林麝源蜡样芽孢杆菌SCBCM001株的分离鉴定及全基因组序列分析

【背景】细菌性疾病是林麝规模化养殖的重要制约因素,蜡样芽孢杆菌曾在林麝化脓灶中检出,但是目前对林麝源蜡样芽孢杆菌的研究报道很少。【目的】对分离自病死林麝肝脏中的一株疑似蜡样芽孢杆菌进行分离鉴定和全基因组序列分析,为林麝相关疾病的防治奠定基础。【方法】将病原菌纯化培养后,对病原菌进行生化试验、药敏试验和小鼠致病性试验;并通过第3代单分子测序技术进行全基因组测序,根据测序结果进一步评估物种间的亲缘关系,并进行基因功能注释和遗传进化分析。【结果】该病原菌经平均核苷酸相似度分类和系统发育树分析属于蜡样芽孢杆菌群,生化结果符合蜡样芽孢杆菌的一般特征,将分离菌株命名为SCBCM001。该菌株对小鼠的半数致死量为8.3×107 CFU,对大多数β-内酰胺类、四环素和磺胺异噁唑耐药,对氨基糖苷类、头孢氨苄、头孢哌酮和亚胺培南等药物敏感;全基因组测序结果表明该菌株的染色体大小为5292570bp,GC含量为35.37%,多位点序列分型显示该菌株属于ST427序列类型。在菌株SCBCM001基因组内发现hblA、hblC、hblD、nheA、nheB、clo和cytK等多种毒力因子,同时菌株携带对β-内酰...     

一株兔源A型多杀性巴氏杆菌的分离鉴定和全基因组测序及分析

【背景】多杀性巴氏杆菌可导致猪肺疫、牛出血性败血症和兔出血性败血症等多种疾病,严重威胁多种动物畜牧养殖业的健康发展。【目的】重庆某兔场送检一批病死兔,为研究其病原和治疗方法,对病原进行了微生物分离和全基因组测序分析。【方法】从2022年重庆某兔场送检兔病料中进行细菌分离纯化、生化试验、16S rRNA基因鉴定、荚膜血清型分型、药敏试验和毒力基因检测,同时通过全基因组测序结果进行毒力、耐药基因注释和遗传进化等分子生物学信息分析。【结果】该菌为兔源A:ST74多杀性巴氏杆菌,命名为LXSS001,基因组序列上传到NCBI数据库(登录号为CP119523.1),药敏试验显示该菌对四环素、杆菌肽、复方新诺明和磺胺异恶唑耐药,对头孢噻肟、头孢哌酮和丁胺卡那等药物敏感。全基因组长度为2 480 671 bp,并注释到了58个毒力基因和9类药物的靶向抗药基因。通过联合建树表明其与3480株一致性最高。【结论】本研究完成了一株A型多杀性巴氏杆菌的分离鉴定和全基因组测序,并揭示了其与国内外其他分离株的进化关系,为多杀性巴氏杆菌的后续研究提供了参考依据。     

一株牛源都柏林沙门氏菌的全基因组测序及毒力与耐药性分析

【背景】沙门氏菌(Salmonella spp.)是重要的人畜共患病原菌,其毒力和耐药性的不断增强引起广泛关注。【目的】了解从通辽市一犊牛死亡病例中所分离牛源都柏林沙门氏菌的毒力及耐药性情况。【方法】以病死犊牛肺脏为材料,经细菌分离纯化及16S rRNA基因测序,鉴定病原为沙门氏菌。采用动物试验、药敏试验和PCR方法对分离菌进行毒力、耐药性,以及毒力基因和耐药基因检测,并对其进行全基因组测序分析。【结果】分离菌具有较强毒力,对小鼠半数致死量为2.8×10⁶ CFU/mL。分离菌为多重耐药菌,仅对多粘菌素B和噻孢霉素敏感,对强力霉素和恩诺沙星中度敏感。检测13种沙门氏菌常见毒力基因,检出率为92.3%。对分离菌进行全基因组测序分析,该菌株为都柏林沙门氏菌,基因组大小为4 965 370 bp,GC含量为52.12%,同时携带2个质粒,大小分别为79 524 bp (pTLS-1)和45 301 bp (pTLS-2)。分离菌中共携带996个毒力基因和24个毒力岛;共携带42个耐药基因,其中4个为可水平转移基因,基因组中存在9个可移动遗传元件,包括插入序列和转座子等。【结论】分离牛源都柏林沙门氏菌菌株具有较强毒力且为多重耐药株,携带大量毒力基因及耐药基因。     

