毛囊蠕形螨与皮脂蠕形螨基因组DNA的RAPD分析和序列比对

【目的】分析毛囊蠕形螨Demodex folliculorum（D.f.）和皮脂蠕形螨D. brevis（D.b.）基因组DNA的多态性, 对相关条带进行测序分析。【方法】采用改良小昆虫DNA提取法提取两种人体蠕形螨基因组DNA, 选择RAPD技术对其进行多态性分析, 将相关条带分别与pMD18-T载体连接, 克隆、测序后进行酶切鉴定和分析。【结果】毛囊蠕形螨共扩增15条带, 皮脂蠕形螨共扩增12条带;两种蠕形螨既有共有条带, 又有特异性条带;根据条带差异计算得到两种间的遗传距离为0.5556. 毛囊蠕形螨约800 bp处特异性条带测序结果显示, 序列片段长度为855 bp（GenBank登录号为FI277970）;特异性引物扩增和酶切鉴定均为毛囊蠕形螨所特有. 序列比对显示与阿糖胞苷DNA区域结合蛋白有46%的序列相似度。两种人体蠕形螨约300 bp处共有条带序列分析显示, 碱基序列均为341 bp（GenBank登录号分别为D.f. FI520176;D.b. FI520175）, 在第84和第165位点有2个碱基不同, 分别是A/G和C/T互换, 同源性高达99.4%. 但未发现有开放阅读框和相似度高的序列。 【结论】序列片段为855 bp的特异性条带为毛囊蠕形螨所特有;341 bp碱基序列为毛囊蠕形螨和皮脂蠕形螨所共有, 同源性高达99.4%. RAPD技术可用于两种人体蠕形螨基因组DNA的多态性分析和物种鉴定。     

益肤净抗面部蠕形螨病及其合并症的效果观察

本文报道了中药制剂——“益肤净”抗人体面部蠕形螨感染及其合并症效果的实验结果。用透明胶带法进行计数检查。202人蠕形螨阳性检出者用药后显示,“益肤净”药剂安全可靠、无毒无不良反应。对102人,其中实验组(给药组)70人,用药后检查,阳性者只有1人(占1.4％);同时检查对照组32人,阳性者5人(占12.5)。两组阴转率有明显差异(P<0.05),表明“益肤净”有明显的抗蠕形螨感染作用。在202例蠕形螨感染中,有17例合并毛囊炎,用药三次后即完全治愈。表明“益肤净”对毛囊炎有抗炎消肿作用。在治疗25例合并痤疮患者中,有23例痊愈,2例好转,证明“益肤净”亦有较好地健美皮肤效能,可兼作美容化妆用品使用。     

人体正常皮肤蠕形螨生态分布的研究

本文报道了大连地区人体正常皮肤蠕形螨的生态分布。共检查551人,阳性153人,定居率为27.8％,检出毛囊螨和皮脂螨共两种。用透明胶带定量计数检查法,研究蠕形螨在面部的分布,结果表明蠕形螨主要分布于颏、鼻、颊和额部位。对10例阳性者,在面部检出毛囊螨和皮脂螨共85只,其中颏31、鼻26、颊17、额11只螨,总定居度为每条胶带(6cm~2)2.1只螨,定居度以颏部位为最高,鼻、颊、额次之。     

动物蠕形螨活动情况初步观察

蠕形螨属Demodex是一类小型螨,寄生于人、家畜、野生动物的皮肤毛囊和皮脂腺内,不仅影响人类健康,并能引起家畜和珍稀动物的蠕形螨病,严重时可以导致动物死亡,目前尚无理想的特效药物。近年来,国内外学者对蠕形螨的形态结构,致病力,感染途径以及诊疗方法等作了不少研究,但对动物蠕形螨的活动情     

