What is leprosy in microbiology?
Leprosy is a chronic infectious disease caused by Mycobacterium leprae. It damages peripheral nerves and can affect the skin, eyes, nose and muscles. Nerve injury in leprosy can cause severe disabling deformities.
What is mycobacteria in microbiology?
Mycobacteria are immobile, slow-growing rod-shaped, gram-positive bacteria with high genomic G+C content (61-71%). Due to their special staining characteristics under the microscope, which is mediated by mycolic acid in the cell wall, they are called acid-fast. This is also the reason for the hardiness of mycobacteria.
Where is Mycobacterium leprae commonly found?
Mycobacterium leprae is the aetiologic agent of leprosy affecting the skin and peripheral nerves. The infection is currently found in over 100 countries often located in high-burden areas against a low-burden background of cases.
What is Lepromin test?
A lepromin skin test is used to determine the type of Hansen’s disease (leprosy) a person has contracted. The lepromin skin test is also called the leprosy skin test. Leprosy, also known as Hansen’s disease, is a long-term (chronic) condition caused by the bacteria Mycobacterium leprae.
What are the classification of leprosy?
Leprosy has traditionally been classified into two major types, tuberculoid and lepromatous. Patients with tuberculoid leprosy have limited disease and relatively few bacteria in the skin and nerves, while lepromatous patients have widespread disease and large numbers of bacteria.
What are the three types of leprosy?
The first system recognizes three types of Hansen’s disease: tuberculoid, lepromatous, and borderline. A person’s immune response to the disease determines which of these types of Hansen’s disease they have: In tuberculoid Hansen’s disease, the immune response is good.
What is the difference between mycobacteria and bacteria?
Mycobacteria have an outer membrane. They do not have capsules, and most do not form endospores. The distinguishing characteristic of all Mycobacterium species is that the cell wall is thicker than in many other bacteria, which is hydrophobic, waxy, and rich in mycolic acids/mycolates.
What is special about mycobacteria?
The hallmark of mycobacteria is their unique abundance in lipid, constituting up to 40% of the dry weight of the tubercle bacillus3,4. The mycobacterial cell wall contains up to 60% of lipids, as compared with some 20% for the lipid-rich cell walls of Gram-negative microorganisms4.
Is Mycobacterium leprae a virus or bacteria?
Hansen’s disease (also known as leprosy) is an infection caused by slow-growing bacteria called Mycobacterium leprae. It can affect the nerves, skin, eyes, and lining of the nose (nasal mucosa). With early diagnosis and treatment, the disease can be cured.
What causes Mycobacterium leprae?
Leprosy (Hansen’s Disease) is a chronic infectious disease that primarily affects the peripheral nerves, skin, upper respiratory tract, eyes, and nasal mucosa (lining of the nose). The disease is caused by a bacillus (rod-shaped) bacterium known as Mycobacterium leprae.
What is the Lepra reaction?
Reversal reaction, or lepra type 1 reaction, is a delayed-type hypersensitivity reaction that arises when borderline leprosy shifts toward borderline lepromatous leprosy with treatment.
What are the two types of reaction observed in lepromin test?
The Fernández reaction occurs within the first 2 days and represents a delayed-type hypersensitivity reaction. At 3 weeks, the Mitsuda reaction is measured. A positive Mitsuda reaction is described as an indurated lesion of more than 4 mm that histologically shows granuloma formation.