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Tb

  1. 1. MYCOBACTERIA Jaime A. Santos
  2. 2. MYCOBACTERIA: CHARACTERISTICS thin,nonmotile and nonspore forming rods obligate aerobes slow growing cell wall has high lipid content and mycolic acid generally catalase positive acid-fast
  3. 3. MYCOBACTERIA: CHARACTERISTICS thin,nonmotile and nonspore forming rods obligate aerobes slow growing cell wall has high lipid content and mycolic acid generally catalase positive acid-fast
  4. 4. CLASSIFICATION Mycobacterium
  5. 5. CLASSIFICATION Mycobacterium M. tuberculosis MOTT M. leprae complex (Nontuberculous) M. tuberculosis M. bovis Runyon 1 to IV M. microti M. africanum
  6. 6. M. TUBERCULOSIS optimal growth:  37 C/ 5-10% CO2/ pH 6.0-7.6. in vivo, it can use a variety of enzymes for anaerobic metabolism requires complex media such as Löwenstein Jensen doubling time of ~18 hours.  Colonies visible in 3-6 weeks multiplies intracellularly in phagosome and prevents phagolysosome fusion
  7. 7. M. TUBERCULOSIS CELL WALL
  8. 8. M. TUBERCULOSIS CELL WALL
  9. 9. VIRULENCE FACTORS Mycolic acid glycolipids Catalase, peroxidase and trehalose 6,6 and lipoarabinomannan dimycolate  (cord - help resist the host factor)- cause cell oxidative response  granuloma formation Sulfatides and trehalose dimycolate- toxic to animal models
  10. 10. MAGNITUDE OF TB PROBLEM >1/3 of world’s population infected 8-9 million new cases annually 3 million deaths annually ~1.3 million of these new cases are in children with ~500 thousand deaths annually Philippines ranks no.1 in Western-Pacific
  11. 11. BACILLI INHALED 2 - 6 wks CMI PATHOGENESIS
  12. 12. IMMUNE RESPONSE
  13. 13. IMMUNE RESPONSE
  14. 14. IMMUNE RESPONSE
  15. 15. IMMUNE RESPONSE
  16. 16. CLINICAL MANIFESTATIONS asymptomatic other symtoms and signs depending on the fever organ involved e.g. CNS, bone, renal cough >3 weeks chest pain hemoptysis lymphadenpathy
  17. 17. CHILDHOOD TB asymtomatic ~50% failure to make a quick return to health after an cough/wheezing > 2 infection e.g. weeks measles,tonsillitis or pertussis fever > 2 weeks failure to respond to painless cervical and/or appropriate antibiotics other lymphadenopathy as in AOM or poor weight gain pneumonia
  18. 18. DIAGNOSIS SIGNS AND SYMPTOMS HISTORY OF EXPOSURE CHEST X-RAY TUBERCULIN TEST BACTERIOLOGIC DIAGNOSIS: SMEAR, CULTURE, PCR HISTOLOGIC
  19. 19. CHEST X-RAY
  20. 20. CHEST X-RAY
  21. 21. CHEST X-RAY
  22. 22. TUBERCULIN TEST Mantoux test 0.1 ml of solution containing or equivalent to1g ( 5 TU PPD-S) read at 48-72 hours using ballpoint pen method results recorded in mm delayed-type hypersensitivity
  23. 23. TUBERCULIN TEST Mantoux test 0.1 ml of solution containing or equivalent to1g ( 5 TU PPD-S) read at 48-72 hours using ballpoint pen method results recorded in mm delayed-type hypersensitivity
  24. 24. CULTURE incubated at 35° to 37° C in an atmosphere of 5 to 10% CO2 cultures should be examined weekly for 8 weeks. solid media e.g. Lowenstein-Jensen allows visualization of colony morphology but requires 3-4 weeks broth systems detecting 14C labelled CO2 (BACTEC) require only 5-12 days
  25. 25. ANTI-TB DRUGS isoniazid (H) - 5 to 10 mg/kg ( max 300 mg) rifampicin (R) - 10 to 15 mg/kg (max 600 mg) pyrazinamide (Z) - 15 to 30 mg/kg (max 2 gm) ethambutol (E) - 15 to 25 mg/kg (max 2.5 gm) streptomycin (S) - 20 to 30 mg/kg (max 1 gm) second-line drugs PROBLEM OF DRUG RESISTANCE
  26. 26. MOTT Nontuberculous mycobacteria (NTM) are soil and water organisms noncommunicable Disease develops in setting of trauma/surgery or immunosuppression. INH resistant Diagnosis is by acid fast staining of the specimen; followed by culture and/or 16s rRNA probes culture
  27. 27. RUNYON CLASSIFICATION Group Growth Pigment Examples Disease 1. similar to TB yellow-orange on light 1. M. kansasii I slow (photochromogen) 2. M. marinum 2. swimming pool granuloma yellow-orange in light II slow or dark M. scrofulaceum cervical adenitis (scotochromogen) M. avium intracellulare similar to TB, III slow no pigment complex (MAC) esp. in AIDS M. fortuitum soft tissue, lung, bone, IV rapid (5 days) no pigment M. cheilonae CNS, eye infections
  28. 28. MYCOBACTERIUM LEPRAE cannot be cultured can be grown in armadillos or in mouse footpads optimal T for M. leprae is lower than core body temp, so it grows on skin and superficial nerves found in macrophages and Schwann cells. complex cell wall has lipoarabinomannan (LAM) & a unique M. leprae-specific phenolic glycolipid (PGL-1).
  29. 29. MYCOBACTERIUM LEPRAE cannot be cultured can be grown in armadillos or in mouse footpads optimal T for M. leprae is lower than core body temp, so it grows on skin and superficial nerves found in macrophages and Schwann cells. complex cell wall has lipoarabinomannan (LAM) & a unique M. leprae-specific phenolic glycolipid (PGL-1).
  30. 30. LEPROSY anesthetic plaques, symmetric skin and asymmetric nodules, plaques, peripheral nerve leonine (i.e., lion-like) trunk involvement, facies, loss of paucibacillary eyelashes and body hair, multibacillary
  31. 31. LEPROSY tuberculoid lepromatous anesthetic plaques, symmetric skin and asymmetric nodules, plaques, peripheral nerve leonine (i.e., lion-like) trunk involvement, facies, loss of paucibacillary eyelashes and body hair, multibacillary
  32. 32. LEPROSY (HANSEN’S DISEASE) M. leprae causes leprosy, which is also known as Hansen’s Disease. The incubation period for leprosy is 5-7 years. Prolonged exposure required to become infected 8 million infected with 600,000 new cases annually
  33. 33. LEPROSY (HANSEN’S DISEASE) M. leprae causes leprosy, which is also known as Hansen’s Disease. The incubation period for leprosy is 5-7 years. Prolonged exposure required to become infected 8 million infected with 600,000 new cases annually
  34. 34. LEPROSY AND THE IMMUNE SYSTEM
  35. 35. DIAGNOSIS clinical signs lepromin skin test (mainly of immune status) biopsy and histology
  36. 36. TREATMENT dapsone, rifampin, clofazimine, and either ethionamide or prothionamide Paucibacillary cases (tuberculoid and borderline tuberculoid) x 6 months, dapsone alone is usually given for up to 3 years after disease inactivity lepromatous or borderline lepromatous leprosy may require primary treatment for 3 years, with dapsone alone continued for the rest of the patient's life antiinflammatory drugs; wound care
  37. 37. Thank you!

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