阴香植物精油对白色念珠菌生物膜的抑制研究

目的观察阴香精油对白色念珠菌生物膜(BF)的抑制作用。方法采用改良Brown平板连续培养法制备生物膜和应用悬液定量杀菌试验法,对阴香精油抑制白色念珠菌生物膜的效果进行了实验室检测。结果用体积分数2.5%阴香精油作用30 min,对培养3 d的白色念珠菌生物膜达到完全杀灭;作用90 min对培养7 d的白色念珠菌生物膜达到完全清除。用体积分数2.5%阴香精油作用10 min,可完全杀灭悬液内白色念珠菌浮游菌。结论阴香精油对白色念珠菌生物膜有清除效应,可抑制生物膜形成,对悬液内浮游菌杀灭效果更好。     

白色念珠菌生物膜的形成及其耐药机制的研究进展

生物膜（biofilm，BF）是一种附着于非生物或生物表面的、由其自身产生的胞外聚合物包裹的有三维结构的菌细胞群体，是细菌、真菌在生长过程中为适应生存环境而形成的一种与浮游细胞相对应的生存方式。近20年来随着癌症放、化疗和器官移植患者的增加，免疫抑制剂和广谱抗生素的大量使用以及插管等医学材料使用的增多，白色念珠菌病的发病率增加了近40倍，其中相当一部分与白色念珠菌形成生物膜密切相关。感染部位一旦形成BF或植人体内的生物材料表面一旦形成了BF，由于其难以被特异性抗体、大多抗真菌药物等物质所彻底杀灭，白念菌BF引起的感染性疾病因而大都是慢性和难治性的。白念菌BF逐渐成为许多学者关注的热点，对其研究在不断深入。     

两种酵母样真菌培养鉴定方法评价

目的 选择和评价实用性强、快速、准确酵母样真菌培养鉴定方法。为临床诊断和治疗真菌感染性疾病提供可靠的病原学依据。方法 将API酵母样真菌鉴定试条鉴定出的白色念珠菌（48株），热带念珠菌（15株），克柔氏念珠菌（19株）。光滑念珠菌（6株）转种科玛嘉酵母样真菌显色平板，经35℃，24—48小时培养，分析科玛嘉酵母样真菌显色平板鉴定结果正确率。结果 科玛嘉显色平板鉴定出白色念珠菌43株，热带念珠菌13株，克柔氏念珠菌8株，光滑念珠菌5株。科玛嘉显色平板法与酵母样真菌鉴定符合率为80％-90％．结论 科玛嘉显色平板法操作简单、快速。价格低廉，可作为酵母样真菌鉴定的初筛方法。     

芍药苷对白色念珠菌生物膜的作用

背景：研究证实中药赤芍有效成分对白色念珠菌有较好的抑制作用,但其单体芍药苷对白色念珠菌生物膜是否有抑制作用未见报道。目的：观察芍药苷对体外白色念珠菌生物膜的影响。方法：用RPMI-1640分别按2倍稀释法制备5个浓度梯度（4,2,1,0.5,0.25 g/L）的芍药苷溶液。用RPMI-1640稀释洗必泰为5个浓度梯度（2%,1%,0.5%,0.25%,0.125%）。采用琼脂扩散法检测不同浓度梯度芍药苷或洗必泰对白色念珠菌的抑菌直径。MTT法检测不同浓度洗必泰或芍药苷对白色念珠菌细胞黏附的作用,以及对白色念珠菌生物膜的抑制作用,并且利用激光共聚焦扫描显微镜和死菌活菌荧光染色技术相结合方法观察常态及药物作用下的白色念珠菌生物膜。结果与结论：洗必泰与芍药苷均有抑菌能力,抑菌环直径与药物浓度呈正相关;除2 g/L芍药苷组与1%,2%洗必泰组抑菌环直径无差异外,其余组间两两比较差异均有显著性意义。不同质量浓度芍药苷对白色念珠菌的细胞黏附都具有抑制作用,对白色念珠菌生物膜也具有抑制作用,且抑制率与药物质量浓度呈正相关。观察48 h时常态生物膜结构中大部分是活菌,有少量死菌存在;随芍药苷质量浓度改变白色念珠菌生物膜中死菌比例不断增高,其抑菌活性相对弱于洗必泰。表明芍药苷对体外白色念珠菌生物膜有较明显的抑制作用。     

