Multi-drug Resistant Tuberculosis Indian Medical PG Practice Questions and MCQs
Practice Indian Medical PG questions for Multi-drug Resistant Tuberculosis. These multiple choice questions (MCQs) cover important concepts and help you prepare for your exams.
Multi-drug Resistant Tuberculosis Indian Medical PG Question 1: Multi drug resistant tuberculosis is defined as resistance to?
- A. Rifampicin and Pyrazinamide
- B. INH and Rifampicin (Correct Answer)
- C. Resistance to all first line drugs
- D. INH and Pyrazinamide
Multi-drug Resistant Tuberculosis Explanation: ***INH and Rifampicin***
- **Multidrug-resistant tuberculosis (MDR-TB)** is specifically defined by resistance to at least **isoniazid (INH)** and **rifampicin** [1], which are the two most potent first-line anti-TB drugs.
- This dual resistance makes treatment significantly more challenging and prolonged compared to drug-susceptible TB.
*Rifampicin and Pyrazinamide*
- While resistance to these drugs is serious, it does not specifically define MDR-TB unless resistance to **isoniazid** is also present.
- **Pyrazinamide** is another first-line drug, but its resistance pattern alone with rifampicin does not meet the MDR-TB criteria.
*Resistance to all first-line drugs*
- Resistance to all four first-line drugs (isoniazid, rifampicin, pyrazinamide, and ethambutol) [1] is classified as **Extensively Drug-Resistant TB (XDR-TB)**, a more severe form of resistance than MDR-TB.
- MDR-TB specifically refers to resistance to **INH and rifampicin**, not necessarily all first-line drugs.
*INH and Pyrazinamide*
- While resistance to both **isoniazid** and **pyrazinamide** is a concern, it does not meet the definition of MDR-TB.
- The definition requires resistance to **rifampicin** in addition to isoniazid.
Multi-drug Resistant Tuberculosis Indian Medical PG Question 2: Which of the following is not included in the Revised National Tuberculosis Control Programme (RNTCP)?
- A. Chest X-rays are used as a diagnostic tool for tuberculosis.
- B. Directly observed therapy (DOT) is a key strategy in tuberculosis control.
- C. Active case finding is a strategy used in tuberculosis control. (Correct Answer)
- D. Daily drug administration is part of the tuberculosis treatment regimen.
Multi-drug Resistant Tuberculosis Explanation: ***Active case finding is a strategy used in tuberculosis control***
- **This is the correct answer** - Traditional RNTCP primarily relied on **passive case finding**, where symptomatic patients self-report to health facilities
- While active case finding (systematic screening of high-risk groups) is now emphasized in NTEP (National TB Elimination Programme), it was **not a major strategy in the original RNTCP framework**
- The classic RNTCP approach focused on identifying patients who presented with symptoms rather than actively seeking cases in the community
*Directly observed therapy (DOT) is a key strategy in tuberculosis control*
- **DOT is a cornerstone** of RNTCP/NTEP to ensure treatment adherence
- A trained provider directly observes the patient taking anti-TB medications
- This prevents treatment default and reduces drug resistance
*Chest X-rays are used as a diagnostic tool for tuberculosis*
- **Chest X-rays are integral** to RNTCP for screening and diagnosis of pulmonary TB
- Used in conjunction with sputum microscopy/molecular tests like CBNAAT
- Helps identify lung involvement and assess disease severity
*Daily drug administration is part of the tuberculosis treatment regimen*
- **RNTCP/NTEP uses daily drug regimens** for most TB categories (replaced older intermittent regimens)
- Daily dosing improves treatment efficacy and patient adherence
- Part of the standardized treatment protocols under the programme
Multi-drug Resistant Tuberculosis Indian Medical PG Question 3: Which of the following is an inclusion criterion for the shorter bedaquiline regimen in the treatment of tuberculosis?
- A. Extrapulmonary TB like Tubercular meningitis
- B. Rifampicin resistance with both KatG and inhA mutation
- C. Rifampicin-sensitive TB
- D. Rifampicin-resistant but fluoroquinolone-sensitive TB (Correct Answer)
- E. Extensively drug-resistant TB (XDR-TB)
Multi-drug Resistant Tuberculosis Explanation: ***Rifampicin-resistant but fluoroquinolone-sensitive TB***
- The **shorter bedaquiline regimen** is specifically recommended for patients with **rifampicin-resistant tuberculosis** who are also sensitive to fluoroquinolones.