人体蠕形螨爬行的观察

蠕形螨为一永久性寄生螨类,寄生于人体及家畜、哺乳类动物,种类繁多,目前报道的有120余种,常见的有40余种,寄生人体的有毛囊蠕形螨(Demodex folliculorum)、皮脂蠕形螨(Demodex brevis)、毛囊蠕形螨中华亚种(Demodex folliculorum sinensis)等,分别寄生于毛囊及皮脂腺内。可引起酒渣鼻、痤疮、眼睑炎等皮肤病,在人群中感染甚为普遍,同时也证实了其感染途径是通过直接接触而传播。为此,对蠕形螨活动力的研究是进一步探索其传病机制及防治的重要环节。人体蠕形螨在不同温度、湿度及酸碱度条件下生活能力的观察曾有报道(Spickett,1961;陈国定,1985)。但对其爬行规律及速度至今尚未见报道,为此我们对蠕形螨在不同温度条件下的爬行规律及速度作了系统的观察。今将结果报道如下。     

宁夏固原市流浪犬寄生虫感染情况的调查

为了解城市流浪犬寄生虫感染情况,2011年7～9月对宁夏固原市随机选择3个小区的56只流浪犬进行了体表寄生虫和肠道寄生虫感染调查.结果显示,流浪犬体表寄生虫总感染率100％,其中54只犬检到犬栉首蚤,56只犬检到犬啮毛虱,26只犬检到犬疥螨,10只犬检到犬蠕形螨;33份粪样中检出虫卵,肠道寄生虫总感染率58.93％,其中20份检出犬弓首蛔虫卵,4份检出犬钩虫卵,9份检出泡状带绦虫卵.可见固原市城市流浪犬寄生虫感染相当普遍和严重,加强宠物饲养管理和流浪犬管理的工作刻不容缓.     

四川省自贡市幼儿园3至5岁儿童乙型肝炎病毒感染情况及影响因素

为了解四川省自贡地区3～5岁幼儿乙型肝炎病毒(HBV)感染情况,并探索与感染有关的因素,1985年调查了1167名幼儿,其HBV总感染率为41.13％,HBsAg阳性率12.68％。幼儿的HBV感染与母亲HBsAg阳性密切相关。共检查母亲409例,38例HBsAg阳性,其幼儿HBsAg阳性率为50％(19/38),HBsAg阴性的母亲371例,其幼儿HBsAg阳性率9.97％(37/371),来自HBsAg阳性母亲的阳性子女占33.3％(19/56)。1986年随访HBV易感幼儿448例,HBV年感染率为12.95％(58/448),HBsAg年阳转率3.79％。HBV年感染率与原幼儿班级HBsAg阳性率的高低有关。     

几种环境因素对两种人体蠕形螨生活力的影响

本文就寄生人体的毛囊蠕形螨和皮脂蠕形螨在实验室条件下,对其在各种温度、湿度和酸碱度中的存活时间进行了观察。 在36℃,高湿的环境中,毛囊蠕形螨和皮脂蠕形螨成虫的存活时间分别达94和95小时。高温与干燥对其生存不利。两种蠕形螨对酸性环境的耐受力都强于碱性环境,特别皮脂蠕形螨更为突出。     

薄荷油体外抗蠕形螨效果及杀螨机制

采用透明胶带粘贴过夜法获取2种人体蠕形螨,随机分组,观察不同浓度的薄荷油的杀虫效果,并在MoticDMB5图像采集软件系统下拍摄虫体在薄荷油作用下的虫体死亡过程。结果表明,薄荷油有很强的体外杀灭2种人体蠕形螨的作用,尤其对皮脂蠕形螨的杀灭作用显著。随着药物浓度的增加及作用时间的延长,蠕形螨死亡率增高。12.5%、3.125%分别是薄荷油体外杀灭毛囊蠕形螨和皮脂蠕形螨的最适杀螨浓度。薄荷油作用于蠕形螨,可见虫体收缩扭动,活动加剧,消化管剧烈收缩,毛囊蠕形螨和皮脂蠕形螨体壁均有渗出物外溢。虫体表现为兴奋—痉挛—失水—松弛—死亡的典型症状。薄荷油对人体蠕形螨的杀灭机制主要通过神经毒性和直接毒杀作用,造成虫体破裂脱水而死亡。薄荷油是一种极具开发潜能的高效的天然杀螨药。     

