2021年云南省玉溪市小反刍兽疫专项监测评估
为全面掌握云南省玉溪市小反刍兽疫(PPR)的病原分布和羊群免疫效果,根据2021年玉溪市PPR专项监测方案,在全市开展PPR监测和流行病学调查。采用多阶段调查的方法,从全市9个县区采集免疫羊血清样品1 631份、眼鼻棉拭子样品6 438份,分别使用阻断ELISA和实时荧光RT-PCR检测方法,进行PPR免疫抗体检测和病毒核酸检测。结果显示:2021年玉溪市PPR群体免疫合格率为82.98%,个体免疫合格率为83.62%,未检测到病原学阳性样品;不同养殖区域、不同性别的免疫抗体合格率均有统计学差异(P<0.05),而不同养殖类型、不同企业疫苗的免疫抗体合格率差异均不显著(P>0.05)。结果表明:玉溪市羊PPR整体免疫效果较好,所用PPR疫苗免疫原性较好,免疫程序合理,但部分县区的免疫合格率较低,因此应继续加强PPR的强制免疫及补免工作;在未引入新疫源的前提下,疫情发生风险较低,但应加大羊只引种检疫和调运监管力度。本次监测评估了玉溪市的PPR总体防控状况,为尽快实现消灭PPR的目标提供了数据支撑。Special Monitoring and Evaluation on PPR in Yuxi City of Yunnan Province in 2021In order to investigate the distribution of pathogen of peste des petits ruminants(PPR)and immune effect in sheep in Yuxi City of Yunnan Province,targeted monitoring and epidemiological investigation were carried out across the city according to the special monitoring plan for PPR published in the city in 2021. A total of 1 631 serum samples and 6 438 eye or nose swabs were collected from immunized sheep in 9 counties/districts in the city by using multi-stage investigation to respectively detect immune antibodies against PPR and virus nucleic acid by blocking ELISA and real-time fluorescent RT-PCR. The results showed that the qualified rates of population and individual animal were 82.98% and 83.62%,respectively,and no positive samples were detected;the qualified rates of immune antibodies in different breeding regions or different genders were of significant statistical difference(P<0.01),but slightly in different breeding types and vaccines produced by different enterprises(P>0.05). In conclusion,the overall immunization effect against PPR was good in the city,with good immunogenicity of PPR vaccines as well as reasonable immunization procedure,but the qualified rate of immunity was lower in some counties/districts,which should continue to implement compulsory or supplementary immunization against PPR;and sheep to be introduced should be strictly quarantined and supervised during transportation,although the risk of outbreak was lower in the context of absence of any infection source. The general status of prevention and control of PPR in the city was monitored and evaluated in the paper,from which a reference was provided for reaching the goal of eliminating PPR soonest.全文下载链接:https://chn.oversea.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202206003&uniplatform=OVERSEAS_CHS&v=vPzqR5W2eDA5b6bairyzxI-xcmvfpBTPr92rdTmp3JGkDchVhYZ2Sp5PHkZpCEs0
2022-06-17
湖北省部分规模猪场猪繁殖与呼吸综合征流行病学调查
为探究猪繁殖与呼吸综合征病毒(PRRSV)在规模猪场的流行特征,2021年从湖北省7个规模猪场疑似PRRSV感染猪群以及所有种公猪群中,共收集样品3 324份,采用三重巢式RT-PCR法进行PRRSV病原学检测,分析不同养殖类型、不同生长阶段、不同季节及不同感染毒株的流行特点,并将阳性产物进行测序和遗传进化分析。结果显示:3 324份样品中共检测出PRRSV阳性样品323份,阳性检出率为9.72%(323/3 324)。育种场阳性检出率最低,为2.66%(20/752);商品猪扩繁场与育肥场阳性检出率相近,分别为11.82%(169/1 430)与11.73%(134/1 142);保育猪群阳性检出率最高,为17.23%(152/882);其余依次为生长育肥猪、哺乳仔猪和母猪,阳性检出率分别为11.30%(121/1 071)、5.26%(30/570)和3.24%(20/618);种公猪中未发现PRRSV感染。PRRSV一年四季均可流行,春、夏、秋、冬季的阳性检出率分别为18.16%(148/815)、6.94%(60/864)、6.10%(34/557)、7.44%(81/1 088),春季阳性检出率显著高于其他季节(P<0.05),而夏、秋、冬季节间差异不显著(P≥0.05)。3种PRRSV毒株均有流行,类NADC30毒株、经典毒株和高致病性变异毒株的占比分别为49.54%、21.36%、29.10%,类NADC30毒株检出占比显著高于其他类型毒株(P<0.05)。结果表明:PRRSV在所调查的7个规模猪场中流行普遍,尤其是商品猪扩繁场与育肥场;保育猪群PRRSV感染风险较高,种公猪感染风险较低,春季是高发季节,类NADC30毒株为优势流行毒株。