The CAMP test (Christie–Atkins–Munch-Petersen) is a test to identify group B β-hemolytic streptococci ( Streptococcus agalactiae)[
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CAMP factor
Although the test is usually used to identify group B streptococcus, there is some evidence that the CAMP factor gene is present in several groups of streptococci, including group A.
CAMP factor is a phospholipase produced by Group B Streptococci (Streptococcus agalactiae) that enhances hemolysis of Staphylococcus aureus.
[Essentials of Medical Microbiology by Apoorba S Sastry]
A similar factor has been identified in Bartonella henselae.
Uses
The CAMP test can be used to identify
Streptococcus agalactiae. Though not strongly beta-hemolytic on its own,
group B strep presents with wedge-shaped colonies in the presence of
Staphylococcus aureus.
It can also be used to identify Listeria monocytogenes which produces a positive CAMP reaction.
Setup
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Streak a beta-lysin–producing strain of aureus down the center of a sheep blood agar plate.
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The test organism streak should be 3 to 4 cm long.
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Streak test organisms across the plate perpendicular to the S. aureus streak within 2 mm. (Multiple organisms can be tested on a single plate).
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Incubate at 35°-37°C in ambient air for 18-24 hours.
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Wedge shaped pattern radiating from the test organism near the S. aureus indicates positivity
Reverse CAMP test
The reverse CAMP test is a method to identify
Clostridium perfringens using β-hemolytic streptococci. The CAMP factor produced by
S. agalactiae and the alpha toxin produced by
C. perfringens act synergistically to produce enhanced hemolysis. Streaking these two organisms perpendicular to each other on a blood agar plate will yield a “bow tie” shaped zone of hemolysis which indicates a positive test.
History
CAMP is an acronym for "Christie–Atkins–Munch-Peterson",
for the three researchers who discovered the phenomenon.
[Christie, R., Atkins, NE and Munch-Petersen, E. (1944). A note on a lytic phenomenon shown by group B streptococci. Aust. J. Exp. Biol. Med. Sci. 22, 197-200]
It is often incorrectly reported as the product of four people (counting Munch-Petersen as two people).
The name of the test bears no relationship to the name of the second messenger cyclic adenosine monophosphate (commonly referred to as cAMP).