应用涡流式冲洗对糖尿病足部溃疡患者换药方法的探讨

目的探讨糖尿病足的换药方法。方法将60例病人随机分为两组,每组30例。实验组采用涡流式冲洗换药方法,对照组采用常规抹洗方法。结果涡流式冲洗法对严重感染的糖尿病足部溃疡的腐烂组织清除优于常规抹洗,差异有统计学意义(P<0.01)。结论涡流式冲洗不仅效果好,还能弥补常规抹洗方法易损新生的肉芽和棉纤维易残留在组织,影响组织愈合[1]的缺点,是一种促进糖尿病足部溃疡伤口愈合的理想换药方法。     

眼部白色念珠菌感染的快速诊断方法

目的介绍一种白色念珠菌的快速检测方法。方法以白色念珠菌标准株为阳性对照,普通酵母菌标准株为阴性对照,采用荧光标记的抗白色念珠菌的单克隆抗体直接免疫荧光法进行测定角膜溃疡病人标本涂片。结果阳性对照、及白色念珠菌感染病人标本中有边缘着绿色,中间为暗红色的阳性菌。普通酵母菌及非白色念珠菌感染对照组酵母细胞染红色。结论该方法快速、简便、特异性强,结果判断直观,并可广泛的推广应用。     

118株酵母样真菌药敏结果分析

目的分析酵母样真菌对目前常用的5种抗真菌药物的敏感性,为临床合理选用抗真菌药物提供依据。方法对云南省第一人民医院2009年1～6月分离的118株酵母样真菌的药敏试验结果进行回顾性分析。结果酵母样真菌感染以白色念珠菌为主,酵母样真菌对5-氟胞嘧啶、两性霉素B敏感率较高,在98%以上,对唑类药物敏感性稍低,为70%～80%。结论酵母样真菌感染以白色念珠菌、热带念珠菌和光滑念珠菌较为常见,而且耐药菌株的检出率呈上升趋势,临床上应慎用抗菌药物,减少耐药菌株的产生。     

低频超声联合盐酸氨溴索对表皮葡萄球菌生物被膜的影响

目的 研究低频超声联合盐酸氨溴索对表皮葡萄球菌(Sepidermidis)RP62A生物被膜(biofilm,BF)结构的影响.方法 建立成熟RP62A BF模型.分组处理,XTT法测BF细菌活性变化;激光共聚焦显微镜结合ISA软件定量分析BF;扫描电镜观察BF结构改变.结果 单独低频超声作用BF无效果,1.875 mg/mL浓度氨溴索能有效清除BF,较空白对照组区域孔率增大,平均扩散距离和结构熵减小,P＜0.05;氨溴索联合低频超声(1、0.5h)组效果更加显著,与单独氨溴索组相比,P＜0.05;扫描电镜显示低频超声能明显促进氨溴索对BF的作用,使BF变薄,结构趋于单一疏松.结论 低频超声能显著促进氨溴索对表皮葡萄球菌BF的清除作用.     

江门地区出国人员体检痰酵母样真菌带菌率、鉴定和药敏

目的研究酵母样真菌在正常人群的带菌率及其生物学特性。方法按标准留取痰标本,无菌接种于血平板和念珠菌显色培养基,同时痰标本直接涂片进行革兰染色。35℃24h培养,需要鉴定和药敏的酵母样真菌上ID32C、ATB Fungus试条,用ATB Expression机进行测定。结果2000例痰标本,痰直接涂片进行革兰染色镜检,可见酵母样真菌孢子和菌丝的仅有4例,血平板和念珠菌显色培养基有160例酵母样真菌生长。结论经过对2005年10月到2007年10月两年2000例江门地区出国人员体检痰培养,得出正常人痰酵母样真菌带菌率小于或等于8％,在临床痰培养中,用半定量法,在2区及2区以上有酵母样真菌和正常菌群或只有1区及1区以上纯酵母样真菌生长,就要对酵母样真菌进行鉴定和药敏,以白色念珠菌更多见,为75％。     

