Background: We investigated the pathogenesis of pneumococcal pneumonia using clinical specimens collected for pneumonia surveillance in The Gambia.
Methods: Lung aspirates and nasopharyngeal swabs from 31 patients were examined by culture, quantitative polymerase chain reaction (qPCR), whole genome sequencing, serotyping, and reverse-transcription qPCR.
Results: Five lung aspirates cultured pneumococci, with a matching strain identified in the nasopharynx. Three virulence genes including ply (pneumolysin) were upregulated >20-fold in the lung compared with the nasopharynx. Nasopharyngeal pneumococcal density was higher in pediatric pneumonia patients compared with controls (P < .0001).
Conclusions: Findings suggest that changes in pneumococcal gene expression occurring in the lung environment may be important in pathogenesis.
Keywords: Streptococcus pneumoniae; lung; nasopharynx; pneumococcus; pneumonia.
© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America.