Colitis induced by C. difficile is one of the most common and costly healthcare-related infections for humans. Probiotics are one of the most promising approaches for controlling CDI. Here, we presented the isolation, safety, and probiotic property evaluation of a novel E. thailandicus strain, d5B, with effective antimicrobial activity against C. difficile. Strain d5B showed strong bactericidal effects on at least 54C. difficile strains. Safety tests showed that strain d5B was sensitive to clinically important antibiotics, and had no haemolytic and cytotoxic activities. Whole genomic analysis showed strain d5B only contained one aminoglycoside resistance gene located in the chromosome. Moreover, d5B was devoid of functional virulence genes. Finally, strain d5B exhibited probiotic properties, such as tolerance to the gastrointestinal tract, and adhered well to HT-29 cells. In conclusion, the E. thailandicus strain d5B should be investigated further for useful properties as a novel candidate probiotic for controlling CDI.

艰难梭菌引起的结肠炎是人类最常见和最昂贵的与医疗保健相关的感染之一。益生菌是控制 CDI 最有希望的方法之一。在这里，我们介绍了一种新的泰国大肠杆菌菌株 d5B的分离、安全性和益生菌特性评估，该菌株对艰难梭菌具有有效的抗菌活性。菌株 d5B 对至少 54 C. difficile显示出强烈的杀菌作用菌株。安全性测试表明菌株 d5B 对临床上重要的抗生素敏感，并且没有溶血和细胞毒活性。全基因组分析显示菌株d5B仅含有一个位于染色体中的氨基糖苷类抗性基因。此外，d5B 缺乏功能性毒力基因。最后，菌株 d5B 表现出益生菌特性，例如对胃肠道的耐受性，并且与 HT-29 细胞具有良好的粘附性。总之，应进一步研究E. thailandicus菌株 d5B 作为控制 CDI 的新型候选益生菌的有用特性。