Streptococcus species from otitis media

Chronic otitis media with effusion is one of the most common childhood diseases in developed countries and is responsible for a significant proportion of hearing loss in children. The disease is caused by microbial biofilms in the middle ear, which trigger the release of effusion fluid. The portal of entry for bacteria to reach the middle ear is not well understood. One possibility is that bacteria transcend the eustacian tube from the adenoids. Here, we isolated strains of Streptococcus spp. from paired middle ear effusion fluid and adenoid samples of two patients. The paired samples from each patient were identified as the same species by MALDI-TOF. In one case, paired isolates were classified as S. oralis, and in the other the isolates were both S. parasanguinis. The genome sequencing project aimed to (i) confirm the species identifications assigned by MALDI-TOF and (ii) determine whether paired isolates were the same strain.