Abstract
Skin and soft tissue infections (SSTIs) are a major cause of global disease burden worldwide, with a leading cause being infections by bacteria including S. aureus, Enterococcal species, and Streptococcal species. When SSTIs are biofilm-associated, this further complicates healing, as antibiotic treatment is ineffective for the eradication of biofilm infections, and there are currently no existing treatments for biofilm infections. Thus, research has focused on developing alternative antibiofilm treatment options with one such option being postbiotic extracts. The BLIS Q24 strain of the bacterial skin commensal Micrococcus luteus was identified to possess a unique antimicrobial spectrum against pathogens. Therefore, we investigated the antimicrobial and antibiofilm efficacy of an BLIS Q24 extract against biofilm forming skin pathogens. The antimicrobial and antibiofilm activity of the extract was determined using a biofilm model, as well as keratinocyte monolayer and human epidermal equivalent skin models to investigate whether treatment with the extract reduces bacterial cytotoxicity and inflammatory markers in biofilm infection. Despite initial antimicrobial efficacy against S. aureus, the BLIS Q24 extract did not have consistent antibacterial or antibiofilm effects on S. aureus, E. faecalis or C. acnes, which might result from method of extraction or experimental design flaws.