结果提示,规模养殖场应根据PRRSV的流行特征,加强免疫和监测,有针对性地制定防控措施。Epidemiological Investigation on PRRS in Some Intensive Swine Farms in Hubei ProvinceIn order to investigate the epidemiological characteristics of porcine reproductive and respiratory syndrome virus(PRRSV)in intensive swine farms,a total of 3 324 samples were collected in 2021 from pigs suspected to be infected with PRRSV and all boars in 7 intensive farms in Hubei Province for pathogenic detection by triple-nested RT-PCR to analyze the prevalent situation in different breeding types,growth stages,seasons and strains,followed by sequencing and genetic evolution of positive products. The results showed that 323 positive samples were detected,with the positive rate of 9.72%(323/3 324);the lowest positive detection rate was 2.66%(20/752)in breeding farms,similar in commercial propagation farms and fattening farms,which were 11.82%(169/1 430)and 11.73%(134/1 142)respectively;highest in nursery pigs(17.23%),followed by growing finishing pigs,suckling piglets and sows,with 11.30%(121/1 071),5.26%(30/570)and 3.24%(20/618)respectively,no PRRSV infection was found in breeding boars;PRRSV could be prevalent throughout a year,and the positive detection rates in spring,summer,autumn and winter were 18.16%(148/815),6.94%(60/864),6.10%(34/557)and 7.44%(81/1 088)respectively;that in spring was significantly higher than those in other seasons(P<0.05),but with slightly difference in summer,autumn and winter(P≥0.05);all three types of strains including NADC30-like strain,classical strain and highly pathogenic variant strain were prevalent,accounting for 49.54%,21.36% and 29.10%,respectively,the proportion of NADC30-like strain was significantly higher than other types of strains(P<0.05). In conclusion,PRRSV was widely prevalent in the 7 farms,especially in commercial propagation farms and fattening farms;the risk of PRRSV infection was high in nursery pigs,lower in breeding boars;and NADC30 like strain was the dominant epidemic strain,especially in spring. Therefore,immunization and monitoring should be strengthened by the farms according to the prevalent characteristics of PRRSV,and targeted measures for prevention and control should be developed.全文下载链接:https://chn.oversea.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202206002&uniplatform=OVERSEAS_CHS&v=vPzqR5W2eDDKKGaMrEXpotlTh1oYw2Bm_YAkX9Gholoy7ec2RZendiMer1XFc86Y
2022-06-17
四川省规模场猪伪狂犬病定性风险评估
为评估四川省规模场猪伪狂犬病(PR)发生风险,通过问卷调查了解省内种猪场、扩繁猪场、商品猪场的生产管理情况,用情景树法描述PR发生的风险路径,在世界动物卫生组织(OIE)风险评估框架下构建评估模型。根据问卷调查结果和本底调查数据,采用定性风险评估方式,用矩阵法估算各风险路径的风险值。结果显示,四川省规模场发生PR的高风险路径为引种、使用精液、未有效控制鼠害、未有效控制犬猫以及地理位置和饮水控制。近年来由于生物安全管理水平提高,经人、车、物、料等传统途径释放PR的风险大大降低,在各类型规模场开展PR净化的条件已较为成熟。在PR净化的同时开展风险评估,能帮助猪场找出风险漏洞,便于提出针对性的防控建议,为PR净化提供有力的技术支撑。