Camp Test Flashcards
Purpose of Camp test:
The Christie, Atkins, and Munch-Peterson (CAMP) test is used to differentiate group B streptococci (Streptococcus agalactiae- positive) from other streptococcal species. Lis teria monocytogenes also produces a positive CAMP reaction.
Principle of camp test:
Certain organisms (including group 8 strepto cocci) produce a diffusible extracellular hemo lytic protein (CAMP factor) that acts synergistically with the beta-lysin of Staphylo- coccus aureus to cause enhanced lysis of red blood cells. The group B streptococci are streaked perpendicular to a streak of S. aureus on sheep blood agar. A positive reaction appears as an arrowhead zone of hemolysis adjacent to the place where the two streak lines come into proximity.
Method of camp test:
. Streak a beta-lysin-producing strain of S. aureus down the center of a sheep blood agar plate.
2. Streak test organisms across the plate perpendicular to the S. aureus streak within 2 mm. (Multiple organisms can be tested on a single plate).
3. Incubate overnight at 35°-37°C in ambient air.
Expected results of camp test:
Positive: Enhanced hemolysis is indicated by an arrowhead-shaped zone of beta- hemolysis at the juncture of the two organisms
Negative: No enhancement of hemolysis
Limitation of camp test:
small percentage of group A streptococci may have a positive CAMP reaction. The test should be limited to colonies with the characteristic group B streptococci morphology and narrow zone beta-hemolysis on sheep blood agar.
Quality control of camp test:
Positive: Streptococcus agalactiae (ATCC13813)-enhanced arrowhead hemolysis
Negative: Streptococcus pyogenes (ATCC19615)-beta-hemolysis without enhanced arrowhead formation
