Application of ELISA-based kit for detecting AOZ and determining its clearance in eel tissues     

Laddawan Krongpong  Kunihiko Futami  Takayuki Katagiri  Makoto Endo  Masashi Maita 《Fisheries Science》2008,74(5):1055-1061

Furazolidone, an antibacterial drug that was once widely used in the livestock industry and aquaculture, is now prohibited in numerous countries. It is difficult to detect residual furazolidone because it is readily metabolized in animal tissues but, by using and liquid chromatography coupled with tandem mass spectrometry, its metabolite, 3-amino-2-oxazolidinone (AOZ) can be detected. Here we describe the validity of an enzyme-linked immunosorbent assay (ELISA) kit to detect AOZ in Japanese eel Anguilla japonica tissue. ELISA is capable of detecting AOZ at 1.0 μg/kg in an eel sample with excellent accuracy and precision. Our results show that ELISA is suitable for regulatory purposes and for studying the fate of AOZ residues in eel treated with furazolidone. To measure the persistence of AOZ in eel tissues, eels (1.4–6.5g) were immersed in tanks containing 2 and 10 mg furazolidone/L for 3 h, and then maintained in a tank supplying well water for the next 160 days. The half-lives of AOZ, calculated from the linear terminal part of the excretion curve, were 25.0 days in muscle and 21.6 days in liver from fish exposed to 2 mg/L furazolidone. In the eels treated with 10 mg/L furazolidone, by contrast, high levels of AOZ were detected in liver and muscle, but the half-lives of AOZ were similar to those in fish treated with 2 mg/L furazolidone. The half-lives of AOZ in eel tissues were prolonged by the condition of low water temperature.  相似文献   

Expression of phenylalanine ammonia-lyase cDNA from rice in E. coli BL21DE3     

CAI Zhu-nan  YU Ying-nian  LUO Jian-hong  QIAN Yu-li  CHEN Xiang-ruo 《园艺学报》2000,16(1):12-16

AIM: To study the expression and its kinetics of rice phenylalanine ammonia-lyase gene encoding into E. coli as the basis of treatment for phenylketouria. METHODS: The phenylalanine ammonia-lyase-1-cDNA(rPAL-1-cDNA) from rice was recombined into E. coli high expression vector pET-28c and transformed into E. coli host strain BL21DE3. Engineering bacteria was then inducted by isopropyl-β-D-thiogalactoside (IPTG) for 1, 3, 5, 7 hours, in order to obtain high level expression. RESULTS: After induction, the expression level of fusion protein was 21.40%, 30.60%, 35.40%, 35.43% respectively. The fusion protein exhibited a band of 78.6 kD on SDS-PAGE analysis, but was not found in controls.The target protein was mainly existed in the form of inclusion body. CONCLUSION:Rice PAL gene expressing E. coli was established by gentic engineering technique.  相似文献   

广东省森林土壤养分异质性析因   总被引：1，自引：0，他引：1  

刘晓彤  李海奎  曹磊  张逸如 《北京林业大学学报》2021,43(2):90-101

[目的]分析不同环境因子对森林土壤养分的影响,探讨造成森林土壤养分异质性的原因,为森林经营和森林立地质量评价提供依据.[方法]基于广东省全国森林资源清查土壤调查数据,以有机质(OM)、碱解氮(AN)、有效磷(AP)和速效钾(AK)为因变量,以地理因子、地形因子、土壤因子和林分因子四大类20个变量(10个定性因子,10个...  相似文献   

Pharmacokinetics,metabolism and excretion of celecoxib,a selective cyclooxygenase‐2 inhibitor,in horses     

Michael Benedict Subhahar  Jaipaul Singh  Peter Henry Albert  Ahmed Mahmoud Kadry 《Journal of veterinary pharmacology and therapeutics》2019,42(5):518-524