Qualitative Risk Assessment on Pseudorabies in Intensive Swine Farms in Sichuan ProvinceIn order to assess possible risk of occurrence of pseudorabies(PR)in intensive swine farms in Sichuan Province,a questionnaire investigation was organized to identify the status of production and management in breeding farms,propagation farms and commercial farms in the province,risk paths of occurrence of PR were described by a scenario tree,and an assessment model was constructed within the risk evaluation framework proposed by OIE. Based on the results of investigation and background survey data,the risk value of each risk path was estimated by a matrix method through a qualitative risk assessment. The results showed that the high-risk paths of PR in the intensive farms in Sichuan Province included introduction of animals,use of semen,ineffective control of rodents,dogs and cats,geographical location and control of drinking water. The risk of PR transmission via personnel,vehicles,supplies,materials and other traditional pathways was greatly reduced due to improvement of bio-safety management level in recent years,and the conditions for PR purification in various intensive farms have been relatively mature. Risk assessment in combination with PR purification could help farms find out their own shortcomings related to risk and put forward targeted suggestions for prevention and control of the disease,which could provide strong technical support for PR purification.全文下载链接:https://chn.oversea.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202206001&uniplatform=OVERSEAS_CHS&v=vPzqR5W2eDALqbekGSBGAi6JZgd7yqe4fN9btKxgvji3ih__y3CaL-pUUHrmifLW
2022-06-17
猪非典型瘟病毒(APPV)研究进展
猪非典型瘟病毒(atypical porcine pestivirus,APPV)是2015年新发现的瘟病毒属病毒,国际病毒分类学委员会2017 年将其确定为瘟病毒属K(Pestivirus K)的代表毒株。该病毒可导致仔猪先天性震颤(congenital tremor,CT),典型症状为仔猪轻微震颤,头部和四肢明显。目前APPV已在全球广泛流行,我国也有相关报道,关于该病毒研究的报道越来越多,但研究进展的报道相对较少,目前已证实其与CT紧密相关。APPV不容易被分离,缺少最重要的病毒攻毒试验结果,疫苗研究也需要在前期基础研究深入的基础上才有可能获得成功。为此,本文从病原学、流行病学、诊断技术及疫苗研发等方面,对取得的最新研究进展进行概述,以期增强人们对APPV的认识,为我国防控与研究APPV提供参考。Advances in the Researches on Atypical Porcine PestivirusAtypical porcine pestivirus(APPV)is a new pestivirus virus firstly detected in 2015,which is determined as the representative strain of pestivirus K by the International Committee on the Taxonomy of Viruses in 2017. Because of the virus,congenital tremor(CT)might occur in piglets with such typical symptoms as slight tremor especially in head and limbs. APPV has been widely prevalent all over the world and also reported in China,but there are few reports related to the advances in relevant researches on the virus although with more reports about the researches. At present,it has been confirmed to be closely related to CT. It is difficult to isolate the virus due to the lack of most important results about virus attack test,and the development on vaccines could be achieved only based on the results of preliminary researches. Therefore,the latest relevant advances were summarized from the aspects of etiology,epidemiology,diagnostic technology and vaccine development,with a view to improving public's awareness for the virus and providing a reference for relevant prevention,control and researches in China.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202205016&uniplatform=NZKPT&v=vPzqR5W2eDDtiw71MCsANnwey_G_1La7qGia53jHi1KSbi1i4gGWqNRZp8Hdwoqn
2022-06-07
mRNA疫苗免疫学机制研究进展
