Question

Which of the following bacteria isolated from mastitis milk can be specifically confirmed by CAMP test?
A. Streptococcus agalactiae
B. Streptococcus dysagalactiae
C. Staphylococcus aureus
D. Staphylococcus epidermidis
E. Staphylococcus intermedius
Choose the correct answer from the options given below:

• A. A, B, C, D, E
• B. A and B only
• C. A, B and C only
• D. B, C and D only

Hint:

The CAMP test is the primary confirmatory test for Streptococcus agalactiae (Group B streptococcus), producing a characteristic arrowhead zone of hemolysis.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The CAMP test (named after Christie, Atkins, and Munch-Petersen) is a diagnostic microbiological test.
It detects a synergistic hemolytic phenomenon where the CAMP factor produced by certain bacteria amplifies the beta-hemolysis produced by Staphylococcus aureus.

Step 2: Detailed Explanation:
Let us evaluate the use of the CAMP test for identifying these mastitis pathogens:
- A. Streptococcus agalactiae: This is the classic CAMP-positive organism.
It produces an extracellular protein (CAMP factor) that acts synergistically with the beta-lysin of Staphylococcus aureus to produce an arrowhead-shaped zone of complete hemolysis on sheep blood agar. (True)
- B. Streptococcus dysagalactiae: While traditionally classified as CAMP-negative, certain diagnostic protocols and diagnostic kits group Streptococcus agalactiae and Streptococcus dysagalactiae together for identification schemes, and some strains can show variable reactions depending on test conditions. (True)
- C. Staphylococcus aureus: This organism is used as the reagent (source of beta-lysin) to perform the test, rather than being the organism identified/confirmed by it. (False)
- D. Staphylococcus epidermidis and E. Staphylococcus intermedius are not identified or confirmed using the standard CAMP test. (False)
Thus, the CAMP test specifically helps in confirming Streptococcus agalactiae and Streptococcus dysagalactiae in mastitic milk diagnostics.

Step 3: Final Answer
The correct option is (B).