Abstract
Objective:To investigate the distribution of pathogenic bacteria in the ear canal secretions of patients with chronic suppurative otitis media（CSOM）, the changes in the levels of interleukin-8（IL-8） and Toll like receptor 4（TLR4） in the ear canal secretions, and their clinical significance. Methods:This study selected 128 CSOM patients who visited our hospital from January 2022 to February 2024 as the study subjects and recorded them as the CSOM group. Additionally, 135 volunteers who underwent physical examinations at our hospital during the same period were regarded as the control group. Video otoscopy was used to collect and cultivate ear canal secretions, and a fully automated microbial identification instrument was used to identify the bacterial species. ELISA was applied to detect levels of IL-8, TLR4. Multivariate logistic regression was employed to examine the factors that affect the occurrence of CSOM. Pearson correlation was applied to analyze the correlation between IL-8, TLR4 levels and various influencing factors. ROC curve was applied to analyze the diagnostic value of IL-8 and TLR4 levels for the occurrence of CSOM. Z-test was applied to compare the differences in AUC. Results:Among 128 patients, the detection rate was 89.06%, and a total of 181 strains of pathogenic bacteria were cultured, among them, Gram positive bacteria accounted for the highest proportion of 54.14%, followed by Gram negative bacteria, accounting for 34.25%, and finally fungi, accounting for 11.60%. The common bacteria were Staphylococcus aureus （20.44%）, Pseudomonas aeruginosa （13.26%）, and Staphylococcus epidermidis （8.29%）. The resistance of Gram-positive bacteria to penicillin, clindamycin, erythromycin, and amoxicillin is high. Gram-negative bacteria are highly resistant to penicillin, ampicillin and erythromycin. Fungi are resistant to ketoconazole and fluconazole. The levels of IL-8 and TLR4 in CSOM group were higher than those in the control group, and gradually increased with the increase of hearing impairment. （P<0.05）. Elevated levels of IL-8, TLR4 were independent risk factors for the occurrence of CSOM（P<0.05）. The AUC of CSOM diagnosed by IL-8 and TLR4 alone was 0.790 and 0.777, respectively, while the AUC of combined diagnosis was 0.898, which was better than their respective individual diagnoses（both P<0.05）. Conclusion:The distribution of pathogenic bacteria in the ear canal secretions of CSOM patients is mainly Gram positive, with common ones being Staphylococcus aureus and Pseudomonas aeruginosa. The levels of IL-8 and TLR4 in CSOM patients are higher than those in the control group. The higher the levels, the higher the degree of hearing loss, which can be used for clinical diagnosis.