Remarkable attachment of lactoferrin to Streptococcus pyogenes during acute pharyngotonsillitis.

The purpose of this study was to establish whether lactoferrin (hLf) attached to Streptococcus pyogenes, one causative agent of acute pharyngotonsillitis (AT), during the course of the disease. Bacterial samples were obtained from the tonsillar surfaces of 7 patients (6 females, 1 male; median age 26 years; range 16-50 years) suffering from AT who were culture-positive for S. pyogenes and from 5 healthy adult controls who were culture-negative for this pathogen. Using gold-labelled antiserum against S. pyogenes and hLf, this pathogen and other bacteria on the tonsillar surfaces coated with hLf could be identified by tracing the gold particles in a transmission electron microscope. In healthy adults, 8% (median value; range 6-12%) of the surface tonsillar bacteria were coated with hLf. In AT patients, 59% (median value; range 42 67%) of S. pyogenes were coated with hLf, in contrast to 9% (median value; range 0-26%) of all other bacteria (p < 0.01). This study hints that hLf might participate in recovery from AT in several ways, e.g. by binding to the S. pyogenes pathogens, in addition to its well-known virtue of iron-binding capacity.

Bacterial coating with immunoglobulins on the palatine tonsils during infectious mononucleosis: immunocytochemical study with gold markers.

Epithelial cells and bacteria were sampled from the tonsillar surfaces of seven patients (six males, one female; median age 16 years, range 10 to 21 years) suffering from acute infectious mononucleosis with concomitant pharyngotonsillitis. By using gold-labelled antiserum to human IgG and secretory IgA (sIgA), micro-organisms on the tonsillar surfaces coated with these immunoglobulins could be identified by tracing the gold particles in the transmission electron microscope. The patients harboured significantly fewer bacteria coated with immunoglobulins than did healthy controls. More bacteria were coated with IgG immunoglobulins than with sIgA. Reduced immunoglobulin-coating of the bacteria on the tonsillar surfaces during infectious mononucleosis can explain their tendency to immense local colonization and proneness to penetrate into the epithelial cells.

Bacterial penetration into tonsillar surface epithelium during infectious mononucleosis.

Bacterial penetration into epithelial cells, scraped from the palatine tonsils of 14 patients (10 males, four females; median age 16 years) with current infectious mononucleosis and concomitant membranous tonsillitis, was studied using the transmission electron microscopic (TEM) technique. Bacteria were seen to adhere to and penetrate the epithelial cells, some of which were completely filled with bacteria. This finding suggests intracellular proliferation of bacteria. Epstein-Barr virus, the causative agent of infectious mononucleosis, especially when associated with growth of beta-haemolytic streptococci on the palatine tonsils, induces bacterial penetration into tonsillar tissue, that in turn might be a causative mechanism in the development of peritonsillar abscess.

SIgA- and IgG-coated Streptococcus pyogenes on the tonsillar surfaces during acute tonsillitis.

Bacterial swabs were collected from the tonsillar surfaces of eight patients with current acute tonsillitis, culture-positive for Streptococcus pyogenes. Using gold-labelled antiserum to S. pyogenes, these micro-organisms could be localized in the samples by transmission electron microscopy. S. pyogenes pathogens were further characterized with gold-labelled antiserum to human IgG and SIgA antibodies. Roughly 90% of the pathogens were found coated with IgG antibodies, irrespective of the duration of the disease, whereas the proportion of SIgA-coated pathogens increased with disease duration. Insufficient IgA coating of pathogens might well be a contributory cause of the induction of tonsillar infection, probably due to inadequate prevention of the attachment of the S. pyogenes bacteria to the tonsillar surface epithelium.