棕榈科植物3株病原菌的拮抗放线菌筛选

以椰子灰斑病菌（Pestalotiopsis palmarum Cooke）、棕榈疫霉菌（Phytophthora palmivora）和霸王榈炭疽病菌（Colletotrichum sp）为指示菌,采用对峙培养法和抑菌圈法,从椰园土壤中筛选到8株具有明显拮抗效果的放线菌,菌株抗菌谱较广,对椰子灰斑病菌、棕榈疫霉菌和霸王榈炭疽病菌有较好的拮抗作用。其中1-1、14.1和WN3-20-1 3株菌株发酵液对3株病原菌均有较强的抑制作用。     

拮抗放线菌BS-112的鉴定及抗菌物质粗提物对家蚕主要病原菌的抑制作用

以绿僵菌(Nomuraea rileyi)和黑胸败血病菌(Bacillus sp.)为靶标,从泰山林地土壤中分离获得一株对多种家蚕病原菌具有强烈拮抗作用的放线菌BS-112。根据该菌株的形态特征、培养特征、理化性质、细胞壁组分及16S rDNA序列分析结果,将其鉴定为吸水链霉菌(Streptomyces hygroscopicus)。该菌株抗菌谱广,抗菌物质耐高温,在酸、碱环境比较稳定,抗菌物质粗提物对黑胸败血病菌和绿僵菌的最小抑菌浓度分别为19.53μg/mL和78.13μg/mL,最小杀菌浓度分别为78.13μg/mL和156.25μg/mL,表明在较低浓度下即可达到杀菌效果。     

一株拮抗放线菌的分类鉴定与发酵条件优化试验

采用形态观察、培养特征、生理生化鉴定以及16SrDNA序列分析方法,对本实验室筛选到的一株放线菌Fyss进行分类鉴定,同时对其发酵液的抑菌活性进行了研究。结果表明,菌株Fyss为链霉菌属,其发酵液对革兰氏阳性细菌具有抑制作用,适宜发酵条件为发酵培养基最适初始pH为8.0,培养时间5d,培养温度28℃,培养转速210rpm。     

中华鳖六株病原菌的分类鉴定及其中草药拮抗研究

为提高养殖质量、达到无公害中华鳖的生产,本研究对来源于不同地域的中华鳖常见疾病的六株致病菌(WG985、TL97427、FS954、JS967、SG978、SS978)菌株进行了分类鉴定与中草药抑菌敏感性测试.结果表明4株为温和气单胞菌,2株分别为嗜水气单胞菌和豚鼠气单胞菌,6菌株对健康中华鳖均有较强毒力.药敏测定显示各菌株对中草药的拮抗作用基本一致,对大多数药物均表现不敏感,仅就地锦草、五倍子等个别药物敏感,但彼此间仍存有一定差异.     

奇异根串珠霉菌拮抗放线菌的筛选与鉴定

本实验以奇异根串珠霉菌（Thielaviopsis paradoxa）为目标菌,通过平板梯度稀释法从槟榔根系土壤中分离获得放线菌,利用平板对峙法筛选对奇异根串珠霉菌具有抑菌活性的菌株,并通过发酵液复筛出4株抑制效果达90%以上的菌株,编号为D2-3、G1-12、D2-9和G9-4。通过培养特征、形态特征、生理生化特性及16S rDNA序列分析对抑制率99.76%的菌株D2-3进行分类鉴定,初步鉴定该菌株为一株链霉菌,与桑树链霉菌（Streptomyces samsunensis）16S rDNA序列相似性为99.41 %。     

香蕉枯萎病拮抗放线菌的分离鉴定及抑菌机理分析

为丰富香蕉枯萎病生防菌资源,探究其抑菌机理,从润楠树（Machilus pingii ）根系土壤中分离筛选对香蕉枯萎病具有拮抗作用的放线菌,基于16S rRNA序列进化分析和生理生化特征,鉴定其种属。利用激光共聚焦显微镜评测盆栽试验的防控效果,并通过扫描电镜、透射电镜分析其对孢子形态结构及超微结构的影响。筛选出一株拮抗效果较好的放线菌,鉴定为链霉菌属,命名为JRGG-11,该菌对枯萎病四号生理小种（Foc 4）的抑菌率为80.48±1. 49%,发酵液的抑菌率为58.77±1.31%。盆栽试验显示JRGG-11发酵液对Foc 4的防控指数为83.1%。菌株JRGG-11提取物对Foc 4菌丝生长抑制的EC50为18.70 μg/ml。当用4×EC50处理时,Foc 4菌丝形态和细胞完整性被严重破坏,孢子萌发完全被抑制。结果表明,链霉菌JRGG-11具有较好的生防潜能。     

