蝎毒多肽Ctry2459抗白色念珠菌机制研究

【目的】探究蝎毒多肽Ctry2459抗白色念珠菌的作用机制。【方法】采用肉汤稀释法并结合平板计数法测定蝎毒多肽Ctry2459对白色念珠菌的最小抑菌浓度和最小杀真菌浓度;通过平板计数法绘制蝎毒多肽Ctry2459对白色念珠菌的时间-杀菌动力学曲线;通过PI吸收实验检测蝎毒多肽Ctry2459对白色念珠菌细胞膜完整性的影响;通过核酸阻滞实验检测蝎毒多肽Ctry2459与核酸间是否具有结合作用;通过流式细胞技术检测蝎毒多肽Ctry2459对白色念珠菌活性氧、线粒体膜电位以及凋亡/坏死的影响。【结果】蝎毒多肽Ctry2459对白色念珠菌的最小抑菌浓度和最小杀真菌浓度分别为25μg/mL和50μg/mL。蝎毒多肽Ctry2459对白色念珠菌的杀菌作用具有时间和浓度依赖性,并可通过直接破坏细胞膜的完整性以及通过ROS介导的线粒体失能导致细胞坏死的方式杀灭白色念珠菌细胞。【结论】蝎毒多肽Ctry2459可以作为抗白色念珠菌药物研发的候选分子或者分子模板。     

苦参-蛇床子药对提取物对白念珠菌VVC临床株的抑制作用研究

目的本文着重研究苦参-蛇床子药对提取物(Extract of Sophorae Flavescentis Radix — Cnidii Fructus Couplet medicines,ESCC)对白念珠菌VVC临床株的抑制作用。方法 实验通过微量液基稀释法检测ESCC对白念珠菌的MIC 80;XTT减低法检测ESCC对白念珠菌VVC临床株细胞增殖活性的影响;倒置显微镜分别在4 h、8 h、12 h观察ESCC对白念珠菌VVC临床株酵母-菌丝二相性转换的影响;扫描电子显微镜观察ESCC对白念珠菌VVC临床株生物膜形成的影响;微孔板观察ESCC对白念珠菌VVC临床株成熟生物膜的影响;qRT-PCR检测ESCC对白念珠菌VVC临床株菌丝和生物膜形成相关基因的影响。结果 实验结果显示,ESCC具有一定的抗真菌作用,MIC 80 在512~1024 μg/mL之间,可显著降低白念珠菌VVC临床株细胞增殖活性;ESCC可抑制白念珠菌VVC临床株酵母-菌丝二相性转换,并可影响成熟生物膜的完整性。PCR结果显示ESCC可显著降低 ALS1 、 ASL3 、 HWP1 等基因转录水平。结论 本实验研究表明,苦参-蛇床子1∶1药对水提物可通过下调白念珠菌菌丝和生物膜形成相关基因转录水平,从而抑制酵母-菌丝二相性转换,影响其代谢活性,抑制生物膜的形成,并可破坏完整生物膜的完整性,从而起到抗真菌作用。     

