黄根醇提物体外抗白念珠菌生物膜作用的研究

目的观察黄根醇提取物体外对白色念珠菌生物膜及相关基因的影响。方法 M27-A2测定黄根醇提取物对白色念珠菌的最小抑菌浓度(MIC);XTT法评价黄根醇提取物对白色念珠菌生物膜形成的影响;实时荧光定量RT-PCR(q RT-PCR)检测黄根醇提取物作用后,ALS基因的表达情况。结果黄根醇提取物对白色念珠菌的MIC为8μg/m L;随着浓度的增加,黄根醇提取物对白色念珠菌生物膜的抑制作用增强,呈正相关性;16μg/m L黄根醇提取物对不同生长阶段的白色念珠菌生物膜均有抑制作用,抑制率随生物膜成熟逐渐降低;q RT-PCR结果显示,药物作用后ALS2、ALS3基因表达降低(7.87±0.27比5.15±0.34;6.24±0.51比2.13±0.23,P<0.05),ALS1基因表达无明显变化(6.11±0.14比5.95±0.31,P>0.05)。结论黄根醇提取物对体外白色念珠菌生物膜有较明显的抑制作用,可能通过抑制ALS2、ALS3基因的表达而实现。     

Differential role of NK cells against Candida albicans infection in immunocompetent or immunocompromised mice

Little is known regarding the role of NK cells during primary and secondary disseminated Candida albicans infection. We assessed the role of NK cells for host defense against candidiasis in immunocompetent, as well as immunodeficient, hosts. Surprisingly, depletion of NK cells in immunocompetent WT mice did not increase susceptibility to systemic candidiasis, suggesting that NK cells are redundant for antifungal defense in otherwise immunocompetent hosts. NK‐cell‐depleted mice were found to be protected as a consequence of attenuation of systemic inflammation. In contrast, the absence of NK cells in T/B/NK‐cell‐deficient NSG (NOD SCID gamma) mice led to an increased susceptibility to both primary and secondary systemic C. albicans infections compared with T/B‐cell‐deficient SCID mice. In conclusion, this study demonstrates that NK cells are an essential and nonredundant component of anti‐C. albicans host defense in immunosuppressed hosts with defective T/B‐lymphocyte immunity, while contributing to hyperinflammation in immunocompetent hosts. The discovery of the importance of NK cells in hosts with severe defects of adaptive immunity might have important consequences for the design of adjunctive immunotherapeutic approaches in systemic C. albicans infections targeting NK‐cell function.     

白色假丝酵母菌pACT1-GFP质粒的构建及表达

目的构建能够稳定表达绿色荧光蛋白（GFP）的白色假丝酵母菌菌株,以便对目的基因进行示踪。方法构建pACT1-GFP质粒,以白色假丝酵母菌CAI4菌株作为感受态进行转化培养后,分别观察绿色荧光蛋白在两相型下的表达情况。结果含有pACT1-GFP的白色假丝酵母菌菌株,99%在两相型下均有较高水平的荧光蛋白表达,且荧光强度没有明显差别。结论pACT1-GFP能够在白色假丝酵母菌体内稳定表达。     

三种义齿基托材料抗白色念珠菌黏附性能的比较

目的比较3种义齿基托材料的抗白色念珠菌黏附性能。方法将热凝基托树脂、不碎胶树脂、弹性材料树脂义齿基托材料制备成粗糙度相同的标准试样,每组10个。用白色念珠菌(ATCC 90028)菌液对各试样黏附培养24h、48h、168h后,分析白色念珠菌对试件表面的黏附。结果在培养24h时,3组试件白色念珠菌黏附量差异无统计学意义(P0.05);培养48h时,除不碎胶树脂组和弹性材料树脂组外,其余两两之间差异均有统计学意义(P0.05);培养168h时,3组试件两两之间差异均有统计学意义(P0.05),白色念珠菌黏附量计数,热凝基托树脂不碎胶树脂弹性材料树脂。结论与传统热凝树脂基托相比较,不碎胶树脂基托和弹性材料树脂基托能减少白色念珠菌的黏附。     

Diversity,frequency and antifungal resistance of Candida species in patients with type 2 diabetes mellitus

Objective: To determine number, species of Candida and Candida resistance to antifungal therapy according to the metabolic control state and the associated salivary changes in patients with type 2 diabetes mellitus (DM2).

Materials and methods: Samples of non-stimulated saliva were collected from 52 patients with DM2. Salivary pH was measured and cultured on Sabouraud glucose agar and the values of CFU/ml were calculated. The species were presumptively identified using CHROMagar Candida^® plates, and identification was confirmed by polymerase chain reaction (PCR). C. albicans isolates were cultured on SGA tetracycline agar with nystatin and fluconazole diffusion disks to measure susceptibility.

Results: Sixty six percent of the yeasts isolated were Candida albicans, followed by C. glabrata (20.7%). In patients with decompensated DM2, there was an inverse association between HbA1c value and salivary pH. At higher levels of salivary acidification, a greater diversity and quantity of yeasts of the genus Candida were observed. With nystatin, higher inhibition was observed at lower pH.

