三种抗菌织物对红色毛癣菌和须癣毛癣菌生长抑制效应的实验研究

目的通过分析汉麻织物、含纳米银锦纶纤维织物和无机银抗菌整理后棉布对红色毛癣菌、须癣毛癣菌生长的影响,探讨抗菌织物对皮肤癣菌的抑制作用。方法制备红色毛癣菌、须癣毛癣菌的菌悬液,分别接种于上述抗菌织物,并紧贴在PDA培养基表面培养,每12 h观察菌落形态及大小,根据菌落平均直径绘制生长曲线。结果三种抗菌织物上24 h内均未见菌落生长。①汉麻布样上,红色毛癣菌和须癣毛癣菌菌落直径分别在36-84 h、36-72 h时间区间内小于棉布组,差异有显著性（P〈0.05）,之后与棉布组渐趋一致。②含纳米银锦纶织物上,在36-108 h内红色毛癣菌菌落直径小于棉布组,差异有显著性（P〈0.05）,120 h时已无显著差异（P〉0.05）,须癣毛癣菌在48 h后才开始生长,在60-108 h区间内菌落直径小于棉布对照（P〈0.05）。③无机银抗菌整理后棉布样上,红色毛癣菌和须癣毛癣菌分别在48 h和60 h后才开始生长,在120 h以内两种皮肤癣菌菌落直径均小于棉布组,差异有显著性（P〈0.05）。结论三种抗菌织物与棉布相比较,在一定时间区间内,均可显著抑制红色毛癣菌和须癣毛癣菌的生长,尤其是经无机银抗菌整理后棉布的抑菌更有效和持久。     

须癣毛癣菌肉芽肿1例

须癣毛癣菌肉芽肿,是由须癣毛癣菌侵入皮肤真皮导致的一种浅部真菌的深在感染。也称为Majocchi肉芽肿,毛囊周围肉芽肿,临床上较少见。作者发现1例,现报告如下。     

须癣毛癣菌所致面部体癣继发癣菌疹1例

报道1例由须癣毛癣菌引起面部体癣后继发的癣菌疹。患者女,10岁,因右眶周红斑、鳞屑10 d就诊。鳞屑直接镜检查见菌丝,培养生长的菌落鉴定为须癣毛癣菌。内服特比萘芬、外用萘替芬酮康唑乳膏治疗8 d后面部及颈胸部出现片状红斑,考虑为癣菌疹,加服抗过敏、抗炎药物(左西替利嗪、复方甘草酸苷片)、外用卤米松/三氯生软膏14 d后皮损消退。     

须癣毛癣菌致成人眉区脓癣1例

报告1例由须癣毛癣菌引起的眉毛区域脓癣。患者女性,46岁,左眉部周围红斑1个月。致病菌株经真菌学鉴定为须癣毛癣菌。给予盐酸特比萘芬250mg/d口服,硝酸舍他康唑软膏外用,治疗1个月后皮损完全愈合。     

须癣毛癣菌的形态学及分子生物学鉴定

目的对临床上分离自人(36株)及狐狸(5株)的须癣毛癣菌菌株进行新的分类系统鉴定,并检测传统的分类方法是否能满足临床鉴定需要。方法①观察原鉴定为须癣毛癣菌菌株在沙氏培养基、1%蛋白胨培养基、溴甲酚紫乳固体葡萄糖琼脂培养基(BCP-MSG)和显微镜下形态学及尿素酶、毛发穿孔等生理学试验表现。②通过ITS区段和LSU区段分子生物学序列分析进行新的分类系统的菌种分型,并对传统形态学和生理学鉴定方法进行检测。结果①41株须癣毛癣菌形态学及生理学试验符合须癣毛癣菌(38株)和红色毛癣菌(3株)菌落的特点。②ITS区段序列分析发现ITS区段能将须癣毛癣菌和红色毛癣菌准确的鉴定到种,但无法明确其种内分型;而LSU区段序列分析可对36株(36/38)须癣毛癣菌有性型做出明确的鉴定。结论传统实验室鉴定方法仍具有其有效性及可靠性。通过分子生物学鉴定,临床分离的须癣毛癣菌皆为指(趾)间毛癣菌(38/38),而LSU区段的序列分析鉴定狐狸源性菌株皆属于本海姆节皮菌,有别于大多数人源性菌株有性型为万博节皮菌,对于须癣毛癣菌的菌种鉴定更优于ITS区段,但分子生物学试验还需结合形态学的观察,才能够对菌种做出正确的鉴定。     

