Pierce's disease of grapevines: evidence for a bacterial etiology

A Gram-positive, rod-shaped bacterium was isolated and grown in pure culture on artificial mediums from the leafhopper Draeculacephala minerva Ball which had fed on plants infected with Pierce's disease. The bacterial culture was injected into uncontaminated leafhoppers which were than allowed to feed on healthy grapevines. After exposure to these leafhoppers, typical symptoms of Pierce's disease developed; however, no symptoms developed on plants exposed to leafhoppers injected with sterile culture medium. The same organism was reisolated from the experimentally inoculated plants. Electron microscopic examination of these infected plants revealed bacterial cells localized in the xylem tissues. No such cells were seen in healthy or control plants.     

Rickettsia-like Bacterium Associated with Pierce's Disease of Grapes

A pleomorphic bacterium was observed by electron microscopy in grape plants infected with Pierce's disease. The organism was located in xylem tissue, and its occurrence was closely associated with symptoms of Pierce's disease. The bacterium resembled a rickettsia in morphology, in its failure to grow on cell-free media, and in its sensitivity to tetracycline antibiotics.     

Pierce's Disease Bacterium: Mechanism of Transmission by Leafhopper Vectors

The bacterium that causes Pierce's disease of grapevines is isolated most consistently from the foregut of its leafhopper vector Graphocephala atropunctata. As seen in light and scanning electron microscopy of infective leafhoppers, the bacteria are attached to the cibarial pump and the lining of the esophagus in the foregut where they appear to multiply. These findings suggest that the bacterium is transmitted from the foregut by egestion during feeding by infective leafloppers.     

Corn stunt spiroplasma: isolation, cultivation, and proof of pathogenicity

A spiroplasma isolated from corn infected with corn stunt disease has been successfully cultivated in vitro. Acid formation was associated with its growth in liquid medium, and fried egg-shaped or granulated colonies developed on solid agar medium. Healthy leafhopper vectors injected with or allowed to feed on isolates from various serial passages through liquid medium were able to transmit the corn stunt agent to healthy corn plants, inducing typical corn stunt disease in the plants. The spiroplasma was reisolated and cultivated from such diseased plants and was indistinguishable morphologically from the original isolates. These results provide the first definite proof that the corn stunt disease is caused by the corn stunt spiroplasma.     

陇南核桃致病性成团泛菌的分离鉴定及其致病性研究

本研究拟从核桃病叶中分离并鉴定其致病菌,以便更好地实施科学防治。以组织分离法分离核桃病叶中的成团泛菌,之后以形态学方法对该病菌进行形态学鉴定,并通过细菌16SrDNA序列分析进行分子鉴定。结果表明,该病原为成团泛菌Pantoea agglomerans。致病性测定结果表明:该菌致病时间短,危害较大。主要通过伤口侵入植株叶片组织使得寄主发病,而植株茎干的损伤对植株发病短期内无明显影响,通过根际土壤接种发现,该细菌并不能直接由根部进入植株体内。     

肇庆地区柑橘内生细菌的分离及初步鉴定

[目的]寻找有效抑制柑橘黄龙病病原菌的拮抗内生菌.[方法]从肇庆地区所属的6个县（市）的柑橘果园中采集24份柑橘植株的枝叶样本,利用平板分离培养方法对其内生细菌进行了分离,并对其进行了鉴定.[结果]从柑橘枝叶样本中共分离得到柑橘内生细菌55株,经显微形态初步鉴定,分属于5个属.[结论]为柑橘黄龙病的防治提供了理论依据.     

