The adult microbiome of healthy and otitis patients: Definition of the core healthy and diseased ear microbiomes

PLoS One. 2022 Jan 24;17(1):e0262806. doi: 10.1371/journal.pone.0262806. eCollection 2022.

Abstract

Otitis media (OM) and externa (OE) are painful, recurrent ear conditions. As most otitis publications focus on the bacterial content of childhood ears, there remains a dearth of information regarding the adult ear microbiome including both bacteria and fungi. This study compares the outer ear microbiome of healthy adults to adults affected by OE and OM using both intergenic-transcribed-spacer (ITS) and 16S-rDNA sequencing. The adult ear core microbiome consists of the prokaryote Cutibacterium acnes and the eukaryotic Malassezia arunalokei, M. globosa, and M. restricta. The healthy ear mycobiome is dominated by Malassezia and can be divided into two groups, one dominated by M. arunalokei, the other by M. restricta. Microbiome diversity and biomass varied significantly between healthy and diseased ears, and analyses reveal the presence of a potential mutualistic, protective effect of Malassezia species and C. acnes. The healthy ear core microbiome includes the bacteria Staphylococcus capitis and S. capitis/caprae, while the diseased ear core is composed of known bacterial and fungal pathogens including Aspergillus sp., Candida sp., Pseudomonas aeruginosa, S. aureus, and Corynebacterium jeikeium. The data presented highlight the need for early detection of the cause of otitis to direct more appropriate, efficient treatments. This will improve patient outcomes and promote improved antimicrobial stewardship.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Case-Control Studies
  • DNA, Bacterial / genetics
  • DNA, Bacterial / isolation & purification
  • Ear / microbiology*
  • Humans
  • Male
  • Microbiota* / genetics
  • Middle Aged
  • Otitis Externa / microbiology*
  • Otitis Media / microbiology*
  • RNA, Ribosomal, 16S / genetics
  • Young Adult

Substances

  • DNA, Bacterial
  • RNA, Ribosomal, 16S

Grants and funding

TLD was funded by the A*STAR Industry Alignment Fund (H18/01/a0/016). The study was funded by Zymo Research Corp. via the salaries of MB, JK, GW, ST, and AP who are employees of Zymo Research. The funder provided support in the form of salaries for authors MB, JK, GW, ST, and AP, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.