M.leprae & Atypical Mycobacteria

Question 1

Slowest growing human bacterial pathogen?

Answer 1

M.leprae

Question 2

Transmission of m.leprae

Answer 2

Contact with infected
Skin lesions and nasal secretions discharge

Question 3

Tuberculoid leprosy vs lepromatous leprosy

Answer 3

1) TL has restricted pathogenic growth whereas LL spreads all over the body
2) TL has high cell mediated immunity whereas LL has poor
3) TL is less severe leprosy whereas LL is most severe

Question 4

Lepromin skin test result in TL and LL

Answer 4

Positive in TL
Negative in LL

Question 5

Skin lesions comparison b/w TL and LL

Answer 5

TL: Hypopigmented macular or plaque like skin lesions, thickened superficial nerves
LL: Multiple painful nodular skin lesions along the extensor surface of tibia and ulna.

Question 6

Treatment of leprosy

Answer 6

Dapsone

Question 7

Risk factors for atypical mycobacterium infections

Answer 7

HIV
Chronic illness (COPD, CF, diabetes)
IV drug abuse
Tattoos
Extreme age

Question 8

Group I of atypical mycobacterium

Answer 8

Photochromogens
-M.kansaii & M.marinum
-kansaii causes lung disease resembling tb (tuberculin test +ve)
-marinum causes swimming pool/fish tank granuloma.

Question 9

Group II of atypical mycobacterium

Answer 9

Scotochromogens
-M.scrofulaceum
-causes scrofula (cervical adenitis) in children

Question 10

Group III of atypical mycobacterium

Answer 10

Non-chromogens
-M.avium & M.intracellulare
-causes pulmonary disease
-primarily in immunocompromised patients

Question 11

Group IV of atypical mycobacterium

Answer 11

Rapidly growing mycobacterium
-M.fortuitum & M.chelonae
-skin and soft tissue infections occur at the site of puncture wounds (tattoo sites)
-in immunocompromised patients and individuals with prosthetic hip joint and indwelling catheters