CAMP test

CAMP test

This is an example of a positive CAMP test indicated by the formation of an arrowhead where the Strep group B (Streptococcus agalactiae) meets the Staphylococcus aureus (white middle streak).

The CAMP test is a test to identify Group B β-streptococci[1][2] based on their formation of a substance (CAMP factor[3]) that enlarges the area of hemolysis formed by β-hemolysin from Staphylococcus aureus. It is frequently used to identify Listeria spp.


  • CAMP factor 1
  • Uses 2
  • History 3
  • References 4

CAMP factor

Although usually used to identify group "B", there is some evidence that the CAMP factor gene is present in several groups of streptococci, including group "A".[4]

A similar factor has been identified in Bartonella henselae.[5]


It can be used to identify Streptococcus agalactiae. Though not strongly beta-hemolytic on its own,[6] it presents with a wedge-shape in the presence of Staphylococcus aureus.[7]


It is an acronym for "Christie Atkins Munch-Petersen",[8][9][10] for the three researchers who discovered the phenomenon.[11]

It is often incorrectly reported as the product of four people (counting Munch-Petersen as two people).[12]

The name has no relationship to Cyclic adenosine monophosphate (cAMP).


  1. ^ Phillips EA, Tapsall JW, Smith DD (August 1980). "Rapid tube CAMP test for identification of Streptococcus agalactiae (Lancefield group B)". J. Clin. Microbiol. 12 (2): 135–7.  
  2. ^ Wilkinson HW (July 1977). "CAMP-disk test for presumptive identification of group B streptococci". J. Clin. Microbiol. 6 (1): 42–5.  
  3. ^ "Laboratory Demonstrations". Retrieved 2008-12-12. 
  4. ^ Gase K, Ferretti JJ, Primeaux C, McShan WM (September 1999). "Identification, cloning, and expression of the CAMP factor gene (cfa) of group A streptococci". Infect. Immun. 67 (9): 4725–31.  
  5. ^ Litwin CM, Johnson JM (July 2005). "Identification, cloning, and expression of the CAMP-like factor autotransporter gene (cfa) of Bartonella henselae". Infect. Immun. 73 (7): 4205–13.  
  6. ^ "Microbiology Primer: Hemolysis". Retrieved 2008-12-12. 
  7. ^ "Streptococcaceae Answers". Retrieved 2008-12-12. 
  8. ^ Ratner HB, Weeks LS, Stratton CW (August 1986). "Evaluation of spot CAMP test for identification of group B streptococci". J. Clin. Microbiol. 24 (2): 296–7.  
  9. ^ Nsagha DS, Bello CS, Kandakai-Olukemi YT (January 2000). "Hippurate hydrolysis and Christie, Atkins, Munch-Peterson tests as epidemiological diagnostic tools for Streptococcus agalactiae carriage in pregnancy". East Afr Med J 77 (1): 34–6.  
  10. ^ Valanne S, McDowell A, Ramage G, et al. (May 2005). "CAMP factor homologues in Propionibacterium acnes: a new protein family differentially expressed by types I and II". Microbiology (Reading, Engl.) 151 (Pt 5): 1369–79.  
  11. ^ Christie, R., Atkins, NE and Munch-Petersen, E. (1944). A note on a lytic phenomenon shown by group B streptococci. Aust. J. Exp. Biol. Med. Sci. 22, 197-200
  12. ^ "Streptococci". Retrieved 2008-12-12.