来自土壤的金孢属四个新记录种

【背景】金孢属是一类重要的嗜角蛋白真菌资源。【目的】对我国甘肃省和云南省土壤中的金孢属资源进行调查。【方法】采集不同环境中的土壤样品,利用鸡毛和头发对土壤样品中的这类资源进行钓饵,分离目标菌株;基于形态特征和ITSrDNA序列进行系统发育分析相结合的方法进行菌株的鉴定。【结果】从土壤中分离发现5个金孢属菌株,其中菌株H5.11在形态上与节状金孢模式菌株的形态特征非常相近,而且系统发育中与GenBank上报道的该种序列以较高的支持率聚在一个亚分支;H10.10菌株的形态特征与乔治金孢模式标本的形态非常吻合,培养基上均呈现红色,同时系统发育分析结果表明该菌株与GenBank上报道的序列较好的聚在一个亚分支中;EB8803M和EB8801M两个菌株在形态特征上与水生金孢模式标本的描述非常吻合,系统发育分析结果显示它们与网上该种序列能较好地聚在一个亚分支中;O1菌株在形态特征上与轮带金孢模式标本的描述非常吻合,其系统发育表明它与GenBank已报道菌株序列能较好聚在一起。因此将它们鉴定为节状金孢Chrysosporiumarticulatum、乔治金孢C.georgiae、水生金孢C.submersum和轮带金孢C.zonatum。【结论】这4个种均为中国新记录种。     

中国虫草一新记录种

【目的】对一个寄生鳞翅目幼虫的虫草标本Dxhir140901进行分类鉴定。【方法】采用形态学比较和基于ITS1-5.8S-ITS2rDNA的系统发育与进化网络分析进行鉴定。【结果】形态学观察：标本的分离菌株形态显示其为典型的被毛孢属真菌,具有两型产孢结构：A型产孢细胞柱状,(1.8?6.3) μm×1.8 μm;B型产孢细胞锥形,基部柱状,向上逐渐变细无明显颈部,基部宽3?3.8 μm,长21?63 μm,颈部宽1.8?2.0 μm,菌丝末端可直接形成产孢细胞;孢子橘瓣形或卵形,(8.1?10.8) μm×(2.7?5.4) μm,具粘液,黏液层厚1.8?2.7 μm。系统发育分析结果显示该菌株与巨针线形虫草Ophiocordyceps macroacicularis聚为一支,支持率为98%,进化网络分析也支持上述结果。【结论】通过与O. macroacicularis的形态比较和分子系统学分析结果,Dxhir140901及其分离株Gzuifr-hir140901为巨针线形虫草Ophiocordyceps macroacicularis S. Ban, T. Sakane & Nakagiri的无性阶段,该种为中国新记录种。     

利用蛋白表达谱鉴定毛壳属真菌2 个种的子囊果毛形态变异性

【目的】毛壳属真菌的子囊果毛形态曾是重要的分类性状,但因容易发生变异,在现代毛壳属的分类中它们的分类学价值受到质疑。印度毛壳(Chaetomium indicum)和绳生毛壳(Chaetomium funicola)是2个依据子囊果毛形态差异定义的物种,本研究旨在从蛋白表达谱水平认识这2个种的差异及其子囊果毛的变异性,同时探讨蛋白表达谱在真菌分类中的应用价值。【方法】通过形态学观察获得印度毛壳和绳生毛壳典型菌株和子囊果毛形态变异菌株,利用双向电泳技术对典型菌株和变异菌株的蛋白表达谱进行分析和比较。【结果】双向电泳(2DE)图谱特征反映出印度毛壳和绳生毛壳之间的蛋白表达谱差异明显。根据Neighbor-joining(NJ)算法生成的系统发育树进一步显示印度毛壳和绳生毛壳分别聚在2个不同分支,即同一种的典型菌株和变异菌株聚在一起。【结论】依据子囊果毛形态特征和种特异性的蛋白表达谱特征对印度毛壳和绳生毛壳的分类结果是一致的,表明子囊果毛特征仍然是毛壳属真菌分类的重要指标。     

