Microbiome analysis of chronic suppurative otitis media and middle ear cholesteatoma in China

Chronic suppurative otitis media (CSOM) and middle ear cholesteatoma (MEC) are two different types of chronic otitis media (COM), and there may be differences in bacterial diversity. Fully exploring the bacterial differences between these two diseases plays an important role in the treatment of the disease and in the study of pathogenic mechanisms. Twelve and twenty-nine patients with CSOM and MEC, respectively, were recruited. Middle-ear lesion tissue was collected intraoperatively after opening the tympanic sinus and mastoid cavity under general anaesthesia and sterile conditions. The full-length 16S rRNA genome sequenced using third-generation sequencing (TGS) was then used to profile the bacterial community of each patient. Principal coordinate analysis (PCoA) showed that PC1 and PC2 could explain more than 50% of the between-group differences. Similarity analysis (ANOSIM) using the Binary Jaccard distance matrix indicated that between-group differences were greater than within-group differences (P < 0.05). Staphylococcus aureus was the most common strain in both groups. At the species level, the abundance of Anaerococcus_octavius was significantly different between both groups (P < 0.05). According to the linear discriminant effect size (LefSe) analysis, at the class and genus levels, Alphaproteobacteria and Bacillus were abundant in the CSOM group, respectively. Peptoniphilus_grossensis and Peptostreptococcaceae_bacterium_oral_taxon_929 were abundant at the species level in the MEC group (P < 0.05). Four COG (Clusters of Orthologous Groups) functions at level 2 were significantly different between the two groups (P < 0.05). The CSOM and MEC groups were inhabited by more diverse microbial communities, and the bacterial diversity of the two diseases differed markedly. This could guide the regular use of antibiotics and decrease the likelihood of multidrug-resistant bacteria formation. Further research on the pathogenic diseases of CSOM and MEC will focus on the functional differences between flora. Twenty-nine patients diagnosed with MEC (B1–B29) and twelve with CSOM (A1-A12) that underwent surgical treatment in the Otolaryngology Department of the First Affiliated Hospital of Kunming Medical University were enrolled in this study.Middle-ear lesion tissues from the MEC and CSOM were collected intraoperatively after opening the tympanic sinus and mastoid cavity. Pathological tissues were immediately stored in liquid nitrogen until batch processing.DNA was isolated from the specimens and processed for microbiome analysis by 16S rRNA gene sequencing, and we evaluate the microbiomes of CSOM and MEC using the full-length 16S rRNA genome sequenced by third-generation sequencing (TGS).