RT Journal Article SR Electronic(1) A1 Humphreys, Gavin J. A1 Kumar, Nirmal A1 McBain, Andrew J.YR 2017 T1 Low incidence of coaggregation amongst bacteria isolated from the upper respiratory tract in health and disease JF Journal of Medical Microbiology, VO 66 IS 9 SP 1338 OP 1341 DO https://doi.org/10.1099/jmm.0.000567 PB Microbiology Society, SN 1473-5644, AB The nasal cavity harbours a commensal microbiota that reportedly provides colonization resistance against respiratory pathogens. Following the onset of chronic rhinosinusitis (CRS), a change in sinus microbiota composition is frequently reported in which atypical anaerobic and/or Gram-negative bacteria predominate. We have investigated pairwise interactions between respiratory bacteria isolated from healthy adults (n=3) and individuals exhibiting CRS (n=3). Antagonism was determined using a spot plate methodology and coaggregation scores were determined using a quantitative spectrophotometric assay. Obligate anaerobes were isolated from all CRS samples and exhibited inter-host growth inhibition of commensal nasal bacteria, including Corynebacterium spp. and Staphylococcus spp. Antagonism between bacteria isolated from healthy individuals was limited to corynebacterial-mediated inhibition of the staphylococci. The frequency of coaggregation was low overall (2/153 pairwise interactions). Antagonism of the nasal microbiota by respiratory pathogens may represent a competitive strategy in the sinus and warrants further investigation., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.000567