Multiple choice questions

Mycobacterium tuberculosis

The scientist who discovered M. tuberculosis was:A: Louis PasteurB: Robert KochC: Jean-Antoine VilleminD: Calmette and Guerin

Correct answer: B

MDR TB: is defined as resistance toA: more than three anti tubercular drugsB: isoniazid and rifampin irrespective of resistance

to any other drugC: INH, PZA and RifampicinD: fluoroquinolones and at least one of the three

injectable second-line drugs used to treat TB

Correct answer: B

XDR TB is defined asA: MDR TB that also is resistant to fluoroquinolones and at least

one of the three injectable second-line drugs used to treat TB (amikacin, kanamycin, or capreomycin)

B: resistant to two most effective first-line therapeutic drugs, isoniazid and rifampin irrespective of resistance to any other drug

C: MDR TB that is resistant to either one of the injectable second line drugs or second-line therapeutic fluoroquinolones

D: Strain resistant to more than one drug (excluding co resistance to INH and rif)

– Correct answer: A

Tuberculosis is transmitted through:A: Infected waterB: Infected handsC: Infected bloodD: Infected air

Correct answer: D

Which of the following statements is incorrect:A: People who are exposed to TB may or may not

develop TB infectionB: People with TB infection may or may not develop

TB diseaseC: risk of developing TB disease is highest in first 2

years after infectionD: Every individual exposed to TB develops disease

Correct answer: D

• Tubercular Granulomas are made up of: A: organized aggregates of immune cells that

surround foci of infected tissuesB: Damaged tissue cells and bacilli onlyC: Fibrous and damaged tissue and bacilli onlyD: Necrotic tissue and damaged tissue and bacilli

only

Correct answer: A

• Cord growth seen on mycobacterial culture is characteristic of:A. Avirulent strainsB. Virulent strainsC. Saprophytic strainsD. Atypical mycobacteria

Correct answer: B

• Which one of the following are constituent of Lowenstein Jensen media except:A. AgaroseB.Malachite greeC. Mineral saltsD. Asparagine

Correct answer: A

• Following are the first line antitubercular drugs except:A. isoniazidB. rifampin C. PASD. streptomycin

Correct answer: C

• Which one of the following anti-tubercular drugs acts best in acidic pH:A. INHB. PyrazinamideC. StreptomycinD. Rifampicin

Correct answer: B

• Mutations in katG gene of Mycobacterium tuberculosis are responsible for resistance to:A. INHB. RifampicinC. PyrazinamideD. Streptomycin

Correct Answer: A

• Which of the following tests are banned for diagnosis of tuberculosis:A. CultureB. ELISAC. PCRD. LPA

Correct result: B

• Which of the following statements is incorrect:A. Mycobacteria are obligate aerobes B. Increased CO2 tension enhances growth

C. Can not grow in cell free mediaD. Doubling time of tubercle bacilli is about 18

hours.

Correct answer: C

One word answer

• Identify the stain– ZN stain

• Identify the organism– M. tuberculosis

• Describe the morphology– Acid fast, Long slender,

curved, bunch, beaded

True/ False

• For people with TB infection and no risk factors, the risk is about 5% in the first two years– T

• For people with TB infection and no risk factors, the risk is about 10% over a lifetime– T

• For people with TB infection and diabetes, the risk is about 30% over a lifetime– T

• For people with TB infection and HIV infection , the risk is about 7% to 10% over a lifetime– F

• Which one of the following is a non cultivable mycobacteria:A. M. tuberculosisB. M. BovisC. M. lepraeD. M. avium intracellulare

Correct Answer: C

• Which one of the following is a rapid grower mycobacteria:A. M. scrofulaceumB. M. kansasiiC. M. fortuitumD. M. avium intracellulare

Correct Answer: C

• Buruli ulcer is caused by:– A. M. tuberculosis– B. M. ulcerance– C. M. marinum– D. M. chelonei

• Correct answer: B

• Swimming pool granuloma is caused by:– A. M. tuberculosis– B. M. ulcerance– C. M. marinum– D. M. chelonei

• Correct answer: c

• Most common cause of disseminated opportunistic infection in AIDS patients in western world is:– A. M. avium intracellulare complex– B. Pneumocystis carinii– C. Cryptosporidium– D. Zygomycetes

• Correct answer: A

• Gerhard Henrik Armauer Hansen,s contribution to Microbiology was; A. First identified M. leprae as the cause of leprosy in 1873B. First identified M. tuberculosis as a cause of TB in 1895C. First identified B. anthracis as a cause of Anthrax in 1872D. First identified that small pox is a contagious disease

• Correct Answer: A

• Which of the following description suits lepra bacilli best:– A. acid-fast rod-shaped organism with parallel sides and rounded

ends, mostly extracellular, often grouped together like bundles of cigars

– B. acid-fast rod-shaped organism with parallel sides and rounded ends, chiefly in masses within the lepra cells (globi), often grouped together like bundles of cigars or arranged in a palisade

– C. acid-fast rod-shaped organism with parallel sides and rounded ends, chiefly intracellular in Chinese letter form

– D. acid-fast rod-shaped organism, extracellular, Chinese letter form

– Correct answer: B

• An adult male is presenting with hypo-pigmented patches on forearm, partial loss of cutaneous sensations in affected areas, presence of thickened ulnar nerve and presence of AFB in nasal smears. Your diagnosis is:– A. Cutaneous Tuberculosis– B. Leprosy– C. Atypical mycobacteriosis– D. Actinomycosis

– Correct answer: B

• A case of leprosy with good Cell mediated immunity usually presents as following form of disease:– A. Lepromatous– B. Tuberculoid– C. indeterminate– D. Borderline

– Correct answer: B

• Erythma nodosum leprosum as seen in patients of leprosy on treatment, is due to:– A. Type I hypersensitivity reaction– B. Type II hypersensitivity reaction– C. Type III hypersensitivity reaction– D. Type IV hypersensitivity reaction

Correct answer: C

• Presence of sulfur granules in pus is pathognomonic of:– A. Subcutaneous mycosis– B. Leprosy– C. Actinomycosis– D. Cutaneous Tuberculosis

– Correct Answer: C

• There is a 30 year old male presenting with lumpy jaw, suppurative inflammation and formation of multiple abscesses and sinus tracts with discharge of pus containing sulfur granules. Most probable clinical diagnosis is; – A. Leprosy– B. Actinomycosis– C. Subcutaneous mycosis– D. Cutaneous TB

– Correct Answer: B

• There is a 30 year old male presenting with lumpy jaw, suppurative inflammation and formation of multiple abscesses and sinus tracts with discharge of pus containing sulfur granules. Following types of microscpic examinations can be ordered to confirm the diagnosis, except; – A. Smear examination for Gram positive bacteria– B. Microscopic examination of Crush smear of granule– C. Smear examination for acid fast bacilli– D. KOH mount

– Correct answer: D

• There is a 30 year old male presenting with lumpy jaw, suppurative inflammation and formation of multiple abscesses and sinus tracts with discharge of pus containing sulfur granules. Best therapy in this case will be:– A. Antitubercular drugs– B. Aminoglycosides– C. Penicillin– D. Co trimoxazole

• Correct Answer: C

• Which one of them is non acid fast:– A. Mycobacterium tuberculosis– B. Nocardia– C. Actinomyces– D. Mycobacterium leprosy

– Correct Answer: C