Demirci, MehmetYigin, AkinDemir, Cemil2022-02-012022-02-012022Demirci M, Yigin A, Demir C. Efficacy of antimicrobial peptide LL-37 against biofilm forming Staphylococcus aureus strains obtained from chronic wound infections. Microb Pathog. 2022 Jan;162:105368. doi: 10.1016/j.micpath.2021.105368. Epub 2021 Dec 20. PMID: 34942309.https://doi.org/10.1016/j.micpath.2021.105368https://pubmed.ncbi.nlm.nih.gov/34942309/https://www.scopus.com/record/display.uri?eid=2-s2.0-85121613323&origin=resultslist&sort=plf-f&src=s&st1=10.1016%2fj.micpath.2021.105368&sid=ce8a3d8f8768b439211fdb4517010d54&sot=b&sdt=b&sl=34&s=DOI%2810.1016%2fj.micpath.2021.105368%29&relpos=0&citeCnt=0&searchTerm=https://hdl.handle.net/20.500.12514/3034https://www.webofscience.com/wos/woscc/full-record/WOS:000788146600003?AlertId=d383397b-4355-449e-9419-70f9e0e77c15&SID=EUW1ED0D20h9VmzTnXJRFru4mp4XrThe antimicrobial peptide LL-37 showed inhibitory effects against Staphylococcus aureus strains, which often responsible for wound infections. Understanding the molecular mechanisms of biofilm-containing wound infections is important. Thus, this study aimed to investigate both the antimicrobial and biofilm efficacy of LL-37 against biofilm-positive methicillin-susceptible S. aureus (MSSA) strains and biofilm-positive methicillin-resistant S. aureus (MRSA) strains obtained from chronic wound infections and its effect on different quorum sensing and virulence genes at suboptimal concentrations. Fifteen biofilm-forming MRSA and 15 biofilm-forming MSSA strains were included in this study. The minimum inhibitory concentration (MIC) values and biofilm formation were tested by microdilution methods. Real-time PCR was performed to determine gene expression levels. MIC values for LL-37 were 89.6 mg/L and 132.3 mg/L for MSSA and MRSA strains, respectively. No statistically significant difference was found between MRSA and MSSA strains in terms of the effect of LL-37 on biofilm formation. A statistically significant difference was found between MRSA and MSSA strains for atlA, RNAIII, and agrA gene expression levels following exposure to a suboptimal concentration of LL-37. Ultimately, the required LL-37 antimicrobial concentration was quite high; however, LL-37 antibiofilm concentration may be acceptable for use in humans against biofilm-forming MRSA and MSSA strains. This is the first study to investigate to effect of a suboptimal LL-37 concentration on gene expression levels of biofilm-forming MSSA and MRSA strains. LL-37 affected quorum sensing and biofilm producing mechanisms, even at suboptimal MIC concentrations.en10.1016/j.micpath.2021.105368info:eu-repo/semantics/closedAccessLL-37, MRSA, MSSA , Gene expression, BiofilmArticleQ2N/AWOS:0007881466000032-s2.0-8512161332334942309