Adherence in the colonization of streptococcus pneumoniae in the nasopharynx in children

The adherence of Streptococcus pneumoniae to epithelial cells in mucus and to the epithelial lining of the nasopharynx in children was studied with the aid of FITC-labelled anti-sera and Omni-serum. By using acridine orange as a counterstain, other bacteria could be visualized as well. S. pneumoniae was seen to adhere more frequently to desquamated cells in mucus than to squamous cells from the nasopharyngeal wall which were obtained by scraping the dorsal side of the soft palate. No bacteria were found to be attached to the ciliated and metaplastic cells collected from the adenoid surface. Although S. pneumoniae appeared in small numbers in most patients and established microcolonies which were predominantly attached to desquamated cells in mucus, signs of an ecological shift were also observed, with S. pneumoniae constituting the majority of the bacteria present. In such cases many S. pneumoniae could also be seen lying free in mucus.