Gram Positive Cocci
A newborn has a temperature of 39.4Â°C (103Â°F). Blood culture grows gram-positive cocci in chains. This is most likely to be which of the following?
|A||Group A Streptococci (Streptococcus pyogenes)|
|B||Group B Streptococci (Streptococcus agalactiae)|
a. Most human infections caused by Streptococci involve the group A organisms (Streptococcus pyogenes).
b. The group B Streptococci are normal commensals of the female genital tract and are important causes of neonatal sepsis and meningitis.
c. They are usually beta-hemolytic (similar to group A), hydrolyze hippurate and give a positive response in the so-called CAMP test (Christie, Atkins, Munch-Peterson). Modified CAMP test is positive in V.cholerae.
d. Detection of the infection and prompt antimicrobial treatment with penicillin is necessary because the infections may become life-threatening.
e. Streptococcus pneumoniae organisms are important in meningitis cases in young children, but are more frequently seen as diplococci forms rather than long chains.