On the CAMP test, a hemolytic organism produces enhanced (arrow-shaped) hemolysis when streaked perpendicular to a beta-hemolytic Staphylococcus aureus streak. This organism most likely is:

• A Streptococcus pyogenes (Group A Streptococcus)
• B Enterococcus faecalis
• C Listeria monocytogenes
• D Streptococcus agalactiae (Group B Streptococcus) ✓

Explanation

The CAMP test (Christie, Atkins, Munch-Petersen) is positive for Streptococcus agalactiae (Group B Streptococcus, GBS). The CAMP factor produced by GBS synergistically acts with Staphylococcus aureus beta-lysin to produce enhanced arrowhead hemolysis. This test is used clinically to confirm GBS, which is the most common cause of neonatal sepsis and meningitis. Listeria is CAMP-positive too but is a small Gram-positive bacillus, not a coccus.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.