Microbiological and histological analysis of tonsil tissue from patients diagnosed with chronic tonsilitis

Abstract

If chronic tonsillitis (CT) is treated surgically, the long-term risks of infections and respiratory diseases are higher, making of high importance to find an alternative for tonsillectomy. In order to isolate and identify the causing agents of CT, a total of 79 postoperative palatine and adenoid tissue samples were obtained from the ENT Clinic, KBC Zvezdara. A total of 82 bacterial species were isolated and identified by MALDI-TOF. They belong to the genera Streptococcus, Staphylococcus, Micrococcus, Rothia, Enterobacter and Stenotrophomonas. Analysis of the incidence of bacteria isolated from tissue samples showed the highest prevalence of Streptococcus oralis (27/33%), followed by S. aureus (17/21%) and Streptococcus parasanquinis (16/20%). Histological analysis of tissue samples was conducted in order to detect the presence of CT-causing bacteria. In addition to interfollicular hyperplasia, colonies of species S. aureus and Stenotrophomonas maltophilia were detected in histological material. The presented results confirm that the colonizers of tonsils tissues can be both G (+) and G (-) bacteria. The presence of S. aureus in the tonsillar tissue even after the antibiotic therapy may be related to its ability to form biofilm. Our study demonstrated that among 17 S. aureus isolates, 13 displays more pronounced biofilm forming ability than the reference strain S. aureus ATCC 11632, and only 4 isolates display lower biofilm forming ability. The presence of biofilm might be the reason for the recurrence of infection. Therefore, a searching for new antibiofilm therapeutics in CT therapy is of great importance.