东北梅花鹿蠕形螨病

东北梅花鹿蠕形螨病是由于蠕形螨科(Demodccidae)蠕形螨属(Demodex)寄生虫侵袭鹿体的皮脂腺和毛囊而引起的一种寄生虫性疾病,也可以称之为“脂螨病”或“毛囊虫病”。 一些动物,甚而人类都能息蠕形螨病,但东北梅花鹿发生本病,至今尚未见有人报道。双辽县鹿场第二鹿队,现养东北梅花鹿332只,自     

Resistance status of the carmine spider mite,Tetranychus cinnabarinus and the twospotted spider mite,Tetranychus urticae to selected acaricides on strawberries

The carmine spider mite, Tetranychus cinnabarinus (Boisduval) and the twospotted spider mite, Tetranychus urticae Koch, are serious pests of strawberries and many other horticultural crops. Control of these pests has been heavily dependent upon chemical acaricides. Objectives of this study were to determine the resistance status of these two pest species to commonly used acaricides on strawberries in a year‐round intensive horticultural production region. LC₉₀ of abamectin for adult carmine spider mites was 4% whereas that for adult twospotted spider mites was 24% of the top label rate. LC_90s of spiromesifen, etoxazole, hexythiazox and bifenazate were 0.5%, 0.5%, 1.4% and 83% of their respective highest label rates for carmine spider mite eggs, 0.7%, 2.7%, 12.1% and 347% of their respective highest label rates for the nymphs. LC_90s of spiromesifen, etoxazole, hexythiazox and bifenazate were 4.6%, 11.1%, 310% and 62% of their respective highest label rates for twospotted spider mite eggs, 3%, 13%, 432,214% and 15% of their respective highest label rates for the nymphs. Our results suggest that T. cinnabarinus have developed resistance to bifenazate and that the T. urticae have developed resistance to hexythiazox. These results strongly emphasize the need to develop resistance management strategies in the region.     

The effect of interspecific mating on sex ratios in the twospotted spider mite and the Banks grass mite (Acarina: Tetranychidae)

Mixed populations of the twospotted spider mite (TSM),Tetranychus urticae (Koch), and the Banks grass mite (BGM),Oligonychus pratensis (Banks), occur on corn and sorghum plants in late summer in the Great Plains. Interspecific matings between these arrhenotokous species occur readily in the laboratory but yield no female offspring. The effect of interspecific mating on female: male sex ratios was measured by examining the F₁ progeny of females that mated with both heterospecific and conspecific males in no-choice situations. TSM females that mated first with BGM males and then with TSM males produced a smaller percentage of female offspring than TSM females that mated only with TSM males (43.1±5.8 and 78.9±2.8% females, respectively). Similarly, BGM females mated with heterospecific males and then with conspecific males produced fewer female offspring than females mated only with BGM males (55.7±5.2 and 77.5±2.5%, respectively). Lower female: male sex ratios were produced also by BGM females that mated with TSM males after first mating with conspecifics (62.4±3.4%). In mixed populations containing males of both species, females also produced lower female: male sex ratios, but these ratios were not as low as expected based on mating propensities and progeny sex ratios observed in no-choice tests. These data suggest that interspecific mating may substantially reduce female fitness in both mite species by reducing the output of female offspring, but in mixed populations this effect is mitigated by unidentified behavioral mechanisms.     

Prey preference of the predatory mite Neoseiulus womersleyi Schicha is determined by spider mite webs

Abstract:  We experimentally verified a proximate cause for the preference of prey species by the predatory mite Neoseiulus womersleyi , which prefers the eggs of Amphitetranychus viennensis Zacher to those of Tetranychus urticae Koch. To separate the effects of spider mite eggs and spider mite webs on the prey preference of the predatory mite, we manipulated combinations of eggs and webs of the two prey species. The number of eggs consumed by adult female N. womersleyi was compared with respect to two factors: eggs of the same species under webs of the different species and eggs of different species under webs of the same species. The results revealed that the prey preference of N. womersleyi was determined by the webs, and not by the eggs.     

