MYCOBACTERIUM Flashcards
M. avium causes severe lesions in cattle. True or False?
False, minimal lesions
These are translucent pearly structures like small grains of tapioca formed when macrophages, lymphocytes, and other leukocytes gather at the primary site, regional lymph nodes and sites of secondary metastasis.
Tubercles
Mycobacterium is able to prevent fusion of _____ and _____ thereby preventing _____ _____.
This effect is called _____.
lysosome and phagosome; intracellular digestion; antifusion effect
What are the diagnoses for M. avium?
- Ziehl-Neehlsen’s
- Isolation on Dorset’s medium
* Reduces tellurite but not nitrate, do not hydrolyze Tween 80
Give the group in Runyon’s classification with the given data:
- Grow slowly and produce yellow pigment when exposed to light
- Produce skin ulcers and pulmonary diseases in humans
Group 1 - Photochromogenic strains
Describe the lesions induced by Mycobacterium.
Caseocalcareous lesions (in the anterior lobes)
Mycobacteria is not an obligate parasite. True or False?
False
Give the group in Runyon’s classification with the given data
- Grow slowly, do not produce pigments
- Form smooth colonies to isoniazid
- Highly pleomorphic and produce filaments resembling Nocardia
- Cause pulmonary diseases in humans
Group 3 - Non-chromogenic strains
Runyon’s classification is based on ?
- Growth rate
- Pigment production
Mycobacterium have toxin or extracellular virulence factor. True or False?
False
Give some components of the lipid content of cell wall of Mycobacterium.
Mycolic acid including trehalose 6, 6 dimycolate (cord factor)
Give the group in Runyon’s classification with the given data:
- Grow slowly and form orange-yellow pigment whether grown in light or dark
Group 2 - Scotochromogenic strains
What are the routes of transmission of Mycobacterium ?
- Aerogenous
- Milk-borne
- Congenital
- Sexually transmitted
What specie of animal is the natural host for Mycobacterium?
Cattle
Mycobacteria is classified as saprophyte. True or False?
True
M. avium falls under what group of Runyon’s classification?
Runyon’s Group 3
What is the available vaccine for M. bovis?
BCG (Bacillus of Calmette and Guerin)
_____ or _____ is a protein or polypeptide released into the medium by Mycobacterium.
Tuberculoprotein or tuberculin
Primary culture of Mycobacterium requires ____ to ____ weeks at 37 C before colonies detected.
6 to 8 weeks
In the growth of Mycobacterium, this alcohol is inhibitory.
Glycerol
What are the serotypes of M. avium virulent for chickens?
Serotypes 1, 2, and 3
These are large masses of smooth, grape-like bodies on serous surfaces.
Tuberculous pleuritis or peritonitis
What are the usual target lymph nodes of Mycobacterium?
- Bronchial
- Mediastinal
- Submaxillary
- Retropharyngeal
Classify Mycobacterium according to their oxygen requirement.
Strictly aerobic
In horses, Mycobacterium lesions typically occur in ?
Pharyngeal region, mesentery, lungs, liver, and spleen
Give the species of Mycobacteria with the given data:
- Affects humans, primates, dogs, pigs, and cattle
M. tuberculosis
In fluid medium, Mycobacterium’s growth is limited to surface unless ____ agents such as ____ ____ is added.
wetting; Tween 80
When Mycobacterium is disturbed, it produces?
Filaments that break into rods or cocci
M. avium easily affects swine. Lesions occur at what lymph nodes?
- Mandibular
- Mesenteric
In administration of Tuberculin Test, what sites of the body are preferred?
- Caudal fold
- Lip of vulva
- Side of the neck
*Intradermal; examined after 72 hours
As growth of tubercles continues, necrosis occurs at the centers and pearls become yellow-white opaques. Eventually, _______ appear.
Giant cells of Langhans (fusion or continued growth of macrophages)
Mycobacterium is gram negative. True or False?
False, gram positive
In cats, Mycobacterium lesions typically occur in ?
Abdominal organs and lungs
In culturing Mycobacteria, what is most frequently used media ? (Hint: food)
Media with egg yolk
* Dorset’s
* Stonebrink’s
In swine, Mycobacterium lesions typically occur in ?
