A 14-year-old girl comes to the physician with dark urine and facial puffiness. About 4 weeks before presentation, she had pustular skin lesions that broke down over a few days to form thick scabs in the lower extremities. Microscopic examination of the urine sediment shows red blood cell casts. The organism responsible for this patient's symptoms would most likely demonstrate which of the following?

Question

A 14-year-old girl comes to the physician with dark urine and facial puffiness.  About 4 weeks before presentation, she had pustular skin lesions that broke down over a few days to form thick scabs in the lower extremities.  Microscopic examination of the urine sediment shows red blood cell casts.  The organism responsible for this patient's symptoms would most likely demonstrate which of the following?

Quizplus · Accepted Answer

Eductional Objective: Glomerulonephritis is associated with prior streptococcal pharyngeal or skin infection; acute rheumatic fever is associated with prior streptococcal pharyngitis but not skin infection.  Streptococci are catalase-negative, staphylococci are catalase-positive.  Streptococcus pyogenes (Group A Streptococcus) is Beta-hemolytic, bacitracin-susceptible, and pyrrolidonyl arylamidase-positive.  Streptococcus pneumoniae is bile-soluble and optochin-susceptible.

A 14-Year-Old Girl Comes to the Physician with Dark Urine