Towards the development of pro- and prebiotics against cryptosporidiosis

隐孢子虫病是一种由多种隐孢子虫引起的肠道感染。 寄生虫。在发展中国家，感染是导致顽固性婴儿的最常见原因之一。 拉肚子。目前还没有有效的药物或疫苗来控制隐孢子虫病。我们发现， 肠道细菌微生物群(微生物群)的组成因对微小弧菌的反应而发生变化 感染。我们也观察到了相反的效果，这表明一种扰动(反生菌) 肠道微生物区系有利于寄生虫的繁殖。本提案关注的是未探索的交互 微小隐孢子虫与肠道生态系统之间的关系。具体地说，我们将调查 不同抗生素对肠道微生物区系的扰动对其增殖有多大影响 微小隐孢子虫。类似于长期使用抗生素治疗的患者增加了对 艰难梭菌，我们假设隐孢子虫病的严重程度受亲属的影响。 肠道中某些细菌类群或微生物群落的丰富。这一假设将得到检验。 有两个特定的目标：目标1。小鼠的天然肠道微生物区系将被一组不同的 不直接抑制微小弧菌且对小鼠无毒的抗生素。结果表明，C. 将测量不同抗生素处理的小鼠的生殖器和16S扩增片段测序 用来量化肠道中细菌分类群的相对丰度。此方法将标识 与隐孢子虫病严重程度呈正或负相关的细菌分类群 所有的抗生素治疗。目标2.我们将调查两者之间是否存在因果关系 目标1中确定的某些细菌类群的丰富程度与微小隐孢子虫的增殖之间的关系。至 为了达到这个目的，我们将把非生物粪便微生物区系移植到无菌小鼠体内。移植接受者将是 感染微小弧菌，并量化感染的严重程度。移植和被动移植 实验将使我们能够评估隐孢子虫病严重程度的任何变化是否直接 由肠道生态系统调节。 意义和未来的研究：这项研究将促进我们对 肠道微生物区系与隐孢子虫寄生虫的相互作用。长期目标是测试 应用PRO-AND控制肠道微生物区系控制隐孢子虫病的可行性 益生元。通过鉴定影响寄生虫的细菌分类群和细菌群落 随着扩散，拟议的研究将使今后能够开展开发低成本预制件和 益生菌以减轻隐孢子虫寄生虫的持续感染。这种方法是新颖的，而且 重要的是要追求，因为到目前为止，传统的药物和疫苗开发战略未能 确定针对隐孢子虫病的有效治疗方法和疫苗。

Cryptosporidiosis is an enteric infection caused by several species of Cryptosporidium parasites. In developing nations, the infection is one of the most common causes of persistent infant diarrhea. No effective drugs or vaccines are available to control cryptosporidiosis. We have found that the composition of the intestinal bacterial microbiota (microbiome) changes in response to C. parvum infection. We have also observed the opposite effect, which suggests that a perturbed (dysbiotic) enteric microbiota can favor parasite proliferation. This proposal focuses on unexplored interactions between Cryptosporidium parvum and the intestinal ecosystem. Specifically, we will investigate to what extent the perturbation of the intestinal microbiota with different antibiotics affects proliferation of C. parvum. In analogy to the increased susceptibility of patients treated long-term with antibiotics to Clostridium difficile, we hypothesize that the severity of cryptosporidiosis is impacted by the relative abundance of certain bacterial taxa or microbial communities in the gut. This hypothesis will be tested with two Specific Aims: Aim 1. The native gut microbiota of mice will be perturbed with a diverse set of antibiotics which do not inhibit C. parvum directly and are not toxic to mice. The proliferation of C. parvum in mice treated with different antibiotics will be measured and 16S amplicon sequencing will be used to quantify the relative abundance of bacterial taxa in the gut. This approach will identify bacterial taxa that positively or negatively correlate in abundance with severity of cryptosporidiosis across all antibiotic treatments. Aim 2. We will investigate whether there is a causal relationship between the abundance of certain bacterial taxa identified in Aim 1 and C. parvum proliferation. To this aim we will transplant dysbiotic fecal microbiota into germ-free mice. Transplant recipients will be infected with C. parvum and the severity of the infection quantified. Transplant and passive transfer experiments will enable us to assess whether any change in the severity of cryptosporidiosis is directly mediated by the intestinal ecosystem. Significance and future research: This research will advance our understanding of the interaction between the gut microbiota and Cryptosporidium parasites. The long-term goal is to test the feasibility of controlling cryptosporidiosis by manipulating the intestinal microbiota using pro- and prebiotics. By identifying bacterial taxa and bacterial communities which influence parasite proliferation, the proposed research will enable future work on the development of low-cost pre- and probiotics to mitigate persistent infection with Cryptosporidium parasites. This approach is novel and is important to pursue because so far traditional drug and vaccine development strategies have failed to identify effective treatments and vaccines against cryptosporidiosis.