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Streptococcus agalactiae Wikipedia

mergefrom|Group B Streptococcus
Streptococcus agalactiae is a gram-positive streptococcus characterized by the presence of group B Lancefield antigen. It is a member of the normal flora of the gut and female urogenital tract. Early perinatal infection causes pneumonia or septicemia, which are associated with a high mortality. During delivery, a baby can acquire S. agalactiae and develop neonatal sepsis, neonatal meningitis, and neonatal pneumonia. Neonates with meningitis do not present with the hallmark sign of adult meningitis, a stiff neck. They display nonspecific symptoms such as fever, vomiting, poor feeding, and irratability. The polysaccharide antiphagocytic capsule is this bacterium's main Virulence|virulence factor.

S. agalactiae displays beta-hemolysis when cultured on a blood agar plate and produce zones of hemolysis that are only slightly larger than the colonies themselves. Group B streptococci hydrolyze sodium hippurate and give a positive response in the CAMP test. S. agalactiae is also sensitive to bile and will lyse in its presence.

Last Modified:   2005-12-23