Amplification of 16S ribosomal RNA gene sequences for the identification of streptococci of Lancefield group B

The 16S rRNA gene of 49 streptococci of serological group B isolated from various origins was amplified by polymerase chain reaction (PCR) and subsequently digested with the restriction enzymes RsaI and MspI. The restriction profiles of all group B streptococci appeared to be identical indicating no intraspecies sequence variations of this gene. A fragment of the gene of two group B-streptococcal reference strains, including the hypervariable V2 region, could be amplified by PCR and sequenced. The sequence appeared to be identical and allowed the design of species-specific oligonucleotide primers. The primer pair used produced an amplicon with a size of 1250 bp and correctly identified all 49 group B-streptococci investigated but none of the control strains of various species and serogroups. This primer could be used in a multiplex PCR and allowed a rapid identification of bacteria of this species. (C) 1999 Harcourt Publishers Limited.