Streptococcus causing neonatal meningitis among the following is:

Infection is classified as early onset & late onset. In early onset it occurs within a week of bih & late occurs between 2nd & 12th week of life. Early onset presents as septicaemia, meningitis or pneumonia. Infection is acquired from maternal vagina during bih. Late onset obtained from environment. Ref: Ananthanarayan and Panicker's, 8th Edition, Page 215