B. pertussis

B. parapertussis

B. bronchosepticus

B. pertussis

B. parapertussis

B. bronchosepticus

Bordetella species of clinical importance

Bordetella species of clinical importance

1. What is the organism and what are its physiologic characteristics?

2. What are the pathogenic factors of this organism?3. Why is there a preponderance of lymphocytes?

4. What is the epidemiology of and prophylaxis for the disease?

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: 100-160) and respiratory rate is 72 (n: 10-20). Chest x-ray is normal. WBC counts are16,000/cm2 with 70% lymphocytes.

Bordetella pertussisBordetella pertussis

Causative agent of whooping cough

Gram negative cocobacillus

Requires special media to grow

Causative agent of whooping cough

Gram negative cocobacillus

Requires special media to grow

Bordetella pertussisBordetella pertussis

Gram negative coccobacilli

Small, transparent hemolytic colonies on BG medium

Gram negative coccobacilli

Small, transparent hemolytic colonies on BG medium

Oxidase+,Urease-; (B. parapertussis: oxidase-, urease+; B. brochosepticus: +/+)

Oxidase+,Urease-; (B. parapertussis: oxidase-, urease+; B. brochosepticus: +/+)

Pertussis: epidemiologyPertussis: epidemiology

pertussis is a

disease mainly

of children

pertussis is a

disease mainly

of children

Pertussis: course of diseasePertussis: course of disease

Pertussis: virulence factorsPertussis: virulence factors

Pertussis toxin (pertussigen)*

Adenylate cyclase toxin

Tracheal toxin

Dermonecrotic toxin

Filamentous haemagglutinin*

Lipopolysaccharide

Pertussis toxin (pertussigen)*

Adenylate cyclase toxin

Tracheal toxin

Dermonecrotic toxin

Filamentous haemagglutinin*

Lipopolysaccharide

Pertussigen:(an AB-toxin, oligopeptide)

Pertussigen:(an AB-toxin, oligopeptide)

Increases histamine and LPS sensitivityIncreases IgE levelsT-cell lymphocytosisImpairs phagocyte functionsADP-ribosylates the Gi protein (results in increased cAMP)

Increases histamine and LPS sensitivityIncreases IgE levelsT-cell lymphocytosisImpairs phagocyte functionsADP-ribosylates the Gi protein (results in increased cAMP)

Pertussigen:Structure

Pertussigen:Structure

Pertussigen: dysregulation of adenylate cyclase

Pertussigen: dysregulation of adenylate cyclase

Pertussistoxin

cAMPATPCholera toxin

Pertussis: adenylate cyclase toxin

Pertussis: adenylate cyclase toxin

Activated by calmodulinActivated by calmodulin

Catalyses ATP to cAMP conversion

Catalyses ATP to cAMP conversion

Ac tox

Ac tox

Calm

cAMP

H2O

Pertussistracheal ToxinPertussis

tracheal Toxin

A peptidoglycan-like molecule

Binds to ciliary epithelial cells

Inhibits ciliary movement

Kills ciliary ciliary epithelial cells

A peptidoglycan-like molecule

Binds to ciliary epithelial cells

Inhibits ciliary movement

Kills ciliary ciliary epithelial cells

Causes pertussis

Pertussis:dermonecrotic toxin

Pertussis:dermonecrotic toxin

Strong vasoconstrictor

Causes ischemia

Synergizes with tracheal toxin

to causes tracheal necrosis

Strong vasoconstrictor

Causes ischemia

Synergizes with tracheal toxin

to causes tracheal necrosis

Pertussis:filamentous haemagglutinin

Pertussis:filamentous haemagglutinin

Causes binding of bacteria to

ciliated epithelial cells

Causes binding of bacteria to

ciliated epithelial cells

B. pertussis:interactions with pneumocyte

B. pertussis:interactions with pneumocyte

B. pertussis: lipopolysaccharideB. pertussis:

lipopolysaccharide

Activates inflammatory

cytokines

Activates complement

In larger quantities, causes

shock and cardiac arrest

Activates inflammatory

cytokines

Activates complement

In larger quantities, causes

shock and cardiac arrest

Pertussis: diagnosis

Pertussis: diagnosis

Based on symptoms

Culture on Bordet-Gengou (potato-

glycerol-blood agar) medium

Based on symptoms

Culture on Bordet-Gengou (potato-

glycerol-blood agar) medium

Laboratory Diagnosis

Specimens Post / per nasal swab (no cotton swab) / cough plate

Microscopy Gram negative coccobacilli

Culture Bordet – Gengou Medium mercury drop pearl appearance colonies

Antibiotic Erythromycin / Co-trimoxazole

Identification Microscopy & slide agglutination

Fluorescent antibody stain

Pertussis: treatment

Pertussis: treatment

Erythromycin is the drug of choice

Vaccine is extremely effective

Erythromycin is the drug of choice

Vaccine is extremely effective

Immunization

D P T VACCINE

Diphtheria Pertussis Tetanus

3 doses

Intervals of 4 - 6 wks

4th dose year after

School entryPrimary Booster

1st Pertussis vaccine- whole cell

Acellular vaccine now used

Combination vaccines

1. What is the organism and what are its physiologic characteristics?

2. What are the pathogenic factors of this organism?3. Why is there a preponderance of lymphocytes?

4. What is the epidemiology of and prophylaxis for the disease?

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: 100-160) and respiratory rate is 72 (n: 10-20). Chest x-ray is normal. WBC counts are16,000/cm2 with 70% lymphocytes.