基于高通量测序技术研究药食两用薏苡仁中污染真菌多样性

目的:调查药食两用薏苡仁中污染真菌多样性,为其安全使用提供参考依据。方法:收集薏苡仁样品18批,提取真菌DNA并扩增ITS2序列,基于Illumina MiSeq PE250平台进行高通量测序。结果:共检测到4门18纲44目99科149属的真菌,子囊菌门Ascomycota是最优势菌门,镰刀菌属Fusarium(3.05%~60.32%)是属水平最优势属,其次是曲霉属Aspergillus(2.20%~45.44%)、白僵菌属Beauveria(0.07%~63.21%)、链格孢属Alternaria(0.80%~11.92%)、Arachnomyces(0.03%~39.36%)和青霉属Penicillium(0.24%~8.03%)。此外,共检测到5种潜在产毒真菌,分别是烟曲霉A.fumigatus、土曲霉A.terreus、梨孢镰刀菌F.poae、囊状青霉P.capsulatum和展青霉P.paxilli。结论:高通量测序技术可以快速有效地检测薏苡仁中污染真菌种类,为薏苡仁污染真菌毒素提供风险预警。     

Liquid‐based cytology of pigmented phaeohyphomycotic lesion of the palm masquerading as a metastatic tumor

Phaeohyphomycosis is a chronic subcutaneous fungal infection caused by dematiaceous fungi, commonly involving the extremities, which present as single or multiple lesions mimicking a benign tumor. Fine‐needle aspiration cytology (FNAC) is an easy method for the diagnosis of the lesion. Morphology of the fungus is characteristic with no difficulty for cytopathologist for identification; with a close differential diagnosis of Candida and Aspergillosis. The special stains like periodic acid schiff (PAS) highlights the fungus and the Masson Fontana confirm the melanin pigment and dematiaceous nature of the fungi. Liquid‐based cytology (LBC) preparation of the aspirated material was attempted, which is not usually performed on day to day basis. However, in our case the conventional smears were better for appreciating the fungal morphology.     

Antioxidantive activities and gastrodin determination of extracts of endophytic fungi isolated from Gastrodia elata Bl.

Gastrodia elata Bl. is a traditional Chinese herbal medicine with special pharmacological effects on headache and numbness. However, its wild sources are now in short supply because of over-excavation. A total of 14 endophytic fungi were isolated from Gastrodia elata Bl collected from Yinjing, in which 10 strains were identified, including Neonectria, Ascomycota, Fusarium, Oidiodendron and Dothiorella. All crude extracts showed some degrees of antioxidant activities by T-AOC method and DPPH methods, especially those from Oidiodendron GeR6 and Ascomycota sp. GeR2, which might be attributed due to their high phenolic contents. However, only Oidiodendron GeR6 contained gastrodin (39.2 μg/g) as the host plant in the crude extracts. In conclusion, the notable activities of GeR6 indicated its medical use as a natural antioxidant agent, as well as substitutable use for Gastrodia elata Bl. in the future.     

Cerebral phaeohyphomycosis due to Cladophialophora bantiana in a French Guianese child

We report a case of cerebral phaeohyphomycosis, a fungal brain infection due to a dark (dematiaceous) fungi in a 6-year-old French Guyanese boy. The child presented fever and drowsiness due to several paraventricular brain abscesses. Neurological surgeries were performed to reduce intracranial hypertension and to obtain abscess biopsies. Mycological cultures of intraoperative samples led to the diagnosis of cerebral phaeohyphomycosis due to Cladophialophora bantiana. The patient neurological status deteriorated and remained critical after several weeks of combination antifungal therapy with voriconazole 8 mg/kg/day, liposomal amphotericin B 10 mg/kg/day and flucytosine 200 mg/kg/day. A complete surgical resection was not possible because of multiple small abscesses. A multidisciplinary ethical staff decided on home medical care with palliative ventriculoperitoneal shunt, nasogastric feeding and analgesics. One year later, the patient's neurological condition had improved and cerebral lesions had regressed, while he had not received any antifungal treatment but only traditional medicines. Cerebral phaeohyphomycosis are rare diseases affecting immunocompromised but also apparently non-immunocompromised patients, as in this case. A complete surgical resection is not always possible and mortality rates are high in spite of treatments with a combination of antifungals. The diagnosis may be difficult because of these dematiaceous fungi's slowly growing and their potential pathogenicity for laboratory staff.     

