AUTHOR=Huang Shuman , Hon Karen , Bennett Catherine , Hu Hua , Menberu Martha , Wormald Peter-John , Zhao Yulin , Vreugde Sarah , Liu Sha 

TITLE=Corynebacterium accolens inhibits Staphylococcus aureus induced mucosal barrier disruption

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.984741

DOI=10.3389/fmicb.2022.984741

ISSN=1664-302X

ABSTRACT=<sec><title>Background</title><p><italic>Corynebacterium accolens</italic> (<italic>C. accolens</italic>) is a common nasal colonizer, whereas <italic>Staphylococcus aureus</italic> (<italic>S. aureus</italic>) is typically regarded a pathogenic organism in patients with chronic rhinosinusitis (CRS). This study aims to evaluate the interaction of the two bacteria <italic>in vitro</italic>.</p></sec><sec><title>Methods</title><p>Clinical isolates of <italic>C. accolens</italic> and <italic>S. aureus</italic> from sinonasal swabs, as well as primary human nasal epithelial cells (HNECs) cultured from cellular brushings of both healthy and CRS patients were used for this study. The cell-free culture supernatants of all isolates grown alone and in co-cultures were tested for their effects on transepithelial electrical resistance (TER), FITC-Dextran permeability, lactate dehydrogenase (LDH), and IL-6 and IL-8 secretion of HNECs. Confocal scanning laser microscopy and immunofluorescence were also used to visualize the apical junctional complexes. <italic>C. accolens</italic> cell-free culture supernatants were also tested for antimicrobial activity and growth on planktonic and biofilm <italic>S. aureus</italic> growth.</p></sec><sec><title>Results</title><p>The cell-free culture supernatants of 3\<italic>C. accolens</italic> strains (at 60% for <italic>S. aureus</italic> reference strain and 30% concentration for <italic>S. aureus</italic> clinical strains) inhibited the growth of both the planktonic <italic>S. aureus</italic> reference and clinical strains significantly. The <italic>C. accolens</italic> cell-free culture supernatants caused no change in the TER or FITC-Dextran permeability of the HNEC-ALI cultures, while the cell-free culture supernatants of <italic>S. aureus</italic> strains had a detrimental effect. Cell-free culture supernatants of <italic>C. accolens</italic> co-cultured with both the clinical and reference strains of <italic>S. aureus</italic> delayed the <italic>S. aureus</italic>-dependent mucosal barrier damage in a dose-dependent manner.</p></sec><sec><title>Conclusion</title><p><italic>Corynebacterium accolens</italic> cell-free culture supernatants appear to inhibit the growth of the <italic>S. aureus</italic> planktonic bacteria, and may reduce the mucosal barrier damage caused by <italic>S. aureus</italic>.</p></sec>