【摘要】：白色念珠菌(Candida albicans),又稱白色假絲酵母(以下簡稱白念),是人體一種極其重要的條件致病真菌。在正常人體中,白念是一種無害的共生真菌,其廣泛地定植于人體的各種生態(tài)位,其中包括健康人體的口腔、胃腸道、陰道和皮膚。但是,在免疫力低下的人群中,如乙肝病人、艾滋病人以及長期罹患糖尿病的病人,白念可引起感染甚至念珠菌病,輕者可導(dǎo)致表面黏膜感染、重者可發(fā)展為系統(tǒng)疾病危及生命。在眾多致病因素當(dāng)中,形態(tài)轉(zhuǎn)變即從酵母形態(tài)轉(zhuǎn)變?yōu)榫z形態(tài),是極其重要的因素之一。 BDSF是一種小分子鉆鏈脂肪酸,來自Burkholderia cenocepacia。在結(jié)構(gòu)上,BDSF與DSF (diffusibe signal factor)十分相似,而DSF是由來自Xanthomonas campestris的RpfF酶合成�；駼cam0581編碼RpfF酶的同源物,對于BDSF的合成是必需的。該基因在Burkholderia cenocepacia中高度保守且廣泛分布。外源添加BDSF,可使DSF缺陷的Xanthomonas campestris的生物膜和胞外多糖表型得以恢復(fù)。 本論文實(shí)驗(yàn)可分為兩部分。第一部分,首先以白念的酵母相為起點(diǎn),對BDSF抑制白念菌絲的生長進(jìn)行了驗(yàn)證；第二部分,以白念的菌絲相為起點(diǎn),檢測BDSF是否能促進(jìn)白念的菌絲相向酵母相轉(zhuǎn)變。實(shí)驗(yàn)過程中,我們選擇GS培養(yǎng)基作為菌絲誘導(dǎo)培養(yǎng)基。GS培養(yǎng)基具有較好的誘導(dǎo)白色念珠菌的酵母態(tài)向菌絲態(tài)轉(zhuǎn)化的能力,白色念珠菌在該培養(yǎng)基中三小時(shí)菌絲形成率高達(dá)90%以上,四小時(shí)菌絲形成率高達(dá)95%以上。 實(shí)驗(yàn)表明,以白念的酵母態(tài)為起點(diǎn),當(dāng)濃度≥30μM時(shí)BDSF具有強(qiáng)烈地抑制白念菌絲生長的能力。對于已經(jīng)形成的菌絲,在30μM和60μM時(shí),BDSF并不抑制菌絲進(jìn)一步生長和分支,但隨著菌絲的生長,新生的菌絲則不斷地轉(zhuǎn)變?yōu)榻湍笐B(tài),盡管早期生成的少量的菌絲并未轉(zhuǎn)變?yōu)榻湍笐B(tài)；當(dāng)BDSF濃度增加至120μM時(shí),BDSF幾乎完全抑制了菌絲生長和分支。
[Abstract]:Candida albicans (Candida albicans), also known as Candida albicans, is an extremely important conditional pathogenic fungus. In the normal human body, Bai Nian is a harmless symbiotic fungus, which is widely located in various ecological sites of the human body, including the oral cavity, gastrointestinal tract, vagina and skin of the healthy human body. However, in people with low immunity, such as hepatitis B patients, AIDS patients and patients with chronic diabetes, candida albicans can cause infections and even candidiasis, and mild cases can lead to superficial mucosal infections. Serious diseases can develop into systemic diseases that are life-threatening. Among the many pathogenic factors, morphological transformation from yeast to hyphae is one of the most important factors. BDSF is a small molecular fatty acid from Burkholderia cenocepacia.. The structure of BDSF is similar to that of DSF (diffusibe signal factor), and DSF is synthesized by RpfF enzyme from Xanthomonas campestris. The gene Bcam0581 encodes the congeners of RpfF enzymes, which are necessary for the synthesis of BDSF. The gene is highly conserved and widely distributed in Burkholderia cenocepacia. Exogenous addition of BDSF, could restore the biofilm and extracellular polysaccharide phenotype of DSF deficient Xanthomonas campestris. The experiment can be divided into two parts. In the first part, the inhibitory effect of BDSF on the growth of the mycelium was verified by using the yeast phase as the starting point, and in the second part, the effect of BDSF on the transformation of the hyphae from the white to the yeast was examined. During the experiment, we chose GS medium as the hyphal induction medium. GS medium had better ability of inducing Candida albicans yeast to hyphae transformation. The mycelium formation rate of Candida albicans was above 90% in three hours and 95% in four hours. The results showed that BDSF had strong ability to inhibit mycelium growth when the concentration was more than 30 渭 M. For the formed hyphae, at 30 渭 M and 60 渭 M, BDSF did not inhibit the further growth and branching of the mycelium, but with the growth of the hyphae, the new hyphae changed to yeast state continuously, although a small amount of hyphae produced in the early stage did not change to yeast state. When the concentration of BDSF increased to 120 渭 M, BDSF almost completely inhibited the mycelium growth and branching.
【學(xué)位授予單位】：復(fù)旦大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2011
【分類號】：R379.4

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 陳靜,陳江野;CEK2和CSK1基因的敲除對白色念珠菌形態(tài)的影響[J];實(shí)驗(yàn)生物學(xué)報(bào);2001年01期

，

本文編號：2272216