Mycobacterium tuberculosis

Everything about Mycobacterium tuberculosis

1. Presented by: Komal Mudgal (Section-A) Mycobacterium tuberculosis

2. History It is generally accepted that Mycobacterium tuberculosis originated from other, more primitive organisms of the same genus Mycobacterium . M. tuberculosis , then known as the " tubercle bacillus ", was first described on 24 March 1882 by Robert Koch. W ho subsequently received the Nobel Prize in Physiology or Medicine for this discovery in 1905; the bacterium is also known as "Koch's bacillus ". Tuberculosis has existed throughout history, but the name has changed frequently over time.

3. Consumption , Phthisis , Scrofula , Pott's disease , and the White Plague are all terms used to refer to tuberculosis throughout history. Origin : Scientific work investigating the evolutionary origins of the Mycobacterium tuberculosis complex has concluded that the most recent common ancestor of the complex was a human-specific pathogen, which underwent a population bottleneck.

4. Introduction Mycobacterium tuberculosis is an obligate pathogenic bacterial species in the family Mycobacteriaceae and the causative agent of tuberculosis . First discovered in 1882 by Robert Koch.

5. Morphology M. tuberculosis has an unusual, waxy coating on its cell surface primarily due to the presence of mycolic acid . This coating makes the cells impervious to Gram staining, and as a result, M. tuberculosis can appear either Gram-negative or Gram-positive . Acid-fast stains such as Ziehl-Neelsen , or fluorescent stains such as auramine are used instead to identify M. tuberculosis with a microscope.

6. Physiology It is highly aerobic and requires high levels of oxygen . It is primarily a pathogen of the mammalian respiratory system, it infects the lungs.

7. Cording M. tuberculosis (H37Rv strain) culture on the luminescent microscopy

8. Culture M. tuberculosis can be grown in the laboratory. S low growth rate, doubling roughly once per day. Commonly used media include liquids such as Middle brook 7H9 or 7H12, egg-based solid media such as Lowenstein-Jensen, and solid agar-based such as Middle brook 7H11 or 7H10. Visible colonies require several weeks to grow on agar plates. It is distinguished from other mycobacteria by its production of catalase and niacin . Other tests to confirm its identity include gene probes and MALDI-TOF.

9. Life cycle

10. There's 5 Stages of Tuberculosis : 1 . Onset (1-7 Days) : The bacteria is inhaled    2 . Symbiosis (7-21 Days) : If the bacteria does not get killed then it reproduces  3.Initial Caseous Necrosis (14-21 Days) : Tuberculosis starts to develop when the bacteria slows down at reproducing, they kill the surrounding non-activated macrophages and run out of cells to divide in. 4 .   Interplay of Tissue-Damaging and Macrophage Activating Immune Response (After 21 days) : Macrophages surround the tubercule but some may be inactive. Tuberculosis then uses it to reproduce which causes it to grow.   5 .  Liquification and Cavity Formation : The tubercules at one point will liquify , which will make the disease spread faster, not everyone will get to this stage. Only a small percent of people will get to this stage.

11. What causes tuberculosis? The Mycobacterium tuberculosis bacterium causes TB. It is spread through the air when a person with TB (whose lungs are affected) coughs, sneezes, spits, laughs, or talks. TB is contagious, but it is not easy to catch. The chances of catching TB from someone you live or work with are much higher than from a stranger.

12. Diagnosis of tuberculosis The most common diagnostic test for TB is a skin test where a small injection of PPD tuberculin, an extract of the TB bacterium, is made just below the inside forearm. The skin test is not 100 percent accurate and has been known to give incorrect positive and negative readings. Other tests that are available to diagnose TB are : Blood tests, chest X-rays, and sputum test

13. Prevention and treatment TB prevention – the BCG vaccine In 1920s the most widely used of all current vaccines, and it reaches more than 80% of all new born children and infants in countries where it is part of the national childhood immunization programme. 1 The BCG vaccine has been shown to provide children with excellent protection against the disseminated forms of TB. However protection against pulmonary TB in adults is variable

14. Treatment With the proper treatment, tuberculosis is almost always curable within 6 to 9 months. These are the three treatment options : Isoniazid (INH) : This is the most common therapy for latent TB. You typically take an isoniazid antibiotic pill daily for 9 months. Rifampin : You take this antibiotic each day for 4 months. It’s an option if you have side effects to INH. Isoniazid and rifapentine : You take both of these antibiotics once a week for 3 months under doctor’s supervision.

15. REFERENCES https :// sites.google.com/site/mycobacteriumtbstudy/home/life-cycle-of-organism https:// en.wikipedia.org/wiki/Mycobacterium_tuberculosis https:// www.medicalnewstoday.com/articles/8856.php

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