A 3-year-old girl is brought to the office after developing fever and a sore throat. The patient recently entered day care, and similar symptoms have been reported in several of the other children. Physical examination shows exudative pharyngitis and enlarged anterior cervical lymph nodes. A rapid antigen detection test confirms the diagnosis of streptococcal throat infection. Her condition resolves with antibiotic therapy. Several weeks later, she is re-exposed to Streptococcus pyogenes. The bacteria penetrating beyond the surface epithelium are immediately coated with preformed IgG antibodies. Which of the following substances acts in the most similar manner to IgG antibodies to facilitate phagocytosis?

Question

A 3-year-old girl is brought to the office after developing fever and a sore throat.  The patient recently entered day care, and similar symptoms have been reported in several of the other children.  Physical examination shows exudative pharyngitis and enlarged anterior cervical lymph nodes.  A rapid antigen detection test confirms the diagnosis of streptococcal throat infection.  Her condition resolves with antibiotic therapy.  Several weeks later, she is re-exposed to Streptococcus pyogenes.  The bacteria penetrating beyond the surface epithelium are immediately coated with preformed IgG antibodies.  Which of the following substances acts in the most similar manner to IgG antibodies to facilitate phagocytosis?

Quizplus · Accepted Answer

Eductional Objective: Opsonization occurs when host proteins such as immunoglobulins or complement bind to foreign cells such as bacteria and coat the surface, enhancing phagocytosis.  The most important opsonins (coating proteins) are immunoglobulin G and complement C3b.

A 3-Year-Old Girl Is Brought to the Office After Developing