01 Acid-fast rod Impossible to grow on artificial media• (Grown in the foot pads of mice, armadillos, and monkeys) Nonmotile Facultative intracellular growth
Metabolism 02 Catalase-positive Grows best at low temperature Phenolase-positive
03Mycobacterium leprae causes leprosy,also called Hansens Disease.
04- Infection occurs when a person is exposedto the respiratory secretions or skin lesions of an infected individual.- Cell-mediated immunity (cellular immunity)limits the spread of the bacteria. However, it causes inflammation and granulomas.
05 WINTERLeprosy damages Templatethe skin (sparingwarm areas such asthe armpit, groin,and perineum), thesuperficial nerves,eyes, nose, andtestes
5 Subdivisions based on the levelof cellular immunity 06• Lepromatous leprosy (LL) Tuberculoid leprosy (TL) Borderline lepromatous (BL) Borderline (BB) Borderline tuberculoid (BT)
Lepromatous leprosy (LL) Severest form of leprosy - Patients with LL cannot mount a delayed hypersensitivity reaction. - Very low cellular immunity Involves skin, nerves, eyes, and testes Acid-fast bacilli are found everywhere LL will lead to death if untreated
Tuberculoid leprosy (TL) Milder and self-limiting disease - Patients with TL can mount a cell- mediated defense - Delayed hypersensitivity reaction is intact. - Patients demonstrate localized superficial, unilateral skin and nerve involvement; non-infectious and spontaneously recover. Bacilli are difficult to find in lesions or blood
BL, BB, and BT 09Borderline lepromatous (BL). Borderline(BB), and Borderline Tuberculoid (BT)Represent a continuum between LLand TL** The skin lesions of BL will be morenumerous and have a greater diversity of shape than those of BT
Spcectrum of Leprosy WINTER Tuberculoid Template Borderline Lepromatous Number of skin lesions Single Several Many Hair growth on skin lesions Absent Slightly decreased Not affectedsation in lesions of the extremities lost Completely Moderately lost Not affected Acid-fast bacilli in skin None Several Innumerable scraping Lepromin skin Strongly positive No reaction No reaction test