MYCOBACTERIUM TUBERCULOSIS overview slide share

Details summary of mycobacterium tuberculosis overview morphology antigenic structure and etc

1. VIVEKANANDHA ARTS AND SCIENCE COLLEGE FOR WOMEN VEERCHIPALYAM-637303,SANKAGIRI,SALEM Dt.,TAMILNADU,INDIA. AFFILIATED TO PERIYAR UNIVERSITY,SALEM;RECOGNISED UNDER SECTION 2(F)&12(B) OF THE UGC ACT 1956) SUBJECT INCHARGE; Dr.R.MYTHILI, HEAD OF THE DEPARTEMENT, Assistant professor, Department of Microbiology, VIAAS,Sankagiri. DEPARTMENT OF MICROBIOLOGY SUBJECT : MEDICAL BACTERIOLOGY SUBMITTED BY; JANAKI SUBRAMANI, III B.SC.MICROBIOLOGY, DEPARTMENT OF MICROBIOLGY, VIAAS,Sankagiri. TITLE : MYCOBACTERIUM TUBERCULOSIS

2. INTRODUCTION Tuberculosis is an ancient disease Spinal tuberculosis in Egyptian mummies. History dates to 1550-1080 BC. Obligate aerobes growing most successfully in tissue with a high oxygen content, such as the lungs. Facultative intracellular pathogens :infect mononuclear phagocytes (e.g.macrophage).

3. HISTROY OF M.TUBERULOSIS 1865 jean-antoine villemin confirmed that TB is contagious. The bacillus causing tuberculosis, was first identified an described on 24 march 1882 by Robert koch. He received the nobel prize in physiology or medicine in 1905 for this discovery. Major human disease-affects healthy people.

4. MYCOBACTERIUM TUBERCULOSIS ON BLOOD AGAR

5. MORPHOLOGY OF M.TUBERCULOSIS M.tuberculosis is straight or slightly curved rod 1 to 4µ long and 0.2 to 0.8µ wide. It may be arranged singly or in groups. Its non-motile, non-sporing, and non-capsulated. The bacterium that causes the tuberculosis. Cannot be classified as either gram-positive or gram negative. The ziehl-neelsen technique is employed for identification of acid-fast bacteria.

6. CULTURE CHARACTERS; It’s aerobic. Its grows slowly (generation time 14 to 15 hours). Colonies appears in 2 to 6 weeks Optimum temperature is 37°c and optimum ph is 6.4 to 7. M.tuberculosis grows luxuriantly in culture (eugonic). Additional of glycerol improves the growth of human types. The enriched media is prepared by adding eggs,glycerol,potatoes,meat,bone marrow infusions or aspargine.

7. MYCOBACTERIUM TUBERCULOSIS

8. LIQUID MEDIA: In liquid media without dispersing agent growth creeps up the side from the bottom,forming surface pellicles extending alone the side of tube. Diffused growth is obtained in Dubo’s medium (contain tween 80). Virulents strains tend to form serpentine cords in liquid media. Liquid media are generally required for sensitivity test,biochemical tests,and perparation of antigen and vaccine.

9. SOLID MEDIA: M.tuberculosis forms dry, rough,raised and irregular colony. It is creamy white first and yellowish or buff colored later on. It is not emulsified easily. The colony of bovis is flat, smooth and white, breaking up easily when touched. Culture technique are more sensitive,than staining procedure, but the major limitation are long time taken for their growth. Tuberculosis bacilli may also be grown on chick embryos and in tissue culture.,

10. M.TUERCULOSIS ON MICROSCOPE :

11. RESISTANCE; Its more resistant to drying and chemical disinfectants. Temperature 60°c for 20 minutes can kill it. Moist heat at 100°c kill it readily. In sunlight the culture may be killed in 2 hours. In sputum it survives 20 to 30 hours even in sunlight. It is killed by tinctured of iodine in 5 minutes and by 80 percent ethanol in 2 to 10 minutes.Phenol solution (5%)kills it in 24 hours.

12. COLONIES APPEARANCE OF M.TUBERCULOSIS

13. ANTIGENIC STRUTURE; Many antigens have been identified. Group specificity is due to polysaccharide. Type specificity is due to protein antigen. Protein antigen is used for tuberculin test. Tuberculin from M.tuberculosis,M.bovis,M.microtic appear to be indistinguishable.

14. BACTERIOPHAGE; Fresh isolate can be classified into 4 bacteriophage type A,B,C,AB. The predominant types in south india are A and AB. PATHOGENESIS; The basis of virulence of bacillus is unknown. Its does not produce toxin May be the various components of bacillus posses different biological activities influencing pathogenesis,allergy and immunity in disease.

15. BIOCHEMICAL REACTION; The important test for its identification are ; NIACIN TEST; POSITIVE ARYL SULFATASE;POSITIVE NEUTRAL RED;NEUTRAL CATALASE TEST;POSITIVE NITRATE REDUCTION;POSITIVE AMIDASE TEST;POSITIVE

16. DETERMINANTS OF M.TUBERCULOSIS PATHOLOGY; These determinants are as under; Cording factors are actually glycolipid derivatives of mycolic acid. They are present in outer surface of tubercle bacilli, they are responsible for; Inhibition of migration of polymorphonuclear leukocytes and ultimately results in the formation of granuloma. Inducing protective immunity as it is immunogenic. Growth of tubercle bacilli in serpentine cord. Cell surface glyolipids inhibits phagoly-some formation. This allows intracellular survival of tubercle bacilli after ingestion by macrophages. Resistance to antituberculosis antibodies which is acquired by mutation. There are two types of lesions; 1)Exudative 2)productive

17. CURRENT LABORATORY DIAGNOSTIC METHODS OF M.TUBERCULOSIS Microscopy (smear for acid-fast bacilli) PCR BACTEC Tuberculosis ELISA test kits Rapid test culture

18. LABORATORY DIAGNOSIS; The collection of sample like sputum,blood,bronhial washings,pleural fluid and cerebrospinal fluid are collected.The sputum should be collected in the early morning. The microscopic examination such as acid-fast bacilli and motility test and biochemical test. Laboratory diagnosis includes isolation of acid-fast bacterium,chest x-ray,gas-liquid chromatography,HPL test, thin-layer chromatograohy,tuberculin skin test and interferon-gamma release test.

19. TREATMENT The anti-mycobacterial drugs are isoniazid,rifampin,pyrazinamide,ethambutol and streptomycin was one in the combination. Prophylaxis for exposure to tuberculosis can include INH for 6 to 9 months. Mostly combined drugs are used for the treatment of tuberculosis,it reduce the resistant nature of pathogen. This combined therapy is administered for 12-24 months.

20. PREVENTION A vaccine for M.tuberculosis is BCG (Bacillus of calmette and guerin). This vaccine is not 100% effective, so it may effective from 60%-80% rate in children. Cover the mouth and nose while sneezing and coughing it reduces the spreading of TB.

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