Vertical dispersal of the two-spotted spider mite Tetranychus urticae, and the predatory mite Phytoseiulus persimilis on dwarf hops

1 The pattern of dispersion within plants of the two-spotted spider mite, Tetranychus urticae, and its predator, the phytoseiid Phytoseiulus persimilis, was studied on the dwarf hop variety First Gold from May to September in 1997 and 1998. 2 Spider mite populations developed on the lower leaves initially but, by late July, as the numbers of mites increased, most were found towards the top of plants. From early August, the numbers of spider mites decreased most rapidly on the upper parts of plants. 3 Where P. persimilis was released, the predator maintained the numbers of T. urticae below those found on non-release plots throughout the season. 4 By early August, the predator’s pattern of dispersion was similar to that of the pest. 5 Predators spread to non-release plots by 20 June in 1997 and 24 July in 1998 and eventually became more numerous than on the plots where they had been released.     

Heat tolerance of strawberry tarsonemid mite Phytonemus pallidus

The heat tolerance of the strawberry tarsonemid mite Phytonemus pallidus ssp. fragariae was studied in northern Sweden by treating adult mites in hot water at temperatures 44°C, 46°C and 48°C. During the summer, the shortest exposure times required to kill all adult mites at these temperatures were 6, 2.5 and 1.25 min, respectively. It is concluded that hot‐water treatment of strawberry runners for 6.5 min at 46°C would suffice to kill all tarsonemid mites on infested runners. This exposure time includes the time needed to raise the temperature of the plant material to that of the water bath. In the autumn, from the middle of September and later, the mites became successively much more heat tolerant as they prepared for hibernation. It is expected that longer exposure periods are needed to kill mites on frigoplants.     

Anatomy and function of the ptychoid defensive mechanism in the mite Euphthiracarus cooki (Acari: Oribatida)

Ptychoidy is a defensive adaptation of several groups of oribatid mites in which legs and coxisternum can be fully retracted into the opisthosoma and protected by a ventrally deflected prodorsum, resulting in a seed-like appearance. Using Euphthiracarus cooki as a model, we examined details of exoskeletal and muscular anatomy in combination with studies of live individuals to provide the first functional analysis of ptychoidy. There are two main functional components: the first is a set of exoskeletal and muscular adaptations, mostly of the podosoma and prodorsum, that combine to effect leg withdrawal and prodorsal deflection; the second comprises adaptations of the opisthosoma that allow control of hydrostatic pressure during the large hemocoel volume adjustments associated with ptychoidy. Adaptations important in the closing process (enptychosis) are found in four body regions. Much of the podosomal exoskeleton (especially pleural) is unsclerotized, which facilitates leg retraction and prodorsal deflection during enptychosis. The coxisternum has several flexible furrows along which it folds in order to bring legs into a tightly parallel arrangement. The prodorsum has specialized attachment surfaces (manubrium and inferior retractor process) for retractor muscles and a paired bothridial scale that participates in prodorsal alignment during enptychosis. The subcapitulum has a prominent capitular apodeme on which important retractor muscles insert. The mineralized notogaster has an anterior "collar" that accommodates the retracted prodorsum; it includes paired notches and receptacles that accommodate the bothridial scales, thereby creating a temporary fixed axis for rotation of the prodorsum in a "lazy hinge" mechanism. Specialized muscles form the retractor system; most conspicuous are the large coxisternal retractors and prodorsal retractors, both of which originate on the notogaster. Other components have adjustor roles; among them are muscles of the endosternal system that control retraction of the subcapitulum and assist leg retraction, and the dorsoventral muscles which adjust the folded coxisternum. Hemolymph pressure control is a function of the opisthosoma, where the principle exoskeletal elements form a pleated venter, having a cross-sectional shape like an inverted "W." Paired holoventral plates (each representing fused genital, aggenital, anal, and anal plates) form the inner angle and are flanked by paired plicature plates. The holoventral plates are connected medially in two ways : 1) by three permanent bridges of sclerotized cuticle that include an anterior phragmatal bridge and two widely spaced, hollow apodemes (preanal, postanal); 2) by temporary zipper-like closures of two different types. Lateral compression of the pleats is effected by a series of transversely arranged, lateral compressor muscles that run from plicature to holoventral plate edges, and from holoventral plate edges to the medial apodemes. Compression increases hydrostatic pressure in the opisthosoma and stores energy in both the slightly deformed, mineralized notogaster and in the three holoventral bridges. During normal activity the compressor system is active and the inflated podosomal region provides support for the extended legs. When the mite is irritated, the prodorsum is hydraulically ejected from its active position in the notogastral collar, then relaxation of the compressors causes a fall in hemolymph pressure and return of the notogaster to an undeformed condition. Muscles of the retractor system then act in specific sequence to retract and adjust the coxisternum and prodorsum until they are precisely positioned at the completion of enptychosis. The process takes between 0.5 and 1 sec. When irritation ceases, partial opening allows sensory leg hairs to "test" the environment. Resumption of normal, active posture (ecptychosis) involves activation of the lateral compressor system and hydraulic inflation of the podosoma, through which legs are extended and the prodorsum is reflected.     

