A newborn has a fever of 103degF. Blood culture grows gram-positive cocci in chains. This is most likely to be which of the following?

Most human infections caused by Streptococci involve the group A organisms (Streptococcus pyogenes). The group B Streptococci are members of the female genital tract and are impoant causes of neonatal sepsis and meningitis. Here we have newborn in the question given, so the most likely organism would be Gr B strep.