Mycobacterium Flashcards
How many species are there in acid fast bacilli
125
Most prominent causing tuberculosis both pulmonary and extra pulmonary
Mycobacterium tuberculosis
This quickly decolorizes bacteria except mycobacterium
95% ethyl alcohol containing 3% HCL
Contains antibiotics to prevent overgrowth or contaminating bacteria and fungi
Selective media
7H11 contains what
Casein hydrolysate
Major component of agar media
Albumin
Neutralizes the toxic inhibitory effects of fatty acids in the specimen or medium
Albumin
Small inocula specimens from patients will grow in about?
3-6 weeks
Middlebrrok 7H9 and 7H12
Broth media
Supports proliferation of small inocula
Broth media
What does Mycobacterium look like in broth media
Clumps or masses
Growth is more rapid than on complex media
Broth media
What is the doubling time of tubercle bacilli
18 hours
Derive energy from simple carbon compounds
Obligate aerobes
Why is mycobacteria more resistant to chemical agents than other bacteria
Hydrophobic nature and clumped growth
Used to eliminate contaminants and for concentration techniques of clinical specimen
Acids and alkali
They are resistant to drying and survive for long periods in dried sputum
Mycobacterium tuberculosis
They are highly susceptible to Mycobacterium tuberculosis
Humans and guinea pig
Analysis of lipids which reveals patterns that aids in the classification of M. tuberculosis
Gas chromatography
They are called chord factors
Wax
Responsible for rope-like arrangement of the organism links to the pathogens pathogenicity
Waxes
They cause caseous/caseation type necrosis which is important to note among mycobacteria
Phosphotides
Form microscopic serpentine cords
Virulence strains
How is Chord factor (trehalose-6,6′-dimycolate) extracted from virulent bacilli
Petroleum ether
It causes chronic garnulomas
Chord factor
This elicit the tuberculin reaction
Proteins
They are rod-shaped, non-sporing aerobic bacteria and resist decolorization by acid or alcohol
Acid-fast bacilli
They are thin, straight rods which grows in coccoid & filamentous forms are seen with variable morphology
Mycobacterium tuberculosis
This type pf media is used for observing colony morphology and susceptibility testing
Semi-synthetic agar media
These contained defined salt, vitamins, cofactors, oleic acid, albumin, catalase and glycerol
Semi-synthetic agar media
Contain defined salts, glycerol and complex organic substances
Inspissated egg media
In this agar Mycobacteria grow in clumps and masses
Broth media
This is partly responsible for the acid fastness of Mycobacterium
Mycolic acids
They bound ti wax and can induce tuberculin sensitivity
Proteins
The zone of the TB granuloma where a large multi nucleated giant cells containing tubercle bacilli
Central area
The zone of the TB granuloma where a pale of epithelioid cells are arranged rapidly
Mid zone
The zone of the TB granuloma where there are fibroblasts and mononuclear cells
Peripheral zone
Where does tuberculosis reactivation begin
Apex of the lung
It is caused by a tubercle bacilli that have survived the primary lesion
Reactivation
Also called the Manto test and the purified protein derivative
Tuberculin test
This is the most sensitive method in identifying tubercle bacilli which provides results rapidly
Selective broth culture
First line of drug for Mycobacterium tuberculosis
Pyrazinamide
It inhibits synthesis of mycolic acid component of cell wall of Mycobacterium spp.
Isoniazid
Inhibits incorporation of mycolic acid into cell wall of Mycobacterium spp.
Ethambutol
It grows optimally at 41 celsius and has a smooth, soft non-pigmented colonies
Mycobacterium Avium Complex
They are cultured from water, soil, food and animals(birds)
Mycobacterium Avium Complex
This is a common opportunistic infection of bacterial origin in AIDS patients
Mycobacterium Avium Complex
Preferred initial therapy for Mycobacterium Avium Complex
Clarithromycin/azithromycin + ethambutol
This is known as a photochromagen which requires complex media for growth
Mycobacterium kansasii
These grow in foot pads of mice and armadillos
Mycobacterium leprae
Drug of choice for Mycobacterium leprae
Dapsone