蒺藜TTS-12对须癣毛癣菌的体内外抗菌活性研究

为考察天然产物蒺藜TTS-12对须癣毛癣菌的体外和体内抗菌活性,本研究采用CLSI的M38-A2方案对须癣毛癣菌进行最小抑菌和杀菌浓度的检测,选取多重指标考察TTS-12对须癣毛癣菌的抑菌作用;建立豚鼠感染须癣毛癣菌豚鼠体癣模型,分组给药观察低、中、高剂量蒺藜TTS-12凝胶剂对豚鼠体癣模型在背部病变程度评分,病灶皮肤真菌培养阴性率,病灶皮肤病理变化的影响。结果发现,TTS-12对须癣毛癣菌的标株菌株的MIC值为1μg/mL,MFC为8μg/mL,其还能够显著抑制须癣毛癣菌的菌丝生长,浓度为4μg/mL的TTS-12作用15天时,菌丝生长抑制率已经高于60%,且对须癣毛癣菌的孢子萌发抑制作用呈时间和浓度依赖性。动物实验中,低、中、高剂量蒺藜TTS-12凝胶剂均能显著降低背部病变程度评分(P<0.01),中、高剂量能增高病灶皮肤真菌培养阴性率(P<0.05),病灶皮肤HE染色切片表明高剂量组棘层肥厚降低,背部炎症减弱,使角质层恢复正常。以上结果表明蒺藜TTS-12在体外抗须癣毛癣菌和豚鼠体癣模型中均有较好的活性。     

须癣毛癣菌致儿童脓癣1例

报道由须癣毛癣菌引起的儿童头部脓癣1例.患儿为4岁幼女,因头皮部丘疹1个月,脓肿4d就诊.内服青霉素V钾无效.取断发镜检查见发外真菌孢子,培养鉴定为须癣毛癣菌,细菌培养为棒状杆菌.经内服和外用特比萘芬抗真菌,静脉输入头孢噻肟钠联合克林霉素及万古霉素抗细菌治疗,12d后脓肿减轻,细菌培养阴转,但真菌培养仍阳性,继续抗真菌治疗2个月后皮损消退,真菌检查阴性.     

须癣毛癣菌致人兔共患体癣3例

报道须癣毛癣菌引起的人兔共患体癣3例.患者皮损均为环状红斑丘疹,上覆鳞屑,炎症明显,伴瘙痒,均与兔子有密切接触史,且兔子均有明显皮损.取患者及兔子的皮屑真菌镜检及培养,鉴定为须癣毛癣菌,经口服及外用抗真菌药物后治愈.     

须癣毛癣菌分类进展

须癣毛癣菌以往被视为单一的菌种,然而随着形态学和分子生物学等试验的研究,逐步探索并明确须癣毛癣菌的菌间分类及有性型的关系.本文综述了须癣毛癣菌在亲宿主性、交配试验、形态学和生理学试验、及分子生物学试验所进行的研究.     

致脓癣的须癣毛癣菌鉴定及体外药敏试验

须癣毛癣菌是皮肤癣菌病中常见的致病真菌之一,其分型复杂,具有多个变种和有性型,引起脓癣的常为亲动物性分离菌。从形态学角度难以明确区分不同种型,需要从分子生物学角度加以鉴定。rDNA序列测定是目前最常用于真菌鉴定的一种方法。我们从一脓癣患儿头部分离出一株须癣毛癣菌,对其形态学、rDNA序列和体外对抗真菌药物的敏感性进行了研究。     

Periodic disorder along ramie cellulose microfibrils

Small angle neutron scattering studies have been carried out on cellulose fibers from ramie and Populus maximowicii (cotton wood). Labile hydrogen atoms were replaced by deuterium atoms, in water-accessible disordered regions of the fibers, to increase the neutron scattering contrast between the disordered and crystalline regions. A meridional Bragg reflection, corresponding to a longitudinal periodicity of 150 nm, was observed when scattering collected from hydrogenated and deuterated dry ramie fibers was subtracted. No Bragg reflection was observed with the cotton wood fibers, probably because of lower orientation of the microfibrils in the cell wall. The ramie fibers were then subjected to electron microscopy, acid hydrolysis, gel permeation chromatography, and viscosity studies. The leveling off degree of polymerization (LODP) of the hydrolyzed samples matched exactly the periodicity observed in the diffraction studies. The weight loss related to the LODP was only about 1.5%, and thus, the microfibrils can be considered to have 4-5 disordered residues every 300 residues.     

