Mycobacterium

Question 1

Generally, what infections do mycobacterium cause?

Answer 1

pulmonary and extrapulmonary infections

Question 2

Mycobacteria are acid-fast. Why?

Answer 2

because of their high lipid content in their cell walls

Question 3

How do mycobacteria show up on gram stain?

Answer 3

they are gram negative rods

Question 4

What type of organisms are Mycobacteria in regards to oxygen?

Answer 4

they are aerobic but they grow better in CO2

Question 5

What type of media is typically used to grow Mycobacteria?

Answer 5

media that is egg-based

Question 6

What disinfectants are mycobacteria resistant to?

Answer 6

halogen and quaternary ammonium disinfectants

Question 7

What can kill mycobacteria?

Answer 7

phenol and substituted cresylic compounds

Question 8

Are infections caused by Mycobacteria acute or chronic?

Answer 8

chronic

Question 9

What type of parasites are Mycobacteria?

Answer 9

facultative intracellular parasites

Question 10

What type of mycobacteria are killed by phagocytic cells and what type kill phagocytic cells?

Answer 10

saprophytic; pathogenic

Question 11

Where in the cell are mycobacteria found?

Answer 11

in the cytoplasm of the macrophage

Question 12

When mycobacteria rypture macrophages and adjoining cells are infected, what is formed as a result?

Answer 12

tubercles

Question 13

Where are lesions from mycobacteria typically localized?

Answer 13

in the lungs, spleen, or liver

Question 14

What are some immune mechanisms and proposed mechanisms by which mycobacteria are able to resist or alter the immune response?

Answer 14

1. promote phagosome-lysosome fusion 2. Aggregate macrophages into epithelioid granulomas to restrict and contain mycobacteria 3. processing and presentation of bacterial antigens 4. Activation of T cells to control infection 5. increase microbicidal capacity of the granuloma by recruiting effector T cells to it

Question 15

Why is the high lipid content of Mycobacteria important in their resistance to killing?

Answer 15

because they produce a variety of phospholipids, glycolipids, and sulfur-containing glycolypids that may interfere with host immune mechanisms

Question 16

What is the immune response to Mycobacterium?

Answer 16

it is largely cellular and almost entirely mediated by macrophages. Leukocytes have been known to release reactive nitrogen and oxygen intermediates

Question 17

What is Freund’s complete adjuvant?

Answer 17

a type of mineral oil that contains killed Mycobacterium smegmatis or M. phlei, but it is not used commercially due to lesions associated with the injection site

Question 18

How is mycobacteria diagnosed?

Answer 18

since mycobacteria induces a delayed-type hypersensitivity reaction, the DTH reaction (intradermal skin test) is used to expose tubercle bacilli associated with mycobacteria

Question 19

What antigen is used in the DTH reaction?

Answer 19

tuberculin

Question 20

What are the different types of tuberculins used in the DTH test?

Answer 20

PPD (purified protein derivative) and OT (old tuberculins)

Question 21

How are PPDs prepared?

Answer 21

by growing the organism on synthetic culture media, autoclaving, removing the cells, and precipitating the proteins with either ammonium sulfate or TCA

Question 22

How are OTs prepared?

Answer 22

by growing bacilli on synthetic culture media

Question 23

What type of tuberculins is used the majority of the time?

Answer 23

PPDs

Question 24

What do drugs used to treat mycobacteria usually contain?

Answer 24

isoniazid and rifampin

Question 25

What species does Mycobacterium tuberculosis infect?

Answer 25

primates

Question 26

What specific disease does Mycobacterium tuberculosis cause?

Answer 26

tuberculosis

Question 27

What famous scientist is associated with Mycobacterium tuberculosis?

Answer 27

Robert Koch

Question 28

What other species does Mycobacterium tuberculosis infect?

Answer 28

zoo animals

Question 29

In humans, tuberculosis is most often _______ in nature.

Answer 29

pulmonary

Question 30

What lesions are associated with tuberculosis in humans?

Answer 30

lung lesions or cavitations that can develop and progress to the point that large blood vessels are compromised and the patient can bleed to death quickly; lesions occur in the vertebral column, kidneys, bladder, larynx, and other sites

Question 31

How is tuberculosis treated?

