香石竹扦插苗茎腐真菌病研究

从香石竹扦插茎腐苗上分离纯化了35株镰刀菌，优势菌为：串珠镰孢（F．moniliform Sheldon）11株，串珠镰孢中间变种（F．moniliforme var．intermedium Neish＆leggestt）9株，尖孢镰孢（Fusarium oxysporum Schlecht）8株，其次还有茄病镰孢蓝色变种（Fusarium solanivat．coeculeum（Sacc．）Booth）等7株，共6个种和变种；选用12株菌检测其致病性，其中11株菌的致病率高达88～100％；农药药效实验表明。大生的效果最好，0．1g／L即能完全抑制5株试验菌的生长；其次为甲霜灵-锰锌；根病必治的效果最差。     

一起多源性污染所致的攀枝花市某高校菌痢爆发调查分析

目的查明该高校菌痢爆发的流行因素，并迅速、有效控制该校菌痢疫情。同时对此次突发公共卫生事件进行分析评价，为制定我区肠道传染病防制对策提供科学依据。方法采用流行病学调查中的现场调查和个案调查，临床和实验室诊断，Excel统计方法。结果该校共发生90例菌痢，无死亡病例；全校学生罹患率为7．21％。；病例大便培养发现志贺氏菌，食堂饮用水采样检测发现细菌总数超标，有2例炊管人员检出奇异变形杆菌，炊具检出奇异变形杆菌、志贺氏菌等。经控制传染源、切断传播途径、保护易感人群等措施后，此次菌痢爆发得到控制。结论此次菌痢爆发是一起多源性污染，主要为局部水源、食品污染及未经处理的生活污水浇灌绿化地而引起的菌痢爆发。其经验教训将为我区制定学校传染病防治对策、紧急应对突发公共卫生事件提供针对性依据。     

鼠奇异变形杆菌的鉴别诊断

目的对一株小鼠奇异变形杆菌进行了鉴定,为实验动物细菌检测、鉴别诊断提供参考依据。方法通过培养特性、菌落形态、染色和系列生化试验等检查,对疑似沙门氏菌的小鼠分离菌株进行初步鉴定,并采用血清凝集试验对小鼠分离菌株作进一步鉴定。结果通过表型生物学特性鉴定,并结合血清学诊断鉴别方法,确证该小鼠分离菌株为奇异变形杆菌。结论尽管检出的奇异变形杆菌不是SPF动物所必须排除的病原菌,但仍需指出:该菌为条件致病菌,对实验动物和研究人员均有潜在的危害,对科学实验也可能造成不利影响,故应引起高度重视。     

外科感染及治疗

目的实时监测和回顾性分析病房感染细菌的菌种和药物敏感率，以指导临床合理用药。方法检索数据库关于外科感染的资料，并进行分析。结果检出株菌中铜绿假单胞菌居首位，检出率为18％；金黄色葡萄球菌次之，检出率为17％；其后为凝固酶阴性葡萄球菌、大肠埃希杆菌、粪肠球菌、肺炎克雷白杆菌、奇异变形杆菌、不动杆菌及阴沟肠杆菌等。抗生素对铜绿假单胞菌敏感率超过50％者有13种。金黄色葡萄球菌（MRSA）仍具有极强的耐药性，而万古霉素对金黄色葡萄球菌（MRSA）为100％敏感。结论长期监测致病菌种及药物敏感性的变化以指导临床合理选择应用抗生素是非常重要的。     

幼兔细菌性感染症的检验与分析

从自然发生的2月龄幼兔肺脏中分离到3种类型的细菌(记作:a,b,c),经对所做的纯培养30株分离菌的形态特征、理化特性等检验,结果表明a菌(17株)为支气管炎博德特氏菌(Bordetellabronchiseptica);b菌(8株)为铜绿假单胞菌(Pseudomonasaeruginosa);c菌(6株)为大肠埃希氏菌(Escherichiacoli)。通过人工感染试验,表明其为相应的致病菌。     

独占春菌根真菌的调查

采用根组织切片法调查独占春菌根真菌，菌根感染率为31．88％；共得到22株真菌，属于半知菌，共计6属，其中刚毛菌属7株，占31．82％，为优势菌；从独占春栽培土壤中分离到21株真菌，其中。丝核菌属12株，占57．14％，为优势菌。     

