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M. leprae.pptx
- 1. By Dr. Rakesh Prasad Sah Associate Professor, Microbiology
- 2. • Leprosy: chronic mycrobacterial disease of ancient world still affecting many parts of world maily Asia and Africa • Leprosy Kushta Roga in Sushruta Samhita, 600 BC. • Caused by Mycobacterium leprae first observed by Hansen in 1868. • First bacterial pathogen of human to described it still remains least understood not possible to grow in artificial culture medium.
- 3. • slender, slightly curved or straight bacillus. • acid-fast, but less than tubercle bacillus 5% H2SO4 is used. • Intracellular & extracellular, single or in group in cells present as bundles bound together by lipid like substance ‘glia’ & these masses are known as “globi”. • Parallel rows of bacilli in globi give appearance of ‘Cigar bndle’ ZN- Staining Uniform & Solid Fragmente d & granular Dead Bacilli Live Bacilli Help to monitor efficacy of the treatme nt
- 4. • slender, slightly curved or straight bacillus. • acid-fast, but less than tubercle bacillus 5% H2SO4 is used. • Intracellular & extracellular,single or in group.in cells present as bundles bound together by lipid like substance ‘glia’ & these masses are known as “globi”. • Parallel rows of bacilli in globi give appearance of ‘Cigar bndle’ ZN- Staining Uniform & Solid Fragmente d & granular Dead Bacilli Live Bacilli Help to monitor efficacy of the treatme nt
- 5. • Have not yet been grown on artificial culture media or tissue culture. • The most important animals used for experimental infection with M. leprae include mouse and nine-banded armadillos. • Nine banded armadillo. • Foot pad of mouse at low temp(200cafter inoculation granuloma devlop at the site in 1—6 mths. if CMI depressed (administration of antilymphocytic serum or thymectomy), generalised infection resembling L.L. • Armadillo L.L.
- 6. • One of best report from ICRC (Indian Cancer Research Institute) acid fast bacilli isolated from leprosy patients employing human foetal spinal ganglion cell culture. • Other Animals • Chimpanzees • Monkeys • Indian Pangolin • Golden hamster • Chipmunks
- 7. • Cell wall 4 layers. Inner peptidpglycan shape & rigidity external to this is lipoarabinomannan—B (LAM-B), attach to this is mycolic acid layer. outermost layer’s major component is phenolic glycolipid-1(PGL-1). LAM-B, PGL-1— used for serodignosisPGL-1supress CMI. • 18kda, 28kda,----
- 8. • Chronic granulomatous disease. • Bacilli localize primarily in the • Skin • Peripheral nerves • Nasal Mucosa • Tissue or organ may be involved • Source • infected patients. • Mode of transmission • droplets • skin lesions. • I.P.—Long, Variable. Preference Of Bacilli Lower Temperature Superficial & Cooler Tissues
- 9. • Types • Lepromatous, • Tuberculoid • Diamorphous • Indeterminate • CMI status-determines type. • Indeterminate occupies position between L.L. & T.T. • Type of leprosy changes with chemotheraopy & alternation in immune status.
- 10. • Seen in individuals either CMI is low or absent. • Severe form & poor prognosis. • More infectious, Lepromin negative deficient CMI. • High conc. of humoral abs No protective role. • Develops nodular lesion on • Face • Ear lobes • Hand • Feet • Less commonly on trunk
- 11. • Is slow and symmetric thickening of peripheral nerves & anesthesia • As a result of loss of sensation nodules ulcerate & secondary infection occur distortation & mutilation of extremities. • Multibacillary. • Skin lesions contain many macrophages packed with bacilli. • Lepra bacilli present in large no. in • Skin lesions • Mucosa of nose • Mouth • Upper respiratory tract • Bacilli shed in • Sweat • Nasal • Oral secretions.