鸡腹泻常见病原菌的分离与鉴定

为了深入了解当前鸡腹泻常见病原菌的种类及毒力等,本研究通过采集腹泻患鸡的病料,分别用细菌分离培养法、染色镜检法、动物试验和血清学方法进行分离与鉴定。试验结果表明：5株为鸡大肠杆菌、3株为肺炎双球菌、2株为链球菌、1株为鸡沙门氏菌,其中大肠杆菌、链球菌和肺炎双球菌均可使动物发病率高达100%。同时试验结果提示：50%（4/8）为混合感染,其余为单独感染。总之,目前引起鸡腹泻的主要病原菌为大肠杆菌、肺炎双球菌、链球菌、沙门氏菌等。本研究为养禽业有关鸡腹泻的正确诊断提供可靠依据,对该病的有效防控具有重要的理论指导意义和经济实用价值。     

动物屠宰常见水肿的鉴定

过多的液体在组织间隙或体腔中积聚称为水肿（液体积聚于体腔内,一般称为积水）。水肿不是单独的一种疾病,而是多种疾病的一种共同的病理过程。所以,宰后发现水肿病变时,必须严格把关。１常见水肿的鉴定１．１水肿的种类根据水肿发生的部位可分全身水肿和局部水肿两种。前者分布于全身,如心性水肿。肾性水肿和肝性水肿等;后者发生于局部,如皮下水肿、肺水肿等。根据水肿的外观是否明显可分隐性水肿和显性水肿。隐性水肿的特点是外观无明显的临床表现,只是体重有所增加;显性水肿的特点是局部肿胀,皮下紧张度增加,按之呈凹陷,稍后…     

17株水产动物病原菌的表型及分子遗传学鉴定

1996-1999年从患病鱼、鳖、蟹等水产动物体内分离并保存了17株病原菌．采用ATB expression细菌鉴定系统对这l7株病原菌进行表型鉴定．并应用优化的热变性温度法（Tm法）分别测定其染色体DNAG＋C mol％含量，进行分子遗传学鉴定，从而确定了17株病原菌的种属。     

成都地区小动物外科感染常见病原菌的鉴定及分析

为了解小动物外科感染的病原分布及感染情况,从成都部分动物医院18例小动物(犬、猫)外科感染病例中,无菌采集病灶浓汁、伤口分泌物等样品进行病原分离培养。通过全自动微生物分析鉴定仪及细菌的16S rRNA基因扩增测序鉴定,得到13种共39株细菌。通过真菌的ITS区序列扩增测序,得到3种共11株真菌。39株细菌中革兰阳性菌22株(占56.4%),常见病原为葡萄球菌属细菌(13株)、粪肠球菌(5株)、屎肠球菌(3株)等;革兰阴性菌17株(占43.59%),常见病原为奇异变形杆菌(4株)、肺炎克雷伯菌(4株)、大肠埃希菌(3株)和阴沟肠杆菌(3株)等。结果表明,革兰阳性菌是小动物外科感染的常见病原菌,其中以葡萄球菌属为主要病原,且伪中间葡萄球菌是优势病原。18例病例中,混合感染为16例,占比高达88.89%,其中以三重感染率最高,占50.00%,其次为二重感染,比例为22.22%。证实成都地区小动物外科感染类型以混合感染为主,在6个病例的样本检测到真菌,占33.33%,与细菌或多种真菌形成混合感染。     

