An amalgam of pathogenic and beneficial endophytic fungi colonizing four Dendrobium species from Meghalaya,India

Endophytic fungi are known to play an important role in driving the evolution of plants by conferring adaptational advantages to their host through the production of secondary metabolites and phytohormones. In this study, we evaluated the diversity and phylogenetic relationship of endophytic fungal communities from four Dendrobium species viz., Dendrobium chrysanthum, Dendrobium heterocarpum, Dendrobium hookerianum, and Dendrobium longicornu of Meghalaya, India. A total of 51 culturable endophytic fungi were isolated from the four selected orchid species. The isolates were identified based on nuclear large subunit sequences into 33 species. Approximately 91% of the isolates showed affinity to Ascomycetes, while 9% of the isolates showed BLAST search similarity to Basidiomycetes. The most common genera were Trichoderma and Xylaria. The most prevalent genera were Fusarium, which was detected in all the four Dendrobium species followed by Diaporthe, which was present in three Dendrobium species viz., D. chrysanthum, D. hookerianum, and D. heterocarpum. The Shannon index value of endophytic fungal communities was the highest in D. chrysanthum (2.66), while D. longicornu (1) had the highest Evenness index. The present study revealed that endophytic fungi in these orchids are an amalgam of pathogenic and beneficial fungi, which have, at the least, switched their lifestyle to asymptomatic endophyte in their host. To our knowledge, this is the first such report on the diversity of endophytic fungi in the four selected Dendrobium species from Meghalaya, India.     

三株长蠕孢属真菌对苗期毛脉酸模根中生物活性成分的影响

目的研究3株长蠕孢属真菌对苗期毛脉酸模根中7种生物活性成分的影响。方法通过长蠕孢属真菌孢子悬浮液对苗期毛脉酸模叶面进行处理,使毛脉酸模感染长蠕孢菌。采用高效液相色谱法对苗期毛脉酸模根样品中的7种生物活性成分进行测定,并对其生物活性成分的量和产量分别进行了方差分析。结果3株长蠕孢属真菌叶面侵染苗期毛脉酸模对其根中白藜芦醇苷、大黄酚苷、大黄素甲醚的量在整个处理期内都没有显著性影响;对其根中白藜芦醇、酸模素、大黄素、大黄酚的量有显著性影响。结论从生物活性成分白藜芦醇的角度考虑,选择大斑病长蠕孢001进行诱导处理,处理时间不宜超过40d。本实验结果将为中药种植及天然药物的开发提供新的思路及理论基础。     

着色真菌蟾蜍分离株小鼠致病试验研究

目的：观察着色真菌蟾蜍分离株的致病性。方法：抽样取着色真菌蟾蜍分离株与标准人分离株对照，制成菌悬液，做小鼠腹腔接种，观察接种后小鼠的外观表现，做菌种逆培养和观察内脏病理变化。结果：蟾蜍分离株卡氏枝孢霉、疣状瓶霉、裴氏着色霉和甄氏外瓶霉与病人分离株一样，在接种28天后，均可从小鼠脏器逆培养出接种的菌种，并引起内脏病变，形成结核样肉芽肿，肉芽肿内均可查见棕黄色硬壳小体。而瓶霉和外瓶霉属菌种逆培养结果均阴性。结论：从野生蟾蜍分离出的卡氏枝孢霉、疣状瓶霉，裴氏着色霉和甄氏外瓶霉与病人分离株一样，对小鼠有致病性，故可能是人着色芽生菌病的致病菌。     

The spectrum of opportunistic filamentous fungi present in the CBS culture collection

The mould collection of the Centraalbureau voor Schimmelcultures, Baarn, The Netherlands, was screened for isolates originating from warm-blooded animals. The range of species indicates that distribution of clinically relevant, pathogenic or opportunistic strains over the fungal kingdom is non-random. Some opportunistic fungi possess adaptations to life under hostile environmental conditions, enabling them to survive inside the human body. Presence of melanin or carotene seems to be an important virulence factor. Opportunistic fungi which sporulate in submersion are able to disseminate or cause severe local mycoses when the aspecific immune system of the host is impaired. Mycoses caused by a few dimorphic fungi, mostly in their natural ecological niche living in association with vertebrates, are promoted by specific immune deficiencies.     

白色念珠菌感染的分子生物学诊断研究进展

综述了白色念珠菌感染的分子生物学诊断研究进展，包括核型分析，限制性片段长度多态性分析，特异的ＤＮＡ探针及ＰＣＲ等方法。     

Accumulation of gliotoxin, a cytotoxic mycotoxin from Aspergillus fumigatus, in blue mussel (Mytilus edulis).

A strain of Aspergillus fumigatus has been isolated from sediments of a mussel bed. When cultured in hyper saline conditions (with sea-water), it produces a cytotoxic and immunosuppressive toxin, gliotoxin, which is excreted in an exudate. In order to know if this toxin could represent a risk for shellfish consumers, an experiment of bioaccumulation of gliotoxin in mussel has been carried out. After 6 days of contamination, toxin was accumulated in the meat of the mussels, at a level up to 2.9 microg/mg of extract weight, with a mode of contamination different to the classical digestive process described for a majority of marine toxins, but similar to the contamination mode of domoic acid.     

Keratinolytic fungi in sewage sludge applied to devastated urban soil. A preliminary experiment

The qualitative and quantitative (q/q) changes of keratinolytic fungi in soil mixtures with added sewage sludge were examined during a preliminary reclamation experiment. Sludge before land application was characterized by the weak growth of keratinolytic fungi. In devastated urban soil, abundant fungal growth was observed. Over a 19‐month reclamation period, decreasing frequency of Chrysosporium concurrent with the enrichment of the mixture with the geophilic dermatophytes Arthroderma quadrifidum and A. uncinatum were clearly seen. The results are discussed with respect to possible ecological factors influencing the occurrence of keratinolytic fungi in the materials examined. The public health risk associated with the application of sewage sludge for reclamation is also discussed.     

伊曲康唑不良反应的国内文献综述

目的：了解伊曲康唑的不良反应及安全性。资料与方法：手工检索《中华皮肤科杂志》等3种中文专业期刊，从对照试验的文献中提取治疗例数和各种不良反应例数，计算发生率。结果：共有14725例涉及有关安全性的报道。伊曲康唑不良反应总的发生率约为1．57％。结论：伊曲康唑较为安全。