Mycobacterium tuberculosis is the bacterium that causes tuberculosis in humans.Mycobacterium means fungus like bacterium.it is an air borne infectious disease.
The bacteria are straight,slender, rod shaped organisms.they are stained by zeil neelson method. once stained they resist decolourisation with acid and alcohol due to the presence of waxy substance mycolic acid in their cell wall.
the organism is sensitive to heat ,u.v light ,phenols and resistant to acids,alkali and alkaloids. they are susceptible to streptomycin,rifampicin and paraamino salicylic acid.
T.B is a slowly progressive chronic disease which often affects lungs, and other tissues and organs may also be affected. five types of strains of tubercle bacilli are known 1)human 2)bovine 3)avian 4)piscine and the 5)vole bacillus.
only th ehuman and bovine strains are pathogenic to man. the human type bacillus cause nearly all pulmonary tuberculosis.
the incubation period varies widely. it may be few weeks,months and years.
the symptoms are loss of appetite,weight loss,persistant cough etc.
the souce of infections are sputum of an infected person,contaminated food articles ,foods and drinks, unpasteurised milk or not properly boiled milk.
BCG vaccine is used to prevent the disease. the vaccine is a live attenuated strain of tubercle bacillus.the vaccine sensitises individuals to the tuberculo protein and increases resistance to disease.
control measures include: patient must be admitted to the hospital and must be kept in the hospital until he becomes sputum negative.patient should not be allowed to spit everywhere.sputum should be collected in the cup containing some disinfectant.
by following all these measures we can control the disease to a great extent.