信使核糖核酸(mRNA)疫苗属于第三代疫苗,具有抗原表达效率高、安全性高、免疫原性强、可编译性强,以及制备工艺简单、易规模化生产和针对病原体变异有效性高等技术优势,在新冠疫情防控中被视作一种革命性的疫苗技术。但mRNA 疫苗稳定性差,传递效率低,在临床应用方面受到很大限制。因此,当前及未来的研究主要集中在保证疫苗安全性的前提下,设计先进和可耐受的递送系统,来提高抗原表达和提呈的效率,以及优化mRNA结构,达到延长和控制表达持续时间的目的。本文从mRNA疫苗的分类、作用机制、技术优势、递送系统4个方面,对mRNA疫苗免疫学机制研究进行综述,旨在为mRNA疫苗研发工作提供参考。Advances in the Immunological Mechanism of mRNA VaccineMessenger ribonucleic acid(mRNA)vaccine,as the third generation vaccine,is characterized by high antigen expression efficiency and safety,strong immunogenicity and compiling,simple preparation technology,intensive production and high efficiency against pathogen variation,and has been regarded as a revolutionary vaccine technology in the prevention and control of COVID-19. However,the mRNA vaccine is with poor stability and low transmission efficiency,which is greatly limited in clinical application. Therefore,advanced and tolerable delivery systems should be designed to improve the efficiency of antigen expression and presentation,to optimize the structure of mRNA and thus to prolong and control the duration of expression,provided that safety of the vaccine could be safeguarded. The immunological mechanism of mRNA vaccine was summarized in the paper from the aspects of classification,action mechanism,technical advantages and delivery system of the vaccine,with a view to providing a reference for future development of the vaccine.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202205015&uniplatform=NZKPT&v=vPzqR5W2eDC7Mw5fpeqWvOQ21WXA_xM3hyjFT3cV01RJxJd7zHADlxQdbPazMzqv
2022-06-07
禽星状病毒研究进展
禽星状病毒(avian astrovirus,AAstV)属于星状病毒科,包含多种亚型,可以引发禽肾炎、鸭肝炎以及火鸡腹泻等多种疾病,禽类感染后表现生长发育迟缓、产蛋下降,严重时可导致死亡,给养殖业造成一定的损失。此外,AAstV具有感染人的潜在风险。目前AAstV的致病机理暂不清楚,只有火鸡星状病毒引发肠炎的致病机制可作为参考。许多方法已用于AAstV检测,如电镜检测、酶联免疫吸附试验、细胞培养和病毒分离以及分子技术检测等。AAstV亚型较多,疫苗和药物研发存在较大难度,给该病防治带来一定的挑战。本文围绕AAstV的病原学、国内外流行情况、感染后临床症状及致病机制以及检测方法和控制措施等进行了综述,以期为后期进一步研究提供参考。Advances in the Researches on Avian AstrovirusAvian astrovirus(AAstV),a member of astroviridae family,includes a variety of subtypes,which may lead to avian nephritis,duck hepatitis,turkey diarrhea and other diseases. Such symptoms as growth retardation and decline in egg production even death may be observed in infected poultry,which would bring certain losses to breeding industry. In addition,the virus may bring potential risk to human. However,its pathogenic mechanism has been unknown,except the one for enteritis caused by Turkey astrovirus that may be used as a reference. The virus may be detected by many methods,such as electron microscopy,enzyme-linked immunosorbent assay(ELISA),cell culture and virus isolation,molecular technology,etc. However,it would be difficult to develop vaccines or drugs due to many subtypes,which brings certain challenges to the prevention and treatment of the disease. In the paper,the etiology,epidemic status all over the world,clinical symptoms,pathogenic mechanism,detection methods and countermeasures were summarized,so as to provide a reference for further researches in the future.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202205014&uniplatform=NZKPT&v=vPzqR5W2eDBeCnQWiQE2jP2g7DOF7Tnk4UroGDd-1gWqfpREXbWVt_DcASTXQcbY
2022-06-07
泰万菌素对猪繁殖与呼吸综合征的防控效果试验
