The CAMP test (named for Christie, Atkins, Munch-Petersen) is a presumptive test for Group B streptococci. Group B streptococci release a protein that enhances activity of the beta-hemolysin released by Staphylococcus aureus.
Some Group B streptococcal strains are hemolytic while others are not.
Specimen: pure isolate of a streptococcus
A streak of Staphylococcus aureus is made down the center of a sheep blood agar plate. The unknown streptococcal isolate is streaked at right angles to the S. aureus streak line, stopping a distance away.
The plate is then incubated in ambient air for 18-24 hours at 35°C.
If the streptococcal isolate is a Group B streptococcus, then there will a large area of enhanced hemolysis between the 2 streak lines.
If the isolate is not a Group B streptococcus, then no enhancement of hemolysis is seen. Any hemolysis will be limited to the growing colonies.
Some group A streptococci can show a similar reaction if incubated in a CO2 atmosphere.
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