Bordetella Pertussis

Question 1

How Bordetella is transmitted?

Answer 1

usually by aerosoles, directly from infected to susceptible individual through the respiratory tract.

Question 2

At which stage the person is the most infectious?

Answer 2

At the catarrhal stage

Question 3

Who are the only reservoir?

Answer 3

Humans are the only natural hosts

Question 4

On which locus are present all the genes related to virulence?

Answer 4

On locus called BVG, Bordetella virulence gene

Question 5

What it’s called the antigenic variation?

Answer 5

Since there is always upstream and downstream expression of some genes in an orchestrated manner

Question 6

What is the phase variation?

Answer 6

It happens after a mutation in BVG such that none of the virulence genes are expressed

Question 7

What are the virulence factors?

Answer 7

The capsule
Pili
Pertussis toxin
Adenylate cyclase toxin
Tracheal cytotoxin
Dermonecrotic toxin
Filamentous hemagglutinin
LPS

Question 8

To which cells pili will adhere?

Answer 8

Ciliated cells

Question 9

Which toxin is the first to be activated?

Answer 9

Adenylate cyclase toxin

It works at the beginning of the infection, initiating it

Question 11

What is the major virulence factor?

Answer 11

Pertussis toxin

Question 12

What induces the tracheal cytotoxin at the beginning of the infection? At the end of the infection?

Answer 12

at the beginning of the infection, it induces ciliastasis (it stops the movement of cilia)
At the end of the infection, it causes extrusion of ciliated epithelial cells.

Question 13

At which stage the person is infectious?

Answer 13

At the end of the infection when there is extrusion of ciliated epithelial cells

Question 14

Which toxin is related to necrosis?

Answer 14

The dermonecrotic toxin

Question 15

What is the importance of the filamentous hemagglutinin?

Answer 15

Ab directed against it inhibit attachment to susceptible cells so those proteins give protection during vaccine

Question 16

What is the clinical presentation?

Answer 16

Whooping cough or pertussis

Question 17

What is the typical manifestation for an infection with Bordetella?

Answer 17

Paroxysmal cough which ends up by vomiting, along with an absolute lymphocytosis in a blood test

Question 18

What is the susceptible age group?

Answer 18

children less than 5 years old

Question 19

What is the incubation period?

Answer 19

7 to 10 days

Question 20

Can we have a bacteremia?

Answer 20

That is very rarely a bacteremia

Question 21

What are the 3 stages of the disease?

Answer 21

Catarrhal stage
Paroxysmal stage
Convalescent phase

Question 22

During which stage we find the highest amount of bacteria?

What happens during this stage?

Answer 22

During the catarrhal stage

During this stage there is only extrusion of bacteria

Question 23

Why proper diagnosis and treatment should be done during this stage?

Answer 23

Because the person is highly infectious and later the number of bacteria will decrease rendering antibiotics less effective

Question 24

What happens during the paroxysmal stage?

Answer 24

There is extrusion of bacteria with ciliated cells

Question 25

What is the paroxysmal cough?

Answer 25

During a single exhalation, there is 10 to 30 repetitive, forceful and sudden coughs which are followed by a single inhalation with spasm of the larynx and glottis which is the whoop

Question 26

What are the manifestations during paroxysmal stage?

Answer 26

The person cannot breathe properly, so there has to be vomiting after each spasm, in order to get rid of excess mucus plugs that weren’t cleared by coughing

Question 27

What do we see in the blood test?

Answer 27

Leukocytosis

Question 28

Which Ab are detected at the end of the paroxysmal stage?

Why did you not have a diagnostic value?

Answer 28

At the end of the stage, Ab test can detect Ab to the filamentous hemagglutinin but it is of no diagnostic value because we passed infectious phase

Question 29

What do we have during the convalescent phase?

Answer 29

There can be a secondary complication by Strep, Staph, Hemophilus

Question 30

Do patients develop permanent immunity?

Answer 30

Yes they do

Question 31

From where the specimen should be taken?

How do we take it?

Answer 31

From the throat
Rather than taking it by cotton swab, we use a nasal saline wash. The saline solution is introduced inside the nose, then washing, then aspiration

Question 32

Are they gram-negative or gram-positive?

Answer 32

Gram negative

Question 33

Are they aerobic, anaerobic or facultative anaerobes?

Answer 33

They are strictly aerobic

Question 34

Are they motile? Spore forming?

Answer 34

They are nonmotile, non-spore forming

Question 35

What is their selective medium? What does it contain?

Answer 35

It is the Bordet-Gengou medium

It contains potato, glycerol, blood, antibiotics that inhibit the growth of other bacteria

Question 36

At which temperature do they grow? What becomes the color of the medium?

Answer 36

They grow at 36°C and the medium will become black

Question 37

Which test is done after the culture?

Answer 37

Fluorescent Ab test

Question 38

Which antibiotics are used?

Answer 38

Erythromycin or tetracycline for at least two weeks

Question 39

Which vaccine is given? From what it is made?

Answer 39

He triple vaccine

It contains the pertussis toxoid and the filamentous hemagglutinin

Question 40

What’s the type of this toxin? What does it cause?

Answer 40

It is an AB toxin

It’s induces lymphocytosis, hypoglycemia since it activates islet cells and increases production of insulin