(Christie, Atkins, Munch, Petersen)
Test is based on some bacteria property to produce a diffusible extracellular protein (CAMP factor) that, together with the beta-lysin of
Staphylococcus aureus, enhances the lysis of red blood cells.
Prepare sheep blood agar as described in "Hemolysis" page.
Streak a single line of Staphylocccus aureus on a blood agar plate then make
streaks of the unknown strain (beta hemolytic streptococci) perpendicularly but not
touching the S. aureus. A 2-3 mm space should remain between the streaks. Invert
the plate and incubate it at 37°C, 24 hours. Reaction is positive if an enhanced
hemolysis in the shape of an arrowhead, at the juncture of the streaks, is observed.
Do not incubate plates under anaerobic conditions.
1. H. Raducanescu, V.Bica-Popii,1986. Bacteriologie veterinara, Ed. Ceres, Bucuresti.
2. Margaret Barnett, 1992. Microbiology Laboratory Exercises. Wm. C. Brown Publishers.
3. Murray, P.R., Baron, E. J., Jorgensen, J.J., Pfaller, M.A., and Yolken, R.H. Manual of Clinical Microbiology, 8th ed. ASM Press:
Washington, DC, 2003.
|CAMP test, lines 2 & 4 from left to right are positive
(c) Costin Stoica