Streptococcus agalactiae (also known as Group B streptococcus or GBS) is
a beta-hemolytic gram-positive streptococcus. S. agalactiae is a species of the normal flora of the female urogenital tract and rectum. Its chief clinical importance
is that it can be transferred to a neonate passing through the birth canal and can cause serious group B streptococcal infection. In the western world, S. agalactiae is
the major cause of bacterial septicemia of the newborn, which can lead to death or long-term sequelae. S. agalactiae can also cause neonatal
meningitis, which does not present with the hallmark sign of adult meningitis, a stiff neck; rather, it presents with nonspecific symptoms such as fever, vomiting and irritability and can consequently
go undiagnosed until it is too late. Hearing loss can be a long-term sequelae of GBS-meningitis. Somewhat more rarely, S. agalactiae can also cause invasive group B streptococcal disease of the adult in
the pregnant, elderly, or immunosuppressed. S. agalactiae is present in up to one-third of women of childbearing age, and one in every thousand live births will be affected by group B streptococcal infection.
In the elderly or persons with compromised immune systems septicemia or other serious infections are seen. This occurs also rarely during pregnancy or maternity.
Abbreviated from Wikipedia.