is characteristically a **bilateral** inflammatory condition affecting both eyes, even if the onset may be asymmetric. - The disease involves widespread inflammation of the **choroid** and **retina**, typically presenting in both eyes simultaneously or sequentially. - Unilateral presentation would be highly atypical and should prompt consideration of alternative diagnoses. *Common in females* - Birdshot retinopathy shows a **clear female predominance**, with approximately **2-3 times more females affected than males** (60-75% of cases). - This demographic trend is a well-established feature of the disease. - However, it does occur in both sexes and is still considered characteristic of the condition. *HLA-A29 positive* - A strong association with the **HLA-A29 allele** is a hallmark of birdshot retinopathy, found in **over 95% of affected individuals**. - This genetic marker is highly specific and often used to support the diagnosis. - HLA-A29 testing is considered part of the diagnostic workup. *Creamy yellow spots* - The presence of characteristic **creamy yellow-white choroidal lesions**, resembling birdshot scatter, is a defining clinical feature. - These lesions are typically located in the **mid-peripheral and posterior fundus**, distributed radially around the optic disc. - The "birdshot" appearance refers to the scattered pattern resembling shotgun pellet distribution.

Q: Snow banking is seen in?

Intermediate uveitis. ***Intermediate uveitis*** - **Snow banking** refers to the accumulation of inflammatory exudates on the surface of the **pars plana** and **ora serrata**, a characteristic sign of intermediate uveitis. - This condition primarily affects the **vitreous** and peripheral retina, often leading to symptoms like **floaters** and **decreased vision**. *White coat syndrome* - This refers to a phenomenon where a patient's **blood pressure is elevated** in a clinical setting due to anxiety, but is normal outside of the medical environment. - It has no ophthalmic manifestations or association with "snow banking." *Eales syndrome* - This is an idiopathic inflammatory condition primarily affecting the **peripheral retinal vasculature**, leading to **vasculitis**, occlusion, and neovascularization. - While it can cause vitreous hemorrhage, it does not typically present with "snow banking" as a primary feature. *Diabetic kidney disease* - This is a complication of **diabetes mellitus** characterized by damage to the small blood vessels in the kidneys, leading to impaired kidney function. - It is a systemic condition with no direct relationship to ocular "snow banking" or uveitis.

Q: Panophthalmitis involves ?

All structures of the eyeball including Tenon's capsule. ***All structures of the eyeball including Tenon's capsule*** - **Panophthalmitis** is a severe inflammation or infection that affects **all coats of the eyeball** (sclera, choroid, retina). - Crucially, it also extends to the **intraocular contents** and the **Tenon's capsule**, leading to potential destruction of the entire eye. *Inner coat of eyeball* - This description is characteristic of **uveitis** (inflammation of the uvea: iris, ciliary body, choroid) or **endophthalmitis** if it extends to the vitreous and retina. - However, **panophthalmitis** is a more extensive condition, involving more than just the inner coats. *Inner and outer coat but sparing tenon's capsule* - This scenario describes **endophthalmitis**, which involves inflammation of the internal structures of the eye (vitreous, retina, choroid) and potentially the sclera. - However, the sparing of Tenon's capsule differentiates it from **panophthalmitis**, which expressly includes involvement of this fibrous sheath. *None of the options* - This option is incorrect because Option C accurately describes the comprehensive nature of **panophthalmitis**, which is an inflammation of all ocular structures, including Tenon's capsule. - The definition of panophthalmitis is critical in distinguishing it from less severe inflammatory conditions of the eye.

