Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
Int J Med Microbiol. 2011 Apr;301(4):359-64. doi: 10.1016/j.ijmm.2010.11.002. Epub 2011 Jan 13.
Salmonella spp. are Gram-negative, facultative, intracellular pathogens that cause several diarrheal diseases ranging from self-limiting gastroenteritis to typhoid fever. Previous results from our laboratory showed that Saccharomyces cerevisiae strain UFMG 905 isolated from 'cachaça' production presented probiotic properties due to its ability to protect against experimental infection with Salmonella enterica serovar Typhimurium. In this study, the effects of oral treatment with S. cerevisiae 905 were evaluated at the immunological level in a murine model of typhoid fever. Treatment with S. cerevisiae 905 inhibited weight loss and increased survival rate after Salmonella challenge. Immunological data demonstrated that S. cerevisiae 905 decreased levels of proinflammatory cytokines and modulated the activation of mitogen-activated protein kinases (p38 and JNK, but not ERK1/2), NF-κB and AP-1, signaling pathways which are involved in the transcriptional activation of proinflammatory mediators. Experiments in germ-free mice revealed that probiotic effects were due, at least in part, to the binding of Salmonella to the yeast. In conclusion, S. cerevisiae 905 acts as a potential new biotherapy against S. Typhimurium infection due to its ability to bind bacteria and modulate signaling pathways involved in the activation of inflammation in a murine model of typhoid fever.
肠炎沙门氏菌是革兰氏阴性、兼性、细胞内病原体，可引起多种腹泻病，从自限性胃肠炎到伤寒热不等。我们实验室之前的结果表明，从“甘蔗酒”生产中分离出来的酿酒酵母菌株 UFMG 905 具有益生菌特性，因为它能够预防鼠伤寒沙门氏菌血清型 Typhimurium 的实验感染。在这项研究中，在伤寒热的小鼠模型中，评估了口服酿酒酵母 905 治疗的免疫水平。用酿酒酵母 905 治疗抑制了沙门氏菌攻击后的体重减轻和存活率提高。免疫数据表明，酿酒酵母 905 降低了促炎细胞因子的水平，并调节了丝裂原活化蛋白激酶 (p38 和 JNK，但不是 ERK1/2)、NF-κB 和 AP-1 的激活，这些信号通路参与了促炎介质的转录激活。无菌小鼠实验表明，益生菌的作用至少部分是由于酵母与沙门氏菌的结合。总之，由于酿酒酵母 905 能够结合细菌并调节参与伤寒热小鼠模型中炎症激活的信号通路，因此它是一种针对鼠伤寒沙门氏菌感染的潜在新型生物疗法。
