Validating quantitative polymerase chain reaction assay for the molecular diagnosis of chronic suppurative otitis media

Abstract

BACKGROUND: Pathogen identification is critical for antibiotic selection in suppurative otitis media. However, bacterial culture challenges from suppurative specimens often cause antibiotic misuse and ineffective treatment. A quantitative polymerase chain reaction (PCR) controlled by the human cells contained in the specimen (HIRA-TAN) has been established in differentiate between pathogens and colonization in the previous pneumonia study. AIM: The aim of this study was to investigate the utility of HIRA-TAN and determine the causative pathogen in chronic suppurative otitis media. METHODS: Thirty-nine patients were recruited to the study. The otorrhea was swab-collected and processed for both bacterial culture and a multiplex PCR-based test. The cutoff of cycle threshold to determinate the pathogens was defined by receiver operating characteristic curves. RESULTS: Thirty-nine patients ranging from 1.7 to 62 years old were enrolled. The hearing impairment was found different between adult and children (p < 0.005) with adults (24/29 patients) had a significantly higher rate. A total of 35.9% of samples were positive for bacterial culture; Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus mirabilis, and Morganella morganii, while Bacteroides fragilis, Acinetobacter baumannii, Moraxella catarrhalis, and Escherichia coli were not identified by culture, although high cycle-threshold values were obtained suggesting the inability of the culture system in detecting some pathogens. CONCLUSION: Our results indicate that HIRA-TAN is a potential diagnostic tool in suppurative otitis media and warrant a larger cohort study.