Celecoxib, a nonsteroidal anti‐inflammatory drug, is frequently used to treat arthritis in humans with minimal gastrointestinal side effect compared to traditional NSAIDs. The primary aim of this study was to determine the pharmacokinetic profile of celecoxib—a selective cyclooxygenase‐2 (COX‐2) inhibitor in horses. Six horses were administered a single oral dose of celecoxib at 2 mg/kg (body weight). After oral dosing, the drug reached a maximum concentration (mean ± SD) in blood of 1,088 ± 324 ng/ml in 4.58 hr. The elimination half‐life was 13.60 ± 3.18 hr, and the area under the curve was 24,142 ± 1,096 ng hr ml^?1. The metabolism of celecoxib in horses was via a single oxidative pathway in which the methyl group of celecoxib is oxidized to a hydroxymethyl metabolite and is further oxidized to form a carboxylic acid metabolite. Celecoxib is eliminated mainly through faeces as unchanged drug and as metabolites in urine. Therefore, instructions for a detection time following therapeutic dosing of celecoxib can be set by the racing practitioner and veterinarians to control illegal use in horse racing based on the results of this study.  相似文献   

抗菌肽NZ2114对奶牛乳房炎源金黄色葡萄球菌细胞膜、基因组和耐药性的影响   总被引：3，自引：3，他引：0  

郭英  滕达  王秀敏  毛若雨  郝娅  范寰  王建华 《中国畜牧兽医》2019,(4):1181-1190

本试验以真菌防御素Plectasin衍生肽NZ2114和奶牛乳房炎源金黄色葡萄球菌为研究对象,旨在阐明抗菌肽NZ2114对金黄色葡萄球菌的体外抗菌机制及其阻遏金黄色葡萄球菌耐药性的效果。通过16S rRNA基因鉴定对55份乳房炎奶样中的病原菌进行分离鉴定,采用纸片扩散法检测其耐药性,通过微量稀释法测定抗菌肽NZ2114对金黄色葡萄球菌的抑菌活性,借助流式细胞术和扫描电镜观察抗菌肽NZ2114对金黄色葡萄球菌细胞膜完整性及细胞形态的影响,通过凝胶阻滞和圆二色谱分析抗菌肽NZ2114对金黄色葡萄球菌基因组DNA的影响,将抗菌肽NZ2114与金黄色葡萄球菌共同孵育以研究抗菌肽NZ2114对金黄色葡萄球菌耐药性的影响,通过PCR进一步分析抗菌肽NZ2114对金黄色葡萄球菌携带的耐药基因的影响。结果表明,共获得10株金黄色葡萄球菌,分离菌对青霉素等9种抗菌药具有耐药性,且50%为多重耐药。抗菌肽NZ2114对10株金黄色葡萄球菌具有强抑菌活性,最小抑菌浓度(MIC)为0.5～1.0μg/mL。抗菌肽NZ2114可导致金黄色葡萄球菌S7细胞皱缩、细胞内容物泄漏,甚至细胞裂解,碘化丙啶(PI)细胞膜穿透率达5%,且抗菌肽NZ2114可与金黄色葡萄球菌S7基因组DNA结合并改变其DNA结构。金黄色葡萄球菌与1/4×MIC抗菌肽NZ2114孵育12 h后发现,除对阿莫西林和磺胺异噁唑的耐药率没有降低外,对其他抗菌药的耐药率均有不同程度的降低(10%～40%),且抗菌肽NZ2114对β-内酰胺类耐药基因(blaZ)及杆菌肽类耐药基因(braRS)的消除率分别达28.57%(2/7)和22.22%(2/9)。上述结果证明,抗菌肽NZ2114对耐药金黄色葡萄球菌具有体外强抑菌活性,其干扰耐药金黄色葡萄球菌细胞膜并结合胞内DNA的作用机制为其低耐药杀菌机制奠定了细胞学基础。同时抗菌肽NZ2114对耐药菌株的耐药性及相关耐药基因均有一定消除作用。由此可见,抗菌肽NZ2114是一种极具前景的治疗金黄色葡萄球菌引起的奶牛乳房炎的抗生素替代品。  相似文献   

