Bordetella Pertussis And Haemophilus Influenzae

Front 1

Staining characteristics and growth profile of Bordetella pertussis

Back 1

tiny, Gram-negative coccobacilli

SLOW growing and requires NAD for growth; high maintenance

Front 2

Order of disease phases in Bordetella pertussis (4)? How long is incubation?

Back 2

1. Incubation = 1-3 weeks
2. Catarrhal Phase
3. Paroxysmal Phase
4. Convalescent Phase

Front 3

Catarrhal phase:

a. How does it present?

b. What happens at the end of this phase?

c. Is the pt contagious?

Back 3

begins as symptoms appear

a. presents like a URI; disease rarely recognized as pertussis.
b. Toward the end of this phase, a dry, nonproductive cough develops
c. highly infectious

Front 4

Paroxysmal phase:

1. When does it occur?

2. Characteristic symptom?

3. Sign seen on serology?

Back 4

1. follows after 1-2 weeks
2. whooping cough
3. Lymphocytosis develops and may exceed 50,000 cells/mm3; this is a diagnostic clue bc you normally expect neutrophils to increase

Front 5

When severe, the paroxysmal coughing causes ____ and is followed by ______

Back 5

When severe, the paroxysmal coughing causes cyanosis and is followed by vomiting

Front 6

Convalescent phase:

1. When does it occur?

2. characterized by?

3. What type of pt STARTS with this phase?

Back 6

1. appears 2-4 weeks later
2. Characterized by a chronic, persistent cough
3. Pts with vaccine will start here

Front 7

How is Bordetella pertussis transmitted?

What pt population is at risk?

Back 7

aerosolized droplets

Pts under 1 y/o and immunocompromised

Front 8

Notable virulence factors of Bordetella pertussis?

Back 8

filamentous hemagglutinin, tracheal cytotoxin, pertussis toxin

Front 9

Filamentous hemagglutinin is a ________ that Mediates attachment to _____ and ______

Back 9

Filamentous hemagglutinin is a Surface protein that Mediates attachment to ciliated respiratory epithelial cells and macrophages

Front 10

Tracheal cytotoxin is a fragment of _______ and causes _____ at low concentrations and ______ at higher concentrations

Back 10

Tracheal cytotoxin is a fragment of Peptidoglycan and causes ciliostasis at low concentrations and cell death/extrusion at higher concentrations; disrupts the normal clearance mechanisms

Front 11

Pertussis toxin:

1. What type of toxin?

2. Mechanism and effect?

Back 11

1. Typical A-B toxin

2. ADP-ribosylates GPCR. This cause adenylate cyclase to continuously increase cAMP, which increases mucus/secretions

Front 12

describe the critical factors that must be considered when collecting and culturing H. influenza and B. pertussis for lab diagnostic tests.

Back 12

Culture is hard and labs can't do it:

Because of diagnostic limitations, pertussis is almost always a clinical diagnosis.

Front 13

basic treatment options for diseases caused by B. pertussis.

Back 13

Erythromycin, azithromycin, or clarithromycin

Supportive therapy includes close monitoring vital signs, nasotracheal suctioning, provision of oxygen, parenteral nutrition and hydration

Front 14

describe the vaccines available for B.pertussis, including the components.

Who should get a booster?

Back 14

Acellular vaccines composed of several antigens, including pertussis toxoid and filamentous hemagglutinin and are combined with diptheria and tetanus toxoids

individuals aged 11-12;

one dose of Tdap to replace Td for ages 19-64; all health care workers.

Front 15

Explain the implications of B.pertussis carriage and disease for vaccination strategies

Back 15

Vaccine uptake in the U.S. is around 98%, but some parents are still refusing to immunize children on either religious grounds or concerns about vaccine safety. Failure to vaccinate against pertussis represents a public health concern

Front 16

Staining characteristics and growth profile of Haemophilus influenzae

Back 16

small, Gram-negative coccobacilli, often
pleomorphic

Fastidious nature and growth requirements:
a. hemin and NAD; supplied by RBCs
b. CO2 enhances growth
c. Microbes lose viability relatively quickly once specimens are collected

Front 17

Is H. influenzae capsulated?

Back 17

Both encapsulated (serotypeable) and non-encapsulated strains (non- typeable) exist; this characteristic corresponds to the organism’s propensity for invasion in non-immune hosts

Front 18

Diseases caused by H. influenzae? (6)

Back 18

1. Bacteremia

2. Meningitis

3. Septic Arthritis

4. Epiglotitis

5. Pneumonia

6. cellulitis

Front 19

What is the most serious acute manifestation of H. influenzae?

What else is notably a medical emergency?

Back 19

most serious = meningitis

other = epiglotits

Front 20

Transmission of H. influenzae?

Back 20

Transmission is via aerosolized droplets

Front 21

Who is at risk for H. influenzae infection?

Back 21

1. children up to 5

2. people without spleens or other immunodeficiencies

3. genetic predisposition

4. having another resp. infection/disease

5. day care or siblings of similar age

Front 22

Major virulence factors of H. influenzae

Back 22

capsule (in encapsulated strains), IgA protease, pili/fimbrae.

Front 23

How does the capsule of H. influenzae contribute to virulence?

What is special about the type b capsule?

Back 23

Anti-phagocytic

H. influenzae Type B capsule is polyribitol phosphate; might be why it is the most/only virulent strain

Front 24

Lab methods of diagnosis of H. influenzae

Back 24

-Gram stain

-Culture

-Direct detection

Front 25

Treatment of H. influenzae

Back 25

Very resistant:

Life threatening illness: Third generation cephalosporins

Non-Life Threatening: Macrolides and Quinolone

Front 26

Vaccine for H. influenzae

Back 26

All licensed vaccines are conjugate vaccines containing PRP capsule

Front 27

explain the implications of H.influenzae and carriage and disease for vaccination strategies.

Back 27

-Vaccine has significantly reduced disease

-Nasopharyngeal colonization rates have dropped

-Estimated cost savings is around $500 million in U.S.