致树鼩腹泻的奇异变形杆菌分离鉴定及药敏试验

目的诊断导致树鼩(Tupaia belangeri)腹泻的肠道致病菌,为疾病预防和控制提供参考。方法采集6只腹泻树鼩新鲜粪便,按常规肠道细菌鉴定方法进行分离培养,观察细菌形态和各菌种比例,对优势可疑菌进行生化和分子生物学鉴定,并进行了8种常用抗菌素的敏感试验。结果培养菌落在营养琼脂培养基上多数呈黄白色,表面光滑湿润;在S.S琼脂培养基上菌落为圆形、中心发黑,有的蔓延成黑色波纹状且有臭味。细菌形态为两端钝圆短杆菌,大小为(0.4—0.6μm)×(1.0—3.0μm),无芽孢和荚膜,革兰氏染色阴性,非抗酸菌。生化鉴定该分离株产硫化氢,鸟氨酸、尿素等反应阳性。核酸扩增后与GenBank中奇异变形杆菌相似度达99%。鉴定为奇异变形杆菌。该分离株对左氧氟沙星、环丙沙星等8种药物均敏感。结论作为条件致病菌的奇异变形杆菌能够引起哺乳期母树鼩和仔树鼩腹泻甚至死亡。实施针对性的饲养管理和药物治疗,可有效地控制该疾病的传播。     

白暨豚体表致病菌的分离鉴定

从白暨豚体表皮肤溃烂处分离得到一株嗜水单气胞杆菌，经过纯化培养，电镜观察，生理生化鉴定及毒力试验，证明该菌为白暨豚体表皮肤致病菌，属于嗜水气单胞菌嗜水亚种。药物抑菌试验表明；广谱抗菌素类药物对该菌都有较强的抑制生长能力。     

应用RAPD技术研究金黄色葡萄球菌和铜绿假单胞菌DNA的多态性

本试验利用RAPD技术对临床上重要的致病菌金黄色葡萄球菌28株和铜绿假单胞菌2l株，用10bp引物进行扩增，结果铜绿假单胞菌和金黄色葡萄球菌的DNA带谱均出现了多态性；根据带谱的不同可将铜绿假单胞菌分成8个型，金葡菌分成3个型；根据铜绿假单胞菌的带型计算各菌间的相似系数，依此系数绘制了系统树，从系统树中清晰可见各菌间的亲缘关系。     

一株产黄酮银杏内生真菌的分离鉴定与培养介质的初步研究

从银杏（Ginkgo biloba L.)叶片中分离获得了一株内生真菌EG4，经形态学分类研究鉴定为刺盘孢Colletortrichum sp.用TLC分析培养液发现该菌可产生黄酮类化合物，培养生物学特性的研究表明不同的碳，氮源对其生长和代谢有不同的影响，蔗糖和葡萄糖，NH4^ ，能够明显促进其生长；乳糖，NO2^-能够明显促进其酮类物质的合成。     

2种拟青霉代谢产物对烟蚜乙酰胆碱酯酶和羧酸酯酶的影响

 以粉拟青霉菌的sw03032菌株和玫烟色拟青霉菌的sw03085为研究对象,比较其代谢产物的杀蚜虫活性和对烟蚜乙酰胆碱脂酶和羧酸酯酶活性的影响.结果表明2种真菌发酵液含有能毒杀蚜虫的毒素物质.且毒素粗提物浓度越大,杀蚜活性越强.经玫烟色拟青霉菌不同浓度毒素粗提液处理的蚜虫乙酰胆碱酯酶比活力分别比对照(CK2)降低了70.4%～29.8%.不同浓度玫烟色拟青霉菌毒素粗提液处理12h后,蚜虫羧酸酯酶比活力分别比对照(CK2)降低79.5%～44.4%.用不同浓度粉拟青霉菌毒素粗提液处理烟蚜12h后,乙酰胆碱酯酶和酸酸酯酶活性分别降低了38%～18.6%和51.6%～59.5%.玫烟色拟青霉菌的sw03085菌株代谢产物对烟蚜的伤害活性明显较粉拟青霉菌sw03032菌株代谢产物高.     