5种植物提取物对猪致病菌的体外抗菌研究

本试验旨在采用气相色谱-质谱联机法对5种植物提取物进行成分分析,并采用试管倍比稀释法研究其对猪大肠杆菌、猪金黄色葡萄球菌的体外抑菌效果。结果表明,5种植物提取物的共有成分和主要成分为洋芹脑、吉马烯D、β-石竹烯、胡椒酮、α-蒎烯、4-萜烯醇、天然维生素E,且其对猪两种致病菌均有较好的抑制作用,其中广西华山蒟提取物杀菌效果最好。结论是5种植物提取物对猪两种致病菌呈现较好地体外抑杀效果,可能是因为其含有洋芹脑、吉马烯D、β-石竹烯、胡椒酮等活性抗菌成分所致。     

放线菌D01对马铃薯4种病原真菌的抑菌作用

采用PDA平板对峙法、生长速率法等方法,研究了放线菌D01对马铃薯干腐病菌、马铃薯黑痣病菌、马铃薯炭疽病菌和马铃薯早疫病菌4种病原真菌的抑菌活性。结果表明,放线菌D01对4种病原真菌均表现出显著的抑菌活性,发酵液抑菌率均在70%以上;经放线菌处理后,病原真菌的基内菌丝不同程度的发生了畸变;放线菌D01对供试靶标真菌均有显著的拮抗作用,其中对马铃薯干腐病菌和马铃薯黑痣病菌的持续抑菌作用最强。     

高尔夫草坪蘑菇圈真菌拮抗木霉菌株的筛选及其抑菌作用

草坪蘑菇圈是一种在高尔夫草坪上普遍发生的严重病害,经常造成草坪草的严重衰退甚至死亡。木霉(Trichoderma)菌对蘑菇圈真菌有良好的抑制作用。从贵阳乐湾国际高尔夫球场草坪出现的蘑菇子实体中分离出当地有代表性的真菌菌株1506,经形态学鉴定为环柄菇属菌株(Lepiota spp.)。并从曾发生过蘑菇圈病害,但第2年未发生蘑菇圈的草坪土壤中分离和筛选出典型拮抗木霉菌8株,其中加纳木霉GCPL175(Trichoderma ghanense)和木霉菌株GGFL12(Trichoderma.sp.)的抑菌能力最强,其发酵液的无菌滤液对1506抑菌率分别达到61.23%,73.13%,显著高出其他菌株95.75%,1178.50%(P0.05),但供试木霉菌株的几丁质酶活性与其对环柄菇属菌株1506的抑菌率无明显相关。     

Protein profiles of dense-centered forms of five chlamydial strains of animal origin.

Purified dense-centered form of 1 bovine strain (LW613) and 3 ovine strains (B577, 034-EYE, and 047-EYE) of Chlamydia psittaci and 1 murine strain of Chlamydia trachomatis (MoPn) were dissociated in the presence of sodium dodecyl sulfate (SDS) and 2-mercaptoethanol. The number of polypeptides detected in the 5 strains varied between 17 and 20, with a molecular weight range of 29,000 to 120,000. Two polypeptides predominated and comprised approximately a third of the total protein in each of the 5 strains. The average molecular weights of the 2 polypeptides were 89,000 and 85,250 for 4 of the strains, and the polypeptide molecular weights were 100,000 and 98,000 for the ovine abortion strain (B577). Molecular weights and proportional composition of the polypeptides permitted differentiation of the chlamydial strains. The 3 strains from naturally occurring conjunctivitis or polyarthritis (LW613, 034-EYE, and 047-EYE) had similar polypeptide profile in the 75,000 to 100,000 molecular weight range. The polypeptides of the ovine abortion strain (B577) differed significantly from these 3 strains. Eight of the polypeptides of this strain had a molecular weight of 100,000 or greater, and 3 of the predominant polypeptides were in excess of 100,000. In contrast, some of the polypeptides of the murine strain had lower molecular weights than the 4 other strains. Three predominant polypeptides had molecular weights below 50,000.     

In vitro competitive adhesion and production of antagonistic compounds by lactic acid bacteria against fish pathogens

The present study describes the screening of five lactic acid bacteria (LAB) for use as probiotics based on their competitive adhesion and production of antagonistic substances against some fish pathogens. A reduction of adhesion of all pathogenic strains tested was obtained with three of the LAB strains (Lactococcus lactis subsp. lactis CLFP100, Lactococcus lactis subsp. cremoris CLFP102 and Lactobacillus curvatus CLFP150). With the exception of fish pathogens Flavobacterium psychrophilum and Renibacterium salmoninarum that were not inhibited by LAB strains, production of antagonistic compounds by all tested LAB was observed against at least one of the indicator strains. Based on mucus adhesion, competitive exclusion, and suppression of fish pathogen growth, the selected LAB strains can be considered for future challenge experiments in fish as a very promising alternative to the use of chemotherapeutic agents.     