不同口腔护理方法对预防呼吸机相关性肺炎的效果观察

目的:探讨不同的口腔护理方法预防呼吸机相关性肺炎的效果观察。方法:将101例经口气管插管患者随机分组,分别采用常规口腔护理方法(对照组),每12 h用0.2%洗必泰口腔护理液冲洗(标准组),每12 h用牙刷刷牙(刷牙组)进行口腔护理。比较三组患者呼吸机相关性肺炎的发生情况。结果:标准组、刷牙组与对照组相比,呼吸机相关性肺炎发生率明显减少(P<0.05),刷牙组与标准组相比,呼吸机相关性肺炎发生率无统计学意义(P>0.05)。结论:0.2%洗必泰口腔护理液冲洗和刷牙均能有效降低呼吸机相关性肺炎的发生率。     

A method for measuring the strength of adhesion of Candida albicans on epithelial cells

A method on estimation of Candida albicans adhesion to epitheliocytes is proposed. The principle consists in the fact that while centrifuging epitheliocytes (1000 cycles/min, 10 min) with adhered Candida albicans through phycoll-verografin (1.077 g/cm3 density), Candida albicans cells having poor adhesion are separated from epitheliocytes trying to rise to the surface of phycoll-verografin. Candida albicans strongly adhered to epitheliocytes settle down to the bottom of test tube. In experiments with buccal epitheliocytes of healthy donors the number of strongly adhered Candida albicans ranged from 13% to 50% and they amounted to 37.0 +/- 7.8% on an average.     

Antifungal activity of amphotericin B,fluconazole, and voriconazole in an in vitro model of Candida catheter-related bloodstream infection

The activity of five simulated antifungal regimens for eradication of catheter-related bloodstream Candida infection was evaluated with an in vitro pharmacodynamic model. Single-lumen central venous catheters were colonized with Candida species by sequentially incubating central venous catheters in plasma and then in growth medium (RPMI plus morpholinepropanesulfonic acid) containing a standardized suspension (10(5) CFU/ml) of Candida albicans, Candida glabrata, or slime-producing Candida parapsilosis. Colonized central venous catheters were then placed in a one-compartment pharmacodynamic model where five antifungal regimens (plus control) were simulated: amphotericin B, 1.0 mg/kg every 24 h; amphotericin B, 0.5 mg/kg every 24 h; fluconazole, 400 mg every 24 h; fluconazole, 800 mg every 24 h; and voriconazole, 4 mg/kg every 12 h. During exposure to the simulated clinical regimens, samples were serially removed from the model over 48 h for quantitation of viable organisms. All antifungal regimens suppressed fungal counts by both peripheral and catheter sampling versus control (P = 0.001). Overall, antifungal activity ranked amphotericin B (1 mg/kg) > amphotericin B (0.5 mg/kg) > or = voriconazole > fluconazole (800 mg) > or = fluconazole (400 mg). No regimen, however, completely eradicated (by culture and electron microscopy) central venous catheter colonization. Regrowth was noted in the model during therapy against C. glabrata and C. parapsilosis but was not associated with an increase in the MICs for the isolates. Lack of in vitro antifungal activity against biofilm-encased organisms appeared to be the primary reason for mycological failure of antifungal regimens in the model.     

