Identification and Detection of Pathogenic Bacteria in Adenoid Tissue of Adenoidectomized Children: Emergence of Staphylococcus aureus as the Most Prevalent Pathogen

Abstract

Background: Adenoids act as reservoirs for pathogenic bacteria and chronic adenoid infection leads to its hypertrophy. Objectives: The present study aimed to determine the frequency of Staphylococcus aureus, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae in children by polymerase chain reaction (PCR) and culture and to determine the antimicrobial resistance patterns of the isolates. Methods: In this cross-sectional study, 200 adenoid tissues were taken from children with adenoid hypertrophy in the operating room under general anesthesia conditions. The isolation and detection of bacteria were performed by culture and PCR methods. The antibiotic susceptibility patterns of the isolates were determined by the disc agar diffusion method according to the CLSI guidelines. Results: Staphylococcus aureus was the most common bacterium (102; 51%) isolated by the culture method, followed by S. pneumoniae (44; 22%), M. catarrhalis (33; 16.5%), and H. influenzae (6; 3%). By multiplex PCR, the detection rate of microorganisms was as follows: S. aureus 40.5% (n = 81), S. pneumoniae 15.5% (n = 31), M. catarrhalis 11% (n = 22), and H. influenzae 4% (n = 8). Haemophilus influenzae strains were sensitive to all of the tested antibiotics. Seven S. aureus isolates were resistant to cefoxitin and identified as MRSA. Conclusions: This study showed the importance of S. aureus in the etiology of adenoid hypertrophy as the most frequent isolate. It may be due to the long-term duration of adenoid hypertrophy in children that helps the colonization of S. aureus in adenoid tissue and leads to chronic infection.