Question

Sputum samples are typically plated on blood agar, chocolate agar (blood agar containing lysed red blood cells), and MacConkey agar. Explain why each of these media may be helpful in identifying pathogens in lower respiratory infections.

Answer 1

Answer:

Firstly there are several pathogens that are involved in lower respiratory infection.

1. Klebsiella pneumoniae
2. Moraxella catarrhalis
3. Pseudomonas aeruginosa

Moraxella catarrhalis is able to grow on both blood and chocolate agar. Furthermore, these both agar are used to identify gram negative cocci.

Pseudomonas aeruginosa is a large gram negative rod shape bacteria that can only grow well on blood agar.

Klebsiella pneumoniae is a large gram negative rod shape bacteria that can only grow on MacConkey Agar.

Therefore all of these agar are important and helpful to identify pathogens that are responsible for lower respiratory infection.