AUTHOR=Mao Yanni , Wang Yuxia , Luo Xiaofeng , Chen Xiaohui , Wang Guiqin 

TITLE=Impact of cell-free supernatant of lactic acid bacteria on Staphylococcus aureus biofilm and its metabolites

JOURNAL=Frontiers in Veterinary Science

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2023.1184989

DOI=10.3389/fvets.2023.1184989

ISSN=2297-1769

ABSTRACT=Lactic acid bacteria (LAB), as a biocontrol agent, can inhibit the growth of pathogenic and food-spoilage bacteria. Its cell-free supernatant (LAB-CFS) is rich in bioactive substances. This manuscript examined the antimicrobial efficacy of LAB-CFS (both from planktonic and biofilm states) against the S. aureus biofilm state. Also, the LAB-CFS-mediated metabolomic alterations in biofilms and the changes in the expression of biofilms-associated genes in S. aureus were examined. LAB-CFS treatment significantly inhibited the bacterial growth, generation of eDNA (extracellular DNA), extracellular polysaccharides, and other physiological traits of S. aureus. Fluorescence microscopy revealed the negative impact of LAB-CFS on S. aureus biofilm. Moreover, LAB-CFS treatment reduced the expression of biofilm-associated genes. Metabolomic investigation revealed that LAB-CFS treatment had higher metabolites in biofilm-state than that in planktonic/monoculture systems, meanwhile, amino acid and nucleotide metabolic pathways were significantly altered. These findings imply that LAB-CFS has strong anti-S. aureus activity and exerts complicated bacterial interactions, both of which can be exploited as a novel therapy for mastitis.