锦绣杜鹃菌根真菌rDNA ITS序列分析及接种效应研究

利用rDNA ITS序列对锦绣杜鹃菌根真菌的16个菌株进行了分类分析。根据菌株ITS序列全长计算各菌株间序列相似度和遗传距离,并与GenBank中最相似菌株序列构建系统发育树。结果表明：16个菌株在系统树上聚为3个大分支。其中7个菌株在支持率为100%的基础上与树粉孢属真菌Oidiodendron sp.聚为一类;2个菌株与未鉴定的杜鹃花科植物根系真菌unidentified root associated fungi聚为一类,支持率为100%;其他7个菌株在98%的支持率上与几种未命名的欧石楠类菌根真菌     

昆明西山森林公园天然虫生真菌及其内生真菌的分离鉴定及多样性分析

【背景】不同地区虫草物种多样性的调查是虫草相关研究的热点之一,虫草真菌区系研究是真菌资源研究的重要内容。【目的】了解云南省昆明市西山森林公园天然虫生真菌及其内生真菌的多样性,增加对虫草真菌区系的认识。【方法】对该地区通过资源调查并采用组织分离法对采集的虫草样本进行虫生真菌及其内生真菌的分离,利用形态特征观察及ITS联合nr SSU、nr LSU、translation elongation factor-1α (tef-1α)、rpb1、rpb2多基因测序进行虫生真菌物种鉴定及多样性分析。【结果】共采集45份云南省昆明市西山森林公园天然虫草样本,鉴定结果表明隶属于2科5属12种,包括虫草科(Cordycipitaceae)的鳞翅虫草属(Samsoniella)(2种,含疑似新种1个)、虫草属(Cordyceps)(4种)和白僵菌属(Beauveria)(4种),以及线虫草科(Ophiocordycipitaceae)的紫枝孢属(Purpureocillium)(1种)和弯颈霉属(Tolypocladium)(1种,为疑似新种),优势属为虫草属(Cordyceps),优势种为环链虫草(C...     

蝉科昆虫病原真菌物种多样性（英文）

蝉科昆虫在自然界具有重要作用,是果树等林木的刺吸性害虫,同时蝉与真菌组成的虫菌共生体也具有重要经济价值。近十年来,通过对我国昆虫病原真菌资源的调查,共采集获得102株蝉科昆虫罹患病原真菌标本,并保存于安徽农业大学昆虫病原真菌研究中心(RCEF)。本研究从蝉科罹患病原真菌标本中分离得到81株菌株,并对其多样性进行了研究。基于不同培养基的形态特征观察并结合ITS、SSU、LSU、TEF、RPB1和RPB2基因构建系统发育树,发现寄生蝉科的菌株属于3科6属15种。本研究重点描述了一个中国新记录种——高水紫孢菌;此外,一些类棒束孢属菌株被修订为蝙蝠蛾萨姆森菌;除上述物种外,还鉴定出球孢白僵菌、绿色绿僵菌、蝉花虫草、柱孢绿僵菌、环链虫草、玫烟色虫草、澳洲白僵菌、布氏白僵菌、细脚虫草、棕色绿僵菌和长座细虫草。其中球孢白僵菌、蝉花虫草和绿色绿僵菌是优势种,多度达总数的58%。而其他12个物种分离频率较低。     

