[Prevalence of colonization by group B Streptococcus in pregnant women from a public maternity of Northwest region of Brazil].

Purpose: to assess the prevalence of group B streptococcus colonization (GBS) in pregnant women in prodrome or in labor.

Methods: vaginal and rectal cultures were collected from 201 pregnant women, in the admission sector of a public maternity center in the northeast region of Brazil (São Luís, Maranhão). The samples obtained were inoculated in a Todd-Hewith's selective culture medium and after that they were sub-cultivated in blood-agar plates.