Q: Most common age for intussusception is

6 months - 3 years. ***6 months - 3 years*** - Intussusception commonly occurs in infants and young children, with the peak incidence between **6 months and 3 years** of age. - This age range coincides with changes in feeding practices and increased exposure to viral infections, which can sometimes precede intussusception. - The **typical age** is 5-9 months, with most cases occurring before 2 years. *0 - 6 months* - While intussusception can occur in this age group, it is **less common** than in slightly older infants. - Intussusception in very young infants may have different underlying causes, such as a **pathologic lead point**. *3 - 5 years* - Intussusception is **less frequent** in this age group compared to infants and toddlers. - When it does occur, there is a higher likelihood of an **identifiable lead point**, such as a Meckel's diverticulum or polyp. *> 5 years* - Intussusception is **rare** in children over the age of 5 years. - In older children and adults, it is almost always associated with a **pathological lead point**, such as a tumor or postoperative adhesions.

Q: Best approach for emergency thoracotomy in acute thoracic trauma is

Anterolateral thoracotomy. ***Anterolateral thoracotomy*** - Provides **rapid access** to the chest cavity for emergent situations, such as **cardiac tamponade** or **massive hemorrhage**, which are common in thoracic trauma. - Allows assessment and management of injuries to the **heart, great vessels, and lungs** with minimal repositioning in a critically ill patient. *Midline sternotomy* - Primarily used for **cardiac surgery**, offering excellent exposure to the mediastinum but is less ideal for general thoracic trauma with potential lateral injuries. - Takes **longer to perform** than an anterolateral approach and may not be suitable in an emergent, unstable trauma setting. *Parasternal thoracotomy* - Offers more limited access compared to other approaches, typically used for specific, localized procedures near the sternum. - Does not provide the **broad exposure** needed to manage the diverse and potentially widespread injuries seen in severe thoracic trauma. *Posterolateral thoracotomy* - Provides excellent exposure to the **posterior mediastinum, spine, and descending aorta**, but requires the patient to be in the lateral decubitus position. - Repositioning a severely injured trauma patient for this approach is often **impractical and time-consuming**, making it unsuitable for initial resuscitation.

Question 1

What is the treatment of choice for a post-operative abscess?

Accepted Answer

Image guided aspiration

Answer

Hydration

Answer

IV antibiotics

Answer

Reexploration

Question 2

Which of the following stimulate adenylate cyclase with G-protein coupled action ?

Accepted Answer

Cholera toxin

Answer

Shiga toxin

Answer

Diphtheria toxin

Answer

Pseudomonas toxin

Question 3

Which MRSA strain type is most commonly associated with hospital-acquired infections?

Accepted Answer

Phage type 80/81

Answer

Phage type 83A

Answer

Phage type 85

Answer

Phage type 84

Question 4

Which is the most common bacterial organism causing bacterial upper respiratory tract infections (including sinusitis, otitis media, and pharyngitis) in adults?

Accepted Answer

Streptococcus pneumoniae

Answer

Staphylococcus aureus

Answer

Haemophilus influenzae

Answer

Streptococcus pyogenes

Question 5

Which organism is responsible for producing Draughtsman (Concentric Rings) on culture?

Accepted Answer

Bacillus anthracis

Answer

B. pertussis

Answer

H. ducreyi

Answer

Pneumococci

Question 6

Birdshot retinopathy is characterized by all except?

Accepted Answer

Unilateral

Answer

Common in females

Answer

Creamy yellow spots

Answer

HLA-A29 positive

Question 7

Snow banking is seen in?

Accepted Answer

Intermediate uveitis

Answer

White coat syndrome

Answer

Eales syndrome

Answer

Diabetic kidney disease

Question 8

Panophthalmitis involves ?

Accepted Answer

All structures of the eyeball including Tenon's capsule

Answer

Inner coat of eyeball

Answer

Inner and outer coat but sparing tenon's capsule

Answer

None of the options

Question 9

Most common age for intussusception is

Accepted Answer

6 months - 3 years

Answer

0 - 6 months

Answer

3 - 5 years

Answer

> 5 years

Question 10

Best approach for emergency thoracotomy in acute thoracic trauma is

Accepted Answer

Anterolateral thoracotomy

Answer

Midline sternotomy

Answer

Parasternal thoracotomy

Answer

Posterolateral thoracotomy

NEET-PG 2013

Dental

Microbiology

Ophthalmology

Pediatrics

Surgery