The frequency of genes encoding three putative group B streptococcal virulence factors among invasive and colonizing isolates

Table 2 PCR primers used to amplify DNA regions specific to the genes encoding the alpha (bca) and beta (bac) C proteins, and the protein Rib (rib).*

Gene	Forward primer Reverse primer	Reference	Size	Annealing temperature	Extension time
bca	5'-TAACAGTTATGATACTTCACAGAC-3'	[11]	535 bp	68°C	33 sec
	5-'ACGACTTTCTTCCGTCCACTTAGG-3'
bac	5'-CTATTTTTGATATTGACAATGCAA-3'	[12]	592 bp	60°C	36 sec
	5'-GTCGTTACTTCCTTGAGATGTAAC-3'
rib	5'-CAGGAAGTGCTGTTACGTTAAAC-3'	[9]	369 bp	58°C	22 sec
	5'-CGTCCCATTTAGGGTCTTCC-3'

* PCR conditions for each reaction included a five minute denaturation step at 95°C, and 30 cycles of the following: 35 second denaturation, 40 second annealing and varying extension times. The extension temperature was 73°C for all reactions.