共查询到20条相似文献，搜索用时 62 毫秒
1.
《渔业科学进展》2016,(2)
根据Gen Bank中公布的虾肝肠胞虫(Enterocytozoon hepatopenaei)(EHP)SSU r DNA序列设计1对特异性引物,建立并优化了EHP的SYBR Green I实时荧光定量PCR(q PCR)检测方法。结果显示,该方法在60℃的退火温度时扩增效果最好,产物的熔解曲线为1个单峰,构建的方法对8.3×101–8.3×108 copies/μl的EHP SSU r DNA片段的检测响应具有良好的线性关系,扩增产物阈值循环数(Ct)与模板起始量的对数[log(Sq)]的关系为Ct=–3.369 log(Sq)+39.364(R2=0.992),扩增效率为98.1%,检测灵敏度下限为8.3×101 copies/μl,在线性范围内具有良好的组内和组间重复性。对实际样品的检测表明该方法比已报道的套式PCR的检测灵敏度约高4倍。利用本方法对采集自江苏、海南和山东的3批凡纳滨对虾样品的肝胰腺组织DNA(Hp DNA)中的EHP SSU r DNA进行了q PCR检测,结果显示,EHP的载量指数与对虾生长速率呈负相关关系,肝胰腺中EHP载量在103 copies/(ng Hp DNA)时代表了较高的风险水平。本研究建立的q PCR方法具有特异、灵敏、快速、定量的优点,所建立的方法及检测数据可为EHP的防控提供技术参考。 相似文献
2.
2013年,河北、天津等地区养殖的凡纳滨对虾(Litopenaeus vannamei)育苗期出现死苗、出苗率低的情况,生产上,仔虾个体大小差异较大,造成了严重损失.本研究采用荧光定量PCR方法(Real-time PCR)对天津大港地区采集的108尾凡纳滨对虾仔虾样品进行单尾病原检测.结果显示,传染性皮下及造血组织坏死病毒(Infectious hypodermal and hematopoietic necrosis virus,IHHNV)和虾肝肠胞虫(Enterocytozoon hepatopenaei,EHP)均有检出.IHHNV阳性检出率100％,每微克对虾组织DNA的病毒拷贝数为103-107,且个体较大的样品(1.2-2.0 cm)携带病毒拷贝数偏高;EHP阳性检出率为49.1％,每微克对虾组织DNA的拷贝数为103-105,且集中于个体较小样品(0.7-1.1 cm).对IHHNV和EHP阳性凡纳滨对虾样品进行生物学体长与病毒载量指数相关性分析,显示IHHNV载量指数与对虾生长速率呈正相关,虾组织IHHNV平均载量达8.51×104 copies/μg DNA,为较高的感染水平;EHP的载量与对虾生长速率呈负相关关系,与较大个体阳性检出率较低相对应,虾组织EHP平均载量达到2.19× 104 copies/μg DNA,为较高的感染水平.由此,该批凡纳滨对虾仔虾患病为IHHNV和EHP的混合感染所致,本研究数据为IHHNV和EHP病原混合感染流行情况及其对养殖育苗期仔虾生长的影响提供科学依据. 相似文献
3.
