Nasopharyngeal colonization with Streptococcus pneumoniae

The ability to colonize the human upper respiratory tract and transmit to a new host are perhaps the strongest selective pressures driving the evolution of Streptococcus pneumoniae. Indeed, many of the mechanisms that have been widely studied in the context of pneumococcal disease play an essential role in the establishment and maintenance of pneumococcal colonization. In this chapter we discuss the various challenges the pneumococcus faces in order to successfully colonize the nasopharynx, the dynamics of S. pneumoniae colonization, and the factors that, in some individuals, contribute to increased pneumococcal colonization and transmission