Reverse CAMP test Principle, Procedure, Result

Reverse CAMP test

• The full form of reverse CAMP test is reverse Christie-Atkinson-Munch-Peterson test.
• Hansen used the synergistic relationship between the two microbes such as Clostridium perfringens and Group B Streptococcus to develop a test, which known as Reverse CAMP test.
• This test is used for the differentiation of Clostridium perfringens from other Clostridium species. 
• In this method, the CAMP factor produced by S. agalactiae is used to detect the Clostridium perfringens from other Clostridium species, that’s why this method is termed as a reverse CAMP test.

Objective of Reverse CAMP test

• To differentiate the Clostridium perfringens from other Clostridium species. 

Reverse CAMP test Principle

In this method, the Group B Streptococcus (CAMP test positive) is streaked in the center of sheep blood agar, and Clostridium perfringens is streaked perpendicular to it. Then the plate is incubated at 37oC for 24-48 hours in anaerobic conditions, an “arrowhead” hemolysis is seen between the growth of Clostridium perfringens and Group B Streptococcus. The “arrowhead” hemolysis is seen because an alpha-toxin is produced by Clostridium perfringens which interacts with CAMP factor and produces synergistic hemolysis.

Material Required for Reverse CAMP test

• CAMP positive S. agalactiae.
• Blood agar
• Petri Plate
• Clostridium perfringens 
• Incubator

Reverse CAMP test Procedure

1. Streak the culture of CAMP positive S. agalactiae on the blood agar plate.
2. Then Streak the Suspected clostridial culture at the right angle to the streak of S. agalactiae (avoid touching the streak of S. agalactia).
3. Incubate the plate at 37°C for 24hours, anaerobically.
4. After incubation observes the zone of hemolysis pointing toward S. agalactiae.

Reverse CAMP test Result

A positive reaction of Clostridium perfringens results in a “bow-tie” zone of enhanced hemolysis pointing towards Streptococcus agalactiae (group B).

Reverse CAMP test positive organisms

Corynebacterium pseudotuberculosis, Corynebacterium ulcerans, Arcanobacterium haemolyticum, Mycoplasma hyorhinis, C. perfringens.

References

• https://healthjade.net/camp-test/
• http://microbesinfo.com/2013/07/camp-test-christie-atkins-and-munch-peterson-test/
• https://microbiologynotes.com/reverse-camp-test-for-the-identification-of-clostridium-perfringens/
• https://www.basu.org.in/wp-content/uploads/2021/01/CAMP_Tests__Standard_and_Rapid__and_Reverse_CAMP_test.pdf