《渔业科学进展》2017,(2)
2013年,河北、天津等地区养殖的凡纳滨对虾(Litopenaeus vannamei)育苗期出现死苗、出苗率低的情况,生产上,仔虾个体大小差异较大,造成了严重损失。本研究采用荧光定量PCR方法(Real-time PCR)对天津大港地区采集的108尾凡纳滨对虾仔虾样品进行单尾病原检测。结果显示,传染性皮下及造血组织坏死病毒(Infectious hypodermal and hematopoietic necrosis virus,IHHNV)和虾肝肠胞虫(Enterocytozoon hepatopenaei,EHP)均有检出。IHHNV阳性检出率100%,每微克对虾组织DNA的病毒拷贝数为10~3–10~7,且个体较大的样品(1.2–2.0 cm)携带病毒拷贝数偏高;EHP阳性检出率为49.1%,每微克对虾组织DNA的拷贝数为10~3–10~5,且集中于个体较小样品(0.7–1.1 cm)。对IHHNV和EHP阳性凡纳滨对虾样品进行生物学体长与病毒载量指数相关性分析,显示IHHNV载量指数与对虾生长速率呈正相关,虾组织IHHNV平均载量达8.51×10~4 copies/μg DNA,为较高的感染水平;EHP的载量与对虾生长速率呈负相关关系,与较大个体阳性检出率较低相对应,虾组织EHP平均载量达到2.19×10~4 copies/μg DNA,为较高的感染水平。由此,该批凡纳滨对虾仔虾患病为IHHNV和EHP的混合感染所致,本研究数据为IHHNV和EHP病原混合感染流行情况及其对养殖育苗期仔虾生长的影响提供科学依据。 相似文献
4.
对山东海阳和潍坊的2个养殖凡纳滨对虾群体取样,采用TaqMan qPCR逐尾检测肝胰腺中的虾肝肠胞虫(Enterocytozoon hepatopenaei, EHP)载量,再将提取的DNA样品按5并1(5∶1)、25并1(25∶1)、50并1(50∶1)、100并1(100∶1)和150并1(150∶1)进行并样,检测并样的EHP载量。设定不同临界循环数为假定灵敏度,定性判断各单尾检测阳性及并样组阳性,比较不同并样模式与检测阳性率、诊断灵敏度、诊断特异性等之间的关系以及定量的准确性。结果表明,检测灵敏度过低,会降低高并样率检测的准确性;阳性率在30%以上时,高并样率的检测结果与单样品检测相符性很好;高载量感染的阳性率不低于6.7%时,50∶1以内的并样能准确得出检测结果;低载量感染的阳性率不低于16%时,25∶1以内的并样能得出较好结果;高载量感染的1.3%阳性率和低载量感染的8%阳性率可能导致所有并样出现假阴性结果;各种并样模式均有很好的诊断特异性,50∶1并样的诊断灵敏度与OIE标准推荐的5∶1并样的接近;各并样检测的EHP载量与单样品检测平均值之比在0.27~2.83范围,二者存在极显著相关性,各种并样模式的定量检测结果在数量级水平能大致反映样品的平均EHP载量。本研究为水生动物疫病诊断和流行病学调查的样品检测提供了参考依据。 相似文献
5.
采用差速离心和密度梯度离心,从感染虾肝肠胞虫(Enterocytozoon hepatopenaei,EHP)对虾的肝胰腺中,尝试纯化出孢子,并应用透射电镜、荧光桃红染色和血球计数板计数的方法对纯化出的孢子进行了观察和计数。结果表明,从1g的EHP载量为(4.7±2.2)×104 copies/ng DNA的肝胰腺组织中经差速离心和密度梯度离心方法分离到EHP的孢子,电镜观察孢子为大小在0.7～1.2μm的椭圆形,纯化孢子悬液用血球计数板计数显示孢子浓度为5.30×103个/μL,蔗糖密度梯度中的纯化孢子区带含有的孢子总数约1.06×106个。 相似文献
6.
根据对虾肝胰腺细小病毒(HPV)保守基因序列,设计特异性的锁式探针及其扩增引物,优化反应条件,建立了肝胰腺细小病毒超分支滚环扩增检测方法。实验中采用一步法连接,探针在Taq DNA连接酶作用下,58℃连接40 min、62℃扩增30 min便可以扩增出明显条带。反应特异性验证实验表明,该体系能够特异性地检测出HPV,而不与供试的其他对虾病原发生交叉反应;灵敏度分析结果显示该方法的检测极限为105 copies/μl,与PCR检测方法相比,一步法连接的滚环扩增的灵敏度低两个数量级。该方法反应过程中温度变化次数少,基本都在等温条件下进行,不需要PCR仪,可发展成为在简便实验条件下使用的简易检测方法。 相似文献
7.
