This is an example of a positive CAMP test indicated by the formation of dark arrowheads where the Strep group B (Streptococcus agalactiae) meets theStaphylococcus aureus (light-yellow/golden middle streak with surrounding dark hemolysis).Example of a workup algorithm of possible bacterial infection in cases with no specifically requested targets (non-bacteria, mycobacteria etc.), with most common situations and agents seen in a New England community hospital setting. CAMP test is shown at bottom left.
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, includinggroup A.[4]
The CAMP test can be used to identifyStreptococcus agalactiae. Though not strongly beta-hemolytic on its own,[6] group B strep presents with wedge-shaped colonies in the presence ofStaphylococcus aureus.[7]
The reverse CAMP test is a method to identifyClostridium perfringens using β-hemolytic streptococci. The CAMP factor produced byS. agalactiae and thealpha toxin produced byC. 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.[9][10]
CAMP is an acronym for "Christie–Atkins–Munch-Peterson",[11][12][13] for the three researchers who discovered the phenomenon.[14]
It is often incorrectly reported as the product offour people (counting Munch-Petersen as two people).[15] The true relationship (three people) is the reason for twoen dashes and then onehyphen in Christie–Atkins–Munch-Petersen.
^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