Answer 31

six months of anti-TB drugs (1/3 kilogram a day)

Question 32

What is the resistant strain of tuberculosis called?

Answer 32

XDR-TB

Question 33

What is the recommended treatment for extensive drug resistant tuberculosis (XDR-TB)?

Answer 33

removal of lungs

Question 34

What is the name of the most widely used human immunizing agent for TB in the world?

Answer 34

Bacille Calmette Guerin (BCG)

Question 35

What does BCG contain?

Answer 35

a weakened live strain of Mycobacterium bovis

Question 36

Who is BCG effective for?

Answer 36

infants and children

Question 37

How do immunized individuals respond to PPD tubergulins?

Answer 37

positive - so it is hard to determine if they are immunized

Question 38

What disease does Mycobacterium bovis cause and in what species?

Answer 38

tuberculosis in cattle, pigs, cats, horses, primates, dogs, sheep, and goats

Question 39

What chemical in media inhibits the growth of Mycobacterium bovis?

Answer 39

glycerol

Question 40

How long does it take for Mycobacterium bovis to grow on media?

Answer 40

3-4 weeks

Question 41

What do cultures of Mycobacterium bovis look like?

Answer 41

rough and waxy

Question 42

How is Mycobacterium bovis destroyed?

Answer 42

via pasteurization or direct sunlight

Question 43

What species are making it difficult for Mycobacterium bovis eradication in the US?

Answer 43

white-tailed deer and farmed elk

Question 44

How is Mycobacterium bovis transmitted?

Answer 44

primarily through a respiratory route and a small percentage of infections occur through the ingestion of milk, congenitally, and possibly venereally

Question 45

What is the pathogenesis of Mycobacterium bovis?

Answer 45

once the individual is infected, the organism is ingested by macrophages, grows in the macrophage, kills and lyses it, then tuburcles made up of organism, macrophages, giant cells, and other inflammatory cells are encapsulated. The organism then travels through the lymph creating secondary metastasis

Question 46

What is the immune response to Mycobacterium bovis?

Answer 46

primarily cell mediated immune responses that are effective about 4 weeks following the infection

Question 47

How is Mycobacterium bovis diagnosed?

Answer 47

with the delayed type hypersensitivity (skin test) with PPD tuberculin (caudal fold test)

Question 48

Explain the testing process within a herd of a suspect bovine tuberculosis patient.

Answer 48

A normal vet will do a caudal fold test, then they will report it to the state, then the state will do a comparative cervical test on that individual and if it comes back positive they will do a single cervical test on the entire herd

Question 49

How are exotic ruminants diagnosed for Mycobacterium bovis?

Answer 49

Cervid TB Stat-Pak test which is a serologic test - only need to handle animals once

Question 50

What is MAC?

Answer 50

Mycobacterium avium complex

Question 51

What disease does Mycobacterium avium cause and in what species?

Answer 51

tuberculosis in avian species and swine

Question 52

Which Mycobacterium avium species are more virulent for birds but can produce disease in swine and other animals?

Answer 52

Serotypes 1, 2, and 3

Question 53

How are serotypes 1, 2, and 3 of Mycobacterium avium transmitted?

Answer 53

by ingestion of contaminated feces or soil in which organisms survive for a long time

Question 54

What lesions are associated with serotypes 1, 2, and 3 of Mycobacterium avium?

Answer 54

lesions in bones, joints, liver, spleen, and the intestinal tract

Question 55

What do lesions in the intestinal tract due to serotupes 1, 2, and 3, of Mycobacterium avium look like?

Answer 55

nodules that open and discharge into the lumen of the intestine

Question 56

What serotypes of Mycobacterium avium typically cause disease in swine?

Answer 56

serotypes 1, 2, 4, and 8

Question 57

What lesions are associated with serotypes 1, 2, 4, and 8 of Mycobacterium avium in swine?

Answer 57

foci in the mandibular and mesenteric lymph nodes and occasionally in the intestinal tract; lesions can occur in the liver and elsewhere

Question 58

How are serotypes 1, 2, 4, and 8 of Mycobacterium avium transmitted in swine?

Answer 58

via ingestion

Question 59

What disease is Mycobacterium leprae associated with and in what species?