近年来,虾肝肠胞虫(Enterocytozoon hepatopenaei, EHP)流行使我国养殖对虾遭受严重经济损失,现场快速检测是EHP防控的重要技术保证。本研究对本实验室研发的EHP现场快速检测试剂盒的分析特异性(ASp)、分析灵敏度(ASe)、诊断特异性(DSp)、诊断灵敏度(DSe)、重复性和稳定性6项性能参数开展了系统评估。ASp测试显示,该试剂盒与对虾白斑综合征病毒(WSSV)、偷死野田村病毒(CMNV)、虾血细胞虹彩病毒(SHIV)、致急性肝胰腺坏死病副溶血弧菌(VpAHPND)、传染性皮下及造血组织坏死病毒(IHHNV)等5种对虾常见病原及健康对虾无交叉反应;ASe测试显示,该试剂盒检测下限为101 copies/反应;以EHP TaqMan RT-qPCR方法为标准,比较了试剂盒对298份临床样品的测试结果,试剂盒的DSp为99.2%、DSe为91.7%;试剂盒对EHP阴性样品及强阳性样品的检测重复率为100%,弱阳性样品检测重复率为95.8%;试剂盒在–20℃和–40℃条件下分别可保存7个月和12个月以上。本研究表明,本实验室研制的EHP现场快速检测试剂盒具操作简便、快速、灵敏度高、特异性强、重复性好和稳定性强等优点,可满足对虾养殖现场对EHP的高灵敏度检测。 相似文献
8.
对来自河北黄骅(HH)、山东平度(PD)、江苏吴江(WJ)和山东日照(RZ)的4个凡纳滨对虾(Litopenaeus vannamei)群体进行了对虾生长参数测量,用Taq Man q PCR检测了凡纳滨对虾各群体的肝胰腺组织中和RZ群体多种组织中的虾肝肠胞虫数量(Amount of Enterocytozoon hepatopenaei,EHP)。结果显示,在主要生长相关参数中,RZ群体最优,该群体EHP载量也最低。不同群体的样本数EHP对数直方图的模式存在差异,HH和PD群体的EHP对数呈双峰分布,而WJ和RZ群体的EHP对数呈单峰分布,代表EHP在不同群体中可能存在不同的传播模式。EHP对数呈单峰分布的群体或从多峰分布的群体中分离出的高EHP对数子群体的对虾体长或体重与EHP对数呈显著的负相关。RZ群体中,各个体不同组织中EHP从高到低的顺序依次是肝胰腺中肠血淋巴鳃肌肉。肝胰腺、中肠和鳃3个组织中EHP对数相互间的相关性为99.9%的极显著水平(P0.001);除了中肠与血淋巴和肝胰腺与血淋巴以外,其余组织间EHP对数的相关性也达到极显著(P0.01)或显著(P0.05)水平。用DIG标记的EHP探针对肝胰腺、肌肉、鳃、肠道组织的原位杂交显示,肝胰腺是主要的EHP感染组织,其他组织中杂交信号较弱,但各组织中有少数细胞的EHP易感。 相似文献
9.
虾苗场3种重要病原同步定量PCR检测技术的建立 总被引：1，自引：0，他引：1
白斑综合征病毒(white spot syndrome virus, WSSV)、虾肝肠胞虫(Enterocytozoon hepatopenaei, EHP)和虾虹彩病毒(decapod iridescent virus 1, DIV1)为近年来凡纳滨对虾(Litopenaeus vannamei)育苗场内的主要生物性危害因素,其中2种或3种病原共感染的现象也较为常见,快速、准确地检测和鉴别这3种病原是大型苗场生物安保体系构建和无特定病原虾苗生产的迫切需求。基于SYBR Green I染料法,建立了同步扩增3种病原的定量PCR检测技术。结果显示,该同步方法对3种病原的标准曲线相关系数(R~2)均大于0.99,且检测限可低至10 copy·μL~(-1),尤其是WSSV,在低至1 copy·μL~(-1)时仍能保持较好的组内和组间重复性。熔解曲线分析显示,该同步定量PCR技术对对虾样品的扩增产物只在78.4℃、79.7℃、83.5℃处出现3个尖锐峰,分别与3种病原(DIV1、EHP和WSSV)扩增产物的T_m值相对应。以上结果表明,建立的同步定量PCR检测技术具有较高的检测灵敏度和良好的病原特异性,可以在50 min内同步完成对3种病原的快速鉴定和组织内病原含量的确定,既可用于对虾育苗场内对这3种病原的监测,也适用于对养殖对虾病原感染与病害发生的风险预测。 相似文献
10.