基于mtDNA和rDNA基因序列的中国按蚊属塞蚊亚属种类的系统发育研究（双翅目：蚊科）

【目的】应用mtDNA和rDNA基因特征重建中国按蚊属塞蚊亚属已知种类的系统发育关系, 以阐明亚属内各蚊种的亲缘关系。【方法】对采自中国的按蚊属塞蚊亚属Anopheles (Cellia) 20种蚊的mtDNA-COⅡ和 rDNA-28S-D3序列进行测定和分析, 以按蚊属按蚊亚属Anopheles (Anopheles)的中华按蚊An. (An.) sinensis和赫坎按蚊An. (An.) hyrcanus为外群, 采用COⅡ和D3单基因, 以及“COⅡ+D3”联合数据组以邻接法（NJ）、 最大简约法（MP）、 最大似然法（ML）和贝叶斯法（BI）等重建这些种类的系统发育树。【结果】 mtDNA-COⅡ和rDNA-28S-D3序列的长度范围分别为685 bp和375～410 bp, 在塞蚊亚属蚊种间的遗传距离分别为0.015～0.117和0.003～0.111。各系统树显示外群被合理分开,除在COⅡ树中新塞蚊系为并系外,各系均聚为单系群,新迈蚊系和迈蚊系亲缘关系最近。联合数据组构建的系统合意树显示中国塞蚊亚属各蚊种形成4支,除伪威氏按蚊与多斑按蚊种团未聚为单系群外,其他各种团和复合体成员种均分别聚在一起,各分支的置信值均大于50%。【结论】本研究获得的分子系统发育树清楚地显示了中国按蚊属塞蚊亚属各种类及系之间的系统发育关系, 对其分类和防治研究具有参考价值。     

埃莎霉素Ⅰ组分高含量、高产量基因工程菌WSJ-IA及其原株的鉴定

【目的】利用调节基因acyB2激活异戊酰基转移酶(ist)基因表达的特点,将ist与调节基因acyB2在异戊酰螺旋霉素(埃莎霉素)Ⅰ产生菌菌株中共表达,获得埃莎霉素Ⅰ单组分的高含量及高产量菌株WSJ-IA。对其及原始螺旋霉素产生菌菌株Streptomyces spiramyceticus F21进行了初步鉴定。【方法】从形态学、培养和生理生化特征、细胞壁化学组成、16S rRNA基因序列、5个看家基因(atpD、gyrB、rpoB、recA和trpB)蛋白分析和系统发育树构建等方面对该菌株及其原株进行了鉴定。【结果】两株菌在形态培养特征、生理生化特征、细胞壁化学组成、16S rRNA基因序列和5个看家基因蛋白水平基本一致,在系统发育树分析中同处在一个分支中。而在16S rRNA基因序列和5个看家基因蛋白水平在系统发育上它们均与已知相近菌株处于不同的分支上,并且与不同基因的相近菌株各有不同,其中无一报道产生螺旋霉素。【结论】Streptomyces spira-myceticus F21可能是一个产生螺旋霉素的链霉菌新种,16S rRNA基因序列和5个看家基因蛋白序列分析可以作为埃莎霉素Ⅰ基因工程菌生产过程中进行鉴别的分子标志。     

埃莎霉素I组分高含量、高产量基因工程菌WSJ-IA及其原株的鉴定

【目的】利用调节基因acyB2激活异戊酰基转移酶(ist)基因表达的特点, 将ist与调节基因acyB2在异戊酰螺旋霉素(埃莎霉素)Ⅰ产生菌菌株中共表达, 获得埃莎霉素Ⅰ单组分的高含量及高产量菌株WSJ-IA。本研究对其及原始螺旋霉素产生菌菌株Streptomyces spiramyceticus F21进行了初步鉴定。【方法】从形态学、培养和生理生化特征、细胞壁化学组成、16S rRNA基因序列、5个看家基因(atpD、gyrB、rpoB、recA和trpB)蛋白分析和系统发育树构建等方面对该菌株及其原株进行了鉴定。【结果】两株菌在形态培养特征、生理生化特征、细胞壁化学组成、16S rRNA基因序列和5个看家基因蛋白水平基本一致, 在系统发育树分析中同处在一个分支中。而在16S rRNA基因序列和5个看家基因蛋白水平在系统发育上它们均与已知相近菌株处于不同的分支上, 并且与不同基因的相近菌株各有不同, 其中无一报道产生螺旋霉素。【结论】Streptomyces spiramyceticus F21可能是一个产生螺旋霉素的链霉菌新种, 16S rRNA基因序列和5个看家基因蛋白序列分析可以作为埃莎霉素I基因工程菌生产过程中进行鉴别的分子标志。     

