A 3-Year-Old Boy Who Recently Immigrated to the United States

A 3-year-old boy who recently immigrated to the United States is brought to the emergency department with fever, malaise, and a painful, swollen right knee.  He is hypotensive and tachycardic.  Medical history is significant for a recent episode of acute otitis media and several vaccinations that are not up to date.  Arthrocentesis of the right knee shows cloudy synovial fluid.  Gram stain of the aspirate reveals pleomorphic, gram-negative coccobacilli.  Cultures performed on a blood agar plate supplemented with a disk containing hematin and nicotinamide adenine dinucleotide (NAD⁺) grow colonies only near the disk.  The organism responsible for this patient's condition most likely produces which of the following virulence factors?

A) Capsule
B) Cytotoxic exotoxin
C) Fimbriae
D) Hemolysins
E) Hyaluronidase

Correct Answer:

Verified

Unlock this answer now
Get Access to more Verified Answers free of charge

Access For Free