氟尼辛葡甲胺对克柔念珠菌生物膜形成的影响及联合唑类药物效果评价

目的本研究旨在评价氟尼辛葡甲胺(FM)对克柔念珠菌生物膜形成的抑制作用以及和唑类药物联用对克柔念珠菌的体外抗菌作用。方法以患真菌性乳房炎奶牛奶样临床分离克柔念珠菌为试验菌株,采用微量稀释法测定最小抑菌浓度(MIC)、最小杀菌浓度(MFC)初步探讨FM对克柔念珠菌的抑菌活性。水-烃两相法测定细胞表面疏水性(CSH)并通过XTT法测定FM对克柔念珠菌生物膜形成早期1～3 h黏附阶段的影响以及培养24 h后成熟生物膜的影响;以部分抑菌浓度指数(FICI)作为检测指标,通过棋盘法检测与唑类药物联用对克柔念珠菌体外静态抗菌作用;采用酶标比浊法测定绘制不同药物处理后的时间-抑菌曲线。结果 FM单药对克柔念珠菌的MIC均为0.625 mg/mL;FM可以降低CSH,对不同生长阶段(早期黏附、成熟)的克柔念珠菌生物膜均有显著抑制作用,抑制作用具有时间和浓度依赖性;联合用药发现,FM与伊曲康唑联用抗克柔念珠菌的FICI介于0.5～1.5之间,表现为协同/相加作用;与酮康唑联合用药的FICI指数介于0.375～1.25之间,表现为协同/相加作用;与氟康唑联用则表现为无关;时间-抑菌曲线显示,部分唑类药物与FM联用能增强其对克柔念珠菌抑制作用,并维持较长的作用时间。结论 FM是一种有效的抗真菌增效剂,可以促进伊曲康唑和酮康唑的抗真菌活性。     

和厚朴酚通过ROS的积累和破坏细胞膜杀死白色念珠菌

[目的]研究在体外情况下和厚朴酚对白色念珠菌的抑制作用及其可能机制。[方法]采用微量稀释法测定和厚朴酚对白色念珠菌的最低抑菌浓度（MIC₈₀）和最低杀菌浓度（MFC）;用透射电镜观察不同浓度和厚朴酚对白色念珠菌超微结构的影响;采用Annexin V-FITC/PI染色法分析不同浓度和厚朴酚对白色念珠菌细胞凋亡的影响;用DCFH-DA染色法测定不同浓度和厚朴酚对白色念珠菌细胞内活性氧积累的影响;用JC-1染色法分析不同浓度和厚朴酚对白色念珠菌线粒体膜电位的影响;用碘化丙啶染色、考马斯亮蓝G-250染色检测和厚朴酚对白色念珠菌细胞膜通透性的影响;通过测定加入麦角甾醇后,和厚朴酚对白色念珠菌的抑制作用的变化,检测和厚朴酚对白色念珠菌细胞膜的影响。[结果]和厚朴酚对白色念珠菌具有很强的抑制作用,MIC和MFC分别为16 μg/mL和32 μg/mL。对白色念珠菌细胞壁、细胞膜和胞浆均有明显的影响。和厚朴酚是通过增加活性氧的产生和破坏线粒体功能来诱导白念珠菌的细胞凋亡和坏死。它也影响细胞膜的通透性,这可能和细胞壁的破坏和与麦角固醇的结合有关。[结论]和厚朴酚通过产生活性氧并伴随着一系列的细胞损伤这种复杂的机制从而对白色念珠菌产生抑制作用,使和厚朴酚成为一种潜在的抗真菌药物。     

葡萄籽原花青素对白色念珠菌抑菌作用的体外研究

目的研究葡萄籽原花青素对白色念珠菌的抑菌作用,通过观察其对生物膜活性的影响,探讨其在口腔微生态中变化的意义。方法采用MTT法确定葡萄籽原花青素体外对白色念珠菌的抑菌作用,激光共聚焦显微镜观察不同浓度药物作用后的效果,并进行红绿荧光染色定量分析。结果与阴性对照组相比,最小抑菌浓度为32 mg/m L,在所实验的浓度范围内随着药物浓度的增加抑菌性逐渐增大,CLSM观察,葡萄籽原花青素作用于白色念珠菌生物膜后可使生物膜内活菌比例下降,生物膜活性降低。结论葡萄籽原花青素对白色念珠菌起到了明显的抑制作用。     

