Intestinal colonization by C.albicans and enteric bacteria

描述（由申请人提供）：口咽念珠菌病（OPC）是艾滋病患者常见的机会性感染，据信是由白色念珠菌引起的，这些白色念珠菌显然是良性定植在患者身上。科门萨尔角白色念珠菌生物体通常定殖于胃肠道和女性阴道，并且在一定程度上定殖于口腔或皮肤。在免疫功能低下的宿主中，肠道定殖者经历转化为能够引起广泛疾病的侵入性病原体。虽然，C.因此，白色念珠菌是重要的病原体的来源，很少有人知道的性质，真菌定植和控制它的因素。白念珠菌在定植过程中的重要活动以及C.白念珠菌定殖对宿主生理的影响。本研究的第一个具体目的是研究C.白念珠菌突变对突变体定殖能力的影响。在第二个具体目标中，假设C.白色念珠菌导致宿主对细菌感染的易感性增加。由于OPC在AIDS患者中的高发病率，AIDS患者很可能经常被C.白色念珠菌此外，在小鼠中的研究表明T细胞在限制C.肠道中的白色念珠菌。因此，艾滋病患者体内很可能存在高水平的C.白色念珠菌假设由C.因此，白色念珠菌的定植可能有助于艾滋病患者对念珠菌病的易感性。当患者发生念珠菌病时，引起感染的生物体是先前在患者体内携带而不引起疾病的生物体。虽然有许多研究已经检查了疾病期间发生的事件，但很少有研究专注于了解疾病发生前生物体的生长。该研究项目的目标是了解生物体在宿主中定植的情况，并了解定植如何影响宿主的健康，特别强调其对肠道病原体感染过程的影响。

DESCRIPTION (provided by applicant): Oropharyngeal candidiasis (OPC), a common opportunistic infection in AIDS patients, is believed to arise from Candida albicans organisms that were apparently benignly colonizing the patient. Commensal C. albicans organisms typically colonize the GI tract and female vagina, and to some extent the oral cavity or the skin. In an immunocompromised host, commensal colonizers undergo a conversion to invasive pathogens that are capable of causing a wide spectrum of diseases. Although commensal C. albicans is thus important as the source of pathogenic organisms, little is known about the nature of commensal colonization and the factors that control it. The research proposed in this application seeks to understand C. albicans activities that are important during colonization and the effect of C. albicans colonization on host physiology. The first specific aim of the proposed research is to study the effects of C. albicans mutations on the ability of mutants to colonize. In the second specific aim, the hypothesis that colonization with C. albicans results in increased host susceptibility to bacterial infection will be tested. Because of the high incidence of OPC in AIDS patients, it is likely that AIDS patients are frequently colonized by C. albicans. In addition, studies in mice indicate the T cells are important in limiting the population size of C. albicans in the intestinal tract. Therefore, it is likely that AIDS patients are colonized to high level by C. albicans. The hypothesized increase in susceptibility to bacterial infection caused by C. albicans colonization may thus contribute to the susceptibility of AIDS patients to diarrheal disease. When a patient develops candidiasis, the organisms responsible for the infection are organisms that were previously carried in the patient's body without causing disease. Although there are many studies that have examined the events that occur during disease, few studies have focused on learning about the growth of the organism before disease arises. The goal of this research project is to understand what the organism does to colonize the host and to understand how colonization affects the health of the host with particular emphasis on its influence on the course of infection by enteric pathogens.