养殖大菱鲆腹水病病原菌的分离与鉴定

[目的]从养殖大菱鲆中分离腹水病病原菌,并对其进行鉴定。[方法]从山东半岛2个不同的养殖场腹水病发病大菱鲆体内分离病原菌,并通过常规生理生化试验和16S r DNA基因序列对比对其进行鉴定。[结果]共分离到2株优势细菌。常规生理生化特征分析表明,这2株菌分别与鲨鱼弧菌(Vibrio carchiariae)和大菱鲆弧菌(Vibrio scophthalmi)表性特征非常相似。系统发育树分析表明这2株菌与鲨鱼弧菌(Vibrio carchiariae)和大菱鲆弧菌(Vibrio scophthalmi)的亲缘关系最近。[结论]这2株细菌被鉴定为鲨鱼弧菌(Vibrio carchiariae)和大菱鲆弧菌(Vibrio scophthalmi)。     

Ratoon stunting disease of sugarcane: isolation of the causal bacterium

A small coryneform bacterium was consistently isolated from sugarcane with ratoon stunting disease and shown to be the causal agent. A similar bacterium was isolated from Bermuda grass. Both strains multiplied in sugarcane and Bermuda grass, but the Bermuda grass strain did not incite the symptoms of ratoon stunting disease in sugarcane. Shoot growth in Bermuda grass was retarded by both strains.     

一例黄沙鳖红脖子病的病原菌鉴定与防治

从患红脖子病黄沙鳖的肝脏、肺脏分离到一株细菌,人工感染黄沙鳖证实为该病的病原菌。对该菌的形态特征、生理生化进行分析和双重PCR鉴定,确定为携带气溶素(aer)基因的致病性嗜水气单胞菌。药敏试验结果显示,该菌对头孢哌酮、氧氟沙星、恩诺沙星3种药物敏感;选用头孢哌酮和恩诺沙星对该病进行防治,获得较好的治疗和控制效果。     

从植物中分离苏云金芽孢杆菌的研究

 苏云金芽孢杆菌是目前研究最深入、应用最广泛的杀虫微生物,广泛分布于世界各地。从热带雨林到北极冻土带,从昆虫尸体、野生动物、动物粪便、贮藏物或尘埃、植物表面、鲜水到土壤中都有Bt存在。以植物叶片作为Bt菌株分离资源的相关研究相对较少,而非维管束植物中分离Bt菌株的报道更是屈指可数。从植物中分离Bt不但能丰富Bt的生态学意义,还能极大地丰富Bt的菌种资源。本文就植物上分离微生物、维管植物分离Bt的研究进展及非维管植物分离Bt的研究前景做简单介绍。     

养殖大菱鲆肠炎病的流行病学和病原学研究

[目的]肠炎病是目前大菱鲆养殖行业中比较常见的疾病之一,该病感染率高,传播迅速。[方法]从山东半岛3个不同的养殖厂肠炎病发病大菱鲆体内分离致病菌,对其进行了常规生理生化特征测试和16S rRNA基因序列对比研究。[结果]从发病大麦鲆体内共分离到了株优势细菌。理化特征分析结果显示这3株菌中有2株分别与溶藻弧菌(Vibrio alginolyticus)和大菱鲆弧菌(Vibrio scophthalmi)表型特征非常相似,另1株细菌被证实为非弧菌属的细菌,具体定种尚需进一步研究。分析这2株弧菌属细菌的16S rRNA基因序列并构建了系统发育树,结果表明这些菌株与溶藻弧菌(Vibrio alginolyticus)和大菱鲆弧菌(Vibrio scophthalmi)的亲缘关系最近。[结论]从发病大菱鲆体内分离菌株的2株细菌被鉴定为溶藻弧菌(Vibrio alginolyticus)和大菱鲆弧菌(Vibrio scophthalmi)。     

福建地区不结球白菜黑腐病病原菌的分离与初步鉴定

为鉴定福州地区不结球白菜黑腐病致病菌,以感染黑腐病的不结球白菜植株为材料进行了病原菌分离和鉴定。通过观察所分离病原菌的形态及接种试验发现其形态和发病症状与黑腐病的形态和发病症状相一致。以细菌通用引物16S对该病原菌进行16SrDNA的PCR扩增测序分析,发现该病原菌与野油菜黄单胞菌(Genbank:CP017308.1)16SrDNA序列同源性为99.8%。从接种病原菌植株中重新分离病原菌,其16SrDNA序列与之前接种菌株序列一致。以上结果初步证明分离的病原菌为不结球白菜黑腐病病原菌,且该病原菌为十字花科黑腐病野油菜黄单胞菌野油菜致病种。     

