The question "Is cAMP positive or negative?" is incomplete. cAMP, or cyclic adenosine monophosphate, is a molecule used in cellular signaling. It does not have an inherent positive or negative value. However, the CAMP test, named after its discoverers, Christie, Atkins, and Munch-Peterson, is a diagnostic test that can be positive or negative, depending on the organism being tested.
Here's a breakdown of the CAMP test and how the terms "positive" and "negative" apply:
The CAMP Test
The CAMP test is a microbiological test used primarily to identify specific types of bacteria. It is not about the molecule cAMP but rather its effect on Streptococcus bacteria.
How the CAMP Test Works
- A bacterial culture is streaked perpendicular to a Staphylococcus aureus streak on a blood agar plate.
- S. aureus produces a beta-lysin.
- If the bacterial culture being tested produces CAMP factor, it will enhance the beta-lysin production of S. aureus, resulting in an arrow-shaped zone of hemolysis (the breakdown of red blood cells).
Results of the CAMP Test
| CAMP Test Result | Explanation | Example Bacteria |
|---|---|---|
| CAMP Positive | A positive result shows a distinctive arrowhead of enhanced hemolysis where the two streaks meet. This indicates the presence of the CAMP factor from the tested bacteria. | Streptococcus agalactiae (Group B) |
| CAMP Negative | A negative result shows no arrowhead of enhanced hemolysis. This indicates that the bacteria does not produce the CAMP factor. | Streptococcus pyogenes (Group A), other Streptococcus species |
Key Takeaways from the Reference
According to the reference:
- The CAMP test helps differentiate between Streptococcus agalactiae (Group B), which is CAMP positive, and other Streptococcus species, like Streptococcus pyogenes (Group A) and non-group B Streptococcus, which are CAMP negative.
Examples
- Example 1: If a test shows an arrowhead of hemolysis on the blood agar plate, it is a CAMP positive result, and the bacteria is likely Streptococcus agalactiae.
- Example 2: If a test does not show an arrowhead of hemolysis, it is a CAMP negative result, suggesting the organism is not Streptococcus agalactiae.
Summary
The CAMP test can be either positive or negative, and it is a way to identify the Streptococcus agalactiae (Group B). A positive test result indicates the presence of the CAMP factor, while a negative test result indicates that the organism is likely not Streptococcus agalactiae.
