A rhesus macaque model of Streptococcus pneumoniae carriage.

ABSTRACT

BACKGROUND: Nasopharyngeal colonization by Streptococcus pneumoniae precedes pneumococcal disease. Elucidation of procedures to prevent or eradicate nasopharyngeal carriage in a model akin to the human would help to diminish the incidence of both pneumonia and invasive pneumococcal disease. METHODS: We conducted a survey of the nasopharynx of infant rhesus macaques from our breeding colony, in search of natural carriers of S. pneumoniae. We also attempted experimental induction of colonization, by nasopharyngeal instillation of a human S. pneumoniae strain (19F). RESULTS: None of 158 colony animals surveyed carried S. pneumoniae in the nasopharynx. Colonization was induced in eight of eight infant rhesus by nasopharyngeal instillation and lasted 2weeks in 100% of the animals and 7weeks in more than 60%. CONCLUSION: Rhesus macaques are probably not natural carriers of S. pneumoniae. The high rate and duration of colonization obtained in our experiments indicates that the rhesus macaque will serve as a human-like carriage model.