基于rDNAITS序列分析Alternaria与相似属的关系及A.leucanthemi的分类地位

对Alternaria,Stemphylium,Ulocladium,Nimbya,Embellisia等五个形态相似属的代表性种进行了5.8S/ITS区段序列测定,连同从GenBank下载的相关有性型Pleospora,Lewia的同项资料,由Neighbor-joining方法构建系统发育树。序列对比结果显示,所有参试的菌株/种的5.8SrDNA序列保守程度较高,ITS序列变化较大,ITS1比ITS2变化更大。由5.8S/ITS构建的系统发育树可以足够将供试菌区分到属;系统发育树显示Alternaria,Ulocladium,Nimbya和Embellisia系统学关系较近,又存在一定的分化;Stemphylium聚在相对较远的分支上,与上述四属关系较远,相对独立进化;有性型的Pleospora与无性型的Stemphylium被聚到一个分支,这种不同阶段菌株在遗传基础上的一致,充分证明所用方法及所选测序的rDNA区段对本类群真菌的分类很有价值。Alternarialeucanthemi位于系统发育树的外侧,较为独立进化,与Alternaria的其它种亲缘关系较远,却与Stemphyliumspp.和Bipolarisspp.关系较近,对其目前的分类地位提出质疑。     

The placement of South African strains of Beauveria in a phylogeny inferred from rDNA ITS1-5.8S-ITS2 sequences

This study aimed to confirm the identity of three strains of the entomopathogenic fungus Beauveria bassiana from South African soils and to investigate their phylogenetic relationship with non-indigenous strains from other geographic regions. Sequences of the rDNA ITS1-5.8S-ITS2 region of 23 strains were compared with the Genbank reference sequences of 20 other cosmopolitan strains. Fitch parsimony and neighbor-joining analyses of the ITS1-5.8S-ITS2 regions resolved the strains into two distinct clades and matched them to four species groups/lineages: Beauveria bassiana, B. cf. bassiana (pseudobassiana), B. brongniartii and B. caledonica. Two of the South African strains initially identified as B. bassiana grouped with B. caledonica, whereas the third strain was confirmed as B. bassiana. Because of the paucity of Genbank references for B. caledonica, we have designated the two South African B. caledonica strains as B. sp. aff. caledonica. Other reassignments included two strains from Norway, originally classified as B. bassiana, being grouped with B. brongniartii, and three of the B. brongniartii reference taxa from Brazil which were clearly placed in the B. bassiana clade. The study provides a first report of the presence of the B. caledonica lineage in Africa and confirms current Beauveria phylogenies inferred from molecular data.     

A Beauveria phylogeny inferred from nuclear ITS and EF1-alpha sequences: evidence for cryptic diversification and links to Cordyceps teleomorphs

Beauveria is a globally distributed genus of soil-borne entomopathogenic hyphomycetes of interest as a model system for the study of entomopathogenesis and the biological control of pest insects. Species recognition in Beauveria is difficult due to a lack of taxonomically informative morphology. This has impeded assessment of species diversity in this genus and investigation of their natural history. A gene-genealogical approach was used to investigate molecular phylogenetic diversity of Beauveria and several presumptively related Cordyceps species. Analyses were based on nuclear ribosomal internal transcribed spacer (ITS) and elongation factor 1-alpha (EF1-alpha) sequences for 86 exemplar isolates from diverse geographic origins, habitats and insect hosts. Phylogenetic trees were inferred using maximum parsimony and Bayesian likelihood methods. Six well supported clades within Beauveria, provisionally designated A-F, were resolved in the EF1-alpha and combined gene phylogenies. Beauveria bassiana, a ubiquitous species that is characterized morphologically by globose to subglobose conidia, was determined to be non-monophyletic and consists of two unrelated lineages, clades A and C. Clade A is globally distributed and includes the Asian teleomorph Cordyceps staphylinidaecola and its probable synonym C. bassiana. All isolates contained in Clade C are anamorphic and originate from Europe and North America. Clade B includes isolates of B. brongniartii, a Eurasian species complex characterized by ellipsoidal conidia. Clade D includes B. caledonica and B. vermiconia, which produce cylindrical and comma-shaped conidia, respectively. Clade E, from Asia, includes Beauveria anamorphs and a Cordyceps teleomorph that both produce ellipsoidal conidia. Clade F, the basal branch in the Beauveria phylogeny includes the South American species B. amorpha, which produces cylindrical conidia. Lineage diversity detected within clades A, B and C suggests that prevailing morphological species concepts underestimate species diversity within these groups. Continental endemism of lineages in B. bassiana s.l. (clades A and C) indicates that isolation by distance has been an important factor in the evolutionary diversification of these clades. Permutation tests indicate that host association is essentially random in both B. bassiana s.l. clades A and C, supporting past assumptions that this species is not host specific. In contrast, isolates in clades B and D occurred primarily on coleopteran hosts, although sampling in these clades was insufficient to assess host affliation at lower taxonomic ranks. The phylogenetic placement of Cordyceps staphylinidaecola/bassiana, and C. scarabaeicola within Beauveria corroborates prior reports of these anamorph-teleomorph connections. These results establish a phylogenetic framework for further taxonomic, phylogenetic and comparative biological investigations of Beauveria and their corresponding Cordyceps teleomorphs.     