氮离子溅射对镍铬合金表面细菌黏附的影响

背景：镍铬合金被广泛应用于口腔修复领域,大量实验正在进行其机械性能、抗腐蚀性能以及生物相容性的研究。目的：观察氮离子溅射对镍铬合金表面细菌黏附能力的影响。方法：制作镍铬合金试件 144 件,随机选出 72 件,采氮离子溅射法对其表面改性,镍铬合金组为对照组,氮离子溅射组为实验组。对两组试件表面黏附血型链球菌、黏性放线菌、白色念珠菌,分别进行细菌体外黏附实验。用菌落形成单位计数法统计分析氮离子溅射前后各种细菌黏附量的变化。结果与结论：在细菌黏附 24,48,168 h,上述 3 种细菌在实验组表面黏附量较对照组表面黏附量显著减少（P 〈 0.001）。提示,氮离子溅射可抑制镍铬合金表面细菌黏附。     

Rabbit model of Candida albicans biofilm infection: liposomal amphotericin B antifungal lock therapy

Catheter-related infections due to Candida albicans biofilms are a leading cause of fungal nosocomial bloodstream infection. In this paper, we describe the development of a model of catheter-associated infection with C. albicans biofilms and show that antifungal lock therapy with liposomal amphotericin B is an effective treatment strategy for these infections. Silicone catheters surgically placed in New Zealand White rabbits were infected with C. albicans, and the rabbits were randomized into three groups: (i) untreated controls, (ii) liposomal amphotericin B lock, and (iii) fluconazole lock. Upon completion of therapy, blood cultures were obtained and the catheters were removed for quantitative culture and scanning electron microscopic analyses. Quantitative cultures revealed that catheters treated with liposomal amphotericin B yielded 0 CFU, which was significant compared to the untreated controls (P < 0.001) and the fluconazole-treated group (P = 0.0079). Although fluconazole treatment tended to have lower CFU compared to untreated controls, there was no difference in mean colony counts between these two groups (1.128 +/- 0.764 and 1.841 +/- 1.141 log(10) CFU/catheter segment, respectively; P = 0.297). Scanning electron microscopy revealed abundant biofilm in the control and fluconazole groups, while the liposomal amphotericin B group was virtually cleared. These findings suggest a possible treatment strategy for the successful salvage of catheters infected with C. albicans biofilms and describe an animal model that may play an important role in the further study of C. albicans biofilm pathogenesis and evaluation of potential antibiofilm agents.     

共同感染对白色念珠菌感染状态的影响研究

目的研究致病大肠杆菌和白色念珠菌共同感染对白色念珠菌侵袭力和破坏性的影响。方法通过构建白色念珠菌和致病大肠杆菌共同感染离体肠上皮细胞（ Caco-2）的模型来研究共同感染对白色念珠菌感染状态的影响。通过倒置显微镜观察感染早期发生侵袭的白色念珠菌特征;通过测定乳酸脱氢酶（ LDH）活性评估上皮细胞被破坏程度;通过实时荧光定量PCR （ qRT-PCR）检测感染相关基因（ ALS3、 PLB1和SAP4）表达调控情况。采用SAS软件包进行数据统计分析。采用方差分析比较进行多组之间的比较,对于组间有差异的数据进一步采用Bonferroni法进行两两比较。以P＜0.05为差异具有统计学意义。结果显微镜观察发现共同感染组比单纯白色念珠菌感染组在感染早期更容易发生上皮细胞侵袭,侵袭的白色念珠菌呈簇状分布; LDH活性检测显示同时共同感染组（组3）最高（与组1、组2、组4、组5比较 F 值分别为14.48、5.48、11.74、3.45, P＜0.05）,致病大肠杆菌继发白色念珠菌感染组（组5）和单纯致病大肠杆菌感染组（组2）之间差异无统计学意义（F＝2.03, P＝0.54）,白色念珠菌继发致病大肠杆菌感染组（组4）和单纯白色念珠菌感染组（组1）之间差异无统计学意义（F＝2.74, P＝0.11）,组5、组2LDH活性值大于组1、组4（P＜0.05）;同时伴随白色念珠菌致病相关基因（PLB1和SAP4）上调, PLB1基因表达组3高于组1（ P ＝0.0143）, SAP4表达组3、组5高于组1（ P 值分别为0.0272、0.0018）。结论致病大肠杆菌和白色念珠菌共同感染增强了白色念珠菌的侵袭力和破坏性,并且增强的程度与两种菌的发病顺序和共存时间长短有关。     