可见光连续环境消毒系统对手术室消毒前后菌群生物气溶胶浓度的影响

目的探讨可见光连续环境消毒系统(CED)对手术室真菌和细菌气溶胶浓度的影响以及与环境因素的相关性。方法以焦作市第二人民医院5间手术室作为研究对象,分别对CED应用前后手术室内生物气溶胶浓度进行检测,并进行真菌和细菌培养,将检测结果进行比较,并与同期检测的消毒前后的室内温度和湿度相关性进行分析。结果消毒前和消毒后强化消毒模式下手术室内细菌、真菌浓度均较常规消毒模式降低,其次术后消毒完成后强化消毒模式下室内相对湿度相比常规消毒降低,差异均有统计学意义(P<0.05)。消毒过程中手术室的相对湿度标准值为(41.12±4.06)%,温度为(23.41±2.07)℃。经Spearman相关分析显示,消毒后真菌和细菌浓度与相对湿度标准值呈正相关(r=0.109,0.107;P=0.034,0.037),与温度无相关性(P>0.05)。结论常规消毒措施上加用可见光连续环境消毒系统能大大降低手术室的菌群生物气溶胶浓度,同时维持室内相对湿度减少细菌和真菌的繁殖。     

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.     

共生真菌对植物抗旱性的影响及机制研究进展

共生真菌分布广泛,与植物形成共生体。研究表明,某些共生真菌可以增强植物对生物胁迫和非生物胁迫,包括干旱、高温、矿物质失调和高盐的耐受性,从而使被内生真菌感染的植株比未感染植株对有限的资源更具竞争力而且生长得更好。植物共生真菌可以通过多样化途径来增强植物体的抗性机能,其提高抗旱性的机制主要表现在营养物质的吸收、植物的保护系统、激素调节、水解酶、水分代谢、相关基因表达、植物防御信号途径等方面。总结共生真菌提高植物耐旱性的机制研究进展,以使读者能全面、及时地了解这一领域的研究动态。     

曲霉菌对唑类抗真菌药物的耐药机制研究进展

侵袭性曲霉病是由致病曲霉菌引起的危及生命的真菌感染,主要致病菌为烟曲霉,而唑类抗真菌药物是临床治疗的首选。目前已上市的唑类抗真菌药物包括伊曲康唑,伏立康唑,泊沙康唑和伊沙康唑。然而,流行病学研究发现曲霉菌对唑类抗真菌药物的耐药率呈逐年上升趋势,给临床治疗造成了威胁。其中,Cyp51A蛋白突变、外排系统高表达以及环境耐药机制等多种因素都参与唑类抗真菌药物的耐药。因此,本文综述近年来有关曲霉菌对唑类抗真菌药物的耐药机制,以期为耐药监测、耐药菌控制和新药研发提供理论依据。     

一株西沙来源软珊瑚共附生真菌Penicillium citrinum（15XS112ZM-18）次级代谢产物及其活性研究

目的 研究1株中国西沙群岛永兴岛海域短指软珊瑚Sinularia cf. molesta共附生真菌Penicillium citrinum (15XS112ZM-18)的次级代谢产物及其生物活性。方法 利用TLC、硅胶柱层析、Sephadex LH-20凝胶柱层析、MPLC、半制备HPLC等方法,对菌株代谢物进行分离纯化;通过1H NMR及13C NMR等波谱学方法,结合相关文献数据,鉴定化合物结构;通过细胞毒活性模型评价化合物抗肿瘤活性。结果 从真菌P. citrinum (15XS112ZM-18)代谢产物中分离得到8个化合物,分别为：penicillenol A1 (1),penicillenol A2 (2),penicillenol B1 (3),penicillenol B2 (4),sorbicillin (5),2",3"-dihydrosorbicillin (6),ergosterol (7)和25–Hydroxyergosta-4,6,8(14),22-tetraen-3-one (8),其中化合物4在30 μmol L-1浓度下对HL-60细胞的抑制率达到100%,其IC50值为22.97 μmol L-1。