- This regimen optimizes treatment outcomes by leveraging the effectiveness of both bedaquiline and a potent fluoroquinolone against sensitive strains.
*Extrapulmonary TB like Tubercular meningitis*
- The shorter bedaquiline regimen is generally not recommended for severe forms of **extrapulmonary TB**, especially those involving the **central nervous system**, due to concerns about drug penetration and efficacy.
- These cases often require longer, individualized regimens with stronger central nervous system penetration.
*Rifampicin resistance with both KatG and inhA mutation*
- The presence of both **KatG** and **inhA mutations** indicates high-level **isoniazid resistance**, which is not the primary criterion for selecting the shorter bedaquiline regimen.
- While these mutations are important for guiding isoniazid use, the core inclusion for this regimen is **rifampicin resistance** and **fluoroquinolone sensitivity**.
*Rifampicin-sensitive TB*
- Patients with **rifampicin-sensitive TB** are usually treated with standard first-line regimens that do not include bedaquiline, as their disease is susceptible to more conventional therapies.
- The shorter bedaquiline regimen is reserved for drug-resistant cases, particularly those with rifampicin resistance.
*Extensively drug-resistant TB (XDR-TB)*
- While **XDR-TB** patients may receive bedaquiline, they typically require **longer, individualized regimens** rather than the shorter standardized regimen.
- The shorter bedaquiline regimen is primarily indicated for **rifampicin-resistant TB** that is **fluoroquinolone-sensitive**, whereas XDR-TB involves resistance to both fluoroquinolones and injectable agents, requiring more complex treatment approaches.
Multi-drug Resistant Tuberculosis Indian Medical PG Question 4: Which of the following is the true statement regarding measures to prevent typhoid transmission in the community?
- A. Typhoid vaccine administration is the best method of preventing transmission.
- B. Person-to-person transmission is the primary mode of spread.
- C. Drug resistance in typhoid is not as big a problem as in TB.
- D. Hygiene practice and clean sanitation control are more important than the typhoid vaccine. (Correct Answer)
Multi-drug Resistant Tuberculosis Explanation: ***Hygiene practice and clean sanitation control is more important than the typhoid vaccine.***
- **Improved sanitation**, safe water supplies, and adequate hygiene practices are fundamental in controlling the spread of **typhoid fever**, as the disease is primarily transmitted through the **oral-fecal route**.
- While vaccines are an important tool, they offer only partial protection and must be combined with **robust public health infrastructure** and **sanitation measures** for effective prevention.
*Typhoid vaccine administration is the best method of preventing transmission.*
- Typhoid vaccines offer protection, but their effectiveness is not 100%, and they typically require **booster doses**
- **Vaccination campaigns** are most effective when implemented alongside improvements in **water and sanitation infrastructure**, as vaccines alone cannot fully prevent transmission in areas with poor hygiene.
*Person-to-person transmission is the primary mode of spread.*
- While person-to-person transmission can occur, especially in settings with poor hygiene, the primary mode of spread for typhoid is through the **ingestion of food or water contaminated** with the feces of an infected person or carrier.
- This emphasizes the crucial role of **water and food safety** rather than just focusing on direct person-to-person contact.
*Drug resistance in typhoid is not as big a problem as in TB.*
- **Antimicrobial resistance (AMR)** in typhoid fever, particularly to fluoroquinolones and extended-spectrum beta-lactamase (ESBL) producing strains, is a **significant and growing global health concern**, complicating treatment.
- While TB also faces serious drug resistance issues, the escalating problem of **extensively drug-resistant (XDR)** and **multi-drug resistant (MDR)** typhoid strains makes it a substantial threat, impacting treatment options and increasing morbidity and mortality.
Multi-drug Resistant Tuberculosis Indian Medical PG Question 5: Not True about Bedaquiline
- A. Inhibits mycobacterial ATP synthase
- B. Contraindicated in pregnancy (Correct Answer)
- C. Given in > 10 years aged patients
- D. Given for MDR-TB patients
Multi-drug Resistant Tuberculosis Explanation: ***Contraindicated in pregnancy***
- While bedaquiline's safety in pregnancy is not fully established, it is generally **not absolutely contraindicated** if the potential benefits outweigh the risks, especially in cases of MDR-TB.
- Current guidelines suggest that it can be used with caution, and a woman taking bedaquiline should use **effective contraception** throughout treatment.
*Inhibits mycobacterial ATP synthase*
- This statement is **true**. Bedaquiline specifically targets the **F0F1-ATP synthase enzyme** in *Mycobacterium tuberculosis*.