Relationship between the likelihood of footrot elimination from a flock and the virulence of the strain of Dichelobacter nodosus present          下载免费PDF全文

MB Allworth  JR Egerton 《Australian veterinary journal》2018,96(10):400-407

  相似文献   

燃料油装卸过程中静电的产生及消除措施     

卢大刚 《油气储运》2013,32(4):431-433,438

介绍了在燃料油装卸过程中静电产生的形式及分布规律。基于人为操作因素、装卸作业环境及油品物化性质等易引起静电火灾的因素，提出了静电消除技术和防护措施：接地、增加空气湿度、加入防静电添加剂、控制液体流速、提高作业环境的通风性等，为评价燃料油储罐安全状况、制定消除静电的措施提供了理论依据与技术支持。（表2，图2，参10）  相似文献   

旅游扶贫效用分析——基于广东省梅州市的实证调查     

李力  闭海霞 《安徽农业科学》2010,38(27):15353-15355,15425

从旅游对消除贫困的贡献的角度，以广东省梅州市为例，通过实地调查旅游发展与旅游扶贫情况，应用SPSS软件分析实地调查问卷数据，找出影响当地旅游扶贫效用的因素，从而提出对梅州市旅游扶贫开发的建议。  相似文献   

棉花的防灾减灾     

吕凯  ;魏凤娟 《商界．城乡致富》2013,(11):45-47

棉花在整个生长期,都可能发生各种气象灾害,导致严重减产。介绍了棉花播种-苗期冷（冻）害、棉花雹灾、棉花雨涝害、棉花旱灾、棉花干热风害、棉花热害、棉花吐絮期霜冻害等灾害的症状,并且针对各种灾害提出了相应的防灾救灾措施。  相似文献   

基于转录组学技术分析绿原酸对鸡源大肠杆菌抑菌及耐药消除的作用机制     

姚姗姗  张石磊  梁存军  张铁  王春光 《中国畜牧兽医》2020,47(12):4156-4165

为探究绿原酸对鸡源抗生素耐药大肠杆菌抑菌及耐药消除的作用机制，以影印法分离绿原酸浓度为1.25 mg/mL（亚抑菌浓度，1/2 MIC）的LB肉汤培养的第3代禽源大肠杆菌耐药逆转菌株，以微板法测定耐药逆转菌株的左氧氟沙星最小抑菌浓度（MIC），并进一步通过转录组测序方法分析绿原酸消除大肠杆菌耐药性的分子机制。结果显示：耐药逆转菌株对左氧氟沙星的MIC由16 μg/mL降低至4~8 μg/mL，说明1.25 mg/mL的绿原酸可在一定程度上消除耐药大肠杆菌的左氧氟沙星耐药性。为进一步解析绿原酸对鸡源大肠杆菌耐药消除作用的分子机制，通过转录组测序方法对耐药性消除前后鸡源大肠杆菌基因表达水平进行对比分析发现：绿原酸作用后共有12个基因的表达量发生显著下调，通过荧光定量PCR验证结果基本一致。经过GO功能富集分析和KEGG代谢通路富集分析发现，差异表达基因在功能上集中于膜组成成分和DNA重组，在代谢通路富集中差异基因均与代谢相关，差异基因中bhsA、cysP为Coli-HB染色质转录RNA（GenBank登录号：CP020933），oqxA、oqxR、emaA、pinR、xerD、folA、repA、repC、adhP、IS26为Coli-HB质粒1转录RNA（GenBank登录号：CP020934）。从差异表达基因的分布可以看出，绿原酸可以抑制细菌DNA重组、使细菌抗逆性减弱、抑制耐药基因活性等，在一定程度上消除大肠杆菌的左氧氟沙星耐药性，起到抑菌及耐药消除作用。  相似文献