Mycobacterium

Question 1

are mycobacterium aerobic or anaerobic

Answer 1

aerobic

Question 2

are mycobacterium intracellular or extracellular

Answer 2

facultative intracellular

Question 3

do mycobacterium form spores

Answer 3

no

Question 4

what morphology are mycobacterium

Answer 4

rods

Question 5

are mycobacterium gram positive or negative

Answer 5

positive

have thick peptidoglycan layer and no cell membrane
- does have mycomembrane

Question 6

are mycobacterium acid-fast positive or negative

Answer 6

positive - have mycotic acid in cell wall

Question 7

mycobacterium cell wall

Answer 7

lipids, glycolipids, peptidoglycans, mycolic acid

allows for survival within macrophages

increases susceptibility to bacteriophages

Question 8

how do mycobacterium differ in growth patterns

Answer 8

• speed: slow, rapid, or unable to grow in media
• pigment
• temperature requirement

Question 9

how do mycobacterium cause disease

Answer 9

tuberculosis, paratuberculosis, granulomatous diseases

can be tuberculous or non-tuberculous

can cause focal or disseminated disease

Question 10

tuberculosis

Answer 10

chronic granulomatous disease caused by a M. tuberculosis complex
- usually M. tuberculosis and M. bovis

Question 11

reservoir of tuberculosis

Answer 11

tuberculous individuals
(humans, cattle, wild mammals, chickens, birds)

Question 12

transmission of tuberculosis

Answer 12

respiratory and ingestion

highest incidence in high density areas

Question 13

pathogenesis of tuberculosis

Answer 13

1. enters through respiratory or oral tract
2. replicates locally
3. gets taken up by macrophages
4. survives and replicates in macrophages
5. forms granulomas from cell-mediated immune response

Question 14

what happens if there fails to be a cell-mediated response

Answer 14

disseminating inflammatory disease throughout the body

need cell response to wall off the mycobacterium in a granuloma

Question 15

clinical signs of tuberculosis

Answer 15

• rapid progressing but NOT an acute presentation (chronic disease)
• debilitating illness from cytokine release

emaciation, erratic appetite, irregular low fever, enlarged LNs, cough, diarrhea

Question 16

immunization for tuberculosis

Answer 16

live attenuated vaccine
- induces stronger cell mediated immune response

should be avoided in animals in areas trying to eradicate TB because can cause false positive mycobacterium tests

Question 17

diagnosis for tuberculosis

Answer 17

sample collection: tracheobronchial or gastric lavage, LN aspirates, urine/feces
- will be acid-fast positive

type IV hypersensitivity test: delayed response to tuberculin injection SQ, conjunctival, or intradermal
- positive test indicates past or present infection

Question 18

what strain of mycobacterium most commonly causes tuberculosis in ruminants

Answer 18

M. bovis

Question 19

what strain of mycobacterium most commonly causes tuberculosis in dogs/cats

Answer 19

M. bovis

M. tuberculosis can be anthropozoonotic

Question 20

what strain of mycobacterium most commonly causes tuberculosis in primates

Answer 20

M tuberculosis: from respiration

M bovis: from ingestion

Question 21

what strain of mycobacterium most commonly causes tuberculosis in birds

Answer 21

M. avium

Question 22

Johne’s disease

Answer 22

chronic, irreversible wasting disease in ruminants

caused by M. avium subspecies paratuberculosis

Question 23

is Johne’s disease reportable

Answer 23

yes

Question 24

reservoir for Johne’s disease

Answer 24

ruminants and rabbits

symptomatic and asymptomatic, wild and domestic

Question 25

transmission of Johne's disease

Answer 25

ingestion or contact with contaminated feces in utero infection from colostrum or milk

Question 26

clinical signs of Johne's disease

Answer 26

chronic weight loss and diarrhea with normal appetite and temperature progresses to fatality

Question 27

lesions of Johne's disease

Answer 27

permanent transverse corrugation of intestinal mucosa - granulomatous inflammation within lamina propria and submucosa enlarged LNs

Question 28

immunization for Johne's disease

Answer 28

reduces losses but antibodies are not protective

Question 29

diagnosis of Johne's disease

Answer 29

sample collection: ileocecal area - acid-fast positive - slow growing molecular diagnosis - PCR - faster

Question 30

atypical mycobacteriosis

Answer 30

chronic wasting condition caused by nontuberculous mycobacteria mammals, fish, frogs, snakes, turtles zoonotic - "fish handler's disease"