Enzyme-retting of flax and characterization of processed fibers

Enzyme-retting formulations consisting of Viscozyme L, a pectinase-rich commercial enzyme product, and ethylenediaminetetraacetic acid (EDTA) were tested on Ariane fiber flax and North Dakota seed flax straw residue. Flax stems that were crimped to disrupt the outer layers were soaked with various proportions of Viscozyme-EDTA solutions, retted, and then cleaned and cottonized with commercial processing equipment. Fiber properties were determined and crude test yarns were made of raw and Shirley cleaned flax fibers and cotton in various blend levels. Cleaned fibers were obtained from both seed and fiber flax types, but with variations due to treatment. Retting formulations produced fibers having different properties, with enzyme levels of 0.3% (v/v as supplied) giving finer but weaker fibers than 0.05% regardless of EDTA level. Experimental yarns of blended flax and cotton fibers varied in mass coefficient of variation, single end strength, and nep imperfections due to sample and formulation. With cost and fiber and yarn quality as criteria, results established a range in the amounts of components comprising retting formulations as a basis for further studies to optimize enzyme-retting formulations for flax. Under conditions examined herein, Viscozyme L at 0.3% (v/v) plus 25 mM EDTA produced the best test yarns and, therefore, established a base for future studies to develop commercial-grade, short staple flax fibers for use in textiles.     

Engineering of PHB synthesis causes improved elastic properties of flax fibers

Flax stem is a source of fiber used by the textile industry. Flax fibers are separated from other parts of stems in the process called retting and are probably the first plant fibers used by man for textile purposes (1). Nowadays flax cultivation is often limited because of its lower elastic property compared to cotton fibers. Thus the goal of this study was to increase the flax fiber quality using a transgenic approach. Expression of three bacterial genes coding for beta-ketothiolase (phb A), acetoacetyl-CoA reductase (phb B), and PHB synthase (phb C) resulted in poly-beta-hydroxybutyrate (PHB) accumulation in the plant stem. PHB is known as a biodegradable thermoplastic displaying chemical and physical properties similar to those of conventional plastics (i.e., polypropylene). The fibers isolated from transgenic flax plants cultivated in the field and synthesizing PHB were then studied for biomechanical properties. All measured parameters, strength, Young's modulus, and energy for failure of flax fibers, were significantly increased. Thus the substantial improvement in elastic properties of fibers from the transgenic line has been achieved. Since the acetyl CoA, substrate for PHB synthesis, is involved not only for energy production but also for synthesis of many cellular constituents, the goal of this study was also the analysis of those metabolites, which interfere with plant physiology and thus fiber quality. The analyzed plants showed that reduction in lignin, pectin, and hemicellulose levels resulted in increased retting efficiency. A significant increase in phenolic acids was also detected, and this was the reason for improved plant resistance to pathogen infection. However, a slight decrease in crop production was detected.     

亚麻荠对小菜蛾幼虫取食和成虫行为反应的影响

亚麻荠是一种很少有害虫危害的油料作物。用室内生测和Y 型嗅觉仪研究了亚麻荠对小菜蛾Plutella xylostella幼虫取食和成虫行 为反应的影响。以甘蓝作对照,用亚麻荠叶片喂养的小菜蛾初孵幼虫3天后校正死亡率为79 .2%,显示了较强的致死作用;喂养小菜蛾3龄幼虫至化蛹,其存活率、化蛹率、蛹重及成 虫寿命都显著降低,表明亚麻荠对小菜蛾幼虫的生长发育有不利影响。在幼虫的取食选择实 验中,有甘蓝叶供选择时,小菜蛾幼虫不取食亚麻荠;在无可选择的情况下,小菜蛾幼虫也 取 食亚麻荠叶片,但取食量很小,与取食甘蓝叶的量相比,差异极显著。行为反应测试表明, 小菜蛾成虫对甘蓝和亚麻荠植株的挥发物都有明显的趋性反应,与对照（净化空气）相比, 差异极显著,而在甘蓝和亚麻荠之间无选择性。说明小菜蛾成虫对亚麻荠植株的挥发物具有 较强的定向反应。     

