Microbiology

Question 1

Bordetella Pertussis

• Characteristic
• Lab
• Clinical importance

Answer 1

Gram negative , coccobacilli, Encapsulated
Aerobic , Catalase +

Virulence 1. Pertactin
2. Fimbria
3. Filamentous Hemagglutinin
Pertussis toxin > increase cAMP > impaired chemokine
Adenylase toxin > interrupt phagocytosis , whooping cough

Media : Bordet-gengou agar (Potato extract)
Regan-Low medium ( charcoal, blood, ATB)
Clinical 3 phases : catarrahal phase, Paroxysmal phase,Convalescense

Treatment : Erythromycin
Post exposure : macrolide reguardless of vaccination

Question 2

Mycobacterium tubercolosis

growth in parallel chains (serpentine cord) undermicroscopy is correlated with

Answer 2

Virulence

TB growth in serpentine cord due to presence of hydrophobic surface glycolipid called “ cord factor”

Cord factors composed of 2 mycolic acid bound to disaccharide
Cord factors forms cyclindrical micelles surround organism and prevent macrophage mediated destruction within phagolysosome