LAUSR

Streptococcus pneumoniae is a frequent colonizer of the upper airways; however, it is also an accomplished pathogen capable of causing life‐threatening diseases. To colonize and cause invasive disease, this bacterium relies on a complex array of factors to mediate the host–bacterium interaction. The respiratory tract is rich in functionally important glycoconjugates that display a vast range of glycans, and, thus, a key component of the pneumococcus–host interaction involves an arsenal of bacterial carbohydrate‐active enzymes to depolymerize these glycans and carbohydrate transporters to import the products. Through the destruction of host glycans, the glycan‐specific metabolic machinery deployed by S. pneumoniae plays a variety of roles in the host–pathogen interaction. Here, we review the processing and metabolism of the major host‐derived glycans, including N‐ and O‐linked glycans, Lewis and blood group antigens, proteoglycans, and glycogen, as well as some dietary glycans. We discuss the role of these metabolic pathways in the S. pneumoniae–host interaction, speculate on the potential of key enzymes within these pathways as therapeutic targets, and relate S. pneumoniae as a model system to glycan processing in other microbial pathogens.