Mycobacteria and Bacillus

Question 1

Mycobacterium tuberculosis

Answer 1

• Obligate aerobe

- Acid-fast rod

Question 2

Tuberculosis (TB)

Answer 2

• Major human disease
• Association with AIDS (grater effect)
• Drug resistance

Question 3

Transmission TB

Answer 3

• Human to human

- Airborne droplets

Question 4

Pathogenesis TB

Answer 4

• Infects lung tissue
• Distributed with macrophages
• Resist lysosomal enzymes
• Inhibits phagosome
• Cord factor (damages mitochondria)

Question 5

Laboratory Diagnosis TB

Answer 5

-Skin testing (delayed hypersensitivity, tuberculin and protein purified derivative, PPD)
-Chest X-ray
(positive skin test does not indicate disease)

Question 6

Injection of tuberculin

Answer 6

• Tuberculin is injected between skin layers

- Injection becomes hard and red in a person with tuberculosis

Question 7

Antibiotic Treatment TB

Answer 7

-Rifampin and Isoniazid

Question 8

Antibiotic Resistance TB MDR-TB

Answer 8

-Resistant to Isoniazid and Rifampicin

Question 9

Antibiotic Resistance TB XDR-TB

Answer 9

-Resistance to a quinolone, kanamycin, capreomycin, or amikacin

Question 10

Vaccination TB

Answer 10

• BCG vaccine (an attenuated strain of M. Bovis)

- Not effective prevention

Question 11

Mycobacterium leprae

Answer 11

• Leprosy
• Infects the skin
• Chronic disease

Question 12

Leprosy symptoms

Answer 12

• Ulcers , resorption of bone

- Nerve damage

Question 13

Tuberculoid Leprosy

Answer 13

• Active cell mediated immunity

- Few organisms

Question 14

Lepromatous Leprosy

Answer 14

• Immunosuppression

- Many organisms

Question 15

Phatogenesis M. leprae

Answer 15

• In vitro (Unculturable)

- In vivo (low temp, armadillo model)

Question 16

Diagnosis of Leprosy

Answer 16

• Lepromin (skin testing)
• Acid fast stains
• Clinical picture

Question 17

Bacillus Anthracis

Answer 17

• Gram-positive
• Aerobic
• Spore forming bacilli
• Encapsulates in 5% CO2
• Spores formed in soil can last for decades

Question 18

Anthrax

Answer 18

• Major disease to animals
• The basis for Koch’s postulates
• Humans are incidental host
• Agent of 2001 bioterrorism

Question 19

Routes of Infection Anthrax

Answer 19

• Direct contact
• Ingestion, infected meat
• Inhalation of infected soil

Question 20

Form of Anthrax

Answer 20

-Cutaneous
-Pulmonary
Gastrointestinal (not seen in the US)

Question 21

Cutaneous Anthrax

Answer 21

• Spores enter the broken skin, germinate and rapidly proliferate at site of entry
• Blue-black edema

Question 22

Inhalation Anthrax

Answer 22

• Spore inhalation and phagocytosis
• germination, replicate and infection of hilar lymph nodes
• Hemorrhagic necrosis of lymph nodes
• Fever, malaise, mayagia and non-productive cough
• Respiratoty failure

Question 23

Virulence factors Anthrax

Answer 23

-Capsule (Plasmid coded)
\+Antiphagocytic
\+Plasmid encoded
\+Not a good immunogen
\+Antibodies to the capsule are not protective against the disease

Exotoxins (Plasmid coded)
+Protective antigen (PA) plus
=edema factor EF
=lethal factor LF

Question 24

Treatment Anthrax

Answer 24

-Ciprofloxacin with
\+Rifampin
\+Vancomycin
\+Penicillin
\+Imipenem
\+Clindamycin
\+Clarithromycin

Question 25

Prevention Anthrax

Answer 25

• Antibody tho the complex is neutralizing and protective
• Vaccine cattle
• Vaccine humans at risk