The Microbiome of the Middle Meatus in Healthy Adults

Abstract

Rhinitis and rhinosinusitis are multifactorial disease processes in which bacteria may play a role either in infection or stimulation of the inflammatory process. Rhinosinusitis has been historically studied with culture-based techniques, which have implicated several common pathogens in disease states. More recently, the NIH Human Microbiome Project has examined the microbiome at a number of accessible body sites, and demonstrated differences among healthy and diseased patients. Recent DNA-based sinus studies have suggested that healthy sinuses are not sterile, as was previously believed, but the normal sinonasal microbiome has yet to be thoroughly examined. Middle meatus swab specimens were collected from 28 consecutive patients presenting with no signs or symptoms of rhinosinusitis. Bacterial colonization was assessed in these specimens using quantitative PCR and 16S rRNA pyrosequencing. All subjects were positive for bacterial colonization of the middle meatus. Staphylococcus aureus, Staphylococcus epidermidis and Propionibacterium acnes were the most prevalent and abundant microorganisms detected. Rich and diverse bacterial assemblages are present in the sinonasal cavity in the normal state, including opportunistic pathogens typically found in the nasopharynx. This work helps establish a baseline for understanding how the sinonasal microbiome may impact diseases of the upper airways.

Viruses and bacteria in Th2‐biased allergic airway disease

“…In CRS, inflammation development takes place in the middle meatus. A high prevalence of Staphylococcus epidermidis (96.4%), S. aureus (67.9%), and Propionibacterium acnes (92.9%) was found in the middle meatus swab of healthy adults (34). Bacteria such as Pseudomonas, Staphylococcus, and Streptococcus were numerically increased in the sinus tissues of CRS patients compared to healthy controls (35).…”

Chronic rhinosinusitis: a microbiome in dysbiosis and the search for alternative treatment options

“…In the past, healthy sinuses were considered sterile environments, and CRS developed when bacteria colonised these sinuses 7 . Nowadays, it is recognised that healthy sinuses house diverse microbiomes with both commensal bacteria and potentially pathogenic bacteria; the pathogens present in these healthy sinuses are present at levels too low to cause disease 6,7 .…”

“…Nowadays, it is recognised that healthy sinuses house diverse microbiomes with both commensal bacteria and potentially pathogenic bacteria; the pathogens present in these healthy sinuses are present at levels too low to cause disease 6,7 . The commensal microbes form a symbiotic relationship with the host, such as by forming a barrier against incoming external pathogens 8 .…”

Dead or Alive: Deoxyribonuclease I Sensitive Bacteria and Implications for the Sinus Microbiome

“…Recent studies have begun to address the question of which bacterial species constitute a healthy sinus microbiome, 7 how it is modified in CRS, [7][8][9][10] and which microbes are associated with recalcitrant disease. 11 However, direct comparison between studies is difficult.…”

“…One limitation is the lack of consistent sinus sampling methods; various studies used brushes, swabs, lavage, and tissue biopsy, all with differing results. 7,[9][10][11][12] Another is that the high level of person-toperson heterogeneity seen in these studies can easily obscure potential differences between healthy and disease-state microbiomes. 10,13 Also, our current 16S rRNA gene analysis protocols are unable to differentiate whether the bacterial species detected are alive or dead.…”