鲤疱疹病毒Ⅱ型TaqMan real-time PCR 检测方法的建立及应用 总被引：1，自引：1，他引：0
针对鲤疱疹病毒Ⅱ型(Cyprinid herpesvirus 2,CyHV-2)DNA解旋酶基因编码区序列设计特异性引物,利用PCR技术扩增出长度为1446 bp的基因编码区片段,克隆到pMD19T载体上,构建重组质粒.经PCR鉴定与测序分析确认正确后,以10倍梯度稀释重组质粒,作为标准模板进行TaqMan real-time PCR扩增,制作标准曲线,建立了鲤疱疹病毒Ⅱ型的荧光定量PCR检测方法.检测结果显示,标准曲线的相关系数(R2)达到0.9991,斜率为-3.412;对初始模板定量检测的范围为1×101～1×107 copies/μL;特异性试验结果表明,该方法可特异性地检测出鲤疱疹病毒Ⅱ型,而对大鲵虹彩病毒(GSIV)、锦鲤疱疹病毒(KHV)以及空白对照无检测信号.取江苏射阳和宝应两地疑似患病鲫组织核酸作为模板进行荧光定量PCR,结果表明反应体系中的病毒量分别为6.89×104 copies/μL和3.02×102 copies/μL.本研究建立的鲤疱疹病毒Ⅱ型TaqMan实时荧光定量PCR方法灵敏度高、特异性强,对因鲤疱疹病毒Ⅱ感染引起的养殖鲫造血器官坏死症的诊断与病毒病原定量检测有重要意义. 相似文献
11.
Liping Li Rui Wang Wanwen Liang Xi Gan Ting Huang Yan Huang Jian Li Yunliang Shi Honglin Luo Ming Chen 《广西水产科技》2014,(1)
Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae(GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the ?rst time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in ?ve provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding36.9%(62/168), 37.5%(63/168) and 19.6%(33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia(95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010,but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during2007–2011, III onlyoccurred in 2012. 14 different PFGE types, including 4 new types(N, O,P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9%(141/168) of the total GBS strains. Ia corresponded to 11 PFGE types(A–H, N–P), in which type D predominated(51%). Ib represented 3 genotypes(I, J and Q) and III harbored only 2genotypes(N and F). Type N and Fsynchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years.Although Iastillpredominated, new rareserotypeIII alreadyoccurred in China. 相似文献
12.
13.
14.
Growth hormone (GH) and reproduction: a review 总被引：5，自引：0，他引：5
Florence Le Gac Odile Blaise Alex Fostier Pierre-Yves Le Bail Maurice Loir Brigitte Mourot Claudine Weil 《Fish physiology and biochemistry》1993,11(1-6):219-232
Interaction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations. 相似文献
15.
