Camp Test

CAMP TEST
This test is used for the presumptive identification of Group B Streptococcus (Streptococcus agalactiae). It is the only beta-hemolytic Streptococcus which yields a positive CAMP test. Thetest has been named after Christie, Atkins, and Munch-Peterson, who described it in 1944. This test detects a diffusible, heat-stable, extracellular protein produced by Group B Streptococcus thatenhances the hemolysis of sheep erythrocytes by Staphylococcus aureus. The CAMP factor acts synergistically with the beta hemolysin produced by S. aureus to induce enhanced hemolysis of sheep or bovineRBCs but not human, rabbit or horse RBCs. A known hemolytic strain of S. aureus (ATCC 25923) is streaked in a straight line across the centre of the sheep blood agar plate. Test inoculum is streaked ina straight line (2-3 cms in length) perpendicular to S.aureus streak but without touching it. A known Group B Streptococcus may also be streaked similarly as a positive control. Four-five testorganisms may be tested per plate. The plate is incubated at 37oC for 18-24 hours. A positive test for CAMP factor appears as “arrowhead” hemolysis between the junction of growth of S.aureus and Group BStreptococcus. There is no enhanced or “arrowhead” hemolysis if the test isolate is not Group B Streptococcus. A similar test has been described for Listeria ivanovii, where an “arrowhead” hemolysisoccurs appear between streaks of Listeria ivanovii and Rhodococcus equi. Reverse CAMP test can be used for differentiation of Clostridium perfringens from other Clostridium species. Here, a CAMP positiveGroup B Streptococcus is streaked in the center of sheep blood agar, and Clostridium perfringens is streaked perpendicular to it. Following incubation at 37oC for 24-48 hours in anaerobic conditions,an “arrowhead” hemolysis is seen between growth of C. perfringens and Group B Streptococcus. This is because of alpha toxin produced by C. perfringens interacts with CAMP factor and produce...