Meningitis and GAS infections

Question 1

pathogenic mechanism of Group A strep in pharyngitis

Main virulence factors include:

Answer 1

• Capsule in some strains (decreased phagocytosis)
• Lipoteichoic acid in peptidoglycan cell wall (adhesion)
• M-protein (inhibits antibody binding and compliment related opsonization)
• Fibronectin binding protein (adhesion)
• vimectin (muscle adhesion)
• streptolysin O
• Hyaluronidase
• Streptokinase
• Streptococcal pyrogenic exotoxin (SPE) A, B, and C toxins

Question 2

Bacterial Meningitis etiologies:

Answer 2

Neonates: E. coli, Group B strep, Listeria
Children: Group B strep, strep pneumo, Meningicoccus, Listeria, H. Influenza type B
Adults: Pneumococcus, meningococcus, Group B strep, H. influenza non-typable, Listeria monocytogenes ( in pregnant and elderly)