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Causes for massive bacterial colonization on mucosal membranes during infectious mononucleosis: implications for
Lars-Eric Stenfors1, Helga-Marie Bye, Simo Räisänen
1Department of Otolaryngology, Institute of Clinical Medicine, University of Tromsø, N-9037, Tromso, Norway. larseric@fagmed.uit.no
Objective:
A common complication of virus-induced upper respiratory tract infections is acute otitis media caused by bacterial pathogens. Simultaneously, increased bacterial colonization in the nasopharynx occurs. Our intention in this study was to identify the causes of this increased colonization of bacteria by evaluating their coating with the antibacterial substances lysozyme, lactoferrin and immunoglobulins IgG, S-IgA and IgM and their ability to penetrate epithelial cells during infectious mononucleosis (IM) caused by Epstein-Barr virus.
Methods:
Cellular samples were collected from the oropharynx of 21 patients (16 males, five females; age range 10-21 years) with current IM. An immunocytochemical assay using gold-labelled antiserum to human lysozyme, lactoferrin, IgG, S-IgA and IgM followed by gold particle and epithelial cell tracing in the transmission electron microscope.
Results:
A significant reduction in bacterial coating with IgG (P<0.05) and S-IgA (P<0.01) was noted, whereas there was a significant increase in coating with lactoferrin (P<0.01) and IgM (P<0.01). No significant change in lysozyme coating of the bacteria was noted, compared with healthy controls. Bacterial penetration into epithelial cells was seen particularly in patients culture-positive for beta-haemolytic streptococci.
Conclusions:
Reduced bacterial coating with IgG and S-IgA immunoglobulins, combined with bacterial penetration into epithelial cells, may exacerbate the bacterial colonization on oropharyngeal mucosal membranes observed during IM.
Insights
Infectious mononucleosis (IM) reduces protective immunoglobulin G (IgG) and S-IgA coating on bacteria, increasing colonization. Bacteria also penetrated epithelial cells, potentially worsening nasopharyngeal infections.
Area of Science:
- Immunology
- Microbiology
- Otolaryngology
Background:
- Virus-induced upper respiratory tract infections commonly lead to bacterial acute otitis media.
- Increased nasopharyngeal bacterial colonization often accompanies these viral infections.
Purpose of the Study:
- To investigate the causes of increased bacterial colonization during infectious mononucleosis (IM).
- To evaluate bacterial coating with lysozyme, lactoferrin, and immunoglobulins (IgG, S-IgA, IgM).
- To assess bacterial penetration into epithelial cells in IM patients.
Main Methods:
- Collected oropharyngeal samples from 21 IM patients.
- Utilized immunocytochemical assays with gold-labelled antiserum.
- Employed transmission electron microscopy for bacterial and epithelial cell analysis.
Main Results:
- Observed significantly reduced bacterial coating with IgG and S-IgA.
- Noted a significant increase in bacterial coating with lactoferrin and IgM.
- Found bacterial penetration into epithelial cells, especially in patients with beta-haemolytic streptococci.
Conclusions:
- Reduced IgG and S-IgA coating on bacteria may contribute to increased colonization.
- Bacterial penetration into epithelial cells could exacerbate oropharyngeal mucosal infections during IM.