Mycoplasma pneumoniae

Question 1

How does Mycoplasma pneumoniae rank in size among free-living organisms?

Answer 1

Smallest free-living organism

Question 2

Why is Mycoplasma pneumoniae insensitive to β-lactam antibiotics?

Answer 2

Because it lack a cell wall

Question 3

What is the colony appearance of Mycoplasma pneumoniae?

Answer 3

• Fried egg appearance
• Dense center
• Less dense periphery

Question 4

M. pneumoniae can grow in this kind of agar?

Answer 4

Eaton agar

Question 5

What stain is used to visualize Mycoplasma pneumoniae colonies, and what does it show?

Answer 5

Dienes stain, shows colonies containing densely stained granules

Question 6

What sugars does Mycoplasma pneumoniae ferment?

Answer 6

Glucose, xylose, mannose, maltose, dextrin, and starch

Question 7

T/F. Mycoplasma pneumoniae produces hemolysin.

Answer 7

True

Question 8

What structural feature does Mycoplasma pneumoniae have instead of a cell wall?

Answer 8

A trilaminar cell membrane rich in sterols

Question 9

How does Mycoplasma pneumoniae reproduce?

Answer 9

Binary fission

Question 10

To which host cells does M. pneumoniae adhere?

Answer 10

• Respiratory epithelial cells
• Red blood cells

Question 11

What type of receptors does M. pneumoniae use for adhesion?

Answer 11

Sialic acid receptors

Question 12

What proteins are involved in M. pneumoniae adhesion?

Answer 12

• P1
• P30
• Proteins B and C
• P116
• HMW1-3

Question 13

What specialized structure does Mycoplasma pneumoniae use for adhesion?

Answer 13

Specialized adhesion organelle

Question 14

What type of motility does Mycoplasma pneumoniae exhibit, and how is it facilitated?

Answer 14

Gliding motility

Question 15

What are the two major strains of Mycoplasma pneumoniae, and how do they differ?

Answer 15

Type 1 and type 2; P1 adhesion protein

Question 16

What cytotoxin does Mycoplasma pneumoniae produce?

Answer 16

Community-acquired respiratory distress syndrome (CARDS) toxin

Question 17

What autoantibodies are produced in response to M. pneumoniae infection?

Answer 17

Isohemagglutinins, which target the l antigen on adult erythrocytes

Question 18

What are cold agglutinins, and when were they first described?

Answer 18

Antibodies that cause reversible agglutination of erythrocytes at 4°C

Question 19

What are the key characteristics of CARDS toxin?

Answer 19

• ADP ribosylating and vacuolating cytotoxin
• Found in inflamed airways
• Triggers antibody production

Question 20

What type of structures do Mycoplasma pneumoniae biofilms form?

Answer 20

Volcano-like structures

Question 21

T/F. There are macrolide-resistant strains of M. pneumoniae.

Answer 21

True

Question 22

Who is most affected by Mycoplasma pneumoniae infections?

Answer 22

Children and adolescents

Question 23

How is Mycoplasma pneumoniae transmitted?

Answer 23

Person-to-person via droplets

Question 24

In what settings do M. pneumoniae outbreaks frequently occur?

Answer 24

Closed populations

Question 25

In which age groups are Mycoplasma pneumoniae infections most common?

Answer 25

Children and young adults

Question 26

How does M. pneumoniae attach to the respiratory epithelium?

Answer 26

Binds sialic acid receptors via attachment organelle

Question 27

What effect does M. pneumoniae attachment have on the respiratory epithelium?

Answer 27

Damages epithelium and impairs cilia function

Question 28

What cytotoxin does M. pneumoniae produce that may damage the respiratory tract?

Answer 28

CARDS toxin

Question 29

T/F. The organism may alter surface antigens on the attached cells, leading to autoantibody formation.

Answer 29

True

Question 30

Are most Mycoplasma pneumoniae infections symptomatic or asymptomatic?

Answer 30

Symptomatic

Question 31

What is the most common syndrome caused by M. pneumoniae in older children and adolescents?

Answer 31

Tracheobronchitis combined with: * Coryza * Pharyngitis * Otitis media

Question 32

What is the predominant syndrome caused by M. pneumoniae in young adults and adults?

Answer 32

Atypical pneumonia

Question 33

How do symptoms of M. pneumoniae pneumonia develop?

Answer 33

Gradually, including: * Low-grade fever * Malaise * Headache * Myalgia * Cough

Question 34

What symptom can coughing or tracheitis cause in M. pneumoniae pneumonia?

Answer 34

Subesternal soreness

Question 35

T/F. Pleuritic chest pain is common in M. pneumoniae pneumonia.

Answer 35

False

Question 36

What is a hallmark symptom of M. pneumoniae pneumonia?

Answer 36

Persistent, frequent, debilitating cough

Question 37

What type of pharyngitis may be present in M. pneumoniae pneumonia?

Answer 37

Nonexudative

Question 38

T/F. Cervival lymphadenopathy is not common in M. pneumoniae pneumonia.

Answer 38

True

Question 39

T/F. M. pneumoniae infection may precipitate exacerbations of childhood asthma.

Answer 39

True

Question 40

What are the gold standard for diagnosing M. pneumoniae?

Answer 40

PCR

Question 41

M. pneumoniae is currently susceptible to which antibiotics?

Answer 41

* Fluoroquinolones * Macrolides * Tetracyclines

Question 42

This drug is preferred to its lower minimum inhibitory concentration (MIC) in M. pneumoniae and fewer contraindications in children.

Answer 42

Azithromycin