以23S rDNA一个多变区作为分子标记对致病杆菌属细菌进行分类鉴定

【目的】致病杆菌属(Xenorhabdus)细菌是一类重要的生物杀虫剂,斯氏属昆虫病原线虫的共生菌,建立快速准确的分类鉴定方法,对研究开发这类细菌至关重要。【方法】本研究PCR扩增测序了本室保藏的26株,含20种已定名致病杆菌属细菌的一段845 bp的23S rDNA序列,构建了基于这段序列的致病杆菌属系统树并与基于几乎全长16S rDNA序列的相应系统树进行比较,分析了两者作为致病杆菌属细菌分类鉴定分子标记的优缺点。【结果】结果表明,与全长16S rDNA序列相比,所选择的23S rDNA序列片段所含可变位点、简约信息位点比例更高,遗传距离数值跨度大。【结论】上述结果显示该序列片段可用于致病杆菌属细菌进行分类鉴定,特别适用于对野外资源调查中采集到的大量菌株进行快速鉴定。     

致蛋鸡血管瘤J亚群禽白血病病毒cDNA全序列分析

【目的】了解近年来我国商品蛋鸡群中以血管瘤为主要表型的J亚群禽白血病病毒(Avian Leukosis Virus subgroup J,ALV-J)的分子生物学特性,为控制ALV-J在鸡群中流行提供基础资料。【方法】采用PCR扩增和序列分析技术,对分离自血管瘤或者血管瘤与髓样细胞瘤(Myeloid Leukosis,ML)并存的3株蛋鸡ALV-J毒株前病毒DNA的全序列及3株商品蛋鸡血管瘤型分离毒和1株商品蛋鸡ML型分离毒的致瘤关键性序列进行研究。【结果】来自血管瘤或者血管瘤与ML并存的商品蛋鸡分离毒株与来自肉鸡分离毒株的全序列差异明显,在遗传进化树上分属两个大的分支;研究发现商品蛋鸡血管瘤及ML混合病例分离毒JS09GY3与JS09GY6株的引物结合位点(Primer Binding Site,PBS)-Leader中出现极为罕见的连续19bp的插入突变,其与劳斯相关病毒1(Rous Associated Virustype1,RAV-1)、劳斯相关病毒2(Rous Associated Virustype2,RAV-2)及劳斯肉瘤病毒施密特-鲁宾二氏[Rous sarcoma virus(strain Schmidt-RuppinB),RSV-SRB]毒株序列相同;通过对U3区调控元件的分析,发现血管瘤商品蛋鸡病例分离毒NHH与JS09GY5的U3区各发生1处连续序列缺失,出现了极为独特的c-Est-1、TCF11及C/EBP结合位点,这些调控元件可能与病毒的致肿瘤特性相关;所测的5株血管瘤商品蛋鸡分离毒均保留完整E元件,而所有肉鸡分离毒的E元件均发生了几乎相同的大部分序列缺失;首次发现血管瘤商品蛋鸡分离毒JS09GY3的E元件中有11bp的连续插入序列。【结论】商品蛋鸡血管瘤型ALV-J与肉鸡分离毒在全序列上差异明显,U3、DR1和E元件等区域有一部分特殊的突变与毒株的宿主类型和肿瘤表型有一定关系,其功能尚需进一步研究。而血管瘤型、髓细胞瘤型ALV-J可能是ALV-J与其它反转录病毒的重组毒。     

Phylogeny of mitosporic entomopathogenic fungi: is the genus Paecilomyces polyphyletic?