仔猪水肿病病原鉴定及免疫预防

从某猪场分离到1株细菌,通过培养特性、菌体形态、菌落形态、染色特性、生化试验及血清学试验等一系列系统鉴定,确定为埃希氏大肠杆菌。动物致病性试验表明,该菌对小白鼠有较强的致病性,并引起死亡。分离菌制成油佐剂灭活菌能有效预防猪群再次暴发仔猪水肿病。     

草鱼铜绿假单胞菌的鉴定及药物敏感性分析

从患病草鱼C tenopharyngodon idella体表病灶上分离到一株优势菌,经分离纯化培养制成细菌悬液,分别以腹腔注射和浸泡两种方式感染草鱼。结果表明：该菌株能感染草鱼,且具较强毒力,腹腔注射0.2mL该菌液（3×109cfu/mL）,可导致受试草鱼100%死亡;创伤浸泡感染（3×108cfu/mL）,死亡率也达100%,受感染鱼出现与自然感染相似的类似赤皮病症状。对该病菌进行形态特征观察和主要理化特性分析,初步鉴定为铜绿假单胞菌Pseudom onas aeruginosa。进一步对该菌进行分子鉴定,共选用16S rRNA、RNA聚合酶β亚单位（rpoB）和促旋酶亚单位蛋白（gyrB）3个基因进行鉴定分析。序列克隆与BLAST分析结果显示,这3个基因均与GenBank上登录的铜绿假单胞菌的相应序列具有很高的同源性,16S rRNA、rpoB和gyrB基因与已知铜绿假单胞菌相应序列的同源性分别在99%、98%和93%以上。综合生理生化与分子鉴定结果,可判定所分离的菌株为铜绿假单胞菌。药敏试验结果显示：该菌对阿米卡星、菌必治、氟哌酸和妥布霉素等11种药物高度敏感,对链霉素和庆大霉素中度敏感,对罗红霉素、红霉素、四环素、苯唑青霉素、新霉素和头孢氨苄等16种药物具有耐药性。     

山瑞鳖嗜水气单胞菌感染的诊断及防治

从患病山瑞鳖的肝脏、肺脏分离到1株细菌,对该菌的形态特征、生理生化进行分析,初步鉴定为嗜水气单胞菌。采用BioFosun-Ⅰ微生物鉴定系统对该菌进一步鉴定,结果显示为嗜水气单胞菌,可能性概率（PROB）为99%,相似性指数（SIM）和位距指数（DIS）分别为0.989和0.099。综合形态特征、生理生化特点及微生物鉴定系统鉴定结果,可将从发病山瑞鳖分离到的病原鉴定为嗜水气单胞菌。人工感染试验表明,该嗜水气单胞菌是引起山瑞鳖发病的病原且具有高度致死性;药敏试验结果则表明,该菌对头孢哌酮、阿米卡星、氧氟沙星、恩诺沙星4种药物敏感;选用头孢哌酮和恩诺沙星对病鳖进行治疗,可获得较好的治疗和控制效果,为今后山瑞鳖养殖生产中更有效地防制由该菌引起的疾病提供参考。     

一株芽孢杆菌的室内抑菌效果

1986年从乌海市土壤中分离到1株细菌,对10种植物病原真菌均有抑制效果。经鉴定属于芽孢杆菌属(Bacillus sp)。室内接种试验表明,对芝麻叶枯病(Alternaria sesami)和黄瓜枯萎病(Fusarium oxysporium f. sp. cucumerinum)均有很好的抗侵染效果。     