改良荚膜肿胀试验

背景:有研究证实白色念珠菌细胞壁外发现有一层分泌的蛋白质,而最近实验发现其具有荚膜结构。目的:通过改良荚膜肿胀试验观察白色念珠菌的荚膜结构。设计:观察对比实验。单位:赣南医学院病原生物学教研室。材料:菌株:中央标准株(菌号:CCCMC1a)由中科院真菌菌种保藏中心提供;国际标准株(菌号:ATCC 14053)由北京大学医院真菌菌种保藏中心提供。2 株临床分离菌株(C1、C2),经中科院真菌菌种保藏中心鉴定为白假丝酵母菌。免疫血清用上述实验菌株全细胞抗原分别免疫家兔(由中山大学动物实验中心提供),常规制备免疫血清,备作荚膜肿胀试验用。方法:实验于 2005-12 在赣南医学院病原生物学教研室完成。①荚膜肿胀实验:将白色念珠菌培养物(C1, C2, CCCMC1a, ATCC)分别涂片,实验组 1 玻片加入相应的兔抗血清,对照组 1 加入正常兔血清,两组都加入 1%美蓝置湿盒,37 ℃,20 min;取出玻片,盖上盖玻片,在油镜下用测微计测定 40 个菌细胞的荚膜厚度,计算平均值。②改良荚膜肿胀实验:将白色念珠菌培养物(C1,C2,CCCMC1a,ATCC)分别涂片,实验组 2 玻片加入相应的兔抗血清,对照组 2 加入正常兔血清,不加美蓝直接置湿盒内,37 ℃,20 min;取出玻片,不盖盖玻片,待其自然干燥,然后用HISS 荚膜染色法进行染色,同样在油镜下用测微计测定 40 个菌细胞的荚膜厚度,计算平均值。主要观察指标:荚膜肿胀实验及改良荚膜肿胀实验各组荚膜厚度平均值。结果:①传统荚膜肿胀实验表现为阳性,实验组 1 白色念珠菌培养物C1, C2, CCCMC1a, ATCC 荚膜厚度分别为 (0.558 0.081),(0.530 0.081),(0.475 0.081),(0.600 0.068)μm,均大于对照组 1[(0.225 0.061),(0.252 0.038),(0.200 0.072),(0.225 0.046)μm,P < 0.01]。②改良荚膜肿胀实验组 2 白色念珠菌培养物 C1, C2,CCCMC1a, ATCC 荚膜厚度分别为 (0.541±0.038),(0.510±0.060),(0.487±0.041),(0.595±0.027) μm,大于对照组 2 [(0.215±0.022),(0.247±0.018),(0.213±0.033),(0.220±0.016)μm,P < 0.01]。③对照组 2 荚膜厚度小于对照组 1(P < 0.01), 实验组 2 荚膜厚度小于实验组 1(P < 0.01)。结论:作为一种定量试验,改良荚膜肿胀试验比传统荚膜肿胀试验更为稳定与准确。     

Reaction of mononuclear cells from patients with bronchial asthma to Candida albicans

This study was undertaken to investigate cytokine production of mononuclear cells (MNCs) from patients with bronchial asthma stimulated by antigens of Candida albicans in vitro. The reaction of MNCs from corticosteroid-dependent patients was restricted to a low level. The level of tumor necrosis factor (TNF)-alpha released into the culture fluid was significantly higher in the high responders (HR) of the atopic corticosteroid-independent (A-CSID) group than those of other asthmatic and control groups (p less than 0.01). The level of IL-1 beta of the A-CSID group was significantly higher than that of the non-atopic corticosteroid-independent group (p less than 0.05), but not significantly different from the controls. In HR of the A-CSID group, the production of TNF-alpha and IL-1 beta was augmented and interferon-gamma production was also increased in these patients. These results suggest that Candida albicans can contribute to the augmentation of cytokine production in bronchial asthma, especially in some of atopic type.     