We analyzed sequences of the divergent domain at the 5' end of the large subunit rRNA gene from the mitosporic entomopathogenic fungi Paecilomyces sp., Paecilomyces fumosoroseus, Paecilomyces farinosus, Paecilomyces lilacinus, Verticillium lecanii, Verticillium psalliotae, Beauveria bassiana, Aschersonia sp., Aschersonia placenta, ascomycetous Cordyceps sp., and Cordyceps militaris. Phylogenetic analysis showed P. fumosorseus as the best characterized out of the analyzed species with the B. bassiana clade as its sister group. Two of the P. farinosus isolates were invariably placed within the Verticillium cluster, which also contained C. militaris. The only analyzed P. lilacinus isolate appeared on the root of the hyphomycetous fungi and was characterized as the most distinct from all the hyphomycetous fungi tested. Polyphyly of the genus Paecilomyces was well supported by the Kishino-Hasegawa test. In all trees based on the small subunit rRNA gene sequences obtained from the GenBank, V. lecanii, V. psalliotae, P. fumosoroseus, P. tenuipes and B. bassiana form, together with that of C. militaris, the best supported cluster in the tree. The rest of Cordyceps spp. constitute a distinct clade. Phylogenetic relationships derived from both tested DNA regions show polyphyly of the genus Paecilomyces and close relationships among entomopathogenic species of the genera Verticillium, Paecilomyces, and Beauveria.     

黏管藻的分子鉴定与生长特性研究

对分布在辽宁大连黑石礁、付家庄、石槽、金石滩、獐子岛与海洋岛沿岸的黏管藻[Gloiosiphonia capillaris (Hudson) Carmichael]的外部形态、营养与生殖结构、生物量、成熟个体比例与成熟个体生物量/总生物量(R/T指数)的变化、温度性质以及rbcL、COⅠ基因序列进行了详细研究。结果表明: (1) 黏管藻配子体为雌雄同体, 直立, 单生或丛生, 主轴明显, 固着器呈圆盘状, 质地胶质, 颜色为红色或紫红色。采集于獐子岛与海洋岛的藻体长度和宽度明显高于其他采集地点; (2) 藻体由皮层及髓部组成, 皮层由6—10层细胞组成, 髓部存在假根丝细胞。成熟囊果小, 突出于藻体表面, 呈球形或半球形, 通常2—4个囊果聚集在一起; (3) 黏管藻配子体的生物量在6月达到最大, 平均生物量为3.628 g/m2。3—6月成熟个体比例逐渐增大, 6月达到100%; (4) 黏管藻配子体生长周期为3—7月, 温度性质属于温带性; (5) rbcL基因序列分析表明, 6个采集地点的样本间无碱基差异, 与产自加拿大的黏管藻聚在一起, 形成一个独立的分支。COⅠ基因序列分析表明, 6个采集地点的样本间无碱基差异, 形成一个独立的分支, 均确定为黏管藻。     

Photorhabdus temperata subsp. stackebrandtii subsp. nov. (Enterobacteriales: Enterobacteriaceae)

The bacterial symbiont of the entomopathogenic nematode Heterorhabditis bacteriophora strain GPS11 was characterized by 16S rRNA gene sequence and physiological traits. The phylogenetic tree built upon 16S rRNA gene sequences clustered the GPS11 bacterial isolate with Photorhabdus temperata strains which have been previously isolated from Heterorhabditis species. The phylogenetic tree further identified four subgroups in P. temperata, and the relationships among these subgroups were confirmed by gyrase subunit B (gyrB) gene sequence analysis. The subgroup containing the GPS11 bacterial isolate differs from other subgroups in sequences of 16S rRNA and gyrB gene, physiological traits, nematode host species, and geographic origin. Therefore, the subgroup comprising the GPS11 bacterial isolate is proposed here as a new subspecies: Photorhabdus temperata subsp. stackebrandtii subsp. nov. (type strain GPS11). The type strain has been deposited in ATCC and DSMZ collections.     