Easy alignment and effective nucleation activity of ramie fibers in injection-molded poly(lactic acid) biocomposites

The poly(lactic acid) (PLA)/ramie fiber biocomposites were fabricated, which exhibited considerable reinforcement effect comparable to the glass fiber at the same loading. The attempts were made to understand the flow-induced morphology of ramie fibers and PLA crystals in the injection-molded PLA/ramie fiber biocomposites, thus revealing its relationship to biocomposite mechanical properties. The polarized optical microscopy (POM) and two-dimensional wide-angle X-ray diffraction (2D-WAXD) were for the first time used to determine the distribution of nature fibers, which interestingly showed the ramie fibers aligned well along the flow direction over the whole thickness of injection-molded parts, instead of skin-core structure. This easy alignment of ramie fibers during the common processing was ascribed to the intrinsically high flexibility of ramie fibers and strong interfacial interaction between PLA chains and cellulose molecules of ramie fibers. Both 2D-WAXD and differential scanning calorimeter (DSC) measurements suggested that the PLA matrix in its ramie biocomposites had rather high orientation degree and crystallinity, which was attributed to effective heterogeneous nucleation induced by ramie fibers and local shearing field in the vicinity of fiber surface. Remarkable improvement of mechanical and thermo-mechanical properties was achieved for PLA/ramie fiber biocomposites, without sacrifice of toughness and ductility. Addition of 30wt% ramie fibers increased the tensile strength and modulus of PLA/ramie fiber biocomposites from 65.6 and 1468 MPa for pure PLA to 91.3 and 2977 MPa, respectively. These superior mechanical properties were ascribed to easy alignment of ramie fibers, high crystallinity of PLA, and favorable interfacial adhesion as revealed by scanning electron microscopy (SEM) observation and theoretical analysis based on dynamic mechanical analysis (DMA) data.     

Biodegradation of chemically modified flax fibers in soil and in vitro with selected bacteria

The extent and rate of degradation of flax (Linum usitatissimum) fibers, both in the native state and after surface chemical modification (acetylation or poly(ethylene glycol), PEG, grafting), was investigated under laboratory conditions in two different biodegrading environments. Degradation of the fibers under aerobic conditions by the action of the microorganisms present in soil is assessed with the ASTM 5988-96 method by monitoring carbon dioxide evolution. In vitro biodegradation experiments were carried out by exposing the fibers to a pure culture of Cellvibrio fibrovorans bacteria and measuring the mass loss as a function of time. Despite the complexity of the system, the results of degradation in soil were satisfactorily reproducible, although the absolute rates were found to change in different experiments using the same soil. The degradation rate of acetylated fibers in soil nearly equals that of unmodified fibers, whereas in the pure culture, acetylated fibers biodegrade slower than native fibers. The opposite happens with the PEG-grafted fibers, which degrade slower than unmodified flax in soil and at a comparable rate upon in vitro exposure to the bacterial culture. The different biodegradation kinetics observed in the two biodegrading environments were attributed to differences of biocenoses, abiotic factors, and biodegradation assessing methods. Nevertheless, the final extent of biodegradation was the same for modified and unmodified fibers both in soil and in the pure culture, showing that the surface chemical modifications applied do not significantly affect biodegradability of the flax fibers.     

土壤镉污染对苎麻的生长毒害效应

通过微区定位试验 ,研究了土壤添加Cd对苎麻的生长毒害效应 .结果表明 ,高浓度Cd能够显著影响苎麻叶片中叶绿素总量及其组成 ,降低苎麻的光合生产力 .当土壤Cd浓度达到 14mg·kg-1时 ,苎麻地上部分生物产量降低 2 0 % ;Cd浓度达到 10 0mg·kg-1时 ,产量只有对照的一半 .影响苎麻经济产量的主导因子是有效分蘖数 .Cd对苎麻纤维品质的影响程度相对较小 .因此 ,将苎麻作为Cd污染区的替代作物栽植时 ,必须采取综合的土壤处理和培管技术 ,在降低土壤Cd的生物毒性的同时 ,提高苎麻对污染环境的耐受性 ,以实现较高的产量水平 .     

