Carbohydrate-dependent gene regulation in Streptococcus pneumoniae

The Gram-positive human pathogen, Streptococcus pneumoniae, has the ability to cause infections like pneumonia, meningitis, otitis media and sepsis, and is responsible for millions of deaths each year especially in children and the elderly. Understanding of the molecular mechanisms responsible for the utilization and transport of carbohydrates needs more attention as the behavior of S. pneumoniae can rapidly change in the fluctuating nutritional environment inside the human body. This thesis revolves around several regulatory responses of S. pneumoniae to varying carbohydrate availability that it is likely to encounter in different niches inside the human body during the infection process. Several transcriptional regulators, responsive to various carbon sources (i.e. lactose, galactose, ascorbic acid, sialic acid and maltose) are characterized and their regulons studied in detail. The results described in this thesis will help us to better understand the molecular biology and virulence of S. pneumoniae by providing new insights into the responses of S. pneumoniae to changing environmental conditions.