Evolution,geographic spreading,and demographic distribution of Enterovirus D68

Worldwide outbreaks of enterovirus D68 (EV-D68) in 2014 and 2016 have caused serious respiratory and neurological disease. We collected samples from several European countries during the 2018 outbreak and determined 53 near full-length genome (‘whole genome’) sequences. These sequences were combined with 718 whole genome and 1,987 VP1-gene publicly available sequences. In 2018, circulating strains clustered into multiple subgroups in the B3 and A2 subclades, with different phylogenetic origins. Clusters in subclade B3 emerged from strains circulating primarily in the US and Europe in 2016, though some had deeper roots linking to Asian strains, while clusters in A2 traced back to strains detected in East Asia in 2015-2016. In 2018, all sequences from the USA formed a distinct subgroup, containing only three non-US samples. Alongside the varied origins of seasonal strains, we found that diversification of these variants begins up to 18 months prior to the first diagnostic detection during a EV-D68 season. EV-D68 displays strong signs of continuous antigenic evolution and all 2018 A2 strains had novel patterns in the putative neutralizing epitopes in the BC- and DE-loops. The pattern in the BC-loop of the USA B3 subgroup had not been detected on that continent before. Patients with EV-D68 in subclade A2 were significantly older than patients with a B3 subclade virus. In contrast to other subclades, the age distribution of A2 is distinctly bimodal and was found primarily among children and in the elderly. We hypothesize that EV-D68’s rapid evolution of surface proteins, extensive diversity, and high rate of geographic mixing could be explained by substantial reinfection of adults. Better understanding of evolution and immunity across diverse viral pathogens, including EV-D68 and SARS-CoV-2, is critical to pandemic preparedness in the future.     

放射污染区古菌分离及多样性分析

【目的】研究放射污染区古菌多样性。【方法】放射污染区采集土样,采用甘油-精氨酸培养基(GJ)、甘油-天冬氨酸培养基(C1)、海藻糖-肌酸培养基(B7)、甘露醇-丙氨酸培养基(Z5)、干酪素-甘露醇培养基(CMKA)、壳聚糖-天冬酰胺培养基(F6)、甘露醇-酸水解酪蛋白培养基(GW1)、CM培养基、HP培养基和KC培养基10种分离培养基,采用梯度稀释法对古菌进行分离,将分离获得的菌株经形态特征,16S rRNA基因片段扩增及限制性内切酶酶切,选取酶切图谱中存在差异性的条带进行测序,最终通过序列比对,聚类分析,获得不同种类的古菌资源。【结果】从该土样中共获得了256株古菌,最终筛选出71株不同类型的古菌,这71株古菌均属于广古菌门,盐杆菌纲,盐杆菌目,盐杆菌科,分布于盐陆生菌属(Haloterrigena)、纳白菌属(Natrialba)、盐球菌属(Halococcus)、盐红菌属(Halorubrum)、盐长寿菌属(Halovivax)、纳线菌属(Natrinema)、盐碱球菌属(Natronococcus)、盐二型菌属(Halobiforma)、盐惰菌属(Halopiger)、盐池栖菌属(Halostagnicola)、富盐菌属(Haloferax)11个属,26个种,其中31株菌的16S rRNA基因序列与已有效发表菌株的序列相似性小于98%,Haloterrigena为该土样的优势菌属。对于分离效果较好的F6培养基采用了梯度营养成分的稀释,最终获得了19株古菌,这些菌株相互之间存在一定的差异性。【结论】本次分离获得了大量的古菌,表明放射污染区存在着较为丰富的古菌资源,其中蕴藏着多种新的物种类型,具有较大的研究价值。