1. MYCOBACTERIA 2/2 M. leprae & Atypical
Professor Sudheer Kher

2. KEYWORDS Atypical Runyon groups Antibiotic resistance
Acid Fast
Ziehl-Neelsen Stain
5% H2SO4
Mycolic acids
M. leprae
Non cultivable
Armadillo, Mouse footpad
Lepromin test
Ridely Jopling classification Tuberculoid / Lepromatous
Lab diagnosis –Skin clippings
Atypical
Runyon groups
Antibiotic resistance
Opportunistic infection
Skin pathogens M.marinum & M. ulcerans
Buruli ulcer

3. Mycobacteria Mycobacterium leprae

4. Hansen's disease, leprosy
Chronic granulomatous communicable disease occurring in tropical and subtropical regions; characterized by inflamed nodules beneath the skin and wasting of body parts; caused by the Mycobacterium leprae.
Chronic disease, disfigurement, common in third world, millions of cases
Infects the skin –neural involvement, low temperature

5. Ridley Jopling Classification of Leprosy
Basis - Immunological
RR-Reversal reaction; ENL-Erythema nodosum leprosum; PB-Paucibacillary, MB-Multibacillary

7. Ulcers, resorption of bone worsened from careless use of hands (nerve damage)

8. Leprosy tuberculoid few organisms active cell-mediated immunity
lepromatous
many organisms
immunosuppression

9. Production of M. leprae antigens and
pathogenesis studies
in vitro
uncultivable
in vivo growth
low temperature
armadillo
mouse footpad

11. Leprosy lepromin skin testing acid-fast stains skin biopsies
clinical picture

12. Tuberculoid Leprosy

13. Lepromatous leprosy

14. Skin biopsy shows intradermal formation of epithelioid granulomas without caseous necrosis (HE). The papillary dermis is involved. Acid-fast staining is negative. Diagnostic hints include clinical information of numbness and histologic identification of nerve involvement by the granulomatous lesion.

15. Lepromatous leprosy (35 y-o) Male
         
Biopsy from erythematous and scaling nodules on the extremities. The bacilli forming "globi" are stained with PAS method.

16. Lepromin test
A test utilizing an intradermal injection of a lepromin, such as the Dharmendra antigen or Mitsuda antigen, to classify the stage of leprosy based on the lepromin reaction, such as the Fernandez reaction or Mitsuda reaction.
It differentiates tuberculoid leprosy, in which there is a positive delayed reaction at the injection site, from lepromatous leprosy, in which there is no reaction (i.e., a negative test result) despite the active malignant Mycobacterium leprae infection; the test is not diagnostic, since normal uninfected persons may react.

17. Erythema Nodosum Leprosum (ENL)
An inflammatory complication of leprosy that results in painful skin lesions on the arms and legs and face
Cause – Type III hypersensitivity Immune complex Vasculitis.

18. Lab Diagnosis Leprosy Easy in Lepromatous, difficult in Tuberculoid.
Demonstration of AFB
Nasal mucosa
Skin Lesion
Ear lobule
Skin clippings from 5-6 areas
Buttocks
Forehead
Chin
Cheek
Ear

19. Mycobacteria Atypical Mycobacteria

20. Mycobacteria other than human or bovine tubercle
Synonyms –
Atypical
Anonymous
Unclassified
Non tuberculous mycobacteria
Paratubercle
Tuberculoid
MOTT Mycobacteria Other Than Tubercle

21. Runyon Classification (1959) Basis – Pigment production & Rate of growth
Group I – Photochromogens
Form pigment after exposure to light
Example – M. kansasii
Habitat – Water & animals
Causes Pulmonary, skin, systemic, LN infections.
Group II – Scotochromogens
Pigment produced in dark
Example – M. scrofulaceum
Habitat – Water, soil, fomites
Causes cervical lymphadenitis in children
Group III- Nonphotochromogens
No pigment production
Examples – M. intracellulare, M. avium & M. xenopi
Habitat – Soil, Seawater, animals
Causes Pulmonary, gastrointestinal, renal, systemic, LN infections Pulmonary, epididymis
Group IV –Rapid growers
Colonies appear within seven days
Example –M. fortuitum,
Habitat- Water, soil & animals
Causes Pulmonary, gastrointestinal, renal, systemic, LN infections