紫花苜蓿根腐病原——厚垣镰刀菌的鉴定及其拮抗菌的筛选

采用常规组织分离法,对甘肃省武威市紫花苜蓿根腐病菌进行分离和致病性测定,并通过形态学特征和分子鉴定方法对致病性最强的菌株进行鉴定。结果表明,MXGF7可造成紫花苜蓿严重根腐,该病原菌大型分生孢子多纺锤形或镰刀形,大小为3.3～4.7μm×14.8～32.0μm;小型分生孢子少,纺锤形或哑铃形,大小2.9～4.2μm×8.4～18.2μm;ITS序列及镰孢菌Fu3/Fu4区基因序列分析表明,病原菌均与Fusarium chlamydosporum的相似度达99%,结合形态学特征将该病原菌鉴定为厚垣镰孢菌F.chlamydosporum。采用平板对峙法,从分离自东祁连山高寒草地牧草的123株内生细菌中筛选出61株菌株对F.chlamydosporum有拮抗效果,且抑菌率均在55%,并利用形态特征和16SrDNA基因序列分析将具有稳定拮抗作用265ZY3菌株鉴定为解淀粉芽孢杆菌Bacillus amylolique　faciens。     

苦豆子及其复方药对奶牛子宫内膜炎5种致病菌的体外抑菌活性研究

采用酸法提取苦豆子(Sophoraalopecuroides L.)的有效成分,并用96孔板微量肉汤稀释法测定苦豆子生物总碱的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。采用(K-B)纸片扩散法,以盐酸小檗碱为对照,考察苦豆子提取物及其复方灌注剂对致病菌的抑菌效果。结果表明,苦豆子总生物碱对表皮葡萄球菌抑制效果最佳,MIC为16g/L,MBC为32g/L。苦豆子总生物碱、复方灌注剂及硫酸小檗碱的抑菌环平均直径分别为14.28,18.61和18.02mm。由此得出苦豆子总生物碱及其复方灌注剂有明显的抗菌作用。     

五大牛种转型记

秦川牛、南阳牛、晋南牛、鲁西牛、延边牛是我国的五大地方良种牛.改革开放30多年来,五大牛种一直致力于转变发展方式,从役用转型为肉用,从农户散养转型为专业化规模养殖,从农耕工具转型为独立的现代肉用牛产业.     

In vitro activity of five tetracyclines and some other antimicrobial agents against four porcine respiratory tract pathogens

The minimal inhibitory concentrations (MIC) of five tetracyclines and ten other antimicrobial agents were determined for four porcine bacterial respiratory tract pathogens by the agar dilution method. For the following oxytetracycline-susceptible strains, the MIC50 ranges of the tetracyclines were: P. multocida (n = 17) 0.25-0.5 micrograms/ml; B. bronchiseptica (n = 20) 0.25-1.0 micrograms/ml; H. pleuropneumoniae (n = 20) 0.25-0.5 micrograms/ml; S. suis Type 2 (n = 20) 0.06-0.25 micrograms/ml. For 19 oxytetracycline-resistant P. multocida strains the MIC50 of the tetracyclines varied from 64 micrograms/ml for oxytetracycline to 0.5 micrograms/ml for minocycline. Strikingly, minocycline showed no cross-resistance with oxytetracycline, tetracycline, chlortetracycline and doxycycline in P. multocida and in H. pleuropneumoniae. Moreover, in susceptible strains minocycline showed the highest in vitro activity followed by doxycycline. Low MIC50 values were observed for chloramphenicol, ampicillin, flumequine, ofloxacin and ciprofloxacin against P. multocida and H. pleuropneumoniae. B. bronchiseptica was moderately susceptible or resistant to these compounds. As expected tiamulin, lincomycin, tylosin and spiramycin were not active against H. pleuropneumoniae. Except for flumequine, the MIC50 values of nine antimicrobial agents were low for S. suis Type 2. Six strains of this species showed resistance to the macrolides and lincomycin.