Lymph nodes of head, neck, and abdomen
M. avium is strongly acid and alcohol fast. True or False?
True
Give the species of Mycobacteria with the given data:
- Induces Johne’s disease, debilitating disease in cattle characterized by chronic or intermittent diarrhea
M. paratuberculosis
Give the morphology of Mycobacterium.
- Short, plump rods in tissues; large, slender, and beaded in culture media
- Acid-fast
Mycobacteria is a facultative intracellular parasite. True or False?
True
Give the clinical signs of chickens affected by M. avium.
- Loss of weight, weakness, listlessness, and eventual death
- Caseous lesions in intestines, liver, and spleen
What are the different diagnoses for Mycobacterium?
- Characteristic lesion at necropsy
- Ziehl-Neelsen’s staining
- Culture, isolation, and identification
- On Lowenstein-Jensen or Kirchner medium
- 6 to 8 weeks at 37 C - Animal inoculation
- Tuberculin test
In sheep, goats, dogs, and cats, M. avium infection is frequent. True or False?
False
Give the group in Runyon’s classification with the given data:
- Rapid growers, mature in less than 1 week at 25 to 37 C
Group 4
Animal Inoculation:
Give the different results of M. tuberculosis inoculated on: Guinea pig, Rabbit, and Chicken. (+ or -)
Guinea pig: +
Rabbit: +/-
Chicken: 0
Animal Inoculation:
Give the different results of M. avium inoculated on: Guinea pig, Rabbit, and Chicken. (+ or -)
Guinea pig: +/-
Rabbit: +
Chicken: +
M. bovis is more potent but less specific than M. tuberculosis. True or False?
False, other way around.
Cord factor is present in virulent strains which is important in stimulating ______ ______.
granulomatous responses
What are the other tests to diagnose Mycobacterium infection>
- Ophtalmic test
- Thermal test
- Stormont test (2 injections at same site, examined 7 days later)
Give the pathogenesis of Mycobacterium .
Inhalation -> deposited in alveolar sac ->< ingested by alveolar
macrophages -> multiplies and kills phagocytes -> reingested by macrophages -> organisms filtered from regional lymphatic system -> intracellular multiplication -> bloodstream -> disseminated to
other body sites -> back to lungs
How can you be immunized from Mycobacterium infection?
Cell-mediated immunity (T-cells)
The lipid content of cell of Mycobacterium is approximately how many percentage?
60%
Mycobacterium is acid-fast. True or False?
True
In sheep and goats, Mycobacterium lesions typically occur in ?
Mainly pulmonary (progressive in young kids)
Give the species of Mycobacteria with the given data:
- Induces tuberculosis in cattle, pig, cat, horses, primates, dogs, sheep
M. bovis
Give the appearance of colonies of Mycobacterium.
- Colonies appear as minute dull flakes that thicken into dry irregular masses
- Light yellow that progresses into deep yellow to brick red when exposed to light
- Develops into confluent growth on surface, becomes rough and wavy which before was thick and wrinkled
Mycobacterium does not grow at what temperature ?
25 C
Give the species of Mycobacteria with the given data:
- Only in tropical countries; causes bovine farcy
M. farcinogenes
How do avians get immunized from M. avium infectioN?
- Cell mediated
- Humoral
Cell of Mycobacterium is made up of ?
- Mycosides (glycolipids)
- Waxes D (mycolic acid)
- Cord factor ( trehalose 6, 6 dimycolate)
The lipid content of cell of Mycobacterium is responsible for ? (Hint: 3 answers)
- Hydrophobicity of bacteria
- Slow growth
- Resistance to acid, disinfectants, antibodies, and dessication
Give the cultural and biochemical features of M. avium.
- Usually growth visible in less than 1 week, well-developed in 2 weeks
- Colonies soft, moist, yellow that becomes yellowish to pinkish with age and exposure to light
Animal Inoculation:
Give the different results of M. bovis inoculated on: Guinea pig, Rabbit, and Chicken. (+ or -)
Guinea pig: +
Rabbit: +
Chicken: 0
M. avium is more variable in shape than M. bovis. True or False?
True
