Mycobacterium

Question 1

Mycobacterium: general

Answer 1

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

Question 2

Mycolic acids assists in

Answer 2

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

Question 3

Types of acid fast stain

Answer 3

Ziehl-Neelson
Kinyons
Auramine Rhodamine

Question 4

The majority of mycobacterium are ___ pathogens

Answer 4

Opportunistic

Question 5

Can ID mycobacterium by

Answer 5

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

Question 6

Virulence factors

Answer 6

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

Question 7

Exception to Cell protein antigen being pathogentic

Answer 7

M. ulcerans- mycolactone/macrolide toxins

Question 8

Main reservoir of M. tuberculosis

Answer 8

Humans

Question 9

Multi-drug resistant TB is resistant to at least

Answer 9

Isoniazid and rifampin

Question 10

cause of zoonotic TB is

Answer 10

M. bovis

Question 11

M. bovis: transmission

Answer 11

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

Question 12

T or F

M. bovis has long survival term in environment

Answer 12

False

only survives a few weeks outside host

Question 13

Other species with high prevalence of M. bovis

Answer 13

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

Question 14

M. bovis: clinical signs

Answer 14

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

Question 15

TB in humans was known as

Answer 15

Consumption

Question 16

M. bovis: pathogenesis

Answer 16

pyogranulomatous lesions in any organ

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

Question 17

casenous lesions of necrosis are surrounded by ___

Answer 17

multinucleated giant cells (Langhan’s cells)

Question 18

Granulomas form as a result of ___ ____ immune response

Answer 18

Cell-mediated immune response- tubercle

Question 19

Common later stage lesions are called

Answer 19

tuberculosis cavitary lesions

Question 20

M. bovis: diagnostic tests

Answer 20

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

Question 21

M. Bovis: treatment

Answer 21

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

Question 22

Elements of bovine TB eradication programs

Answer 22

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

Question 23

Mycobacterium leprae causes

Answer 23

Leprosy or Hansen’s disease

Question 24

Only known reservoir for M. leprae is ___

Answer 24

nine-banded armadillo

Question 25

Paucibacillary

Answer 25

Tuberculoid leprosy, few AFB | cell mediated immune response, small number of bacteria

Question 26

Multibacillary

Answer 26

Lepromatous leprosy | no cell mediated response, severe disease with numerous AFB

Question 27

Leprosy general features

Answer 27

Chronic granulomatous debilitating disease | numbing skin lesions, nerve thickening, tissue sloughing

Question 28

Leprosy transmission

Answer 28

nasal secretions

Question 29

M. lepraemurium

Answer 29

Feline and murine leprosy

Question 30

M. lepraemurium: pathology

Answer 30

Granulomatous Dermatitis Panniculitis single or multiple SQ nodules and ulcerated lesions fastidious organism (hard to culture)

Question 31

M. lepraemurium: diagnosis

Answer 31

Direct staining- Geimsa or acid fast | culture, biopsy/histo, PCR

Question 32

In Geimsa or Gram stain ____ stained bacilli are seen

Answer 32

Negative stained organisms

Question 33

M. lepraemurium: Treatment

Answer 33

surgical excision (difficult), Rifampin, Clarithromycin, Clofasimine- long term (intracellular)

Question 34

In dogs, ____ is effective drug

Answer 34

Doxcycline

Question 35

M. avium subsp. paratuberculosis

Answer 35

Johne's disease in ruminants

Question 36

Johne's bacterium is found in

Answer 36

soil and water (even treated)

Question 37

Johne's primary host

Answer 37

Cattle | also infects sheep, goats, llamas, alpacas, deer

Question 38

Johne's disease: pathogenesis

Answer 38

chronic, progressive granulomatous enteritis

Question 39

Johne's effect spread is known as ___

Answer 39

Iceberg effect | 1 animal maybe clinically affected with several more subclinically affected

Question 40

Johne's disease: clinical signs

Answer 40

Diarrhea, weight loss, bottle jaw, thickened ileal mucosa, enteritis

Question 41

Johne's: Gold standard test

Answer 41

Direct fecal culture on Herrold's egg yolk medium | difficult, long (16 weeks)

Question 42

Johne's: diagnosis

Answer 42

PCR, ELISA, biopsy of tissue, Johnin skin test

Question 43

Johne's: contol

Answer 43

removing infected, management to reduce infection | antimicrobial treatment not recommended

Question 44

Johne's disease incubation period can last up to __

Answer 44

2 years | young animals are the most susceptible

Question 45

Johne's ELISA can result in false negatives in advanced stages due to __

Answer 45

Anergy