为检验泰万菌素对猪繁殖与呼吸综合征(PRRS)的防控效果,用2种泰万菌素制品(A、B)和黄芪多糖饲喂妊娠母猪,通过统计临床生产指标、母猪和仔猪抗体水平、病毒检出率以及细胞因子IL-2、IFN-γ表达水平等,综合评价泰万菌素的PRRS防控效果。结果显示:泰万菌素的PRRS防控效果明显优于黄芪多糖,其中泰万菌素A、B组母猪的产健仔率由试验前的84.98%分别提高到94.44%、91.89%,产弱胎、死胎或木乃伊胎率相应降低;泰万菌素A、B组母猪流产率降低,体内抗体下降速率减缓,所产仔猪抗体稳定性和整齐度提高,母猪血液中的PRRS病原检出率和浓度降低,IL-2表达水平下降,IFN-γ表达水平上升。结果表明,泰万菌素可降低妊娠母猪因PRRS造成的繁殖障碍率,同时可通过调控细胞因子水平增强机体免疫力,从而起到防控PRRS的作用。本研究为PRRS防控提供了一种新思路。Evaluation of Prevention and Control Effect of Tylvalosin on PRRSIn order to evaluate the prevention and control effect of tylvalosin on porcine reproductive and respiratory syndrome(PRRS),pregnant sows were fed with two kinds of tylvalosin products(A and B)and astragalus polysaccharide to comprehensively evaluate the effect of tylvalosin by means of clinical production indicators,antibody levels in sows and piglets,virus detection rate and expression level of cytokines IL-2 and IFN-γ. The results showed that,compared to astragalus polysaccharide,tylvalosin was more effective for PRRS,for groups tylvalosin A and B,the healthy litter rates of sows were increased from 84.98%(prior to evaluation)to 94.44% and 91.89%,respectively,and the rates of weak fetus,stillbirth or mummified fetus decreased accordingly;the abortion rate decreased,the decline rate of antibody level in vivo slowed down,the stability and uniformity of antibody level in their piglets increased,the detection rate and concentration of PRRS pathogens in sows' blood decreased,the expression level of IL-2 decreased,and that of IFN-γ increased. In conclusion,tylvalosin could reduce the reproductive disorder caused by PRRS in pregnant sows,enhance immunity by regulating the level of cytokines,and consequently prevent and control PRRS. A new idea was thereby provided by the study for PRRS prevention and control. 全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202204014&uniplatform=NZKPT&v=vPzqR5W2eDCvfIyFR9ITE4EXTmGwX9N6aCUokDUO8EEmm-LgXq_LsMPU8IKVP5Mv
2022-04-20
戊型肝炎研究进展
戊型肝炎(hepatitis E,HE)是由戊型肝炎病毒(hepatitis E virus,HEV)引起的一种病毒性人兽共患传染病。自1997年在美国首次从家猪体内发现HEV以来,已确定该病毒能够感染人类以及猪、鹿、兔、骆驼、大鼠等多种动物。HEV通常会导致肝衰竭、慢性肝炎以及肝外神经和肾脏疾病。该病主要通过粪口途径传播,也可以通过血液传播。据估计,全球每年约有2 000万人感染HEV,年轻人病死率为0.5%~3.0%,而孕妇感染后死亡率可高达30%,因此HEV对公共卫生安全构成了巨大的威胁。本文主要对HEV的病原学、流行病学、诊断、防控等方面的研究情况进行综述,旨在进一步提高相关从业人员等对本病的认识,以便做好研究和防控应对工作。Introduction to the Studies on Hepatitis EHepatitis E(HE)is a viral zoonosis caused by infection with hepatitis E virus(HEV). Since 1997,when HEV was firstly detected from domestic pigs in the United States,it has been confirmed that human,pigs,deer,rabbits,camels,rats and other animals could be infected with the virus. HEV usually leads to liver failure,chronic hepatitis and extrahepatic nerve and kidney diseases. The disease is mainly transmitted through fecal-oral route in addition to blood. It is estimated that about 20 million people are infected with HEV every year in the world,with a mortality of 0.5% to 3.0% in young people,and up to 30% in pregnant women with infection,posing a great threat to public health safety. In the paper,the studies on the etiology,epidemiology,diagnosis,prevention and control of HEV were summarized,with a view to further improving the awareness of relevant practitioners to make them better research or respond to future outbreak. 全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202204013&uniplatform=NZKPT&v=vPzqR5W2eDCdCWwoQEPMqGCoD7M3B4PtQ2ac0IW9ZIXAgMK-D6QHX_3uApSruhRE
2022-04-20
弓形虫实验室诊断技术研究进展