Answer 59

leprosy in humans and armadillos

Question 60

How is Mycobacterium leprae transmitted?

Answer 60

via respiratory to respiratory

Question 61

What disease is associated with Mycobacterium lepraemurium and in what species?

Answer 61

leprosy-like disease in cats and rats

Question 62

What lesions does Mycobacterium marinum cause and in what species?

Answer 62

swimmin pool granuloma on the arms and legs of humans and granulomatous lesions in cold-blooded aniimals

Question 63

How do humans become infected with Mycobacterium marinum?

Answer 63

the organism travels from a site of trauma on an extremity that has contact with water

Question 64

What occurs to Mycobacterium marinum when grown in the presence of light?

Answer 64

it produces a yellow pigment

Question 65

What lesions does Mycobacterium kansasii cause and in what species?

Answer 65

lymph node lesions in cattle, deer, and swine

Question 66

Mycobacterium kansasii is the second leading cause of ____-_________ mycobacterial _______ and causes both ______ and occasionally ________________ lesions in humans.

Answer 66

non-tuberculosis; infections; pulmonary; extrapulmonary

Question 67

Mycobacterium kansasii is a _____ grower and is ________.

Answer 67

slow; photochromogenic

Question 68

What lesions are associated with Mycobacterium fortuitum and in what species?

Answer 68

it produces pulmonary disease in dogs and humans

Question 69

As compared to other Mycobacterium species, Mycobacterium fortuitum is _____ growing?

Answer 69

fast

Question 70

What species does Mycobacterium chelonae typically infect?

Answer 70

swine, cold-blooded animals, and humans

Question 71

What type of lesions does Mycobacterium chelonae cause in swine and cold-blooded animals?

Answer 71

lymph node lesions

Question 72

What type of lesions does Mycobacterium chelonae cause in humans?

Answer 72

skiin lesions associated with patients receiving porcine heart valve transplants

Question 73

True or False: Mycobacterium chelonae is a fast growing bacteria.

Answer 73

TRUE

Question 74

What is MAP?

Answer 74

Mycobacterium avium subspecies paratuberculosis

Question 75

What does MAP cause?

Answer 75

Johne's disease

Question 76

What lesions does Johne's disease cause?

Answer 76

chronic proliferative enteritis

Question 77

What species does Johne's disease affect?

Answer 77

cattle, sheep, goats, camels, llamas, and some wild ruminants

Question 78

What is the morphology of MAP?

Answer 78

smaller than the tubercle bacilli; short rod

Question 79

Where is MAP found in infected species?

Answer 79

in tissues and feces

Question 80

How long does it take for MAP to grow?

Answer 80

4-16 weeks on solid media

Question 81

What compound is required for primary isolation of MAP?

Answer 81

mycobactin - an iron chelating compound

Question 82

Where is MAP found in the environment?

Answer 82

in soil

Question 83

What can kill MAP?

Answer 83

moderate heat, 5% formalin or 5% phenol

Question 84

How is MAP transmitted?

Answer 84

from feces of individuals in the later stage of the disease to calves by ingestion; in utero ingestion is also found

Question 85

What is the pathogenesis of MAP?

Answer 85

once ingested, the organism penetrates into the epithelium of the ileum and colon and is phagocytosed by macrophages, the organism multiplies within the macrophages and stimulates a granulomatous response that spreads through the intestines and regional lymph nodes. The intestine becomes very thickened due to proliferation of epitheliod cdells

Question 86

What are the symptoms of clinical disease in cattle affected with Johne's disease?

Answer 86

intermittent diarrhea and emaciation

Question 87

How is MAP diagnosed?

Answer 87

PCR, culture, serologic responses, acid fast stain, and delayed type hypersensitivity testing

Question 88

When diagnosing MAP, what are PCRs done on (what organic material)?

Answer 88

feces

Question 89

What is the additive used to detect MAP in DTH?

Answer 89

johnin which is produced from culture filtrates of MAP

Question 90

Is there treatment for MAP?

Answer 90

No - it is not attempted

Question 91

How is Johne's disease controlled?

Answer 91

immunization only in populations that have confirmed cases

Question 92

Where is the Johne's vaccination injected?

Answer 92

into the brisket of young calves