耐碳青霉烯酶肺炎克雷伯菌的分离鉴定及生物学特性分析

以临床尿路感染患者尿液为研究对象,通过分离培养及16s rDNA进行肺炎克雷伯菌的分离鉴定;采用Kirby-Bauer纸片法进行药敏实验,并对分离株进行碳青霉烯酶表型筛选;通过PCR检测常见的碳青霉烯酶耐药基因、荚膜血清型和毒力基因分布情况;对分离的肺炎克雷伯菌株进行了生物被膜形成能力及其对小鼠致病力的分析。本研究从采取的86例尿液标本中分离检出11株耐碳青霉烯酶肺炎克雷伯菌,分离率为12.79%。耐碳青霉烯酶基因PCR检测结果显示,blaNDM、blaVIM、blaIMP和blaKPC基因在分离株中均呈现不同程度的分布。耐药性分析发现11株肺炎克雷伯菌对氨苄西林耐药率为90.91%,对头孢噻肟耐药率为63.64%,对链霉素、庆大霉素、氯霉素和诺氟沙星的耐药率较低。耐碳青霉烯类肺炎克雷伯菌荚膜分型结果显示,分离的11株细菌中10株均为强毒力型菌株（90.9%）,其中K57血清型4株（36.4%）,K1血清型1株（9.1%）,K2血清型1株（9.1%）,K5血清型1株（9.1%）,K20血清型3株（27.3%）,提示该批分离株具有较强的致病力。此外,毒力因子分布结果显示,其毒力因子rmpA（54.5%）、Aerobactin F（54.5%）在菌株中分布较为广泛。生物被膜形成能力检测及小鼠致病性试验结果显示,9株分离株均有较强的生物被膜形成能力,菌株致病力可能与荚膜血清型及生物被膜形成能力相关。综上所述,临床分离的致尿路感染病原肺炎克雷伯菌呈现多重耐药特征,强毒力菌株以K57荚膜型为主,K1、K2均有分布,提示对尿路感染病原应加强耐药监测,合理使用抗菌药物,有效防控多重耐药和强毒力菌株的感染与流行。     

Characterization of nitrogen-fixing moderate halophilic cyanobacteria isolated from saline soils of Songnen Plain in China

Twenty out of 200 isolates of cyanobacteria mainly from saline soils of Songnen Plain of China were successfully grown on BG11 N-free medium. The nitrogen-fixing activity was then demonstrated for the twenty isolates in modified BG11 medium using the acetylene reduction assay. All of them possessed appreciable nitrogenase activity (acetylene reduction) under non-saline conditions; however, at 5 % NaCl only 60 % of the isolates exhibited a high rate of this activity and 25 % were completely negative under these conditions. The cyanobacteria isolates grew well in BG11 medium; nevertheless, growth of the majority of isolates was reduced by about 25%-85% in the same medium containing 5% NaCl. Cellulolytic activity was detected in 50% of the twenty strains, amylolytic in 45%, and pectinolytic in 10% of the isolates. The cyanobacteria isolates showed also enzymeatic activity under saline conditions (6%). The preliminary identification indicated that seven isolates were Nostoc, two were Microcystis, four were Oscillatoria, six were Anabaena, and one isolate was Synechococcus.      

Genetic diversity of rhizobial populations recovered from three Lotus species cultivated in the infra-arid Tunisian soils

Eighty-three bacterial strains isolated from root nodules of Lotus creticus, L. pusillus, and L. arabicus grown in infra-arid Tunisian soils were characterized using a polyphasic approach including phenotypic analysis, rep-PCR and PCR-RFLP analyses of the 16S rRNA gene. Phenotypically, all isolates are fast growers the majority of which grow at a pH of between 5.5 and 9. Most of the tested isolates tolerate NaCl concentrations from 1.39% to 3.48%. By rep-PCR fingerprinting, the genomic similarity varied from 30% to 98%. All tested isolates were clustered into 32 rep-PCR clusters at the similarity level of 80%. The genomic divergence of strains revealed by rep/PCR analysis appeared to be very important since a molecular polymorphism delimiting symbionts for each species of Lotus was identified. With the high-resolution of rep-PCR profiles of the isolates obtained using Pearson’s/UPGMA analysis, the isolates were resolved into 60 different profiling groups to undergo 16S ARDRA analyses. The analysis of all restriction fragments from each strain based on the UPGMA algorithm from the combined patterns showed that Lotus isolates are very diverse and that they were affiliated to Sinorhizobium, Rhizobium, and Mesorhizobium genera.     

Ovicidal activity of two fungal pathogens （Hyphomycetes）against Tetranychus cinnabarinus （Acarina：Tetranichidae）

The carmine spider mite, Tetranychus cinna-barinus, is an economically important pest that devastates varieties of crops worldwide and develops significant resistance to common chemical pesticides, most of which lack ovicidal activity. In the present study, two isolates of entomopathogenic fungi, Beuaveria bassiana SG8702 and Pae-cilomyces fumosoroseus Pfrl53, were bioassayed against T. cinnabarinus eggs at 25 ℃ under a photophase of 12 : 12 (L:D). Infected eggs on Vicia faba var. minor leaves failed to hatch due to distortion and shrinkage and had fungal outgrowths when maintained under moist conditions. Sprays of B. bassiana conidia to T. cinnabarinus eggs (on leaves) at the concentrations of 58, 298 and 1306 conidia/mm2 (3 replicates per concentration and 35-65 fresh mite eggs per replicate) resulted in corrected egg mortalities of 20.4±4.2%, 36.0±7.6% and 64.6±12.5% (F=43.14, P <0.01), respectively; sprays of P. fumosoroseus at 129, 402 and 2328 conidia/mm2 caused egg mortalities of 16.1±11.1%,     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most e?ective isolate.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most e?ective isolate.     

