Bacterial Communities Vary between Sinuses in Chronic Rhinosinusitis Patients

Abstract

Chronic rhinosinusitis (CRS) is a common and potentially debilitating disease characterized by inflammation of the sinus mucosa for longer than 12 weeks. Bacterial colonization of the sinuses and its role in the pathogenesis of this disease is an ongoing area of research. Recent advances in culture-independent molecular techniques for bacterial identification have the potential to provide a more accurate and complete assessment of the sinus microbiome, however there is little concordance in results between studies, possibly due to differences in the sampling location and techniques. This study aimed to determine whether the microbial communities from one sinus could be considered representative of all sinuses, and examine differences between two commonly used methods for sample collection, swabs, and tissue biopsies. High-throughput DNA sequencing of the bacterial 16S rRNA gene was applied to both swab and tissue samples from multiple sinuses of 19 patients undergoing surgery for treatment of CRS. Results from swabs and tissue biopsies showed a high degree of similarity, indicating that swabbing is sufficient to recover the microbial community from the sinuses. Microbial communities from different sinuses within individual patients differed to varying degrees, demonstrating that it is possible for distinct microbiomes to exist simultaneously in different sinuses of the same patient. The sequencing results correlated well with culture-based pathogen identification conducted in parallel, although the culturing missed many species detected by sequencing. This finding has implications for future research into the sinus microbiome, which should take this heterogeneity into account by sampling patients from more than one sinus.

Bacterial community collapse: a meta‐analysis of the sinonasal microbiota in chronic rhinosinusitis

“…The levels of Cyanobacteria in this study accounted for a very small relative abundance (< 1%). A different study, conducted by Joss et al (2015), reported Cyanobacteria at a much lower abundance than the Aurora study (< 2.4% relative abundance). Variation between studies in reported Cyanobacteria abundance is likely due to differences in sequence processing and taxonomic classification databases, highlighting the importance of using standardized sequence processing protocols.…”

“…This lack of understanding is due to many factors, including small sample sizes, inadequate stratification of cohorts, insufficient taxonomic resolution of gene-targeted sequencing data and a restricted focus on the presence/ absence of microbes (community diversity) rather than community interaction and function. Additionally, much of the bacterial research in this field is limited to culturebased approaches which may not capture the extensive community diversity within the sinonasal cavity (Joss et al, 2015;Hoggard et al, 2017).…”

Mapping and comparing bacterial microbiota in the sinonasal cavity of healthy, allergic rhinitis, and chronic rhinosinusitis subjects

“…Staphylococcus was enriched in CRSwNP, supporting culture‐based studies that have found elevated S. aureus colonization rates in the MM and S. aureus enterotoxin (SAE)‐specific immunoglobulin E (IgE) antibodies in a subset of patients with high eosinophilic inflammation . Alloiococcus spp., also enriched in CRSwNP, have been detected in the sinuses of CRS and healthy controls, and co‐colonization with Staphylococcus , Streptococcus , and anaerobic taxa in the maxillary sinuses of CRS patients has been reported . While co‐colonization may play an important role in bacterial behavior modification, whether and how this organism contributes to sinus inflammation is still unknown.…”

Investigation of sinonasal microbiome spatial organization in chronic rhinosinusitis

“…A recent investigation comparing surface swab to tissue biopsy demonstrated no difference in the microbial diversity revealed by the two methods, suggesting that swabs may serve as an adequate sampling method [52], a finding that has since been confirmed by a number of other groups. A recent publication also investigated inter-sinus differences, although only one subject studied had all sinuses from both sides sampled [53]. The authors found that compared sinuses were identical using unweighted UniFrac comparisons, suggesting no difference in presence or absence of taxa between specimens; using weight UniFrac distances that account for relative abundance, they concluded that when taking inter-individual variation into account, differences between sample sites were quite low.…”