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

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Presentation on theme: "MYCOBACTERIA 2/2 M. leprae & Atypical MYCOBACTERIA 2/2 M. leprae & Atypical Professor Sudheer Kher."— Presentation transcript:

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

2 KEYWORDS Acid Fast Ziehl-Neelsen Stain –5% H 2 SO 4 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 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 casesChronic disease, disfigurement, common in third world, millions of cases Infects the skin –neural involvement, low temperatureInfects the skin –neural involvement, low temperature Hansen's diseaseHansen's disease, leprosyleprosy

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

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

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

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

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

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.testintradermalinjectionleprominDharmendra antigenMitsuda antigenstageleprosylepromin reactionFernandez reactionMitsuda 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.differentiatestuberculoid leprosy positivedelayed reactionsite lepromatous leprosyreactionnegativeresultactive malignantMycobacterium lepraeinfectiondiagnosticnormalpersons react

17 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. Erythema Nodosum Leprosum (ENL)

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) Runyon Classification (1959) Basis – Pigment production & Rate of growth Group I – PhotochromogensGroup I – Photochromogens –Form pigment after exposure to light –Example – M. kansasii –Habitat – Water & animals –Causes Pulmonary, skin, systemic, LN infections. Group II – ScotochromogensGroup II – Scotochromogens –Pigment produced in dark –Example – M. scrofulaceum –Habitat – Water, soil, fomites –Causes cervical lymphadenitis in children Group III- NonphotochromogensGroup 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 growersGroup 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 not transmitted man -man – healthy people

23 tuberculosis-like tuberculosis-like leprosy-like leprosy-like Atypical mycobacterial diseases

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

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

26 Mycolic acids mycobacteriamycobacteria –longest chain length –strongly acid fast nocardianocardia –intermediate chain length –weakly acid fast corynebacteriacorynebacteria shortest chain lengthshortest chain length –not acid fast

27 Mycobacterium avium complex (MAC) 1)Most common bacterial opportunistic infection (OI) in adults infected with HIV in the developed world. 2)Most found in US – Rare in Africa. 3)Annual frequency in AIDS – 10-20%. 4)Occurs late in HIV infection. Mean CD4+ Count ~ 10-30/μL. (TB occurs early.) 5)Inhaled or ingested from environment. 6)Spreads via lymphatics then hematogenously. 7)Taken up in reticuloendothelial organs.

28 Mycobacterium avium complex (MAC) Symptoms in the AIDS Patient: 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) (Alkaline Phosphatase)

29 MAC in the Non-HIV/AIDS Patient: 1)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 CDC/Dr. Edwin P. Ewing, Jr. ← MAC infection of lymph node. Acid-fast bacilli within plump histiocytes histiocytes. Colon Biopsy Mycobacterium avium – avium – Acid Fast Stain → © Dr. Peter Anderson, University of Alabama at Birmingham, Dept of Path.

32 Mycobacteria SKIN PATHOGENS

33 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. NAME OF DISEASE: Buruli ulcers, Mycoburuli ulcers

34 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 Mycobacterium marinum 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 Swimming pool granuloma: Localized nodular skin inflammation (small reddish raised areas of skin) caused by a bacterium called Mycobacterium marinumMycobacterium marinum

35 KEYWORDS Acid Fast Ziehl-Neelsen Stain –5% H 2 SO 4 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


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