Seroepidemiological study on Coxiella burnetii and associated risk factors in ruminants at Kurdistan Province,west of Iran

Q fever is zoonotic disease caused by Coxiella burnetii. Ruminants are the main reservoir of this pathogen, which is often asymptomatic but lead to abortion. This study aims to survey the seroprevalence and risk factors of this zoonose among ruminants in Kurdistan province, the west of Iran. 480 blood samples were collected from ruminants including sheep, goats and cows, each 160 samples, in the age groups of <1, ≥1−3, >3−5 year with and without the history of abortion in two groups border and non-border cities in Kurdistan province. Serums were tested by use of indirect ELISA to determine specific antibodies against C. burnetii. The results indicate the seroprevalence of 46.6 % for Q fever. Seroprevalence in sheep, goats and cows were 28.58 % (n = 64), 45.53 % (n = 102) and 25.89 % (n = 58), respectively. Seroprevalence is significantly higher in animals with abortion than in those without such history (P < 0.05). The seroprevalence in the border cities has been significantly higher than other geographical areas (P < 0.05). Seroprevalence had no significant correlation with animal age (P> 0.05). This study is the first seroepidemiological study done on Q fever in ruminants of Kurdistan province, Iran. The results indicate the high seroprevalence of Coxiella burnetii in the area under the study. Therefore, doing an epidemiologically study aimed at isolating C. brunetii in the human population of Kurdistan province is recommended, so that the epidemiological aspect of this pathogen in the people of Kurdistan province be clarified and subsequently disease control and prevention programs be applied.     

猪瘟病毒结构蛋白抗体间接ELISA检测方法的建立及评价

通过研究猪瘟(CSF)疫苗免疫猪抗结构蛋白E2、E0和C抗体的产生规律,为临床制定合理的CSF疫苗免疫程序提供参考。利用间接ELISA方法检测CSF疫苗免疫猪过程中,抗E2抗原血清抗体的产生特征;分别以重组猪瘟病毒(CSFV)结构蛋白E0和C为抗原,建立检测血清抗体的间接ELISA方法,评价其敏感性和特异性,并检测疫苗免疫过程中抗E0和C蛋白抗体的消长规律。结果显示:CSFV-E0和CSFV-C间接ELISA抗体检测方法的抗原最佳包被质量浓度分别为2.09和1.59μg/mL,待检血清样本最适稀释度分别为1∶60和1∶80,酶标二抗稀释度分别为1∶100和1∶350,2种ELISA方法与常见猪病原的阳性血清无交叉反应,具有良好的特异性。CSF疫苗免疫后第7天即可检测到抗E2、E0和C蛋白的抗体,其中抗E2和E0的抗体在免疫后第21天达到最高水平,E2抗体滴度先上升后下降,E0抗体在免疫后第21天开始下降并最终趋于稳定;C蛋白抗体在免疫后第7天出现,随后开始下降,在第28天转为阴性。结果表明,利用重组抗原建立的CSFV血清抗体ELISA检测方法,可以用于评价CSF疫苗免疫后血清中针对3种结构蛋白的抗体消长特点,从而为临床猪瘟疫苗免疫程序的制定提供参考。     

鲤细胞因子多克隆抗体的制备及检测

为从蛋白质水平研究细胞因子在鲤体内免疫应答过程中的合成变化,本研究采用PCR技术克隆TNF-α、IL-1β、IL-6、IL-12、IL-10和TGF-β基因含有部分抗原决定簇的片段,引入双酶切位点Bam HⅠ和HindⅢ后连接至p ET-32a/21a,构建相应的表达载体,制备多克隆抗体。采用ELISA检测抗体效价,并以此作为实验工具,检测经嗜水气单胞菌感染后鲤血清中炎性细胞因子的合成变化。结果显示,基因TNF-α、IL-1β、IL-6、IL-12、IL-10和TGF-β融合蛋白分子量分别约为31.8、31.7、35.3、32.5、18.0和33.6 ku;抗体效价达到2.4×106;在病原菌感染后的不同阶段,促炎细胞因子TNF-α、IL-1β、IL-6、IL-12和抗炎细胞因子IL-10、TGF-β呈现出不同的合成变化。研究表明,制备的抗体具有较高的效价、亲和力和特异性,可用于鲤细胞因子的定量研究,该抗体的获得为鲤免疫应答与细胞因子合成的系统研究奠定了基础。同时,获取的鲤细胞因子TNF-α、IL-1β、IL-6、IL-12、IL-10和TGF-β的抗体亦可用于其他鱼类细胞因子蛋白质水平的定量研究。     

Pearl grafting: Tracking the biological origin of nuclei by straightforward immunological methods

French Polynesia is renowned for the production of Tahitian black pearl. These gems are obtained by grafting a nucleus into the gonad of a receiving oyster together with a graft, i.e. a small section of mantle tissue of a donor oyster. This procedure initiates the formation of a pearl sack around the nucleus, and subsequently, the deposition of concentric layers of nacre. The nucleus plays a key‐role in pearl formation and its characteristics influence markedly the quality of the final product. As it is manufactured from mollusc shells, it contains a small percentage of organics. In the present paper, we used a set of biochemical techniques to characterize and compare the organic matrices from two types of nuclei that are currently used in French Polynesia: that from the freshwater mussel Amblema sp., and that from the pearl oyster Pinctada sp. To this end, we extracted the matrices from nuclei and performed FT‐IR, monodimensional electrophoresis, and enzyme‐linked immuno‐sorbent assay (ELISA). Our data show that the matrix associated with Amblema nuclei has a very different biochemical signature from that of Pinctada nuclei, a fact that may explain the improved tolerance of grafted oysters to nuclei of Pinctada origin. In the absence of complex physical methods of investigation, simple immunological techniques and FT‐IR performed on the extracted organic matrix are extremely reliable and effective for discriminating nuclei from these two sources. We assert that such techniques can be used as a diagnostic test to track unambiguously the biological origin of nuclei to avoid fraud.     