Conclusions: The antifungal therapies could be more effective if it consider, qualitative salivary characteristics as pH, that could determine the susceptibility of species of Candida to at least to nystatin, which is the most used antifungal for treatment to oral candidiasis in patients with DM2.     

四型念珠菌与抗念珠菌血清的交叉免疫反应

目的 分析4型不同念珠菌抗血清的免疫应答状况,为念珠菌疫苗的研制奠定实验基础.方法 将白色念珠菌、热带念珠菌、吉利蒙念珠菌、假热带念珠菌4型念珠菌分别超声破碎,0.5％甲醛溶液灭活,加入弗氏完全佐剂制成灭活全菌疫苗.分别在1、4、8、12周腹腔注射免疫小鼠,4周后收集小鼠抗体血清,分别按10、100、1000倍稀释,再分别加入含200μl4种念珠菌的沙氏培养液中,观察其抑菌作用.结果 所有抗体均为10倍效果最佳,1000倍基本无效.白色念珠菌抗体血清对白色念珠菌、吉利蒙念珠菌、热带念珠菌有明显的抑菌作用（P＜0.01）;热带念珠菌抗体血清对白色念珠菌和热带念珠菌有抑菌作用（P=0.01）;吉利蒙念珠菌抗体血清对吉利蒙念珠菌、热带念珠菌有抑制作用（P＜0.01）;假热带念珠菌抗体血清对热带念珠菌、假热带念珠菌有抑制作用（P＜0.01）.结论 小鼠念珠菌免疫抗体血清对念珠菌的生长有一定的抑制作用.     

白念珠菌生物被膜耐药株麦角甾醇检测的方法学研究

目的：分别采用高效液相色谱法和气相色谱质谱联用法测定白念珠菌麦角甾醇含量,并对这两种方法进行比较。方法：采用浓度梯度递增法诱导白念珠菌耐药株,采用KONT真菌显色MIC药敏系统鉴定耐药性。构建6、12、24h生物被膜,采用高效液相色谱法和气相色谱质谱联用法测定麦角甾醇含量。结果：高效液相色谱法检测出麦角甾醇含量,最低检出浓度为0.05mg/L,而气相色谱质谱联用法未检测出麦角甾醇含量。结论：高效液相色谱法能准确测定白念珠菌麦角甾醇含量。与气相色谱质谱联用法比较,高效液相色谱法简单、高效和可靠。     

老年煤工尘肺患者合并白色念珠菌感染85例临床分析

目的 探讨老年煤工尘肺合并肺部白色念珠菌感染患者的疾病特点和临床诊治方法.方法 选取我院在2010年1月～2011年10月期间收治的85例老年煤工中尘肺合并有肺部白色念珠菌感染患者为研究对象,对其临床资料进行回顾性分析.结果 煤工尘肺患者合并白色念珠菌感染在肺部真菌感染中占主要情况,疾病的发生可能和年龄、合并症、肺部疾病和使用抗生素等因素有关.结论 及早的对患者进行诊断和治疗,根据患者的实际情况选取合适的抗真菌药物,可以降低患者的病死率.     

29例念珠菌性角膜炎的临床特点和治疗预后

目的：分析念珠菌性角膜炎的发病特征和临床表现,并评估其治疗预后。方法：回顾性系列病例研究。 收集2013年1月至2019年12月于山东第一医科大学附属眼科医院明确诊断为念珠菌性角膜炎的患者29例（29眼）,其中男18例,女11例,均为单眼发病;1例患者为7月大女婴,其余28例患者年龄为 29～91（59.0±13.5）岁;发病时间为2～90 d,中位数12 d。分析其发病趋势、感染前相关因素、临床表现、角膜激光共聚焦显微镜图像特点、治疗方法和疗效。结果：角膜念珠菌培养阳性共29例（其 中白念珠菌10例,近平滑念珠菌6例,其他菌种13例）,占同期真菌性角膜炎患者2%。感染前患者最常见的情况是眼部手术史26例（90%）,其次是局部糖皮质激素使用史24例（83%）、全身疾病9例 （31%）和眼部外伤2例（7%）,25例（86%）患者合并2个或更多上述因素。念珠菌性角膜炎结膜充血一般较轻,不伴有典型的伪足、苔被、免疫环等体征。4例早期患者角膜病变表现为单个或多个孤立圆点状病灶,角膜病灶切除联合药物治疗治愈。病变进展后病灶表现多样,最常见为散在多灶性浸润灶（10例,占35%）。最终23例（80%）患者需行手术治疗。结论：念珠菌性角膜炎患者的眼部手术史和局部激素使用史是感染前常见的情况,发病早期特征性表现为孤立圆点状病灶,病灶清除联合药物治疗预后好,晚期病灶表现多样,多数患者需要行角膜移植手术治疗。