- By inhibiting this enzyme, bedaquiline disrupts the **energy production** pathway of the bacteria, leading to bacterial death.
*Given in > 10 years aged patients*
- This statement is **true**. Bedaquiline is approved for use in patients with **multidrug-resistant tuberculosis (MDR-TB)** who are **12 years of age and older**.
- Its use in younger children is still under investigation, though some compassionate use cases exist.
*Given for MDR-TB patients*
- This statement is **true**. Bedaquiline is a key drug in the treatment of **multidrug-resistant tuberculosis (MDR-TB)** and **extensively drug-resistant tuberculosis (XDR-TB)**.
- It is often used as part of a **combination regimen** to overcome drug resistance to first-line agents.
Multi-drug Resistant Tuberculosis Indian Medical PG Question 6: A 50-year-old farmer presents with cough, fever, and weight loss. CXR shows upper lobe cavitary lesions. Sputum culture reveals acid-fast bacilli resistant to isoniazid and rifampin. What is the next best drug?
- A. Linezolid
- B. Fluoroquinolone (Correct Answer)
- C. Ethambutol
- D. Pyrazinamide
Multi-drug Resistant Tuberculosis Explanation: **Fluoroquinolone**
- In cases of **multidrug-resistant tuberculosis (MDR-TB)**, which is defined by specific resistance to both **isoniazid** and **rifampin**, fluoroquinolones are a crucial second-line agent [1].
- They demonstrate excellent **mycobactericidal activity** and are a cornerstone of MDR-TB treatment regimens [1].
*Linezolid*
- While **Linezolid** is used in highly resistant TB cases (XDR-TB), it is generally reserved for situations where other core second-line drugs (like fluoroquinolones) cannot be used or are resistant.
- Its use often carries a higher risk of **myelosuppression** and **neuropathy**, making it less preferred as an initial choice for MDR-TB.
*Ethambutol*
- **Ethambutol** is a first-line antitubercular drug, but it is typically used in conjunction with isoniazid and rifampin to prevent resistance development [1].
- It would not be the "next best" drug when **TB is already resistant to isoniazid and rifampin**, as single-drug therapy is ineffective for MDR-TB and could lead to further resistance.
*Pyrazinamide*
- **Pyrazinamide** is another first-line drug primarily effective against semi-dormant bacilli in acidic environments [1].
- Similar to ethambutol, it is not appropriate as the "next best" drug to manage **MDR-TB** when resistance to standard first-line agents has already been identified.
Multi-drug Resistant Tuberculosis Indian Medical PG Question 7: Multidrug-resistant (MDR) tuberculosis shows resistance to which of the following drugs?
- A. Isoniazid, rifampicin, and fluoroquinolone
- B. Fluoroquinolone
- C. Isoniazid, rifampicin, and kanamycin
- D. Isoniazid and rifampicin only (Correct Answer)
Multi-drug Resistant Tuberculosis Explanation: ***Isoniazid and rifampicin only***
- **Multidrug-resistant (MDR) tuberculosis** is specifically defined by resistance to both **isoniazid** and **rifampicin**.
- These two drugs are considered the most effective first-line anti-TB medications, making resistance to both a significant treatment challenge.
*Isoniazid, rifampicin, and fluoroquinolone*
- Resistance to **isoniazid**, **rifampicin**, and *any* fluoroquinolone defines **pre-extensively drug-resistant (pre-XDR) TB**, not MDR-TB.
- Adding resistance to a fluoroquinolone indicates a more severe and harder-to-treat form of tuberculosis.
*Fluoroquinolone*
- Resistance to **fluoroquinolone** alone does not define MDR-TB; it is only one component of resistance that, when combined with resistance to isoniazid and rifampicin, signifies pre-XDR or XDR-TB.
- While fluoroquinolones are important second-line drugs, their resistance in isolation does not meet the criteria for MDR-TB.
*Isoniazid, rifampicin, and kanamycin*
- Resistance to **isoniazid**, **rifampicin**, and *any* second-line injectable agent (like **kanamycin**, capreomycin, or amikacin) defines **extensively drug-resistant (XDR) TB**, not MDR-TB.
- XDR-TB represents an even more complex and difficult form of the disease to treat, requiring highly specialized regimens.
Multi-drug Resistant Tuberculosis Indian Medical PG Question 8: Which of the following methods is not suitable for testing anti-tubercular drug susceptibility?
