Abstract
Background: Tonsillitis is an inflammation of the tonsils due to either viruses or bacteria. Here, we report the bacteria patterns on the tonsillar surface and tonsillar core tissue among patients scheduled for tonsillectomy at Bugando Medical Centre (BMC), Mwanza Tanzania.

Methods: The study included 120 patients planned for tonsillectomy between April and July 2019. Swab samples from tonsillar surface pre-tonsillectomy and core post-tonsillectomy were collected. Culture was performed following the microbiology laboratory standard operating procedures. Data analysis was completed using STATA version 13, as per the study objectives.

Results: The slight majority of participants were males (73; 60.83%) with median age of 6 years (interquartile range 4–11). The proportion of positive culture growth was higher on the surface than in core swab samples: 65 (54.2%) vs. 42 (35.0%), p = 0.003. The commonest bacterial pathogen detected from the surface and core were S. aureus in 29 (40.3%) and 22 (51.2%) participants, followed by S. pyogenes in 17 (23.6%) and 11 (25.6%), respectively. Methicillin-resistant Staphylococcus aureus (MRSA) was observed in 20/51 (39%) of isolates. Streptococcus pyogenes resistance to macrolides ranged from 8.3% for core isolates to 35.3% for surface isolates. Features suggestive of tonsillitis on histology were reported in 83 (73.5%) samples.

Conclusion: More than two-thirds of patients undergoing tonsillectomy had a positive culture for possible bacterial pathogens. Staphylococcus aureus and Streptococcus pyogenes were the predominant bacteria detected with more than one third of Staphylococcus aureus being MRSA. More studies to investigate the treatment outcome of these patients are highly recommended