弓形虫病(toxoplasmosis)是由刚地弓形虫(Toxoplasma gondii)感染引起的一种人兽共患寄生虫病,在世界各地都有分布,宿主种类十分广泛,人间和动物的感染率都比较高,对人类健康和公共卫生构成了威胁。目前,弓形虫病没有理想的药物用于治疗,早期诊断是防控该病的重要手段之一。病原学诊断是最早建立的弓形虫诊断方法,操作简单,结果可靠,但耗时较长,无法满足快速、高效、批量检测的需求,因此在实验室诊断方面应用逐步减少。免疫学检测方法以ELISA和IHA方法为主,已有较为成熟的商品化试剂盒或诊断试剂,在大规模的检测和流行病学调查中起到了很大作用。分子生物学方法与传统的病原学检测方法相比,其速度、通量、特异性、敏感性各方面都有提升,相较于免疫学诊断,避免了获得性免疫带来的假阳性结果,是未来弓形虫病实验室诊断的主要发展趋势。本文从病原学、分子生物学和免疫学方面对弓形虫的实验室诊断技术进行论述,以期为弓形虫的实验室诊断和防控措施的制定提供参考。Advances in Laboratory Diagnostic Techniques for Toxoplasma gondiiToxoplasmosis is a zoonosis caused by infection with Toxoplasma gondii,and widely distributed all over the world,with wide range of host species and high infection rates in human and animals,posing a threat to human health and public health. Considering that no ideal drug has been available for the disease,early diagnosis is one of the important means to prevent and control the disease. Etiological diagnosis is the initial method for Toxoplasma gondii,and is simple with reliable results but time-consuming,which failed to meet the needs of rapid,efficient and batch detection,and became decreasing in its application in laboratory diagnosis. Immunological detection methods mainly include ELISA and IHA,and relatively mature commercial kits or diagnostic reagents are available,which have played a great role in large-scale detection and epidemiological investigation. Compared with traditional pathogenic detection methods,molecular biological methods have been improved in speed,throughput,specificity and sensitivity,and avoided false positive results caused by acquired immunity as compared with immunological diagnosis,which represent the main development trend of laboratory diagnosis for toxoplasmosis in the future. In the paper,the laboratory diagnosis technology for Toxoplasma gondii were discussed from the aspects of etiology,molecular biology and immunology,with a view to providing a reference for the laboratory diagnosis for Toxoplasma gondii and development of measures fighting against toxoplasmosis.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202204012&uniplatform=NZKPT&v=vPzqR5W2eDDvN3i09AaxeTq4bSAnb50ZtBYX-R2auVZdzGB80AQs6oMt30Dkv88v
2022-04-20
猪源多杀性巴氏杆菌的分离鉴定及其主要抗原蛋白的原核表达
2021年3月,山东省龙口市某养猪场发生了一起以败血症为主要临床症状的烈性传染病。为对引起此次疫病的病原进行确诊,无菌采集发病死亡仔猪的肝脏、脾脏等脏器进行染色镜检、病原分离培养、生化鉴定及PCR检测。结果显示,本次分离株的形态结构、培养特性及生化结果与多杀性巴氏杆菌较为一致,且可特异性扩增出多杀性巴氏杆菌特异性基因Kmt,因此本次分离菌株为一株猪源多杀性巴氏杆菌,命名为LK01。随后,对该分离株的5个主要抗原蛋白基因(OmpH、OmpA、AspA、pIpE和TAA)进行克隆与原核表达。先将PCR成功扩增出的目的片段与双酶切回收后的pCold-I载体进行同源重组连接,测序结果正确的重组质粒转化至大肠杆菌BL21(DE3)感受态细胞中,随后经IPTG诱导后进行Western blot检测。结果显示,在30.0、21.5、52.0、37.5和45.5 kDa处出现特异性条带,表明各重组蛋白均成功表达。本研究为开展猪源多杀性巴氏杆菌病的流行病学研究,开发新型重组疫苗与诊断试剂奠定了基础。Isolation and Identification of Porcine Pasteurella multocida Strain and Prokaryotic Expression of Its Major Antigen ProteinsIn March 2021,a severe infectious disease with major symptom of septicemia occurred in a swine farm in Longkou City,Shandong Province. In order to identify the pathogen leading to the disease,livers and spleens of dead piglets were aseptically collected for staining microscopic examination,bacterial isolation and culture,biochemical identification and PCR detection. The results showed that the morphological structure,culture characteristics and