家蝇Phormicin蛋白表达及对白色念珠菌的抑菌活性分析

防御素是一类具有广普抗菌活性的阳离子抗菌肽,而家蝇(Musca domestica)的Phormicin属于防御素超家族.白色念珠菌(Candida albicans)是临床上常见的引起人体感染的条件致病真菌.随着免疫缺陷病、糖尿病等疾病发生率的增加,在病人体内植入设备的白色念珠菌残留及附带感染日益成为临床感染的常见类型.本研究制备了家蝇Phormicin A、Phormicin B的原核表达蛋白,将其作用于白色念珠菌.微量液体稀释法测定了其最小抑菌浓度为2.5mmol/L和1.875mmol/L.进一步绘制了其对白色念珠菌的时间杀菌曲线.结果显示,二者对白色念珠菌都具有一定的抑菌效果.本研究为进一步探索Phormicin参与家蝇天然免疫和揭示家蝇抗真菌防御中的机制提供理论参考,为开发多肽类抗真菌药物提供线索.     

家蝇抗真菌肽衍生物MAF-1C抗白色念珠菌活性研究

[目的]探究家蝇抗真菌肽衍生物MAF-1C结构特点及抗白色念珠菌活性。[方法]采用氨基酸替代法设计MAF-1A衍生肽MAF-1C,生物信息学分析其理化特性,微量液体稀释法、菌落计数法检测体外抗白色念珠菌活性,扫描电镜观察对菌细胞结构的影响。[结果]MAF-1C为非跨膜阳离子线状多肽,带8个正电荷,二级结构以α螺旋为主。对白色念珠菌具有抗菌活性,MIC、MFC值分别为0.2 mg/m L和0.5 mg/m L,2×MIC浓度的MAF-1C从作用一开始就发挥抗菌作用,其作用后白色念珠菌细胞表面出现明显的凹陷、裂痕,之后细胞皱缩、裂解死亡,并且菌细胞损伤程度与肽浓度及作用时间呈正相关。[结论]MAF-1C结构参数及对白色念珠菌的抗菌活性均显著优于模板肽,对比模板肽改造后的肽阳离子电荷增加了6个,总平均疏水值(GRAVY)由-1.081升高到0.588,不稳定系数由42.27降低到5.83,MIC由0.6 mg/m L降低到0.2 mg/m L,MFC由0.7 mg/m L降低到0.5 mg/m L,其可通过破坏白色念珠菌细胞结构发挥抗菌作用。     

茶多酚对白色念珠菌致病因子CDR1、CDR2、MDR1的研究

目的研究茶多酚对白色念珠菌生物膜抑菌效果及对某些致病因子转录或表达的影响。方法 96孔板建立白色念珠菌生物膜模型,MTT法计算茶多酚对白色念珠菌生物膜的抑制率;RT-PCR技术检测在不同药物浓度作用下白色念珠菌致病因子表达水平的变化。结果茶多酚对白色念珠菌生物膜的抑菌作用随其浓度的增大而增强。RT-PCR结果表明茶多酚抑制了致病因子CDR1、CDR2的表达,茶多酚浓度变化对MDR1的表达影响较小。结论茶多酚对白色念珠菌生物膜具有抑制作用,并在白色念珠菌毒力因子CDR1、CDR2的表达过程中起到显著抑制作用,对MDR1的无抑制作用。     

白芷对白色念珠菌毒力因子作用的初步研究

目的研究白芷乙醇提取物对白色念珠菌生物膜抑菌效果及对毒力因子CPH1、EFG1转录或表达的影响。方法体外建立白色念珠菌生物膜模型,MTT法计算白芷乙醇提取物对白色念珠菌生物膜的抑制率;激光共聚焦观察不同浓度白芷乙醇提取物对相同时间白色念珠菌生物膜的抑菌效果;RT-PCR技术检测在不同药物浓度作用下白色念珠菌毒力因子CPH1、EFG1表达水平的变化。结果白芷乙醇提取物对白色念珠菌生物膜的抑菌作用随其浓度的增大而增强。激光共聚焦观察显示白芷乙醇提取物使生物膜内活菌死菌比例下降。RT-PCR结果表明白芷乙醇提取物在药物浓度为50、25、12.5mg/mL时抑制白色念珠菌毒力因子CPH1、EFG1mRNA的表达,在浓度为50mg/mL时则完全抑制毒力因子EFG1mRNA的表达。结论白芷不仅对白色念珠菌生物膜具有明显的抑制作用,而且对白色念珠菌毒力因子CPH1、EFG1表达过程产生抑制作用。     

