Prac: Anaerobes

Question 1

What is the most important toxin of type A Clostridium perfringens?

Answer 1

Lecithinase

Question 2

What is the action of the alpha toxin lecithinase?

Answer 2

Splits lecithin into:
: diglyceride
: phosphorylcholine

Question 3

Three features of C.perfringens alpha toxin?

Answer 3

Lethal
Necrotising
Haemolytic

Question 4

What are two examples of obligate anaerobes?

Answer 4

Clostridium spps. and Bacteroides fragilis

Question 5

What type of bacteria are the Clostridia?

Answer 5

Gram-positive spore forming anaerobic bacteria

Question 6

What is a key characteristic of obligate anaerobes?

Answer 6

Production of volatile fatty acids

Question 7

How may volatile fatty acids be detected?

Answer 7

Gas-liquid chromatography

Question 8

What is the application of GLC in the identification pure cultures grown in vitro?

Answer 8

Different genera and species vary in range of volatile fatty acids produced
Valuable in identification

Question 9

What is the application GLC in clinical material?

Answer 9

Anaerobes produce characteristic fermentation products in vivo; detection pus therefore rapid method detecting anaerobic infection

Question 10

What is contained in the pus from infections due to aerobes/facultative anaerobes?

Answer 10

Acetic and propionic acids only; no detectable volatile fatty acids