Insights Into Pneumococcal Pneumonia Using Lung Aspirates and Nasopharyngeal Swabs Collected From Pneumonia Patients in The Gambia

Abstract 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. We investigated the pathogenesis of pneumococcal pneumonia using clinical samples. Results demonstrated that pneumococci in the lung originated from the nasopharynx and suggested that changes in pneumococcal gene expression in the lung are a feature of pneumococcal pneumonia.