和厚朴酚通过ROS的积累和破坏细胞膜杀死白色念珠菌（英文）

【目的】研究在体外情况下和厚朴酚对白色念珠菌的抑制作用及其可能机制。【方法】采用微量稀释法测定和厚朴酚对白色念珠菌的最低抑菌浓度(MIC80)和最低杀菌浓度(MFC);用透射电镜观察不同浓度和厚朴酚对白色念珠菌超微结构的影响;采用Annexin V-FITC/PI染色法分析不同浓度和厚朴酚对白色念珠菌细胞凋亡的影响;用DCFH-DA染色法测定不同浓度和厚朴酚对白色念珠菌细胞内活性氧积累的影响;用JC-1染色法分析不同浓度和厚朴酚对白色念珠菌线粒体膜电位的影响;用碘化丙啶染色、考马斯亮蓝G-250染色检测和厚朴酚对白色念珠菌细胞膜通透性的影响;通过测定加入麦角甾醇后,和厚朴酚对白色念珠菌的抑制作用的变化,检测和厚朴酚对白色念珠菌细胞膜的影响。【结果】和厚朴酚对白色念珠菌具有很强的抑制作用,MIC和MFC分别为16μg/mL和32μg/mL。对白色念珠菌细胞壁、细胞膜和胞浆均有明显的影响。和厚朴酚是通过增加活性氧的产生和破坏线粒体功能来诱导白念珠菌的细胞凋亡和坏死。它也影响细胞膜的通透性,这可能和细胞壁的破坏和与麦角固醇的结合有关。【结论】和厚朴酚通过产生活性氧并伴随着一系列的细胞损伤这种复杂的机制从而对白色念珠菌产生抑制作用,使和厚朴酚成为一种潜在的抗真菌药物。     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Molecular phylogeny of Phebalium (Rutaceae: Boronieae) and related genera based on the nrDNA regions ITS 1+2

Parsimony analyses of the internal transcribed spacer regions of nuclear ribosomal DNA (ITS 1 & ITS 2) for 38 taxa sampled from the Phebalium group (Rutaceae: Boronieae) and two outgroups confirm that, with the exception of Phebalium sensu stricto and Rhadinothamnus, six of the currently recognised genera within the group are monophyletic. The data indicate that Phebaliums. str. is paraphyletic with respect to Microcybe, and Rhadinothamnus is paraphyletic with respect to Chorilaena. Rhadinothamnus and Chorilaena together are the sister group to Nematolepis. Drummondita, included as an outgroup taxon, clustered within the ingroup as sister to Muiriantha and related to Asterolasia.The phylogeny suggests that the evolution of major clades within a number of these genera (e.g. Phebalium) relates to vicariance events between eastern and south-western Australia. Leionema is an eastern genus, with the most basal taxon being the morphologically distinct Leionema ellipticum from northern Queensland. Leionema also includes one species from New Zealand, but this species (as with some others) proved difficult to sequence and its phylogenetic position remains unknown. Taxonomic changes at the generic level are recommended.The authors wish to thank Paul G.Wilson, PERTH, for advice and discussion, and Paul Forster, BRI, for collecting and providing material of Leionema ellipticum. The project was supported by a Melbourne University Postgraduate Award (to BM), the Australian Biological Resources Study (ABRS), Australian Systematic Botany Society and Wolf Den (Australia) Investments.     

