(III) Fastidious Gram Negative Rods (7) Legionella pneumophila

Question 1

What stain is used to visualize Legionnella?

Answer 1

(1) Silver
(2) Gram (-), kind of

Question 2

What growth medium is used for Legionella

Answer 2

(1) Charcoal yeast
(2) + Iron
(3) + Cysteine

Question 3

What self-limiting disease is caused by Legionella?

Answer 3

Pontiac fever

Question 4

What activity is common among people who get Legionaires’ disease?

Answer 4

Smoking

Question 5

What type of pneumonia does Legionella cause?

Answer 5

Atypical with consolidation in one lobe

Question 6

Which atypical pneumonia commonly presents with hyponatremia?

Answer 6

Legionaires’

Question 7

Name 3 signs/symptoms of pneumonia due to Legionella (unrelated to lungs)

Answer 7

(1) CNS symptoms
(2) Diarrhea
(3) HIGH fever

Question 8

What test is used for rapid diagnosis of Legionaires’?

Answer 8

Urine antigen test

(Culture the sputum for definitive diagnosis)

Question 9

Treatment (2) : Legionaires’ disease

Answer 9

(1) Flouroquinolones
(2) Macrolides

(Flouroquinolones are preferred over macrolides due to similar efficiacy with fewer side effects)

Question 10

Name an organism which is oxidase (+) and causes atypical pneumonia

Answer 10

Legionella

Question 11

Legionella pneumophila infection

Can be found in:
[…]

Transmission:
[…]

Clinical presentation:
[…]

Diagnosis:
[…]

Answer 11

Legionella pneumophila infection

Can be found in:
grows in water (eg. in cooling tower of air conditioning plant), poorly maintained water supplies, medical equipment, etc

Transmission:
Aerosolized contaminated water (NOT person to person or airborne)

ief influenza-like illness, less dangerous

Diagnosis:
Urine antigen test is favourite, but BAL culture, IF stain and NAT also can