Mycobacteria

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mycobacteria 1

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 Structure &microbiological characteristics of mycobacteria. 2 mycobacteria  Definition of mycobacteria:  Mycobacteria is a genus of Actinobacteria .  Includes pathogens known to cause serious diseases in mammals.  Ex. Tuberculosis and Leprosy .

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mycobacteria 3  Classification of Mycobacteria

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mycobacteria 4  Continued : Microbiological structure  Mycobacteria characters: Aerobic & non motile except Mycobacteria marinum.  Acid-alcohol fast stain: Why?  Morphology of mycobacteria: Found as bacilli or rod-shaped. Cell wall coated with thick waxy coat. Thick , lipid rich ,waxy cell wall.

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mycobacteria 5 Outer lipid Lipoarabinomannan (LAM) Mycolic acid Polysaccharides Peptidoglycan Lipid bilayer  Mycobacterial cell wall

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mycobacteria 6  Types of Mycobacteria

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mycobacteria 7  Pathogenicity  Transmission of Mycobacteria: Occurs primarily by the aerosol route but can also occurs through the GIT tract .  Multiplication: Firstly , no symptoms waiting accumulation of the number. The role of macrophage.

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mycobacteria 8  Pathogenicity Stages of infection:

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mycobacteria 9  Pathogenicity  Primary and post primary disease:  Primary is usually characterized by a single lesion in the middle or lower right lobe with enlargement of the draining lymph node.

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mycobacteria 10 Host defense  Role of CD4 and CD8 cells. Immune response is double-edged sword.

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mycobacteria 11  Applications of Mycobacteria  Pharmaceutical applications : 1-Proteins carrying antigenic determinant originating from biological agent other than M.bovis can be used in immunization against other diseases 2-Confirming diagnosis of Borelli infection; leptospirosis...by serum samples taken from patients affected by disease with no known history of tuberculosis. 3-Mycobacteria Smegmatis is common in soil and water is used as surrogate host for genetic analysis of Mycobacteria tuberculosis.

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mycobacteria 12  Pharmaceutical applications : 4-Characterizaton of five C19 steroids by microbial transformation of cycloartenol: 24-methylenecycloartanol and lanosterol with Mycobacterium sp.(NRRL B-3805 5-Isolation of a number of high molecular weight proteoglcans with immunological activity from M.vaccae . 6- Enhancing immunogenicity of DNA vaccines against M.tuberculosis by cod on optimization of Mycobacterial antigens .  Environmental applications : some types of mycobacteria can secrete organic substances in the soil useful to plants.

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mycobacteria 13 Diseases caused by Mycobacteria 1-Tuberculosis  T.B is a deadly infectious disease caused by Mycobacterium tuberculosis.  T.B attacks the lungs but may also attack other system in the body.  There are many species of Mycobacteria can cause T.B. 2- Leprosy

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mycobacteria 14 : Scientific classification Tuberculosis

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mycobacteria 15  Diagnosis: 1-Chest x-rays

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mycobacteria 16  Diagnosis: 2-Tuberculin test: Test to discover the sensitivity of the human body to the Tuberculo-protein.

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mycobacteria 17  Diagnosis: 2-Tuberculin test:  Methods: 1-mantous test. 2- heaf test. Interpretation: 1-Tuberculin +ve. 2-Tuberculin -ve. 3-weak +ve.

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mycobacteria 18  Diagnosis: 3-Blood tests. 4-Microscopic examination. 5-Microbiological culture of bodily fluids.  Symptoms of tuberculosis: Fever. Night-time sweating. Loss of weight. Loss of appetite

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mycobacteria 19  Epidemiology:  Generation of M.tuberculosis.  Infection with M.tuberculosis.  Predisposing factors:  Age.  Sex.  Race.  Place.  Occupation  Associated pulmonary disease.  Associated pulmonary infection. Associated systemic disease.

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mycobacteria 20  Treatment  General care: 1-Hospital admission & bed rest in : seriously ill, positive sputum, extensive disease. 2-proper nutrition.  Symptomatic treatment: 1-Mucolytics and expectorants for productive cough. 2-Bronchodilator may be indicated. 3-Antipyretics for fever.  Aims of treatment: 1-Cure the patient. 2-Prevent death. 3-Prevent relapse 4-Prevent transmission.

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mycobacteria 21  Treatment  Specific treatment:  Anti T.B drugs: Include Rifampcin, Insoniazeid, Ethambutol, Sreptomycin.  Corticosteroid therapy.  Immunotherapy in TB.  MDR-TB(multiple drug resistant Tuberculosis)  New anti- TB drugs.

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mycobacteria 22  Treatment  Special cases in treatment:  Treatment of TB in children  The same as adult.  General rules: are same as for adults.  Bacteriological evaluation: is done through gastric lavage-BAL.  Ethambutol is contraindicated in children because report their visual complaints.

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mycobacteria 23  Treatment  Treatment of TB in pregnant women  Treatment of active disease during pregnancy should not stop.  This drug should not be taken (Sterptomycin - Cyloserin- other Aminoglycosides – Ethionamide – pyrazinamide.  TB in pregnancy should be treated by at least two drugs of (INH – Rifamcin – Ethambutol.)  Infants of tuberculosis mother  No BCG in the first 40 days.  Do sputum examination for the mother.

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mycobacteria 24  Treatment  TB associated with other disease  TB in DM: diabetic patient are more liable to TB infection.  TB in renal failure: Streptomycin , other Amonoglycosides , Ethambutol are not to be taken .  TB in liver insufficiency: -Liver function should be monitored when one or more of following drugs are given: INH ,Rifampcin & Pyrazinamide. -The drug should be stopped if : Jaundice develops - liver enzymes increased 5 times.

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mycobacteria 25  Drugs used to treat TB  Quinolones:  Dose: A number of quinolones are developed and show activity against TB. 300 mg or 800 mg ofloxacin single daily dose for 6 months.  Toxicity: 1-GIT irritation, hypersensitivity & phototoxicity. 2-Contraindicated in pregnancy & nursing mothers & children less than 18 years.

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mycobacteria 26  Drugs used to treat TB  Rifampicin:  Dose: 10- 20 mg/kg/day  Toxicity: 1-Hepatotoxicity. 2-Hypersensitivity reaction. 3-GIT disturbance. 4-Renal comlications.  Streptomycin:  Dose: 15 mg/kg/day  Toxicity: Nephrotoxicity , hypersensitivity ,not used in pregnancy.

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mycobacteria 27 Diseases caused by Mycobacteria 2- Leprosy Leprosy is a chronic , communicable disease caused by Mycobacterium leprae.

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mycobacteria 28  Leprosy  The clinical spectrum of disease reflects the following:  Bacterial proliferation and accumulation at the site of infection. The immunological response.  Peripheral neuritis.

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mycobacteria 29  Diagnosis:  A person living in an endemic area with the following signs is considered to have leprosy:  Skin lesion with definite sensory loss.

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mycobacteria 30  Test for identification of M.leprae:  Lepromin test  Predisposing factors:  Children are highly susceptible to infection .  Malnutrition  Poor hygiene  Inadequate housing  Low standard of living and education.

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mycobacteria 31  Leprosy treatment:  Most widely used is sulphone (sulpphone+riamicin+clofazimine) Given for at least 2 years.

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