Lecture 2: Respiratory Diseases

Question 1

ToF: Infections of the pharynx are mostly bacterial

Answer 1

False.
Mostly viral

Question 2

What strains are common bacterial causes for a pharynx infection?

Answer 2

Streptococcus pyogenes
Lancefield Group C and G streptococci

Question 3

4 Identifying factors for Streptococcus Pyogenes

Answer 3

Gram Positive Coccus
Catalase Negative
Beta Haemolytic
Agglutination with Antibodies directed against Lancefield Group A

Question 4

What capsular type is Acute Epigolottitis?

Answer 4

B

Question 5

What culture would you use to incubate Haemophilus influenzae?

Answer 5

Heated blood/Chocolate Agar in 5% CO2

Question 6

Does Haemophilus influenzae grow better in chocolate or blood agar?

Answer 6

Chocolate agar has better growth

Question 7

What is released by RBC that Haemophilus influenzae likes?

Answer 7

X (haemin) and V (nicotinamide adenine dinucleotide) dependant

Question 8

What is the second most common Hospital Acquired Infection after UTi?

Answer 8

Pneumonia

Question 9

Identification factors of Streptococcus pneumoniae

Answer 9

Alpha Haemolytic on blood agar
Gram positive diplococcus
Catalase negative
Optochin sensitive
Soluble in bile salt (10% desoxycholate) solution

Question 10

How long does Legionella culture need to grow?

Answer 10

3-5 days

Question 11

Identification factors for Legionella species?

Answer 11

Gram negative rod
Weakly catalase positive
Will only grow on L-cysteine enriched BCYE
Does not grow on blood agar or non-cysteine enriched BCYE media

Question 12

What methods are used for speciation of Legionella?

Answer 12

PCR
DNA probes