New biocomposites based on bioplastic flax fibers and biodegradable polymers

A new generation of entirely biodegradable and bioactive composites with polylactic acid (PLA) or poly‐ε‐caprolactone (PCL) as the matrix and bioplastic flax fibers as reinforcement were analyzed. Bioplastic fibers contain polyhydroxybutyrate and were obtained from transgenic flax. Biochemical analysis of fibers revealed presence of several antioxidative compounds of hydrophilic (phenolics) and hydrophobic [cannabidiol (CBD), lutein] nature, indicating their high antioxidant potential. The presence of CBD and lutein in flax fibers is reported for the first time. FTIR analysis showed intermolecular hydrogen bonds between the constituents in composite PLA+flax fibers which were not detected in PCL‐based composite. Mechanical analysis of prepared composites revealed improved stiffness and a decrease in tensile strength. The viability of human dermal fibroblasts on the surface of composites made of PLA and transgenic flax fibers was the same as for cells cultured without composites and only slightly lower (to 9%) for PCL‐based composites. The amount of platelets and Escherichia coli cells aggregated on the surface of the PLA based composites was significantly lower than for pure polymer. Thus, composites made of PLA and transgenic flax fibers seem to have bacteriostatic, platelet anti‐aggregated, and non‐cytotoxic effect. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012     

Resistance of cotton genotypes with different leaf colour and trichome density to Bemisia tabaci biotype B

The silverleaf whitefly (SLW), Bemisia tabaci biotype B, is considered one of the most serious pests in cotton worldwide. Its control is based on the use of pesticides, which are well‐known for their harmful effects on non‐target organisms and the environment. Here, we examined resistance of several cotton genotypes in terms of antixenosis and antibiosis against SLW. We also investigated the mechanisms of cotton genotypes involved in antixenosis against SLW by correlating with leaf trichome density and leaf colour parameters. In choice tests, we selected resistant cotton genotypes, Gossypium hirsutum palmeri, Aubum 56‐7, G. hirsutum morrilli, Mocó, Nu‐16 (B2 B3 B6)‐ 78/658, Paymaster 53‐816 and ‘IAC 23’, based on SLW oviposition and host preference. No‐choice tests with these genotypes confirmed antixenosis effect on SLW; however, no antibiosis resistance was detected in terms of developmental period and adult emergence rate. We found SLW oviposition preference was positively correlated with trichome density in the abaxial leaf surface, while adult host preference was mostly explained by high levels of green intensity of adaxial surface. Nevertheless, both SLW oviposition and host preference were negatively correlated with the lightness level of adaxial leaf surface. Probably, the underlying mechanism of cotton resistance is based on more than just these two parameters, but our study will contribute to selecting resistant cotton genotypes and helps to understand the mechanisms involved in cotton resistance against SLW. To our best knowledge, this is the first work showing that cotton leaf colour parameters are related to resistance against SLW.     

Enzymatic degumming of ramie bast fibers

Bast fibers from ramie (Boehmeria nivea) were treated with cell-free culture supernatants from an Amycolata sp. and a recombinant Streptomyces lividans strain expressing the Amycolata pectate lyase to investigate the degumming effects of different extracellular polysaccharide-degrading enzymes. Culture supernatants from the Amycolata sp. with high pectate lyase activities were most effective in fiber separation and reduced the gum content of ramie fibers by 30% within 15 h. Xylanase activity produced by the Amycolata sp. contributed little to the degumming. Electron micrographs showed that the crude pectate lyase from the Amycolata sp. removed plant gum more efficiently from decorticated ramie bast fibers than the purified enzyme. Similarly, degumming with the crude enzyme of the Amycolata sp. and the recombinant S. lividans strain for 24 h resulted in fibers with a residual gum content of 14.7 and 17.3%, respectively. Degumming with the crude enzyme of the recombinant Streptomyces strain was slightly improved by the addition of a commercial pectinesterase. No significant degumming was observed with the crude enzyme from an S. lividans strain that did not produce the Amycolata pectate lyase. These results indicate that the pectinolytic activity of the Amycolata sp. plays an active role in degumming of ramie bast fibers.