- 12. • Localised form of disease CMI good. • few skin lesions Non elevated hypo or hyper pigmented macular patches involving • Face • Limbs • Trunk • Bacilli very few of absent tissues. • Lepromin positive intact CMI • abs. rarely produced. extend into big nerve trunks Involvement of local nerves become thickened, hard and tender lead to deformities of limbs
- 13. Feature Lepromatous leprosy Tuberculoid Leprosy Lepra Bacilli in lesion Numerous Scanty CMI Deficient / absent Adequate Lepromin test Negative Positive Infectivity Highly infectious Usually non infective Mycobacterial Antibodies Abundant Rarely produced
- 14. • Lesion resembels TL but bacteriological & immunological picture is of LL. • Shifting of the form to any of the two extreme type depends upon chemotherapy & alteration in immune status of host.
- 15. • Neither characteristic of TT nor LL. • Lesions in the form of maculoanashthetic patches. • Type 1 Reaction (Reversal Reaction) • seen in borderline patient who developed CMI and shift toward tuberculoid spectrum. • It may lead to permanent nerve damage. • This is due to DTH. • Type 2 ( erythema nodosum leprosum) • seen in LL patients under treatment. • This is due to formation of Ag-Ab complexes. • Clinically crops of red nodules appears on skin which last for 1-2 days.
- 16. Characters TT BT BB BL LL Bacilli in the skin - +/- + ++ +++ Nasal secretion - - - + +++ Granulomma formation +++ ++ + - - Lepromin Test +++ - +/- - - Ab to M. Leprae +/- +/- + ++ +++
- 17. • First described by Mitsuda in 1919. • Original lepromin antigen- boiled, emulsified, lepromatous tissue rich in lepra bacilli. • Nowadays, Lepromin-A or Lepromin-H. • Are of 2 types- • 1) Integral Antigen • 2) Bacillary Lepromin.
- 18. • Procedure 0.1ml intradermal. • Biphasic response • Early reaction of Fernandez erythema & induration in 24-48 hrs, remains for 3-5 days. Histologicaly serous exudates with lymphocytic infiltration. • Late reaction of Mitsuda appears after 1-3 wks of injection and peak in 4wks reaction the form of nodule-may ulcerate. Histologically infiltration with lymphocytes, epitheloid, giant cells. • Mitsuda indicates resistance to leprosy.
- 19. • Classification of leprosy. • Assessment of prognosis. • Assessment of resistance.(field workers)
- 20. • Specimen : Nasal Mucosa, skin lesions, & ear lobules. • The specimens from skin are obtained by “slit and scrape” method. • Skin- six diff areas including • buttocks • chin • cheek, • forehead • ears. Smear on slide Air dry & fix Stain (ZN- Pinch the Sight Scrape & Collect material Incise
- 21. • AFB staining • Grading- • 1-10 in 100 fields ---- 1+ • 1-10 in 10 fields----- 2+ • 1-10 per field--------3+ • 10-100 per field-----4+ • 100-1000 per field---5+ • More than 1000 bacilli, clumps & globi in every field = 6+
- 22. • Bacteriological Index:- • Defined as number of total bacilli in tissue. • Calculated by grades (number of pluses, +s) scored in all smears divided by no. of smears taken. • E.g. if 7 smears examined have total of 14+ BI will be 2. • For calculation minimum of • 4 skin lesions • nasal swab and • both ear lobes examined. • Morphological Index • Defined as percentage of uniformly stained bacilli out of total no. of bacilli counted. • Useful for assessing chemotherapy
- 23. • Animal inoculation • Lepromin test: - not diagnostic but to assess prognosis and response to treatment. • Serological test: Anti PGL-1 Antibodies detection. High titer in LL and LOW in TL.
- 24. • Chemotherapy : Dapsone. Emergence of Dapsone resistance hence WHO recommended MDT. • Immunotherapy: Efforts to induced effective CMI by IV inj of transfer factor, and extract of lymphocytes from patients suffering from TL etc. • Administration Of Vaccine: