Comparative investigation of the culture of palatine tonsils by superficial and deep methods and investigation of microbial resistance in frequent tonsillitis patients referred for tonsillectomy

Introduction: The tonsils are part of the immune system and tonsillar infection is one of the most common causes of diseases, especially in children. Tonsillitis sometimes does not respond to empirical treatment and the presentation of recurrent tonsillitis eventually leads to tonsillectomy. The aim of this study was to determine and compare palatal tonsil culture by superficial and deep methods in frequent tonsillitis patients referred for tonsillectomy. Materials and Methods: This cross-sectional study was performed on all patients aged > 3 years with chronic recurrent tonsillitis referred for tonsillectomy during 2019-2020. After obtaining the informed consent of the patient's legal guardian, the patient underwent sampling of the right palatine tonsil with a swab through the mouth before tonsillectomy. After tonsillectomy, a sampling of the surface and deep tissue of the tonsil was performed. Microbiological examination, antibiogram determination, and blood culture before and after tonsillectomy were performed. Results: A total of 80 patients were recruited in this study of which 50% were male. In 87.1% of patients, the report of staphylococcus (as the most common organism found) had poor consistency in both surface and deep culture methods. This rate reached 81.3% in comparison between deep tissue culture results and secretions (swab) and 72.7% in comparison between surface samples and secretions (swab) (P<0.001). There was the lowest amount of negative cultures in the comparison of 3 surface cultures, deep cultures and secretions (swap) in deep samples. The highest antibiotic susceptibilities against tonsillar organisms were observed in clindamycin, erythromycin, cefoxitin, gentamicin, and doxycycline. Conclusion: Blood cultures before and after tonsillectomy were negative in all samples. Based on the results, it seems that no persistent infection enters the blood during tonsillectomy in otherwise healthy patients. It also seems that the use of deep culture is more beneficial compared to surface culture because it has a lower false negative rate.