New species and new combinations in Peruvian Orchidaceae

seventeen new species and combinations are proposed in the generaChondrorhyncha, Cischweinfia, Cochlioda, Eloyella, Encyclia, Kefersteinia, Koellensteinia, Macroclinium, Rodriguezia, Solenidiopsis, andStenia. All new species are illustrated. A key is provided for 2-flowered species ofMacroclinium, PeruvianSigmatostalix, and PeruvianStenia. Solenidium (Solenidiopsis) peruvianum Schltr. is lectotypified.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Phylogenetic investigations of Sordariaceae based on multiple gene sequences and morphology

The family Sordariaceae incorporates a number of fungi that are excellent model organisms for various biological, biochemical, ecological, genetic and evolutionary studies. To determine the evolutionary relationships within this group and their respective phylogenetic placements, multiple-gene sequences (partial nuclear 28S ribosomal DNA, nuclear ITS ribosomal DNA and partial nuclear β-tubulin) were analysed using maximum parsimony and Bayesian analyses. Analyses of different gene datasets were performed individually and then combined to generate phylogenies. We report that Sordariaceae, with the exclusion Apodus and Diplogelasinospora, is a monophyletic group. Apodus and Diplogelasinospora are related to Lasiosphaeriaceae. Multiple gene analyses suggest that the spore sheath is not a phylogenetically significant character to segregate Asordaria from Sordaria. Smooth-spored Sordaria species (including so-called Asordaria species) constitute a natural group. Asordaria is therefore congeneric with Sordaria. Anixiella species nested among Gelasinospora species, providing further evidence that non-ostiolate ascomata have evolved from ostiolate ascomata on several independent occasions. This study agrees with previous studies that show heterothallic Neurospora species to be monophyletic, but that homothallic ones may have a multiple origins. Although Gelasinospora and Neurospora are closely related and not resolved as monophyletic groups, there is insufficient evidence to place currently accepted Gelasinospora and Neurospora species into the same genus.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Changes of dung beetle communities from rainforests towards agroforestry systems and annual cultures in Sulawesi (Indonesia)

Little is known about how tropical land-use systems contribute to the conservation of functionally important insect groups, including dung beetles. In a study at the margin of Lore Lindu National Park (a biodiversity hotspot in Central Sulawesi, Indonesia) dung-beetle communities were sampled in natural forest, young secondary forest, agroforestry systems (cacao plantations with shade trees) and annual cultures (maize fields), each with four replicates (n = 16 sites). At each site we used 10 pitfall traps, baited with cattle dung, along a 100 m transect for six 3-day periods. The number of trapped specimens and species richness at the natural forest sites was higher than in all land-use systems, which did not significantly differ. Each land-use system contained, on average, 75% of the species richness of the natural forest, thereby indicating their importance for conservation. However, a two-dimensional scaling plot based on NESS indices (m = 6) indicated distinct dung beetle communities for both forest types, while agroforestry systems and annual cultures exhibited a pronounced overlap. Mean body size of dung beetles was not significantly influenced by land-use intensity. Five of the six most abundant dung beetle species were recorded in all habitats, whereas the abundance of five other species was significantly related to habitat type. Mean local abundance and number of occupied sites were closely correlated, further indicating little habitat specialisation. The low dung beetle diversity (total of 18 recorded species) may be due to the absence of larger mammals in Sulawesi during historical times, even though Sulawesi is the largest island of Wallacea. In conclusion, the dung beetle fauna of the lower montane forest zone in Central Sulawesi appears to be relatively robust to man-made habitat changes and the majority of species did not exhibit strong habitat preferences.     

安徽牯牛降的丝孢菌Ⅰ

本文报导作者采自安徽枯牛降自然保护区的18种丝孢菌,分属于5个属,其中有3个新种:牛皮冻生尾孢(Cercospora paederiicola),山鸡椒假尾饱(Pseudocercospora litseae-cubebae),鸡血藤生假尾孢(P. millettiicola)和2个中国新纪录。文中对新种进行了描述及绘图,新记录种作了简要说明。研究的标本保存在中国科学院微生物研究所真菌标本室(HMAS)。