Microbiology 12: Respiratory Tract Infections

Question 1

Blood culture from a young women isolates a gram +ve diplococcus, alpha-haemolytic bacteria which is optochin sensitive.

What is the most likely causative organism of her pneumonia?

Answer 1

Streptococcus. Pneumoniae

Question 2

List the 3 most common causative organisms of pneumonia in neonates 0-1 months old ?

Answer 2

E.coli
Group B streptococcus (GBS)
Listeria monocytogenes

Question 3

List the 3 most common causative organisms of pneumonia in children 1-6 months old ?

Answer 3

Chlamydia trachomatis
Staphylococcus aureus
RSV

Question 4

List the 2 most common causative organisms of pneumonia in children 6 months - 5 years old ?

Answer 4

Mycoplasma pneumonia

Influenza

Question 5

List the 2 most common causative organisms of pneumonia in people ages 16-30 years old ?

Answer 5

Streptococcus pneumonia

Mycoplasma pneumonia

Question 6

List the 2 typical organisms causing CAP

Answer 6

Streptococcus Pneumoniae

Haemophilus influenza

Question 7

List the 4 atypical organisms causing CAP

Answer 7

Legionella
Mycoplasma
Coxiella burnetii (Q-fever)- exposed to farm animals
Chlamydia psittaci (psittacosis)- exposure to birds, you get a haemolytic anaemia

Question 8

List 3 organisms that cause cavitation on CXR ?

Answer 8

Staph aureus (Swiss cheese type pattern)
Klebsiella pneumonia
TB

Question 9

Which atypical organism is transmitted by inhalation of infected water droplets e.g from saunas, AC and is grown on buffered charcoal yeast extract ?

Answer 9

Legionella Pneumophila

Question 10

What is the antibiotic treatment for atypical CAP ?

Answer 10

Macrolide - Azithromycin/ clarithromycin
+
Doxycycline

Question 11

An auramine stain and ziehl-Nielsen stain are used to identify which organism ?

Answer 11

TB

Question 12

What are the most common causative organisms of HAP ?

Answer 12

Enterobacteriaciae (e.coli, klebsiella pneumonia)
S.aureus
Pseudomonas aeruginosa

Question 13

Which organisms causes bilateral ground glass shadowing (bat’s wing appearance)?

Answer 13

Pneumocystis Jirovecii (PCP)

Question 14

What is a special physical test to diagnose Pneumocystis jirovecii ?

Answer 14

The walk test (attach oxygen saturation and get them to walk) - shows desaturation on exertion

Question 15

Which organisms causing LRTIs are more common in patients with neutropenia ?

Answer 15

Fungi - aspergillus

Question 16

Which organism typically causes LRTIs in patients with bone marrow failure ?

Answer 16

CMV

Question 17

What is the 1st line antibiotic treatment for HAP ?

Answer 17

CEFTAZIDME

MRSA= vanco

Pseudo = tazocin + genta

Question 18

Which atypical organism causes Pneumonia with cold agglutinins And erythema multiforme (target lesion) on palms ?

Answer 18

Mycoplasma Pneumonia

Question 19

Which organism causes a pneumonia with cough, myalgia and rose spots on the abdomen and is commonly seen in ornithologists (bird handlers)?

Answer 19

Chlamydia Psittaci

Question 20

Which organism causes pneumonia with target shaped lesions on the palm ?

Answer 20

Mycoplasma pneumonia

Question 21

Which 2 organism commonly Infect people with cystic fibrosis ?

Answer 21

Pseudomonas aeruginosa

Burkholderia capacia

Question 22

Which organism when stained with Gomori’s methenamine silver stain shows “Flying saucer” shaped cysts ?

Answer 22

Pneumocystis jirovecii

Question 23

Which coccus bacteria arranges in grape-like clusters ?

Answer 23

Staphylococcus aureus

Question 24

Which organism causes acute exacerbation of COPD and otitis media in children ?

Answer 24

Moraxella Caterrhalis