Bordetella Pertussis Flashcards
Morphology of Bordetella Pertussis on staining?
Gram Negative Coccobacilli
Structural characteristics of B.Pertussis
No capsule Adhesins PT : pertussis toxin Adenylate Cyclase toxin Tracheal cytotoxin: peptidoglycan fragment Dermonecrotic toxin Endotoxin- LPS
What is pertactin?
Adhesin surface protein of bordetella pertussis for
What is Fha?
Filamentous Hemagglutinin: pilus like structure that binds integrins on membranes of ciliated respiratory cells and CR3 glycoprotien on macrophages
Promotes phagocytosis -> intracellular survival
What does pertussis toxin do?
S2 bind to glycolipid on ciliated cells and S3 binds to receptors on phagocytic cells
What does the AB subunit of Pertussis Toxin do?
A: S1 enzymatic: ADP ribosylation of Gi protein to prevent inactivation of AC => inc cAMP->increased resp secretions and mucous production
B:adhesin on ciliated cells and phagocytic cells
What does the tracheal cytotoxin do?
Peptidoglycan fragment that causes extrusion of ciliated tracheal epithelial cells and stimulate IL-1 release to cause fever
What does dermonecrotic toxin do?
causes ischemic necrosis
what is the pathogenesis of bordetella pertussis?
attach to ciliated cells via adhesins -> tracheal cytotoxins destroy ciliated cells -> PT cause systemic sx, mucus production cough, lymphocytosis
Does NOT invade respiratory tract cells
What is another term that Pertussis is called?
100 day cough; convalescent stage lasts for months
How is B.Pertussis diagnosed in lab?
Lymphocytosis
Charcoal Blood Agar: strict aerobe, non-motile
Difficult and slow to grow
Direct Immunofluorescence
PCRnow standard
How is Bordetella Pertussis treated?
Azithromycin (macrolides)- once cough starts->doesn’t make a huge diff but helps prevent spread
Alternative: Trimethoprim/sulfamethoxazole
How is B.Pertusses prevented?
DTaP Vaccines: acellular pertussis antigens; recommended for all children
Tdap: Adult vaccine 1x every 10 years
