Vaccine-preventable Childhood Bacterial Diseases

Question 1

What is passive antibody

Answer 1

Administration of pre-formed antibody

Question 2

Toxoid

Answer 2

Inactive toxin but can help immune system learn to target it

Question 3

What toxoid vaccines do we have?

Answer 3

Tetanus, diptheria, anthrax

Question 4

Discuss polysaccharide alone vs. conjugate vaccines

Answer 4

Polysaccharide alone vaccines are the old school vaccines like pneumococcal 23 valent and 4 valent meningococcal.

The problem with these is that children under two can’t use this to become immune because these are T-independent antigens

However, if this polysaccharide is conjugated to a protein, any age can get it because the T Cell Helpers can pull in the protein complex. We now use this conjugated variant, specifically for 13 valent-pneumococcal and 4-valent meningococcal

Question 5

Tell me about Bordetella Pertussis

Answer 5

Causes pertussis (whooping cough), an acute infectious disease of the tracheobronchial tree with characteristic clinical picture.

Question 6

What makes Bordatella Pertussis so infective?

Answer 6

Filamentous hemagglutinin, a pili that allows it to attach to respiratory epithelium

Question 7

Discuss Bordatella Pertussis Toxin

Answer 7

• ADP Ribosylates protein Gi, an inhibitor of cAMP, leading to increased cAMP leading to increased fluid secretion in the URT
• Stops lymphocytes from leaving blood supply to enter the skin, causing lymphocytosis of the blood

Question 8

Discuss Bordatella’s Adenylate cyclase toxin

Answer 8

Acts like adenylate cyclase to directly stimulate cAMP production

(looks like anthrax toxin)

Question 9

Discuss the Bordatella Tracheal toxin

Answer 9

• Part of the cell wall of Bordatella Pertussis, this guy damaged the cillia of respiratory epithelium

Question 10

Discuss the phases of symptoms for Bordatella

Answer 10

Catarrhal phase: 1-2 weeks, lacrimation and conjuctivae (best time for culture)

Paraoxysmal phase: 2-4 weeks - Whooping sound, lots of coughing. Leukocytosis, vomiting also

Convalescent stage: Few months, reduction in symptoms (worst time for culture)

“100 day cough”

Question 11

Treatment for Bordatella

Answer 11

Macrolides can kill Bordatella in the Respiratory Epithelium but won’t help the circulating toxin

Question 12

Vaccines for Bordetella

Answer 12

Killed Vaccine - No longer available in U.S.

Acellular Vaccine - Purified antigens of the bacteria, part of DTaP (a-cellular Pertussis). Tdap is also given, which is DTaP with less diptheria toxoid

Question 13

Structure of Bordatella

Answer 13

Gram negative, short coccobacilli.

Question 14

Growth Requirements for Bordatella

Answer 14

Needs enriched media that binds fatty acids like Bordet-Gengou agar or Regan Lowe charcoal medium that is supplemented with horse blood.

“Mercury Drop” colonies in 3-7 days

PCR can be used, but nothing is FDA approved

Question 15

Discuss the structure of Corynebacterium diptheriae

Answer 15

• Gram positive
• Club shaped
• V or Y formations
• Metachromatic granules - Stain makes granules red and the rest of the cell blue

Question 16

Discuss the toxin of diptheriae

Answer 16

A - Active subunit - ADP ribosylation of elongation factor 2 to stop protein synthesis in ribosomes leading to cell death and creation of pseudomembranes in the oropharynx (looks like cotton candy)
B - Binding subunit

Question 17

Symptoms of Diptheriae

Answer 17

• Psuedomembranes lead to lymphadenopathy (bulls neck with a thick neck) or coughing/choking
• Heart - Arrhythmias, myocarditis, heart block (lethal effect)
• Local paralysis that begins in posterior oropharynx and can spread to cranial nerves due to myelin damage by the toxin

Question 18

Lab Findings for Diptheriae

Answer 18

• Culture on: Tellurite agar or Loeffler’s medium
• Toxin assay to distinguish between toxic and non-toxic diptheriae - Elek’s Test (if toxin sticks to paper, it’s toxic)