The key difference between CAMP and reverse CAMP test is that the CAMP test is a test to identify group B β hemolytic streptococci such as Streptococcus agalactiae, while the reverse CAMP test is a test to identify Clostridium perfringens using β-hemolytic streptococci.
CAMP and reverse CAMP tests are two common laboratory tests to detect pathological bacteria such as Streptococcus agalactiae and Clostridium perfringens. Christie, Atkins, and Munch Petersen first described the CAMP test in 1944. It detected that Streptococcus agalactiae produced an extracellular and heat-stable protein known as the CAMP factor. The CAMP factor acts synergistically with the beta hemolysin protein usually produced by Staphylococcus aureus. When both Streptococcus agalactiae and Staphylococcus aureus are grown in sheep blood agar medium, the effect is a zone of enhanced lysis in this media. Therefore, this test is commonly used for the identification of group B streptococci like Streptococcus agalactiae. On the other hand, the reverse CAMP test was found by Hansen to identify Clostridium perfringens.
CONTENTS
1. Overview and Key Difference
2. What is CAMP Test
3. What is Reverse CAMP Test
4. Similarities – CAMP and Reverse CAMP Test
5. CAMP vs. Reverse CAMP Test in Tabular Form
6. Summary – CAMP vs. Reverse CAMP Test
What is CAMP Test?
The CAMP test is a test to identify group B streptococci like Streptococcus agalactiae. This test is based on the formation of a protein called CAMP factor by Streptococcus agalactiae, which enlarges the area of hemolysis in sheep blood agar medium formed by the β hemolysin protein of Staphylococcus aureus.
Figure 01: CAMP Test
In this test, the Staphylococcus aureus is first streaked in the center of the sheep blood agar medium. Then, the Streptococcus agalactiae is streaked perpendicular to it. Later, the plate is incubated from 35oC to 37oC for 15 to 24 hours in anaerobic conditions. A wedge-shaped pattern radiating from the Streptococcus agalactiae near the Staphylococcus aureus indicates a positive result.
What is Reverse CAMP Test?
A microbiologist called Hansen used the synergistic relationship between Clostridium perfringens and Group B Streptococci, such as Streptococcus agalactiae, to develop the reverse CAMP test. It was detected that Clostridium perfringens produces a protein known as alpha toxin. The alpha toxin acts synergistically with the CAMP factor usually produced by Streptococcus agalactiae. Therefore, when both Clostridium perfringens and Streptococcus agalactiae are grown in sheep blood agar medium, the effect is a zone of enhanced lysis in this medium.
Figure 02: Reverse CAMP Test
In this test, the Streptococcus agalactiae is first streaked in the center of the sheep blood agar medium. Then the Clostridium perfringens is streaked perpendicular to it. Later, the plate is incubated at 37oC for 24 to 48 hours in anaerobic conditions. An arrowhead type of enhanced hemolysis is seen between the growth of Clostridium perfringens and Streptococcus agalactiae, which indicates a positive result.
What are the Similarities Between CAMP and Reverse CAMP Test?
- CAMP and reverse CAMP tests are two common laboratory tests to detect pathological bacteria such as Streptococcus agalactiae and Clostridium perfringens.
- Both tests are microbiological laboratory tests.
- Both tests use sheep blood agar as the medium.
- They use proteins and enhanced hemolysis on the sheep blood agar principle to identify the bacteria.
- They are cheap and cost-effective techniques.
What is the Difference Between CAMP and Reverse CAMP Test?
CAMP test is a test to identify group B β hemolytic streptococci such as Streptococcus agalactiae, while the reverse CAMP test is a test to identify Clostridium perfringens using β-hemolytic streptococci. Thus, this is the key difference between CAMP and reverse CAMP Test.
The infographic below presents the differences between CAMP and reverse CAMP Test in tabular form for side-by-side comparison.
Summary – CAMP vs. Reverse CAMP Test
CAMP and reverse CAMP tests are two common laboratory tests to detect pathological bacteria. Both tests use sheep blood agar as the medium. However, the CAMP test identifies group B β hemolytic streptococci such as Streptococcus agalactiae, while the reverse CAMP test identifies Clostridium perfringens. So, this summarizes the difference between CAMP and reverse CAMP test.
Reference:
1. “Camp Test: Principle: Uses: Procedure.” Microbiologie Clinique.
2. “Reverse CAMP Test for the Identification of Clostridium Perfringens.” American Society for Microbiology
Image Courtesy:
1. “CAMP test” By Blueiridium – Own work (CC0) via Commons Wikimedia
2. “CAMP-Test zur Bestimmung von Listerien auf einer Blutagarplatte” By Lemi15 – Own work (CC BY-SA 3.0) via Commons Wikimedia