Anti-metabolic activity of caspofungin against Candida albicans and Candida parapsilosis biofilms

OBJECTIVES: Candidiasis can be associated with the formation of biofilms on bioprosthetic surfaces and the intrinsic resistance of Candida albicans biofilms to the most commonly used antifungal agents has been demonstrated. In this study, we report on the antifungal activity of caspofungin at two different concentrations, on C. albicans and Candida parapsilosis biofilms with different ages of maturation. METHODS: Fifteen strains of C. albicans (10 strains susceptible to fluconazole in vitro and five strains resistant to this antifungal agent) and six strains of C. parapsilosis (all were susceptible to fluconazole in vitro) were studied. The antifungal activity of caspofungin was assessed by looking for a significant inhibition of the metabolic activity of yeasts within biofilms. Biofilms of Candida were produced in vitro, on silicone catheters. RESULTS: Caspofungin used at MIC did not modify the metabolic activity of C. albicans, whatever the maturation age of the biofilms. The same concentration of caspofungin significantly reduced the metabolism (P相似文献   

Pulmonary defence mechanism in mice. A comparative role of alveolar macrophages and polymorphonuclear cells against infection with Candida albicans

The protective roles of alveolar macrophages and polymorphonuclear cells were analyzed against intratracheal challenge with Candida albicans in mice. When mice were treated with carrageenan, a known cytotoxic agent for macrophages, there was no change in susceptibilities to the challenge in terms of the survival and the progressive elimination of fungi from the lung and kidney, in spite of a decreased in vitro phagocytosis of Candida albicans by their alveolar macrophages. On the other hand, irradiated mice (whole body irradiation with 800 rads) showed an enhanced mortality and a progressive growth of Candida albicans in their lungs and kidneys, although no change was observed in the in vitro phagocytic activity of alveolar macrophages until day 6 after irradiation. In normal and carrageenan treated mice, there was a progressive increase in the recruitment of polymorphonuclear cells into the lung after the challenge as shown by bronchoalveolar lavage and histological examination. In irradiated mice, on the other hand, there was a decreased recruitment of polymorphonuclear cells at 24 hr after the challenge, and a complete impairment at a late stage. When phagocytes were obtained from normal mice and examined for in vitro phagocytic activity to Candida albicans, polymorphonuclear cells showed higher activity than that of alveolar macrophages. These results suggest that polymorphonuclear cells play a very important role in the protection against intratracheal infection with Candida albicans.     

Activation of macrophages for enhanced release of superoxide anion and greater killing of Candida albicans by injection of muramyl dipeptide

The adjuvant muramyl dipeptide (MDP) has been shown to affect a number of macrophage functions in vitro. We studied the effect of subcutaneous injection of MDP into mice. Cultured peritoneal macrophages from treated mice displayed increased spreading, total cell protein, and specific activity of beta-glucosaminidase a constituent of macrophage lysosomes, and of lactate dehydrogenase. Generation of superoxide anion (O2-) by MDP-treated macrophages stimulated by contact with phorbol myristate acetate was enhanced by over fivefold to levels achieved by macrophages from bacillus Calmette-Guerin-infected mice. The enhancement in stimulated O2- release was noted by 1 h after injection of MDP, peaked by 3 h, and remained high for at least 48 h. Priming for enhancement of O2- release by MDP was similar in athymic nude mice and in normal littermates, suggesting that mature T lymphocytes are not involved in this MDP effect. Priming for enhanced stimulated O2- release, and morphologic and enzymic changes, were not achieved by injection of the D-D stereoisomer of MDP. Phagocytosis of Candida albicans was only slightly greater by macrophages from mice give MDP, but MDP-stimulated cells killed two times more C. albicans in vitro than did cells from untreated animals. When MDP was given 18 h before, simultaneously with, or 24 h after lethal infectious challenge with C. albicans, treated mice were protected compared with controls. These results suggest that injection of MDP effectively and rapidly activates macrophages in the recipient animal. This agent should serve as an important probe of macrophage physiology and, perhaps ultimately, as a means of enhancing host defense in humans.