Antimicrobials from a feline skin commensal bacterium inhibit skin colonization and infection by drug-resistant S. pseudintermedius

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is an important emerging zoonotic pathogen that causes severe skin infections. To combat infections from drug-resistant bacteria, the transplantation of commensal antimicrobial bacteria as a therapeutic has shown clinical promise. We screened a collection of diverse staphylococcus species from domestic dogs and cats for antimicrobial activity against MRSP. A unique strain (S. felis C4) was isolated from feline skin that inhibited MRSP and multiple gram-positive pathogens. Competition experiments in mice showed that S. felis significantly reduced MRSP skin colonization and an antimicrobial extract from S. felis significantly reduced necrotic skin injury from MRSP infection. Fluorescence and electron microscopy revealed that S. felis antimicrobials disrupted bacterial but not eukaryotic cell membranes. LC/MS identified several S. felis phenol-soluble modulin beta (PSMβ) peptides that exhibited antimicrobial and anti-inflammatory...耐甲氧西林假中间葡萄球菌（Methicillin-resistant Staphylococcus pseudintermedius，MRSP）是一种重要的新发人畜共患病原体，可引发严重皮肤感染。为对抗耐药菌引发的感染，将共生抗菌细菌作为治疗手段进行移植的疗法已展现出临床应用前景。本研究从家养犬与猫体内筛选了一组多样性葡萄球菌菌株，以检测其对MRSP的抗菌活性。研究人员从猫皮肤中分离出一株独特的菌株（S. felis C4），该菌株可抑制MRSP以及多种革兰氏阳性病原体。小鼠体内的竞争实验结果显示，S. felis可显著降低MRSP的皮肤定植量；而S. felis的抗菌提取物则可显著减轻MRSP感染引发的坏死性皮肤损伤。荧光显微镜与电子显微镜观察结果表明，S. felis产生的抗菌物质可破坏细菌细胞膜，但不会损伤真核细胞膜。液相色谱-质谱联用法（Liquid Chromatography-Mass Spectrometry，LC/MS）检测发现，S. felis可分泌多种酚可溶性调节蛋白β（phenol-soluble modulin beta，PSMβ）肽类物质，这些物质兼具抗菌与抗炎……