No detrimental effect of Bt maize pollen containing Cry1Ab/2Aj or Cry1Ac on adult green lacewings Chrysoperla sinica Tjeder

Adult Chrysoperla sinica Tjeder is a common pollen feeder in maize fields. They are thus directly exposed to insecticidal proteins by consumption of genetically engineered maize pollen containing Bacillus thuringiensis (Bt) proteins. Here we assessed the potential effects of Cry1Ab/2Aj- or Cry1Ac-containing Bt maize pollen on the fitness of adult C. sinica via a dietary-exposure assay under laboratory conditions. Survival, pre-oviposition, fecundity and adult dry weight did not differ between adult C. sinica consuming Bt or the corresponding non-Bt maize pollen. The stability of the Cry protein in the food sources and uptake of the Cry protein by adult C. sinica during the feeding experiment were confirmed by ELISA. These results demonstrate that adult C. sinica are not affected by the consumption of Cry1Ab/2Aj- or Cry1Ac-containing maize pollen, suggesting that production of Bt maize expressing cry1Ab/2Aj or cry1Ac genes will pose a negligible risk to adult C. sinica.     

Generation of mouse monoclonal antibodies specific to tilapia immunoglobulin using fish immunoglobulin/BSA complex for monitoring of the immune response in Nile tilapia Oreochromis niloticus

The simple immunoprecipitation method was used to isolate tilapia immunoglobulin (Ig) for immunization in order to produce monoclonal antibodies (MAbs) specific to tilapia Ig. First, the tilapia antiserum against bovine serum albumin (BSA) was prepared by peritoneal injection of BSA into tilapia, and the tilapia anti‐BSA antiserum was used to precipitate BSA to form the Ig/BSA immune complex. The Ig/BSA immune complex was then injected into Swiss mice for hybridoma production. After fusion, three hybridoma clones producing MAbs specific to the tilapia antibody were selected by dot blot and Western blot. All MAbs (101A, 59G, and 11A) were bound specifically to the heavy chain of immunoglobulin M (IgM). The MAbs 101A and 59G demonstrated twofold higher affinity than MAb 11A and the commercialized antibody. However, MAbs 11A could also bind to the heavy chain of IgM in Asian seabass, Lates calcarifer, as well. These MAbs can be used to monitor the immune responses of individual fish by indirect ELISA upon exposure to various antigens.     

Recent progress in analytical method development to ensure the safety of gluten-free foods for celiac disease patients

As laid down by the Codex Alimentarius, products bearing a gluten-free label must not contain gluten levels above 20 mg/kg to be safe for consumption by celiac disease patients. Analytical methods to detect gluten from wheat, rye and barley need to be sufficiently sensitive, specific, suitable for routine analyses and validated by collaborative studies. With continuous progress in the field of gluten analysis, the aim of this paper is to provide an up-to-date overview of legislation regarding gluten-free products worldwide, as well as immunochemical, proteomics-based, genomics-based and other methods designed to analyse gluten traces. While ELISA test kits and PCR are still most widely used in quality control, liquid chromatography tandem mass spectrometry (LC-MS/MS) is gaining more and more importance by providing unprecedented insights into gluten. Several other methods such as immunosensors, other sensors and microarrays are being developed. The pro's and con's of the different methods are discussed as well as the remaining challenges, including the need for improved extraction procedures, comprehensive reference materials and independent reference methods.     

基于单克隆抗体的O型口蹄疫病毒抗体固相竞争ELISA检测方法的建立

为建立评价O型口蹄疫病毒(FMDV)疫苗免疫水平的方法,本研究以单克隆抗体(MAb)3D9为捕获抗体,以HRP标记的MAb 8E8作为检测MAb,经过条件优化建立了基于MAb的检测O型FMDV抗体的固相竞争ELISA(SPCE)方法。对该方法进行了特异性、敏感性、重复性试验。结果显示,MAb 3D9的最佳稀释度为1:25 000,灭活O型FMDV抗原的最佳稀释浓度为1:3,HRP标记的MAb 8E8的最佳稀释度为15 000,当血清1:32稀释时,检测的临界值确定为45%。该方法分别检测A型FMDV抗体阳性参考血清以及牛冠状病毒、牛轮状病毒以及猪繁殖与呼吸障碍综合征病毒、猪圆环病毒、猪瘟病毒的标准阳性血清,检测结果均为阴性,未出现交叉反应。经检测,当阳性标准血清的抗体稀释度在1:512时,该方法仍具有较好的敏感性;批内和批间重复性试验的变异系数均小于10%,表明其重复性较好。并将该方法与液相阻断ELISA(LPBE)方法和病毒中和试验(VNT)的相关性进行了比较,结果显示该方法与LPBE和VNT的相关性分别为0.896和0.923。本研究为国内评价O型FMDV疫苗免疫水平建立了一种新的方法。     

饲料中沙门氏菌的快速检测方法及预防措施

本文介绍了近些年来饲料中沙门氏菌的检测方法,并提出了预防饲料中沙门氏菌污染的措施,具体包括饲料原料选择、生产加工过程的控制以及包装、运输、储存、使用过程的控制等方面内容,以期为饲料安全生产提供参考。