Anti-biofilm and anti-virulence potential of cell free supernatant of <i>Akkermansia muciniphila</i> against <i>Salmonella</i>
Jiaxiu Liu, Wenxiu Zhu, Huanhuan Liu, Xiaomeng Ren, Ningbo Qin, Xiaodong Xia
Abstract
<em>Akkermansia muciniphila</em> is one of the commensals residing within the mammalian gut and co-evolving with the host. Numerous studies have demonstrated the benefits of <em>A. muciniphila </em>in ameliorating metabolic disorders, while little is known about the antimicrobial potential of <em>A. muciniphila</em> against pathogens. Here, we examined the antimicrobial and anti-virulence properties of cell free supernatant (CFS) of <em>A. muciniphila </em>against<em> Salmonella </em>Typhimurium. CFS retarded bacterial growth and inhibited the motility of<em> S. </em>Typhimurium SL1344 and <em>S. </em>Typhimurium 14028. CFS dose-dependently reduced cell hydrophobicity and auto-aggregation of both strains. Also, CFS from<em> A. muciniphila</em> significantly attenuated biofilm formation. Compared with untreated bacteria, CFS-treated bacteria significantly decreased adhesion and invasion to Caco-2 cells, and reduced intracellular survival in macrophages. CFS maintained antimicrobial properties after treatment with high temperatures and various proteases, while it lost its antimicrobial activity after pH neutralization<em>. </em>Gas chromatography-mass spectrometry (GC-MS) confirmed that <em>A. muciniphila</em> produced a certain amount of acetate and propionate, and ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) identified other organic acids and metabolites in CFS. In summary, CFS from <em>A. muciniphila </em>exhibited anti-biofilm and anti-virulence properties against <em>Salmonella</em> and could be potentially utilized in the food industry for controlling <em>Salmonella </em>contamination and reducing infection.