1. Bordetella species of clinical importance
B. pertussis
B. parapertussis
B. bronchosepticus

2. A 2-year-old male is presented to you with a 10-day history of persistent cough. The long cough spells are followed by a deep breath. The cough often leads to choking, vomiting, gasping and cyanosis. His pulse rate is 190 (n: ) and respiratory rate is 72 (n: 10-20). Chest x-ray is normal. WBC counts are16,000/cm2 with 70% lymphocytes.
What is the organism and what are its physiologic characteristics?
What are the pathogenic factors of this organism?
Why is there a preponderance of lymphocytes?
What is the epidemiology of and prophylaxis for the disease?

3. Bordetella pertussis Causative agent of whooping cough
Gram negative cocobacillus
Requires special media to grow

4. Bordetella pertussis Gram negative coccobacilli
Small, transparent hemolytic colonies on BG medium
Oxidase+,Urease-; (B. parapertussis: oxidase-, urease+; B. brochosepticus: +/+)

5. Pertussis: epidemiology
pertussis is a disease mainly of children

6. Pertussis: course of disease

7. Pertussis: virulence factors
Pertussis toxin (pertussigen)*
Adenylate cyclase toxin
Tracheal toxin
Dermonecrotic toxin
Filamentous haemagglutinin*
Lipopolysaccharide

8. Pertussigen: (an AB-toxin, oligopeptide)
Increases histamine and LPS sensitivity
Increases IgE levels
T-cell lymphocytosis
Impairs phagocyte functions
ADP-ribosylates the Gi protein (results in increased cAMP)

9. Pertussigen: Structure

10. Pertussigen: dysregulation of adenylate cyclase
Pertussis
toxin
Cholera toxin
ATP
cAMP

11. Pertussis: adenylate cyclase toxin
H2O
Activated by calmodulin
Ac tox
cAMP
Ac tox
Catalyses ATP to cAMP conversion
Calm

12. Pertussis tracheal Toxin
A peptidoglycan-like molecule
Binds to ciliary epithelial cells
Inhibits ciliary movement
Kills ciliary ciliary epithelial cells
Causes pertussis

13. Pertussis: dermonecrotic toxin
Strong vasoconstrictor
Causes ischemia
Synergizes with tracheal toxin to causes tracheal necrosis

14. Pertussis: filamentous haemagglutinin
Causes binding of bacteria to ciliated epithelial cells

15. B. pertussis: interactions with pneumocyte

16. B. pertussis: lipopolysaccharide
Activates inflammatory cytokines
Activates complement
In larger quantities, causes shock and cardiac arrest

17. Pertussis: diagnosis Based on symptoms
Culture on Bordet-Gengou (potato-glycerol-blood agar) medium

18. Laboratory Diagnosis Specimens
Post / per nasal swab (no cotton swab) / cough plate
Microscopy
Gram negative coccobacilli
Fluorescent antibody stain
Culture
Bordet – Gengou Medium mercury drop pearl appearance colonies
Identification
Microscopy & slide agglutination
Antibiotic
Erythromycin / Co-trimoxazole

19. Pertussis: treatment Erythromycin is the drug of choice
Vaccine is extremely effective

20. 1st Pertussis vaccine- whole cell Acellular vaccine now used
Immunization
1st Pertussis vaccine- whole cell
Acellular vaccine now used
Combination vaccines
D P T VACCINE
Diphtheria
Pertussis
Tetanus
Primary
3 doses
Booster
School entry
Intervals of wks
4th dose year after

21. A 2-year-old male is presented to you with a 10-day history of persistent cough. The long cough spells are followed by a deep breath. The cough often leads to choking, vomiting, gasping and cyanosis. His pulse rate is 190 (n: ) and respiratory rate is 72 (n: 10-20). Chest x-ray is normal. WBC counts are16,000/cm2 with 70% lymphocytes.
What is the organism and what are its physiologic characteristics?
What are the pathogenic factors of this organism?
Why is there a preponderance of lymphocytes?
What is the epidemiology of and prophylaxis for the disease?