Two gonadotropins (GtH; Qa and Qb) were purified by gel filtration and ion exchange chromatography from the pituitaries of Indian walking catfish (Clarias batrachus). The presence of GtH during purification was assessed by in vitro oocyte maturation and in vivo steroidogenic activity, and their identities were determined by elution profiles, molecular weight, biological activities and yield. The molecular weights of Qa and Qb were 37 and 42 kDa, respectively, and composed of distinct subunits (Qa: 20 and 14 kDa and Qb: 26 and 18 kDa). Polyclonal antibodies raised against Qa immunostained Qa, Qb and pituitary GtH cells. A competitive Qa‐ELISA was developed whose sensitivity was 6.25 ng mL?1 (1.25 ng well?1) with intra‐ (3.5%) and inter‐ (12.4%) assay coefficients of variation. Displacement curves parallel to the standard were obtained with plasma and pituitary extracts of catfish, Qb and carp GtHII. The assay was validated by measuring the plasma Qa levels after LHRH treatment and in relation to ovarian growth in the female catfish during different reproductive phases. Based on the results, Qa and Qb corresponded to fish LH and FSH respectively. The findings will increase the knowledge of the mechanisms controlling fish reproduction and identification of sensitive phases in fish in captivity for hormonal manipulation. 相似文献
16.
Controlled infection of Poecilia reticulata Peters (guppy) with Tetrahymena by immersion and intraperitoneal injection 
下载免费PDF全文
下载免费PDF全文 G Sharon M Pimenta‐Leibowitz M C L Vilchis N Isakov D Zilberg 《Journal of fish diseases》2015,38(1):67-74
Tetrahymena is a protozoan parasite, which infects guppy, Poecilia reticulata Peters, and causes substantial economical losses in commercial farms worldwide. Studies of guppy infected by Tetrahymena require standardized infection protocols. The LD50 for Tetrahymena infection of guppies by intraperitoneal (IP) injection was calibrated, and the level obtained was 946 parasites per fish. Guppy infection with Tetrahymena by immersion, imitating the natural route of infection via the integument, was studied under normal or stress conditions. Exposure to cold and netting (CNI) and to cold only (CI) followed by immersion exposure to 10 000 Tetrahymena per mL resulted in 22.5% and 19.2% mortality, respectively, as compared to 14.2% and 10% in groups that were netted only (NI) or non‐stressed (I). Histopathology revealed that immersion infection resulted in a systemic infection. Lysozyme levels, measured 3 weeks after infection, were significantly higher in the CNI group (288 μg per mg protein) compared with CI‐, NI‐ and I‐treated groups (94.5, 64 and 62.3 μg mg?1, respectively). There was no evident parasite immobilization activity in body homogenates, suggesting no development of acquired immunity. Re‐infection by IP injection revealed no increase in protection in any of the treatment groups, mortality range of 56.3–75%, higher than in the non‐exposed control (40.6% mortality). 相似文献
17.
Iciar Martinez Amaya Velasco Ricardo Pérez-Martín Eskil Forås Michiaki Yamashita Carmen G. Sotelo 《Journal Of Aquatic Food Product Technology》2013,22(4):289-297
The purpose of this work was to evaluate the suitability of a method based on the presence of two restriction sites (for Hae III and Hindf I) in the mitochondrial NADH dehydrogenase subunit 5 (mt ND5) gene to identify Scomber species. The evaluation was performed on 144 reference and market samples by sequencing of the entire 505-bp fragment of the mt ND5 gene and of a 464-bp fragment of the Kocher fragment of the cytochrome b gene (mt Cytb). Sequence analysis of any of the two fragments allows the identification of each of the four Scomber species, but S. japonicus and S. colias had the same restriction sites at the ND5 amplicon and would not have been differentiated by this analysis. Similarly, loss of the Hae III site in some S. scombrus individuals would have misidentified them as not being Scomber. All the market products were correctly labeled except one acquired in Spain labeled as originating in the Atlantic and containing S. japonicus. 相似文献
18.
