Nasopharyngeal Microbiota Analysis in Healthy and Otitis-prone Children: Focus on History of Spontaneous Tympanic Membrane Perforation

Background: Recurrent acute otitis media (RAOM) is common in children, and it may result in spontaneous tympanic membrane perforation (STMP), management of which is often challenging. In the upper respiratory tract (URT), resident microorganisms play a pivotal role in otitis media pathogen-esis and prevention, as they are able to inhibit the colonization process and otopathogens growth. In particular, Dolosigranulum spp. and Corynebac-terium spp. have been associated with respiratory health in several studies. This study aims at comparing both nasopharyngeal microbiota of children with RAOM versus matched controls and nasopharyngeal microbiota of children with a history of RAOM with STMP.Method: Nasopharyngeal swabs were collected from 132 children, median age 3.51 (2.13–4.72), including 36 healthy children, 50 with RAOM without STMP, and 46 with RAOM with STMP. Bacterial DNA was subsequently extracted and 16S rRNA gene V3-V4 regions were polymerase chain reac-tion amplified and sequenced using Illumina MiSeq technology.Results: A higher relative abundance of Dolosigranulum and Corynebac-terium genera was detected in the nasopharynx of healthy children (16.5% and 9.3%, respectively) in comparison with RAOM without STMP (8.9% and 4.3%, respectively) and RAOM with STMP (5.2% and 2.8%, respec-tively). A decreasing pattern in relative abundance of these 2 pivotal genera through disease severity was detected. In all groups, the most abundant gen-era were Moraxella, Streptococcus and Haemophilus, followed by Dolosi-granulum and Corynebacterium.Conclusions: Our study provides a characterization of the URT microbiota in otitis-prone children with and without history of recurrent STMP, sug-gesting that the role of Dolosigranulum and Corynebacterium in regulating the healthy URT microbiota should be further studied.