22. Atypical mycobacteria
infect immunocompromised host
not transmitted man -man
healthy people

23. Atypical mycobacterial diseases
tuberculosis-like
leprosy-like

24. M. avium is much less virulent than M. tuberculosis
Mycobacteria and AIDS
M. avium is much less virulent than M. tuberculosis
does not infect healthy people
infects AIDS patients
M. avium infects
when CD4 (helper T cell) count greatly decreased
M. tuberculosis infection
infects healthy people
earlier stage of disease
more systemic

25. Other atypicals pigmented or not pigmentation in the light in the dark
growth
fast
slow

26. Mycolic acids mycobacteria longest chain length strongly acid fast
nocardia
intermediate chain length
weakly acid fast
corynebacteria
shortest chain length
not acid fast

27. Most found in US – Rare in Africa. Annual frequency in AIDS – 10-20%.
Mycobacterium avium complex (MAC)
Most common bacterial opportunistic infection (OI) in adults infected with HIV in the developed world.
Most found in US – Rare in Africa.
Annual frequency in AIDS – 10-20%.
Occurs late in HIV infection. Mean CD4+ Count ~ 10-30/μL. (TB occurs early.)
Inhaled or ingested from environment.
Spreads via lymphatics then hematogenously.
Taken up in reticuloendothelial organs.

28. Mycobacterium avium complex (MAC) Symptoms in the AIDS Patient:
Disseminated Gastrointestinal
Fever Chronic Diarrhea & Night Sweats Abdominal Pain
Weight Loss Malabsorption
Malaise Cholestatic Jaundice
Anemia
Elevated LFTs
(Alkaline Phosphatase)

29. MAC in the Non-HIV/AIDS Patient:
More common as a cause of pulmonary disease in persons born in United States than TB.
2) Increasing in incidence over the last years.
3) Progressive pulmonary disease on x-ray and clinically.
4) Sputum culture positive.
5) Dissemination rare to non-existent.

30. Diagnosis of MAC in AIDS
Biopsy of the involved reticuloendothelial
organs with acid fast stain and/or culture.
Blood culture. (85% of
patients with disseminated
MAC are mycobacteremic.)
EID CDC

31. ← MAC infection of lymph node.
Acid-fast bacilli
within plump
histiocytes.
CDC/Dr. Edwin P. Ewing, Jr.
Colon Biopsy
Mycobacterium
avium –
Acid Fast Stain →
© Dr. Peter Anderson, University of Alabama at Birmingham, Dept of Path.

32. Mycobacteria SKIN PATHOGENS

33. NAME OF DISEASE: Buruli ulcers, Mycoburuli ulcers
ETIOLOGICAL AGENT:
Mycobacterium ulcerans. It grows only at temperatures below 37° C, is non-chromogenic and niacin-negative and extracellular  
OVERVIEW:
An ulcer of the skin and underlying tissue is the sole symptom due to the unique temperature requirements of the organism. The disease is most common along the Nile River but is also found in Southeast Asia, Australia and Mexico.
PATHOGENESIS:
The organism can apparently penetrate the unbroken skin where it produces an ulcer. Despite extensive necrosis, lesions are painless, symptoms of systemic disease are absent and there is little histological evidence of an initial acute inflammatory response. Focal necrosis extends through the dermis and adipose tissue and into muscle. The cause of this necrosis is mycolactone.

34. Mycobacterium marinum
Swimming pool granuloma: Localized nodular skin inflammation (small reddish raised areas of skin) caused by a bacterium called Mycobacterium marinum
Atypical Mycobacterium found in salt and fresh water. M marinum is the most common atypical Mycobacterium to cause infection in humans. Infection occurs following primary inoculation of a skin abrasion or puncture and manifests as a localized granuloma
Contact with an aquarium, salt water, or marine animals such as fish or turtles. Exposure to M marinum via swimming pools is rare these days because most pools are chlorinated.
Cultures at 25-32°C may grow acid-fast bacilli in 7-21 days. The organisms are photochromogens

35. KEYWORDS Atypical Runyon groups Antibiotic resistance
Acid Fast
Ziehl-Neelsen Stain
5% H2SO4
Mycolic acids
M. leprae
Non cultivable
Armadillo, Mouse footpad
Lepromin test
Ridely Jopling classification Tuberculoid / Lepromatous
Lab diagnosis –Skin clippings
Atypical
Runyon groups
Antibiotic resistance
Opportunistic infection
Skin pathogens M.marinum & M. ulcerans
Buruli ulcer