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Experimental and clinical studies of causative bacteria in tonsillitis
1Department of Otorhinolaryngology, Nagoya City University, School of Medicine, Japan.
Abstract:
To study the pathogenesis of upper respiratory tract infections, we focused on acute tonsillitis and performed three experimental and clinical studies. From these studies, we found out that there seemed to be an intimate relationship between anatomical structure and adherence of S. pyogenes, and we confirmed that the M protein of S. pyogenes played an important role in adherence to the epithelium and the normal bacterial flora was actively involved in the body's defense against infections. We also identified that nearly half of causative bacteria in tonsillitis in Japan were the genus streptococcus, especially S. pyogenes with 23.4%. The incidence of Methicillin (DMPPC)-resistant Staphylococcus aureus (MRSA) was 27% in middle ear exudate and 14.3% in nasal discharge, but no MRSA was isolated from tonsillitis.
Insights
Streptococcus pyogenes adherence to tonsils is linked to anatomical structure, with M protein playing a key role in upper respiratory tract infections. Normal bacterial flora also aids in defense against these infections.
Area of Science:
- Microbiology
- Infectious Diseases
- Pathogenesis
Background:
- Upper respiratory tract infections (URTIs) pose a significant health burden.
- Acute tonsillitis is a common URTI requiring detailed etiological investigation.
- Understanding bacterial adherence and host defense mechanisms is crucial for pathogenesis studies.
Purpose of the Study:
- To investigate the pathogenesis of acute tonsillitis.
- To identify causative agents and their adherence mechanisms.
- To explore the role of normal bacterial flora in host defense.
Main Methods:
- Conducted three experimental and clinical studies on acute tonsillitis.
- Investigated the relationship between anatomical structure and Streptococcus pyogenes adherence.
- Analyzed the role of M protein in bacterial adherence and quantified bacterial isolates.
Main Results:
- A strong correlation was observed between anatomical structure and S. pyogenes adherence.
- The M protein of S. pyogenes was confirmed as critical for epithelial adherence.
- Streptococcus genus, particularly S. pyogenes (23.4%), comprised nearly half of tonsillitis pathogens in Japan; Methicillin-resistant Staphylococcus aureus (MRSA) was not found in tonsillitis samples.
Conclusions:
- Anatomical factors and S. pyogenes M protein are key in tonsillitis pathogenesis.
- Normal bacterial flora actively contributes to the body's defense against URTIs.
- S. pyogenes is a major bacterial cause of tonsillitis in Japan, distinct from MRSA prevalence in other URTIs.