Mycobacterium

Question 1

Genus Mycobacteria

Answer 1

Ubiquitous, rod shaped, non motile, non spore forming
Non capsulated and resist decolorization
Cell walls have mycolic acid and acid-fast bacilli

Question 2

What does mycolic acid do?

Answer 2

Inhibits uptake of nutrients into bacterial cell
Causes cell to clump

Question 3

The generation or doubling time for M tuberculosis is __________

Answer 3

18-24 hours

Question 4

Mycobacterium growth

Answer 4

Löwenstein-Jensen medium
Readily killed by heat (pasteurization)
Resistant to chemical change and drying

Question 5

Most mycobacteria are _________

Answer 5

Non pathogenic (soil and water organisms)

Question 6

M. Tuberculosis transmission

Answer 6

Humans tuberculosis (TB)
From milk without proper pasteurization, human to human (resp. aerosols)

Question 7

M. Tuberculosis Epidemiology

Answer 7

1/3 world pop carries (not infections but (TB+)
8 mill cases / year
3 mill deaths/ year

Question 8

M. Tuberculosis Pathogenesis

Answer 8

Chronic infectious disease
Inhaling droplet with tubercle bacilli
Resist macrophages and multiply intracellularly

Question 9

Tubercle bacilli size significance

Answer 9

Because they’re small, they’re airborne for long periods of time —> ingestion

Question 10

Mycobacterium Bovis

Answer 10

Live attenuated bovine strain
Media is Bacille-Calmette-Guerin
Used to immunize humans

Question 11

How does M. Bovis affect cattle?

Answer 11

Affects respiratory tract + adjacent LNs
Hematogenous dissemination with liver and kidneys
Uterus= fetal infection
Abortion (less than 2%)

Question 12

Clinical signs of M. Bovis

Answer 12

Lesion in lung
Infection of udder
Contaminated milk
Coughing and sneezing

Question 13

M. Bovis spread

Answer 13

Contaminated feed, aerosol form other cattle

Question 14

M. avium spp. avium

Answer 14

Poultry infections via alimentary canal, disseminate to liver and spleen
Psittacine resistant but susceptible

Question 15

Dogs and cats with mycobacteria

Answer 15

Infected with M. Bovis
Dogs susceptible to M. Tuberculosis

Question 16

Horses with mycobacterium

Answer 16

Rarely infected but more with M. Avium ssp. Hominissuis

Question 17

Primates infected with My bacterium

Answer 17

Susceptible to M. Tuberculosis than M. Bovis. Resistant to M. Avium

Question 18

Diagnosis of mycobacterium

Answer 18

Ziehl- Neelsen/ acid-fast stain
Smear with red stain carbon-fuschin
Counter stain with methylene blue

Question 19

Cold stain modification for mycobacterium diagnosis

Answer 19

The carbol-fuschin first dissolved in detergent

Question 20

TB skin test (Mantoux tuberculin test)

Answer 20

Intradermal injection Of Ags
Human: Purified protein derivative
Cattle: comparative Intradermal tuberculin

Question 21

Tuberculin testing sites

Answer 21

Human: inner arm
Bovine: skin of caudal folds
Swine: skin of ear
Avian: wattles (swelling +)

Question 22

Treatment for Mycobacteria

Answer 22

First-line and second-line drugs
Prophylactic treatment with isoniazid for pets

Question 23

Mycobacteria control/ prevention in cattle

Answer 23

ID and elimination of infected
No BCG vx in low prevalent situations
Distinguish infected from vaccinated

Question 24

M. Avium spp. paratuberculosis (MAP)

Answer 24

Broad host range, high degree of tropism
Causes chorionic enteritis and chronic granulomatous disease

Question 25

Paratuberculosis

Answer 25

Chronic inflammation of intestine caused by M . Paratuberculosis Chron’s disease in humans Johne’s disease of ruminants

Question 26

Where is M. Avium spp. paratuberculosis (MAP) found?

Answer 26

Isolated from gut/ feces In milk, feces, and meat of infected cattle In water supplies with infected cattle feces

Question 27

What is MAP resistant to?

Answer 27

Standard food processing techniques (pasteurization and cooking) Standard water treatment methods

Question 28

Clincal symptoms of MAP

Answer 28

Emaciation Unresponsive to dewormers and antibiotics Profuse water diarrhea (cattle) Intermandibular edema

Question 29

Differential diagnosis of paratuberculosis

Answer 29

Intestinal parasitism, chronic malnutrition, caseous lymphadentitis, ovine progressive pneumonia, environmental toxins, cancer

Question 30

Johne’s disease public health

Answer 30

Most serious disease affecting cattle industry Difficult to recognize, control and treat Increased milk contamination

Question 31

Diagnostic tests for MAP

Answer 31

Culture of feces 8-24 weeks incubation Blood tests, ELISA, acid-fast staining of intestinal mucosa PCR

Question 32

Leprosy

Answer 32

M. Leprae (human) M. Lepraemurium (rodent) More common in tropical countries Not highly contagious

Question 33

How is leprosy transmitted

Answer 33

When exudate of mucous membrane lesions and skin ulcers reach broken skin Young children and males susceptible