Transcriptome adaptation of group B Streptococcus to growth in human amniotic fluid. Streptococcus agalactiae

We have discovered that GBS significantly remodels its transcriptome in response to exposure to human amniotic fluid. A large number of the affected genes are of unknown function, which means that much remains to be learned about the full influence of amniotic fluid on GBS. The majority of the observed changes in transcripts affects genes involved in basic bacterial metabolism and is connected to AF composition and nutritional requirements of the bacterium. The observation that many genes encoding adhesions are down-regulated, and genes encoding known virulence factors such as a hemolysin and a potent IL-8 proteinase are up-regulated likely have consequences for the outcome of host-pathogen interactions. Overall design: Streptococcus agalactiae, serotype III strain NEM316 was grown in human amniotic fluid. Samples of bacteria were collected in mid log, late log and stationary growth phases and were used for RNA isolation for microarray analysis