一株猪葡萄球菌的分离鉴定、生物学特性研究及全基因组测序分析

【背景】2021年6月,广东省茂名市某散养户送检了一头发病仔猪,猪身上长有脓疱,四肢关节肿大,关节内可见脓液。【目的】确定引起仔猪发病的病原菌,分析其药物敏感性,为临床用药提供指导;对分离菌株进行全基因组序列分析,挖掘其毒力因子和耐药基因,揭示该菌致病和耐药的分子机制。【方法】取关节脓液分离细菌;通过革兰氏染色、16S rRNA基因和全基因组测序分析,鉴定细菌种类;通过溶血试验、血浆凝固酶试验和生长曲线测定,确定分离菌株的溶血活性、血浆凝固酶活性和生长特性;用小鼠感染模型评估分离菌株的致病性;用纸片扩散法测定分离菌株的药物敏感性;通过全基因组序列分析挖掘分离菌株的毒力因子和耐药基因。【结果】分离菌株被鉴定为猪葡萄球菌(Staphylococcus hyicus);该菌不溶血,无血浆凝固酶活性,在胰蛋白胨大豆肉汤培养基中于37℃、120r/min条件下生长良好;小鼠感染试验结果显示,该菌具有高致病性;药敏试验结果显示,该菌对苯唑西林、大观霉素等7种药物敏感,对青霉素G、红霉素等9种药物耐药;全基因组序列分析结果显示,该菌携带多个毒力因子和耐药基因。【结论】从发病仔猪的关节脓液中分离到一株猪葡萄球菌,可用苯唑西林、大观霉素等药物防控该菌感染;解析了该菌的基因组信息,为后续深入研究该菌致病和耐药的分子机制奠定了基础。     

一株林麝肺源创口博德特氏杆菌全基因组及细胞致死性肿胀毒素分析

【目的】为探究林麝的死亡原因,本研究无菌采集1只死亡林麝肺脏后进行细菌的分离鉴定。【方法】通过细菌分离纯化、生化试验和16S rRNA序列分析,对分离菌株进行鉴定;然后通过药敏试验、全基因组测序与分析以及细胞致死性肿胀毒素(cytolethal distendin toxin subunit B,CDTB)分析,对分离菌株耐药性和致病性进行研究。【结果】在死亡林麝肺脏中分离出1株革兰阴性菌,经鉴定为创口博德特氏杆菌,命名为ZL0001。经过细胞培养观察和CDTB分析表明该菌为胞内寄生菌,含有细胞致死性肿胀毒素,能导致细胞凋亡。药敏结果表明该分离株对氨苄西林、亚胺培南、链霉素和四环素等药物敏感;对氨曲南、林可霉素、克林霉素和呋喃妥因耐药。全基因组测序分析结果表明,该菌株与其他创口博德特氏杆菌的平均核苷酸一致性(average nucleotide identity,ANI)值均97%,基因组大小为4350644 bp,共发现22个耐药相关基因。此外,该菌株基因组包含63个毒力相关基因,其参与鞭毛蛋白、脂多糖、铁摄取、抗血清蛋白以及细胞致死性肿胀毒素等毒力因子的合成。【结论】本研究首次在动物呼吸道中分离出创口博德特氏杆菌,并证明其为胞内寄生菌,对林麝肺炎的发病机理研究具有重要意义。     

