Prevalence and Spectrum of Core Adenotonsillar Microbiology Among Saudi Population

Abstract Background: Adenotonsillectomy is the most common surgical procedure in ENT practice, which is indicated for chronic adenotonsillitis unresponsive to medical management. This study aimed to identify the predominant bacterial pathogens of adenoids and tonsils among the Saudi population in Eastern Province and to compare the outcome with the reported findings in the literature. Materials and Methods: This prospective observational study included 170 patients undergoing adenotonsillar surgery. Core tissue specimens from tonsils and adenoids were cultured and analyzed microbiologically, and antibiotic susceptibility testing was performed. Results: A total of 230 specimens were cultured, including 109 tonsils and 121 adenoids. Of the participants, 201 (87.4%) were children under 12 years of age, with a male-to-female ratio of approximately 1.2:1. Positive bacterial growth was observed in 85 (78.0%) tonsillar and 97 (80.2%) adenoidal specimens, whereas 24 (22.0%) tonsillar and 24 (19.8%) adenoidal specimens showed no growth. Among positive cultures, 68 (62.4%) tonsils and 73 (60.3%) adenoids grew a single pathogen, while 17 (15.6%) tonsils and 24 (19.8%) adenoids yielded polymicrobial growth. The most common organisms isolated were Staphylococcus aureus (tonsils 39.7%; adenoids 31.5%), Haemophilus influenzae (tonsils 23.5%; adenoids 28.7%), and group A β- Hemolytic Streptococcus (tonsils 36.7%; adenoids 17.8%). All isolates were sensitive to amoxicillin/clavulanate and cephalosporins, and no methicillin-resistant S. aureus strains were identified. Conclusion: The majority of chronic adenotonsillitis that require surgical management are secondary to bacterial infection, which is either mono-or poly-microbial in origin. The commonest bacteria involved among the Saudi population are similar to that of published reports. Understanding local microbial patterns can help guide empirical antibiotic selection and enhance the therapeutic benefits with the avoidance of unnecessary surgery.