紫菜叶状体的红烂病研究

从福建省平潭岛野生坛紫菜群体中发现有患细菌性红烂病的叶状体,从患病的叶状体上分离得到病原细菌一株,经16S rDNA序列分析发现其与细菌域海螺菌目(Oceanospirillales)、盐单胞菌科(Halomonadaceae)、Cobetia属的海科贝特菌(Cobetia marina)的相似度达100%。病原细菌经液体培养基扩大培养后,将适量的菌液接种到不同种紫菜和坛紫菜不同品系的叶状体圆盘块上进行人工回复感染试验以确定其感染特性。结果发现该病原细菌能感染健康野生坛紫菜且出现的病症与海区患病坛紫菜相同,且该病原细菌对不同种紫菜(坛紫菜、条斑紫菜、未定名紫菜)的叶状体圆盘块和不同品系的坛紫菜(AN-2,YZ-6,JIU-7,ZS-1)叶状体圆盘块均能快速感染,所产生的病症与野生坛紫菜叶状体感染红烂病的症状相同:均出现了铁锈红色的死亡细胞,且同时含有少量被解离的单离细胞。上述结果说明分离到的病原细菌是坛紫菜红烂病的病原细菌,可以快速感染各种不同的紫菜叶状体。     

紫菜叶状体的红烂病研究

从福建省平潭岛野生坛紫菜群体中发现有患细菌性红烂病的叶状体,从患病的叶状体上分离得到病原细菌一株,经16S rDNA序列分析发现其与细菌域海螺菌目(Oceanospirillales)、盐单胞菌科(Halomonadaceae)、Cobetia属的海科贝特菌(Cobetia marina)的相似度达100%。病原细菌经液体培养基扩大培养后,将适量的菌液接种到不同种紫菜和坛紫菜不同品系的叶状体圆盘块上进行人工回复感染试验以确定其感染特性。结果发现该病原细菌能感染健康野生坛紫菜且出现的病症与海区患病坛紫菜相同,且该病原细菌对不同种紫菜(坛紫菜、条斑紫菜、未定名紫菜)的叶状体圆盘块和不同品系的坛紫菜(AN-2,YZ-6,JIU-7,ZS-1)叶状体圆盘块均能快速感染,所产生的病症与野生坛紫菜叶状体感染红烂病的症状相同:均出现了铁锈红色的死亡细胞,且同时含有少量被解离的单离细胞。上述结果说明分离到的病原细菌是坛紫菜红烂病的病原细菌,可以快速感染各种不同的紫菜叶状体。     

Male-killing bacteria in a parasitic wasp

A rod-shaped bacterium has been isolated that kills male eggs of the wasp Nasonia vitripennis, a pupal parasite of flies. Only some wasps of this species express this son-killer trait, and these wasps have bacterial infections in various organs. The bacterium was isolated from son-killer wasp tissue and from the hemolymph of fly pupae parasitized by wasps expressing the son-killer trait. Bacteria are apparently transferred to parasitized fly pupae during wasp oviposition, and developing wasp offspring are subsequently infected perorally. Sex-ratio distortion by microorganisms is found in a variety of plants and animals. The infectious peroral transmission of this trait variety of plants and animals. The infectious peroral transmission of this trait is in contrast to the typical pattern of cytoplasmic inheritance of sex-ratio distortion in these other systems.     

Vibrio damsela, a Marine Bacterium, Causes Skin Ulcers on the Damselfish Chromis punctipinnis

A previously undescribed marine bacterium, Vibrio damsela, was isolated from naturally occurring skin ulcers on a species of temperate-water damselfish, the blacksmith (Chromis punctipinnis). Laboratory infection of the blacksmith with Vibrio damsela produced similar ulcers. Vibrio damsela was pathogenic for four other species of damselfish but not for members of other families of fish. The bacterium has also been isolated from water and from two human wounds and may be a cause of human disease.