Ultrahistology of oogenesis and vitellogenesis in the spider mite Tetranychus urticae

Histology of the ovary of the spider mite Tetranychus urticae is described light and electron microscopically with special reference to oogenesis and vitellogenesis of this mite. Morphology of the ovary is comparable to the typical sac-like chelicerate ovary with oocytes protruding from the ovarian surface, thus resulting in a grape-like appearance. According to different oogenetic stages, a germ, pre-vitellogenic and vitellogenic region can be observed. Oogonia and primary oocytes characterized by extranuclear material or 'yolk nuclei' are situated in the germ region. Primary oocytes develop into three-nucleated nurse cells situated in the periphery of the pre-vitellogenic region, and into pre-vitellogenic oocytes protruding from the ovarian surface. Growth of oocytes is performed while they are in ovarian pouches by uptake of nurse cell cytoplasm and following extraovarian yolk precursors. Intraoocyte yolk synthesis interpreted from altered cytoplasmic organelles also occurs. Processes taking place during oogenesis and vitellogenesis in T. urticae are compared to published information on yolk synthesis of other animal species.     

尘螨连续石蜡切片的制备及染色技术

研究尘螨连续石蜡切片的制备技术。利用琼脂预包埋后再以塑化石蜡包埋,经切片和HE染色,获得结构完整、定位准确、染色清晰的连续切片。探讨制片过程中一些步骤的改进和注意事项,为尘螨显微结构的形态学研究提供可能,也为免疫组化、原位PCR及过敏性疾病尘螨特异性变应原的定位等研究奠定良好的基础。     

淮南地区粉螨群落结构及其多样性

在淮南地区仓储、人居、工作、野外4类生境中采集粉螨样本,行分离、镜检,共检获粉螨3 650头,隶属于7科20属,共32种。结果表明,其物种数S、丰富度指数R、多样性指数H′排序均为仓储环境>野外环境>人居环境>工作环境,野外环境中粉螨群落的均匀度指数最大,工作环境中粉螨的优势度指数最大。工作和野外环境的群落相似性指数最低,达到极度不相似水平。结果表明,粉螨群落的结构及多样性与其生境条件直接相关,人类活动是较为重要的影响因素。     

A new fungal pathogen of the scavenger mite,Tydeus gloveri

A new fungal pathogen, Hirsutella tydeicola, was found causing epizootics in populations of the scavenger mite, Tydeus gloveri, during the summer of 1979 and 1980 on citrus in Florida. The fungus is described in association with its host using light and scanning electron microscopy. H. tydeicola is compared with a closely related species, H. thompsonii, a coexisting pathogen of the citrus rust mite. All attempts to isolate the fungus on various agar media failed.