The rise of antibiotic resistance has increased the need for alternative ways of preventing and treating enteropathogenic bacterial infection. Various probiotic bacteria have been used in animal and human. However, Saccharomyces boulardii is the only yeast currently used in humans as probiotic. There is scarce research conducted on yeast species commonly found in kefir despite its claimed potential preventative and curative effects. This work focused on adhesion properties, and antibacterial metabolites produced by Kluyveromyces lactis and Saccharomyces unisporus isolated from traditional kefir grains compared to Saccharomyces boulardii strains. Adhesion and sedimentation assay, slide agglutination, microscopy and turbidimetry assay were used to analyze adhesion of Salmonella Arizonae and Salmonella Typhimurium onto yeast cells. Salmonella growth inhibition due to the antimicrobial metabolites produced by yeasts in killer toxin medium was analyzed by slab on the lawn, turbidimetry, tube dilution and solid agar plating assays. Alcohol and antimicrobial proteins production by yeasts in killer toxin medium were analyzed using gas chromatography and shotgun proteomics, respectively. Salmonella adhered onto viable and non-viable yeast isolates cell wall. Adhesion was visualized using scanning electron microscope. Yeasts-fermented killer toxin medium showed Salmonella growth inhibition. The highest alcohol concentration detected was 1.55%, and proteins with known antimicrobial properties including cathelicidin, xanthine dehydrogenase, mucin-1, lactadherin, lactoperoxidase, serum amyloid A protein and lactotransferrin were detected in yeasts fermented killer medium. These proteins are suggested to be responsible for the observed growth inhibition effect of yeasts-fermented killer toxin medium. Kluyveromyces lactis and Saccharomyces unisporus have anti-salmonella effect comparable to Saccharomyces boulardii strains, and therefore have potential to control Salmonella infection.

抗生素耐药性的增加增加了对预防和治疗肠致病性细菌感染的替代方法的需求。各种益生菌已用于动物和人类。然而，布拉氏酵母是目前人类唯一用作益生菌的酵母。尽管声称具有潜在的预防和治疗作用，但很少对开菲尔中常见的酵母菌进行研究。这项工作的重点是粘附特性，以及从传统开菲尔谷物中分离出的乳酸克鲁维酵母和单孢酵母产生的抗菌代谢物与布拉氏酵母相比菌株。粘附和沉降测定、载玻片凝集、显微镜和比浊测定用于分析沙门氏菌和鼠伤寒沙门氏菌在酵母细胞上的粘附。通过草坪平板法、比浊法、试管稀释法和固体琼脂平板测定法分析了杀伤毒素培养基中酵母菌产生的抗菌代谢物对沙门氏菌生长的抑制作用。分别使用气相色谱法和鸟枪法蛋白质组学分析了酵母在杀伤毒素培养基中产生的酒精和抗菌蛋白。沙门氏菌粘附在有活力和无活力的酵母菌分离细胞壁上。使用扫描电子显微镜观察粘附。酵母发酵杀伤毒素培养基显示沙门氏菌生长抑制。检测到的最高酒精浓度为1.55%，在酵母发酵杀伤培养基中检测到具有已知抗菌特性的蛋白质，包括cathelicidin、黄嘌呤脱​​氢酶、粘蛋白-1、乳粘素、乳过氧化物酶、血清淀粉样蛋白A蛋白和乳转铁蛋白。这些蛋白质被认为是酵母发酵杀伤毒素培养基观察到的生长抑制作用的原因。乳酸克鲁维酵母和单孢酵母具有与布拉氏酵母菌株相当的抗沙门氏菌作用，因此具有控制沙门氏菌感染的潜力。