- A. Resistance ratio method
- B. Disc diffusion method (Correct Answer)
- C. Radiometric broth method
- D. Molecular method
Multi-drug Resistant Tuberculosis Explanation: ***Disc diffusion method***
- The **disc diffusion method** is generally **not suitable** for *Mycobacterium tuberculosis* due to its **slow growth rate** and the **hydrophobic cell wall** that hinders drug diffusion.
- This method requires a relatively fast-growing organism to produce a measurable zone of inhibition within a standard incubation period, which *M. tuberculosis* does not.
*Resistance ratio method*
- The **resistance ratio method** is a conventional susceptibility testing method for *Mycobacterium tuberculosis* that compares the **minimum inhibitory concentration (MIC)** of a drug against the test strain to a susceptible reference strain.
- This method is considered reliable for assessing drug resistance in *M. tuberculosis* but can be time-consuming.
*Molecular method*
- **Molecular methods** (e.g., **PCR-based assays**, **GeneXpert**, **gene sequencing**) are highly suitable for detecting **anti-tubercular drug resistance** by identifying specific mutations in genes associated with resistance (e.g., *rpoB* for rifampicin, *katG* for isoniazid).
- These methods offer **rapid results** and can detect resistance even in paucibacillary samples.
*Radiometric broth method*
- **Liquid culture systems** such as **BACTEC MGIT 960** are rapid and automated methods commonly used for *M. tuberculosis* susceptibility testing.
- **MGIT 960** uses a **fluorescence-based** detection system that measures **oxygen consumption** by metabolizing mycobacteria (fluorescence quenching), providing faster results than traditional solid media methods.
- The older **BACTEC 460** used a true radiometric method (detecting **¹⁴CO₂** from radiolabeled substrates) but has been largely replaced by non-radiometric systems.
Multi-drug Resistant Tuberculosis Indian Medical PG Question 9: Anti-tubercular drug susceptibility can be done by all of the following methods, except?
- A. Molecular method
- B. Resistance ratio method
- C. Disc diffusion method (Correct Answer)
- D. Radiometric broth method
Multi-drug Resistant Tuberculosis Explanation: ***Disc diffusion method***
- The **disc diffusion method** is generally not reliable for *Mycobacterium tuberculosis* due to its slow growth rate, unique cell wall, and lipophilic nature, which hinder effective diffusion of antimicrobial agents.
- This method is primarily used for rapidly growing bacteria, unlike the **slow-growing** *M. tuberculosis*.
*Molecular method*
- **Molecular methods**, such as PCR-based assays, rapidly detect resistance-associated mutations in genes (e.g., *rpoB* for rifampicin, *katG* for isoniazid).
- They provide quick and accurate results for drug susceptibility testing, which is crucial for timely treatment initiation.
*Resistance ratio method*
- The **resistance ratio method** quantifies drug resistance by comparing the minimum inhibitory concentration (MIC) of a test strain to that of a susceptible reference strain.
- A resistance ratio greater than 1 indicates resistance, offering a precise measure of drug efficacy.
*Radiometric broth method*
- The **radiometric broth method**, like BACTEC MGIT 960, detects growth of *M. tuberculosis* by measuring CO2 production from radiolabeled palmitic acid, providing rapid susceptibility results.
- This method significantly reduces the time for susceptibility testing compared to conventional solid media methods.
Multi-drug Resistant Tuberculosis Indian Medical PG Question 10: Multiple drug resistance is transferred through -
- A. Transduction
- B. Transformation
- C. Conjugation (Correct Answer)
- D. Mutation
Multi-drug Resistant Tuberculosis Explanation: ***Conjugation***
- Conjugation is a primary mechanism for the spread of **antibiotic resistance genes** among bacteria, including those responsible for multiple drug resistance.
- It involves the direct transfer of **plasmids** (which often carry resistance genes) from one bacterial cell to another through a pilus.
*Transduction*
- Transduction is the process where bacteria acquire foreign DNA, including resistance genes, via a **bacteriophage (virus)**.
- While it can transfer resistance, conjugation is a more common and clinically significant route for **multidrug resistance** spread.
*Transformation*
- Transformation involves the uptake of **naked DNA** from the environment by a bacterial cell.
- While bacteria can acquire resistance genes this way, it is less efficient for widespread, rapid transfer of **multiple resistance traits** compared to conjugation.
*Mutation*
- Mutation refers to a change in the bacterial organism's own DNA, which can lead to the development of **drug resistance**.
- However, mutation explains the *origin* of resistance in a single bacterium, not the *transfer* of resistance genes (especially multiple resistance) between different bacteria.
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