the results of biochemical test of the isolate were relatively consistent with those of Pasteurella multocida(PM),then Kmt,the specific gene of PM was successfully amplified,it was identified that the isolate was a porcine PM named as LK01. Subsequently,its five major antigen genes(including OmpH,OmpA,AspA,pIpE and TAA)were cloned and expressed in prokaryotic expression system. By homologous recombination,the target fragments amplified by PCR were linked with the pCold-I that was after double digestion. The recombinant plasmid with correct sequencing results was transformed into E. coli BL21(DE3)cells and induced by IPTG for Western blot detection. It was observed that specific bands appeared at 30.0,21.5,52.0,37.5 and 45.5 kDa,indicating that all recombinant proteins were successfully expressed. A foundation was thus provided for further epidemiological study on porcine PM and for development of new recombinant vaccines and diagnostic reagents.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202204007&uniplatform=NZKPT&v=vPzqR5W2eDC80-MzvwQzQfqaORuBw6l2HfPDjPUNminpICQvcKvjTO4pmkroMcNw
2022-04-20
4株鸡源多杀性巴氏杆菌生物学特性分析
禽多杀性巴氏杆菌可引起禽出血性败血症,又称为禽巴氏杆菌病、禽霍乱,发病快,死亡率高。为对禽多杀性巴氏杆菌的致病机制研究及临床防治提供支持,通过PCR鉴定、耐药性分析、生物被膜形成能力试验以及半数致死量(LD50)测定,对4株临床分离的鸡源多杀性巴氏杆菌(Pm01、Pm03、1801及1803)进行了相关生物学特性分析。PCR鉴定结果显示,4株多杀性巴氏杆菌均为荚膜血清A型,均含有pfhA、exBDtonB、nanB、oma87、ompH、hgbB、hgbA、sodC、sodA 9种毒力基因,不含有toxA、nanH、ptfA 3种毒力基因;耐药性分析结果显示,4株多杀性巴氏杆菌对克林霉素、红霉素、四环素、卡那霉素、阿莫西林、头孢噻吩和氨苄西林等7种抗生素表现出全部或部分耐药;生物被膜形成能力试验结果显示,Pm01菌株能形成极强的生物被膜,而Pm03、1801以及1803菌株几乎不能形成生物被膜;LD50测定结果显示,4菌株LD50分别为1.33×101、2.74×102、4.22和4.22 CFU。结果表明,4株鸡源多杀性巴氏杆菌含有多种毒力基因,均具有较强的致病性,其毒力与生物被膜形成能力不完全相关,且对多种抗生素耐药。本研究为禽巴氏杆菌病防治提供了技术支撑与参考数据。Analysis on the Biological Characteristics of Four Strains of Pasteurella multocida Derived from ChickenAvian hemorrhagic septicemia,also known as avian pasteurellosis or avian cholera,is caused by Pasteurella multocida,with rapid occurrence and high mortality. In order to support future researches on the pathogenic mechanism of the bacteria as well as prevention and control of the disease in practice,relevant biological characteristics of four strains of Pasteurella multocida(Pm01,Pm03,1801 and 1803)were analyzed through PCR identification,drug resistance analysis,biofilm formation ability test and median lethal dose(LD50)determination. It was showed that,by PCR identification,all the four strains were capsular serotype A and contained 9 virulence genes including pfhA,exBDtonB,nanB,oma87,ompH,hgbB,hgbA,sodC and sodA,except toxA,nanH and ptfA;by drug resistance analysis,the four strains were fully or partially resistant to 7 antibiotics including clindamycin,erythromycin,tetracycline,kanamycin,amoxicillin,cefotaxime and ampicillin;by biofilm formation ability test,a very strong biofilm was formed by Pm01 strain,but failed by Pm03,1801 and 1803;and by the LD50 determination test,the LD50 values of the four strains were 1.33×101,2.74×102,4.22 and 4.22 CFU,respectively. In conclusion,all the four strains contained a variety of virulence genes that were with strong pathogenicity,for which the virulence was not completely related to the biofilm formation ability,and resistant to a variety of antibiotics. A technical support and reference data were provided for future prevention and control of avian pasteurellosis.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202204022&uniplatform=NZKPT&v=vPzqR5W2eDDek5QoglmXmOjNANS1XBh7FovRVaOHHwT9187EAklnIYM-4ITWcDa6