红色赤潮藻对球形棕囊藻的化感作用研究

红色赤潮藻(Akashiwo sanguinea)和球形棕囊藻(Phaeocystis globosa)都是近年来在我国近岸海域频繁引发赤潮的藻类。为了探索红色赤潮藻和球形棕囊藻之间是否存在化感作用及作用方式,本研究采用不同起始密度培养红色赤潮藻与球形棕囊藻,并将前者的完整细胞培养液、无细胞滤液、藻液超声破碎液分别与球形棕囊藻进行混合培养,分析红色赤潮藻对球形棕囊藻细胞生长的影响。结果显示,在红色赤潮藻细胞起始密度保持5×10⁵ cells/L的混合培养条件下,起始密度分别为5×10⁵、1×10⁶、2×10⁶、1×10⁷ cells/L的球形棕囊藻生长均受到明显的抑制;无论是含有红色赤潮藻完整细胞的培养液,还是其无细胞滤液或藻液超声破碎液,均对球形棕囊藻的生长具有显著抑制作用(P<0.01),抑制强度由强至弱依次为完整细胞培养液、无细胞滤液和藻液超声破碎液;相反,球形棕囊藻的存在对红色赤潮藻细胞的生长无显著影响(P>0.05)。因此,红色赤潮藻具有抑制球形棕囊藻生长...     

基于SSR的广西同色兜兰和带叶兜兰遗传多样性分析

评估四季开花型同色兜兰（Paphiopedilum concolor）和春季开花型带叶兜兰（P.hirsutissimum）的遗传多样性和种群结构,探究不同开花习性兜兰属物种间的遗传分化,为兜兰的可持续利用和野生资源保护提供理论依据。本研究利用10个多态性EST-SSR位点对12个同色兜兰和带叶兜兰种群的231个个体分型,开展遗传多样性、瓶颈效应、系统发育、遗传结构、遗传分化、距离隔离和环境隔离分析。结果表明,同色兜兰种群的大多数遗传多样性指标都显著（P<0.05）低于带叶兜兰;分子方差分析（AMOVA）结果显示,两者来自种群间的变异都较少,且带叶兜兰来自个体内的遗传变异高于同色兜兰。在同色兜兰的两个种群中检测到显著（P<0.05）瓶颈效应,而在带叶兜兰全部种群中均未检测到。群体水平的非加权平均（UPGMA）树和个体水平的邻接（NJ）树均显示同色兜兰和带叶兜兰间系统发育关系相对较近,并各自聚为一支。主坐标分析（PCoA）和Structure分析结果均支持系统发育分析结果。此外,遗传分化系数（F_ST）证实两个物种间的种群分化已达到较高水平。狭窄的自然分布和过去的种群瓶颈可能导致了同色兜兰的部分遗传多样性丧失。地理隔离是驱动同色兜兰和带叶兜兰种群遗传分化的主要因素,而环境隔离的作用较小。     

Green fluorescent protein （GFP） as a vital marker for studying the interaction of Phytophthora sojae and soybean

Transgenic Phytophthora sojae strains that produce green fluorescent protein （GFP） were obtained after stable DNA integration using the Hsp70 promoter and the Ham34 terminator of Bremia lactucae. The expression of GFP during different developmental stages of P. sojae was observed using fluorescent microscopy. Based on this reporter system, the histopathologic events caused by the pathogen in soybean leaves, hypocotyls and roots were monitored. Meanwhile, the difference in resistance between different soybean cultivars against P. sojae was analyzed microscopically in roots. The results indicate that GFP can be stably expressed in zoosporangia, zoospores, cysts, hyphae and oospores of P. sojae. Using the GFP marker, the infecting pathogens in leaves, hypocotyls and roots of host could be distinctly visualized. The germ tube length of cysts germinating on the roots of resistant cultivar Nannong 8848 was longer than that on the roots of susceptible cultivar Hefeng 35. These results show for the first time that this eukaryotic reporter can be used in P. sojae as a stable and vital marker, allowing the study of genetics of this hemibiotrophic pathogen.