两株不同宿主源化脓隐秘杆菌分离鉴定及其plo基因生物信息学分析

【背景】化脓隐秘杆菌是一种能够感染人类及多种动物的条件致病菌,常引起动物的各种非特异性化脓性感染。【目的】探究不同宿主疑似化脓隐秘杆菌感染的菌属种类和病原特性。【方法】对林麝皮下脓肿和鸭跗关节脓肿进行细菌分离,通过革兰氏染色、细菌16S rRNA基因分析等方法对病原菌进行鉴定,通过生长曲线测定、药敏试验和毒力基因检测分析2株病原菌的生物学特性,对溶血素plo基因进行序列分析和结构预测。【结果】分离鉴定到林麝源和鸭源化脓隐秘杆菌各1株,分别命名为FTP-1和DTP-1;生长曲线测定发现,2株病原菌的生长繁殖速度差异较大;药敏试验表明,2株病原菌对β-内酰胺类、磺胺类和利福霉素类抗生素耐药,对氨基糖苷类、喹诺酮类抗生素敏感;毒力基因检测显示,2株病原菌均携带plo、nanH、nanP、fimA和fimE基因,鸭源分离株还携带有fimC基因;生物信息学分析软件预测显示,2株病原菌溶血素plo基因核苷酸序列存在宿主特异性差异,但二者氨基酸序列相同,蛋白结构预测发现化脓隐秘杆菌溶血素(pyolysin, PLO)与胆固醇依赖性溶细胞素家族其他成员之间相似性较高。【结论】在云南宜良地区分离到林麝源和鸭源化脓隐秘杆菌各1株,二者plo基因亲缘关系较近,相关生物学特性分析可为推进该病原菌的研究和防控提供参考。     

下一代底盘微生物Vibrio sp. FA2的抗生素抗性

【背景】细菌耐药是当前人类面临的重大挑战之一,抗生素耐药性研究是解决耐药问题的重要途径。Vibrio sp. FA2是环境中分离的一株快速生长菌,其生长速度快于目前报道的快速生长的需钠弧菌(Vibrio natriegens) 14048,并且具有多样的碳源利用能力,是具有较大潜力的下一代微生物底盘,可用于开发化合物高效生产菌株。【目的】前期对FA2菌株的常见抗生素耐药性测试发现该菌具有多重抗生素耐受性,不利于基因工程操作,并且在工业应用中会带来生态安全风险,因此有必要研究其抗生素抗性,并敲除其耐药性基因。【方法】采用抗生素药敏试验测试菌株耐药性,并且利用基因组注释分析筛选目标基因,通过基因敲除构建了关于目标基因的敲除突变株,并比较了FA2野生株和敲除株的抗生素敏感性和生长情况。【结果】系统分析了FA2菌株对以氨苄西林为代表的β-内酰胺类及氨基糖苷类等多种抗生素的耐受性,分析筛选出一系列与FA2菌株耐药性相关的基因。其中,FA2菌株对几种β-内酰胺类抗生素都有较强的耐受性,并且注释到carB6、ampC2和ampC1这3个可能的氨苄西林耐受性基因。研究了氨苄西林耐受性,对3个基因进行了...     

肌苷生产菌枯草芽孢杆菌ATCC 13952的全基因组测序及序列分析

摘要:【目的】枯草芽孢杆菌ATCC 13952是一株肌苷工业生产菌株。为深入研究ATCC 13952菌株积累肌苷的分子机制以及为进一步分子育种研究提供序列背景信息,有必要解析ATCC 13952菌株的基因组序列信息。【方法】本研究采用高通量测序和Sanger测序相结合对ATCC 13952菌株进行全基因组测序,然后使用相关软件对测序数据进行基因组组装、基因预测与功能注释、GO/COG 聚类分析、共线性分析等。【结果】枯草芽孢杆菌ATCC 13952整个基因组大小为3876276 bp,GC含量为45.8%,序列已提交至GenBank 数据库,登录号为CP009748。比较基因组及嘌呤代谢相关基因分析结果显示:枯草芽孢杆菌ATCC 13952与其他几株芽孢杆菌具有较好的基因组共线性关系,嘌呤代谢相关基因编码的蛋白与标准菌株比较发生了一些缺失和突变。【结论】本研究首次报道了一株肌苷生产菌枯草芽孢杆菌ATCC 13952的全基因组序列,分析了基因组基本特征,初步探讨了该菌株积累肌苷的分子机制,为后续的进一步分子育种提供了理论基础。     

