20 Anthrax

Question 1

what causes anthrax

Answer 1

Bacillus anthracis is the etiological agent of the disease known as anthrax

Question 2

what is anthrax gram

Answer 2

Gram-positive

Question 3

what is the ‘respiration’ of anthrax

Answer 3

aerobic

Question 4

what shape is anthrax

Answer 4

rod

Question 5

does anthrax move

Answer 5

non-motile

Question 6

do anthrax form spores

Answer 6

key characteristic is that it forms endospores which are oval and located centrally in the cell

Question 7

where are anthrax spores

Answer 7

spores persist in the environment

Question 8

what disease is anthrax

Answer 8

anthrax primarily disease of herbivores

Question 9

what animals is anthrax common in

Answer 9

sheeps, goats, cattle, horse

Question 10

how do humans get anthrax

Answer 10

Infections result from direct contact with an infected animal or from exposure to spores in animal products. Person-to-person transmission is extremely rare

Question 11

how do spores enter humans

Answer 11

Spores enter through skin lesions and mucous membranes

Question 12

what happens when B. anthracis replicates or its spores germinate

Answer 12

Toxins are produced and accumulate

The toxins cause fluid accumulation (swelling, edema) and cell damage

Question 13

what happens from cutaneous anthrax

Answer 13

Because of fluid accumulation and cell damage a papule starts to develop which will ulcerate and necrotise to form an Escher

Question 14

what happens if spores are inhaled

Answer 14

pulmonary anthrax

Question 15

symptoms of pulmonary anthrax

Answer 15

growth and toxin production in lungs causes:

> swelling mediastinal (thoracic cavity) haemorrhage, septicaemia and possibly death

Question 16

what happens if spores are ingested

Answer 16

intestinal anthrax

Question 17

symptoms of intestinal anthrax

Answer 17

rapid onset abdominal pain and abdominal swelling due to haemorrhage, septicaemia and death

Question 18

what may cutaneous anthrax cause when disseminate

Answer 18

10% of cases disease will disseminate and may result in

• Septicaemia (bad)
• Haemorrhagic meningitis (very bad)
• If the colonising bacteria continue to multiply and produce toxins then there is the risk of death (worse than very bad)

Question 19

how many anthrax toxins are there

Answer 19

three toxin subunits

Question 20

what are the three toxin subunits

Answer 20

1. Protective antigen (PA) 2. Lethal factor (LF)

3. Edema factor (EF)

Question 21

what is protective antigen

Answer 21

will bind the other two factors

- Which is the receptor binding subunit

Question 22

what is the lethal factor

Answer 22

(LF)

- Enzyme subunit

Question 23

what is Edema factor (EF)

Answer 23

subunits can form two active toxins, lethal toxin (LT) (PA + LF) and edema toxin (ET) (PA +EF)

Question 24

which are the non-toxic subunits

Answer 24

PA, LF and EF are non-toxic alone

Question 25

where does the protective antigen bind

Answer 25

binds to the host cell membrane and to lethal factor or edema factor

Question 26

what is endocytosed

Answer 26

lethal toxin or edema toxin complex is endocytosed

Question 27

what is released from endosome

Answer 27

Inside the cell LF or EF are released from the endosome

Question 28

what does LF do

Answer 28

LF alters host cell signal pathways to trigger apoptosis

Question 29

what does EF trigger

Answer 29

EF triggers rapid increase in cAMP levels resulting in edema

Question 30

the anthrax toxin mode of action

Answer 30

Once in the phagosome – release of toxins into the host cell

Question 31

B. anthrasis capsule composed of

Answer 31

poly-D-glutamic acid

Question 32

how is anthrax detected

Answer 32

Swab and Gram stain to reveal - Large Gram-positive bacilli, often in chains Culturing samples from blood, skin lesions or respiratory secretions on blood agar

Question 33

what is anthrax like when swabbed

Answer 33

- Non-haemolytic (anthrax is non-haemolytic) | - Characteristic colonies

Question 34

where do antitoxins bind

Answer 34

bind to protective antigen with high affinity in a dose-dependent manner

Question 35

how are antitoxins administered

Answer 35

adjunct to intravenous antimicrobials if there is a high level of clinical suspicion for systemic anthrax

Question 36

what makes B. anthracis a good weapon

Answer 36

Can be easily manufactured using standard laboratory equipment Persistence of endospore in environment Delayed onset of recognisable symptoms renders treatment ineffective Pathogenicity No obvious colour, taste, or odour