Evidence for the role of Haemophilus influenzae in the pathogenesis of recurrent tonsillitis

Abstract number: 1733_320

Skoulakis C., Tigiroglou E., Malli E., Klapsa D., Papadakis C., Petinaki E.

Objectives: Frequently, cultures of tonsils from patients with recurrent tonsillitis did not reveal the presence of pathogenic bacteria such as S. pyogenes. The bacteria probably enter into the core and conventional methods failed to detect them. In this study, the tonsils of 60 patients undergoing tonsillectomy were studied in order to determine the correlation between bacteria isolated from tonsillar surface and core using conventional and molecular methods.

Methods: Sixty tonsillar tissues, from patients with recurrent tonsillitis (n: 29), as well from individuals undergoing tonsillectomy for snoring or sleep apnea (control group, n: 31), were collected. Samples from both surface and core were cultured, while the identification of bacteria isolated was done using conventional methods. In addition, DNA was extracted from specimens obtained exclusively from tonsil core using a commercial kit (QIAGEN), and then it was PCR amplified with a pair of primers targeting the 16SrRNA gene, followed by sequence analysis. The viability of microorganisms were detected by RT-PCR, after RNA extraction, by using specific primers for bacteria whom DNAs were detected.

Results: Among patients with recurrent tonsillitis, 25% of the surface cultures did not grow any bacteria, while 75% showed the presence of Streptococcus mitis and oralis; in some cases we observed the co-existence of Staphylococcus aureus (17%) and Haemophilus parainfluenzae (20%). On the other hand, the core cultures were negative for bacteria. However, into the core of nineteen tonsils, molecular methods revealed the presence of mRNA of S. pyogenes in three cases (10.3%) and H. influenzae in sixteen cases (55%) confirming their viability. Among the control group, surface cultures showed the presence of Streptococcus mitis and S. oralis (72%), with the co-existence of Staphylococcus aureus (5%) and Haemophilus parainfluenzae (20%), while the core cultures remained negative. No bacterial DNAs were detected in the core of the control group.

Conclusions: The high incidence of H. influenzae isolated in patients with recurrent tonsillitis, comparing to the control group, suggests the potential pathogenic role of this bacterium in this type of infection.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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