Has Antimicrobial Activity against and Methicillin-Resistant Pathogens Isolated from the Sinonasal Niche of Chronic Rhinosinusitis Patients.

is the predominant species of the healthy human nasal microbiota, and its relative abundance is decreased in the context of chronic rhinosinusitis (CRS). This study aimed to evaluate the antimicrobial potential of isolated from a healthy human nasal cavity against planktonic and biofilm growth of () and methicillin-resistant (MRSA) clinical isolates (CIs) from CRS patients. Nasal swabs from twenty non-CRS control subjects were screened for the presence of using microbiological and molecular techniques. CIs and their culture supernatants were tested for their antimicrobial activity against eight and eight MRSA 4CIs and ATCC25923. The anti-biofilm potential of cell-free culture supernatants (CFCSs) on biofilms was also assessed. Of the 20 nasal swabs, 10 CIs were identified and confirmed with gene sequencing. All isolates showed variable antimicrobial activity against eight out of 8 and seven out of eight MRSA CIs. Culture supernatants from all CIs exhibited a significant dose-dependent antibacterial activity ( < 0.05) against five out of five representative and MRSA CIs. This inhibition was abolished after proteinase K treatment. supernatants induced a significant reduction in metabolic activity and biofilm biomass of and MRSA CIs compared to untreated growth control ( < 0.05). exhibited antimicrobial activity against and MRSA CIs in both planktonic and biofilm forms and holds promise for the development of innovative probiotic therapies to promote sinus health.