Bacterial Infections USMLE Step 1 Practice Question
A 4 year old unimmunized boy is brought to the emergency department for high fever, muffled voice, drooling, and respiratory distress. He is sitting upright and leaning forward. Lateral neck radiograph shows a swollen epiglottis. Which of the following virulence factors most likely allowed the causative organism to evade phagocytosis?
Answer choices
- AAntigenic shift of surface glycoproteins
- BMycolic acid rich cell wall
- CM protein
- DPolyribitol phosphate capsuleCorrect answer
- EProtein A
- FLipopolysaccharide O antigen
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