There has been growing concern about the overuse of antibiotics in the ornamental fish industry and its possible effect on the increasing drug resistance in both commensal and pathogenic organisms in these fish. The aim of this study was to carry out an assessment of the diversity of bacteria, including pathogens, in ornamental fish species imported into North America and to assess their antibiotic resistance. Kidney samples were collected from 32 freshwater ornamental fish of various species, which arrived to an importing facility in Portland, Oregon from Colombia, Singapore and Florida. Sixty‐four unique bacterial colonies were isolated and identified by PCR using bacterial 16S primers and DNA sequencing. Multiple isolates were identified as bacteria with potential to cause disease in both fish and humans. The antibiotic resistance profile of each isolate was performed for nine different antibiotics. Among them, cefotaxime (16% resistance among isolates) was the antibiotic associated with more activity, while the least active was tetracycline (77% resistant). Knowing information about the diversity of bacteria in imported ornamental fish, as well as the resistance profiles for the bacteria will be useful in more effectively treating clinical infected fish, and also potential zoonoses in the future. 相似文献
19.
Effect of iodophor disinfection of non‐hardened Salmo trutta eggs on their bacterial and fungus load 下载免费PDF全文
下载免费PDF全文 Franz Lahnsteiner 《Aquaculture Research》2017,48(7):3901-3909
This study investigated the efficiency of iodophor disinfection (135 ppm active iodine for 15–30 min) of non‐hardened Salmo trutta eggs against different groups of bacteria and against fungus. Egg samples were taken from non‐disinfected and from disinfected eggs, microorganisms were cultured on specific nutrient media and their mass was measured by turbidimetric methods. Bacteria and fungus mass of non‐hardened eggs could be reduced but not eliminated by iodophor disinfection with 135 ppm active iodine for 15 min. The extent of reduction was 47–65% (Experiment 1). The efficiency of disinfection increased with disinfection time as the reduction in bacteria and fungus mass was 40–55% after 15 min and 58–74% after 30 min (Experiment 2). Disinfection efficiency of iodophor solution diluted in water (reduction 49–57%) and of iodophor solution diluted in sodium chloride solution iso‐osmolar to the oocytes (reduction 52–61%) was similar (Experiment 3). The reduction in bacteria and fungus mass was persistent as it was 39–72% lower in embryos deriving from disinfected eggs than in embryos deriving from non‐disinfected ones (Experiment 4). In conclusion, the tested disinfection method is inadequate to eliminate pathogens completely but it could positively influence immune defence of eggs and embryos. 相似文献
20.
The endemic, anadromous cyprinidChalcalburnus tarichi is the only fish species known to occur in alkaline Lake Van (Eastern Anatolia, Turkey). EightC. tarichi were maintained individually in Lake Van water (17 – 19°C; pH 9.8; 153 mEq·I–1 total alkalinity; 22 total salinity) and tank water samples analyzed for 24 h in 2 to 4 h intervals. At zero time, < 1µM ammonia was present and urea was undetectable in the tank water; at 24 h, total ammonia and urea made up 114±32 and 35±25µM, respectively. Over the experimental period, ammonia-N and urea-N excretion averaged 1041±494 and 607±169moles·kg–1 fish·h–1, respectively. The extent of urea excretion was highly variable between specimens. Uric acid excretion was not detectable.Urea was present at high concentrations in all tissues and plasma (25 – 35moles·g–1·ml–1) of freshly caughtC. tarichi; total ammonia content of the tissues was by a factor of 1.9 (liver) to 3.0 (brain) lower. High arginase activity (2.4±0.2 U·min–1·g–1) was detected in the liver ofC. tarichi but ornithine carbamoylphosphate transferase, a key enzyme of the ornithine-urea-cycle, was absent. Ureagenesis is likely through degradation of arginine and/or uricolysis. High glutamine synthetase activity (11±0.6 U·min–1·g–1) and low ammonia content in brain suggest that, like other teleosts,C. tarichi has an efficient ammonia detoxification in the brain, but in no other tissue.Nitrogenous waste excretion at alkaline pH is discussed. The ability ofC. tarichi to excrete high levels of ammonia at extremely alkaline pH is unique among teleosts studied so far. The mechanism of ammonia excretion under Lake Van conditions remains to be elucidated. 相似文献