Medical Microbiology Essay

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MORPHOLOGY Rosenblatt et al in 1942 examined them by electron microscope and demonstrated that the tubercle bacilli vary in length from 0.8 to 5.5pm and width from 0.2 to 0.6pm. However there are numerous variations from different ultureand even in same culture. Predominant form is rod shaped with rounded or slightly flattened ends, but curved bean - shaped or oval forms are common. Human form is longer and slender, and the bovine form is short and stumpy. Avian type is pleomorphic on morphological grounds alone organisms cannot be identified. STAINING PROPETY Acid fastness is due to the presence of lipoid fraction containing free hydroxyl groups known as mycolic acid' in the capsule of the organisms (Anderson 1938). According tolamanna the…show more content…
Medical Microbiology. 24thed USA, McGrawHill; 2007, chapter 24, p310-327. Bacilli contain the following constituents: PROTEINS : Non toxic to non-tubercular. But in small doses reaction occurs in infected subjects, purified protein derivatives contain a mixture of small proteins(10 kda). There are 3 antigenic compounds (menses and Hardleberg 1933). But do not provoke protective capacity in body. CARBOHYDRATRES…show more content…
A clinician’s guide to tuberculosis. India: Lippincott Williams and Wilkins; 2000. Chapter 1, Tuberculosis down through the centuries; p.2,4,7,14-17,51-53. The bacillus is filtered in nostrils and adenoids and produce lesion in the draining lymphnodes. The bacilli can be carried by droplet infection. DROPLET INFECTION : With the process of coughing and sneezing, droplets may be ejected right onto the face. Bacilli thus intiated easily take up their place in host without losing much of its vitality. Human type can flourish best when they are immediately carried from one mass to another. They begin to lose their vitality outside human body although they are known to cling to dust, screen, clothes, utensils of the room for several weeks. "Iliberculous carriers may possess thousands of bacilli in throat and nasal passages which when ejected in process of coughing in the neighbourhood of susceptible persons. DUST INFECTION : Bacilli laden sputum spit - out to open public street which is dried, pulvarised, and carried as dust before the bacilli can enter the system of inhalation but its importance is only second to the droplet infection, because thebacilli in dust more often perish. Tubercle bacilli however can remain alive for 3 months in darkeness screen and in protected corners (Frimodt

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