Mycobacterium Flashcards

(45 cards)

1
Q

Mycobacterium: general

A

Gram (+), acid fast positve
discovered by Robert Koch
contain mycolic acid

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2
Q

Mycolic acids assists in

A

Acid fast staining
drug, chemical, environment resistance
immunomodulating activities
prevent phagocytic killing

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3
Q

Types of acid fast stain

A

Ziehl-Neelson
Kinyons
Auramine Rhodamine

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4
Q

The majority of mycobacterium are ___ pathogens

A

Opportunistic

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5
Q

Can ID mycobacterium by

A

growth patterns
Biochemical patterns
total cell fatty acid analysis
nucleic acid detection/PCR

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6
Q

Virulence factors

A

Mycolic acid containing cell wall lipids- surviving in macrophages, stimulate cytokine prod., immunomodulating effects
Cell protein antigens- do not play big role in disease

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7
Q

Exception to Cell protein antigen being pathogentic

A

M. ulcerans- mycolactone/macrolide toxins

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8
Q

Main reservoir of M. tuberculosis

A

Humans

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9
Q

Multi-drug resistant TB is resistant to at least

A

Isoniazid and rifampin

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10
Q

cause of zoonotic TB is

A

M. bovis

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11
Q

M. bovis: transmission

A

ingestion, inhalation, possibly by mucous membranes and broken skin
Main portal of entry is GIT

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12
Q

T or F

M. bovis has long survival term in environment

A

False

only survives a few weeks outside host

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13
Q

Other species with high prevalence of M. bovis

A

Cervids, badgers in UK, Feral brush tail possums in New zealand

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14
Q

M. bovis: clinical signs

A

Signs vary greatly, enlarged regional lymph nodes, Cachexia, pulmonary forms with chronic cough

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15
Q

TB in humans was known as

A

Consumption

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16
Q

M. bovis: pathogenesis

A

pyogranulomatous lesions in any organ

bacilli are phagocytosed by macrophages, casenous necrosis in center of lesion

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17
Q

casenous lesions of necrosis are surrounded by ___

A

multinucleated giant cells (Langhan’s cells)

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18
Q

Granulomas form as a result of ___ ____ immune response

A

Cell-mediated immune response- tubercle

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19
Q

Common later stage lesions are called

A

tuberculosis cavitary lesions

20
Q

M. bovis: diagnostic tests

A

Tuberculin hypersensitivity skin lesions
Caudal fold tuberculin test
comparative cervical tuberculin skin test
interferon gamma release assay, necropsy, imaging, culture

21
Q

M. Bovis: treatment

A

not practical or efficacious
anti-tubercular drugs
single drugs use is limited

22
Q

Elements of bovine TB eradication programs

A

disease surveillance, pre and post moving test, cull positive animals, wildlife control

23
Q

Mycobacterium leprae causes

A

Leprosy or Hansen’s disease

24
Q

Only known reservoir for M. leprae is ___

A

nine-banded armadillo

25
Paucibacillary
Tuberculoid leprosy, few AFB | cell mediated immune response, small number of bacteria
26
Multibacillary
Lepromatous leprosy | no cell mediated response, severe disease with numerous AFB
27
Leprosy general features
Chronic granulomatous debilitating disease | numbing skin lesions, nerve thickening, tissue sloughing
28
Leprosy transmission
nasal secretions
29
M. lepraemurium
Feline and murine leprosy
30
M. lepraemurium: pathology
Granulomatous Dermatitis Panniculitis single or multiple SQ nodules and ulcerated lesions fastidious organism (hard to culture)
31
M. lepraemurium: diagnosis
Direct staining- Geimsa or acid fast | culture, biopsy/histo, PCR
32
In Geimsa or Gram stain ____ stained bacilli are seen
Negative stained organisms
33
M. lepraemurium: Treatment
surgical excision (difficult), Rifampin, Clarithromycin, Clofasimine- long term (intracellular)
34
In dogs, ____ is effective drug
Doxcycline
35
M. avium subsp. paratuberculosis
Johne's disease in ruminants
36
Johne's bacterium is found in
soil and water (even treated)
37
Johne's primary host
Cattle | also infects sheep, goats, llamas, alpacas, deer
38
Johne's disease: pathogenesis
chronic, progressive granulomatous enteritis
39
Johne's effect spread is known as ___
Iceberg effect | 1 animal maybe clinically affected with several more subclinically affected
40
Johne's disease: clinical signs
Diarrhea, weight loss, bottle jaw, thickened ileal mucosa, enteritis
41
Johne's: Gold standard test
Direct fecal culture on Herrold's egg yolk medium | difficult, long (16 weeks)
42
Johne's: diagnosis
PCR, ELISA, biopsy of tissue, Johnin skin test
43
Johne's: contol
removing infected, management to reduce infection | antimicrobial treatment not recommended
44
Johne's disease incubation period can last up to __
2 years | young animals are the most susceptible
45
Johne's ELISA can result in false negatives in advanced stages due to __
Anergy