马齿苋多糖对产志贺毒素大肠杆菌的毒力影响作用及抑菌效果评价OA

Conventional antibiotic treatment may induce the lysis of Shiga toxin producing Escherichia coli(STEC)prophages,thereby triggering toxin release and exacerbating clinical harm.Therefore,inhibiting STEC toxin production and progeny phage release is crucial for the prevention and control of STEC infection.In vitro antibacterial studies revealed that Portulaca oleracea polysaccharide(POP)inhibits E.coli,Staphylococcus aureus,and Pseudomonas aeruginosa,with a minimum inhibitory concentration(MIC)of 125 mg/mL against STEC strain Min27.At the subinhibitory concentration of 62.5 mg/mL(1/2MIC),POP significantly impaired the swarm motility of STEC Min27,resulting in smoother colony margins.Concurrently,bacterial adhesion to macrophages decreased approximately 100-fold,and the titer of Stx phage progeny was reduced by approximately two orders of magnitude compared to the control group.The findings indicate that POP exerts multiple inhibitory effects on STEC.In addition to exhibiting potent antibacterial activity,it interferes with key virulence phenotypes such as motility,biofilm formation,and adhesion,and effectively inhibits the lytic release of Stx phages.Thus,POP is an agent with both antibacterial activity and the potential to inhibit horizontal gene transfer,providing a novel approach for controlling STEC infection.