Mycobacterium leprae

1. Acid-fast, cannot be grown on artificial medium

2. Infectivity low, chronic granulomatous disease of peripheral nerves and nasal mucosa

   1. Tuberculoid

      1. Large, flattened plaques on face, trunk, and limbs with raised erythematous edges.

      2. Dry, scaly, hairless centers.

      3. Peripheral nerves invaded- local noncontiguous anesthesia.

      4. Cell-mediated immunity works

      5. Delayed hypersensitivity to lepromin, tuberculin analog from leprous tissue

   2. lepromatous

      1. multibacillary

      2. cell-mediated immunity is deficient, T2 response

      3. no rxn to lepromin

      4. growth unimpeded. dense infiltration, may reach blood

      5. extensive, symmetric, depiliated, and diffuse

      6. analogous to military TB

3. Ziehl-Neelson stain the scrapings of tissue. Tuberculoid- clinically dx and histologic full-thickness biopsies

4. Sulfones block para-aminobenzoic acid metabolism, with 0rifampin and clofazimine (to prevent resistant mutants) for 6 months- controls or cures tuberculosis leprosy. Tx continued for 2 years

Category: Microbiology Notes