林麝源支气管败血波氏杆菌FMDBb1株的分离鉴定及全基因组序列分析

[背景] 呼吸系统疾病是圈养麝常见疾病之一,其中部分由支气管败血波氏杆菌引起,但目前关于林麝源支气管败血波氏杆菌的研究甚少。[目的] 对分离自患病林麝鼻黏液的一株疑似支气管败血波氏杆菌进行分离鉴定和全基因组序列分析,为林麝相关疾病的防治奠定基础。[方法] 将病原菌纯化培养后,通过菌落形态和生化试验初步鉴定病原菌类型,然后进行药敏试验和小鼠致病性试验以观察其耐药和毒力表型,最后对其进行全基因组测序,通过平均核苷酸一致性（Average Nucleotide Identity,ANI）比对在全基因组水平进一步评估物种间的亲缘关系,并进行基因功能注释和遗传进化分析。[结果] 该病原菌经ANI分类属于经典波氏杆菌亚种,结合菌落形态和生化结果综合鉴定为支气管败血波氏杆菌,菌株命名为FMDBb1,药敏表型显示其对林可霉素、利福平及大多数β-内酰胺类抗生素耐药,对小鼠的半数致死量为8.55×10⁶ CFU。全基因组测序显示该菌基因组大小为5 133 936 bp,基因功能注释显示其拥有强代谢能力,基因组内检测到65个经典波氏杆菌毒力因子,以及1个粉霉素和1个利福平的靶向耐药基因,同时发现19个插入序列和1个噬菌体区域的存在。序列类型为ST33,克隆复合体类型为CC6,管家基因联合建树分析显示与分离于韩国短毛猫的KVNON-570株相似性最高。[结论] 研究分离了林麝源支气管败血波氏杆菌并对其进行了全基因组测序及分析,为该病原菌感染的防治提供了宝贵的信息。     

林麝源铜绿假单胞菌噬菌体vB＿PaeM＿PAMD02的生物学特性与全基因组序列分析

【背景】圈养林麝一半以上的死亡是由铜绿假单胞菌引起的化脓性疾病导致。另外,由于细菌的抗性增加,噬菌体是继抗生素后的另一抗菌选择。【目的】以分离自病死林麝肺脏的铜绿假单胞菌为宿主菌分离一株噬菌体,对其进行生物学特性、全基因组序列分析与体内抑菌试验。【方法】通过双层平板法分离纯化一株裂解性噬菌体,测定其裂解谱、最佳感染复数、一步生长曲线、热稳定性、最适生长pH等生物学特性,通过电镜观察其具体形态,进行全基因组测序与序列分析,并进行小鼠体内抑菌试验。【结果】分离到一株裂解性铜绿假单胞菌噬菌体并命名为vB＿PaeM＿PAMD02,该噬菌体具有透明且边缘清晰无晕环的噬菌斑,其裂解谱较窄,最佳感染复数为0.1,裂解潜伏期为40 min,裂解暴发量较高,热稳定性较高,可耐受弱碱环境。其全基因组大小为66 264 bp,GC含量为55.59%,序列注释结果显示该噬菌体具有92个开放阅读框,不含毒力与耐药基因,属于肌尾噬菌体科。小鼠体内抑菌试验结果显示了PAMD02对其宿主菌良好的抑菌效果。【结论】本研究分离的噬菌体PAMD02有较高的裂解效率,对不利环境有较好的耐受性,不含毒力基因与耐药基因,具有应用...     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Demographic characteristics of an intertidal bay goby (Lepidogobius lepidus)

Synopsis In a fourteen month study (May 1976 – June 1977) I examined the following characteristics of an intertidal bay goby (Lepidogobius lepidus) in Morro Bay, California, U.S.A.: annual and seasonal patterns of abundance, age composition and growth rates, survivorship and mortality patterns, and the reproductive cycle for female gobies. Fishes were collected with the aid of quinaldine and otoliths and ovaries removed. Age and growth rates were estimated from otolith annuli using a back calculation formula and a Brody-Bertalanffy growth curve. Mortality rates were derived using the methods of Heincke (1913), Robson & Chapman (1960), mean age, and a catch curve (Ricker 1975). A gonad index was used to describe the annual reproductive cycle. Results indicated that abundance fluctuated seasonally and that these fluctuations appeared to be caused by reproductive emigrations. Bay gobies reached an age of 7+ and a standard length of 87 mm. Growth was relatively constant (6 mm yr⁻¹) until age 5, at which point it began to decline. The mean rates of survivorship, mortality, and instantaneous mortality were 0.75, 0.25, and 0.29 respectively. Mortality rates for individual age classes ranged from 0.13 to 0.51 and increased with age. This stock appears to reproduce mainly during the winter.     

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.