2022-04-20
新疆和田鹅源沙门氏菌血清型鉴定及耐药性分析
为了解新疆和田地区鹅源沙门氏菌流行血清型及其耐药性,无菌采集和田地区两个鹅场(A场和B场)病死鹅内脏、肛拭子样本,用常规方法进行沙门氏菌分离鉴定,利用PCR进行验证和血清型鉴定,用K-B法进行分离株耐药性检测。结果显示:共分离出14株沙门氏菌,总分离率为1.81%(14/773)。A场死亡鹅内脏样本的沙门氏菌分离率为1.33%(4/300),肛拭子样本分离率为1.66%(5/300),在存活病鹅肛拭子中未分离出沙门氏菌(0/25);B场死亡鹅内脏样本的沙门氏菌分离率为20.00%(4/20),肛拭子样本中未分离到沙门氏菌(0/19),存活病鹅肛拭子样本分离率为0.91%(1/109)。共分离出4种血清型,占比分别为鼠伤寒沙门氏菌42.86%(6/14)、肠炎沙门氏菌21.43%(3/14)、德比沙门氏菌7.14%(1/14)、纽兰沙门氏菌7.14%(1/14)。沙门氏菌分离株对多黏菌素B、哌拉西林-他唑巴坦、阿莫西林-棒酸和头孢吡肟较为敏感,对其余10种抗菌药物具有一定耐药性,其中对氨苄西林和链霉素耐药性极强。结果表明,和田地区鹅源沙门氏菌血清型复杂,其中鼠伤寒沙门氏菌为优势血清型,不同养殖场流行的血清型种类及优势血清型有差异;流行的鹅源沙门氏菌耐药较为普遍,且表现为多重耐药。结果提示,各养殖场应根据流行的具体血清型沙门氏菌株,科学合理使用临床抗菌药物。Serotype Identification and Drug Resistance Analysis of Salmonella of Goose Origin in Hotan,XinjiangIn order to identify the prevalent serotypes and drug resistance of Salmonella of goose origin in Hotan,Xinjiang,visceral and anal swabs of dead geese and anal swabs of sick geese were aseptically collected from two farms(Farm A and Farm B)in Hotan for isolation and identification of Salmonella by conventional methods,followed by validation and serotype identification by PCR,then drug resistance analysis of the isolates by Kirby-Bauer disk diffusion susceptibility test(KB test). The results showed that 14 strains of Salmonella were isolated,with a total isolation rate of 1.81%(14/773). For Farm A,the isolation rate of visceral samples of dead geese was 1.33%(4/300),and that of anal swab samples was 1.66%(5/300),but no Salmonella was isolated from anal swabs of sick geese(0/25). For Farm B,the isolation rate of Salmonella from visceral samples of dead geese was 20.00%(4/20),none was isolated from anal swab samples(0/19),and that of anal swab samples of sick geese was 0.91%(1/109). Four serotypes were isolated,including Salmonella typhimurium accounting for 42.86%(6/14),Salmonella enteritis for 21.43%(3/14),Salmonella derby for 7.14%(1/14)and Salmonella newland for 7.14%(1/14). The isolates were sensitive to polymyxin B,piperacillin tazobactam,amoxicillin clavulanic acid and cefepime,and resistant to other 10 antibiotics to some extent,especially extremely resistant to ampicillin and streptomycin. In conclusion,the serotypes of Salmonella in Hotan were complex,in which Salmonella typhimurium was the dominant one,and the prevalent and dominant serotypes were different depending on different farms;the drug resistance,especially multiple one,of the prevalent Salmonella strains,was common. It was therefore recommended that antibiotics should be scientifically and reasonably used in clinical practice according to specific serotypes prevalent in each farm.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202204006&uniplatform=NZKPT&v=vPzqR5W2eDCGPtZcByjXTb36z7qYTRdIHLaFpZvohiohcBBQL_JS6VoguSJjlwDw
2022-04-20
我国部分地区病死畜禽无害化处理中心病原灭活情况调查
为了解我国病死畜禽无害化处理环节病原灭活效果,2020年对11个省(自治区)52个病死畜禽无害化处理中心开展抽样检测、问卷调查。通过对样品进行病毒核酸检测和病毒核酸阳性样品病原活性检测发现,化制法、发酵法、碳化法、酸解法均可灭活非洲猪瘟、猪瘟、口蹄疫和猪繁殖与呼吸综合征等4种疫病病原。通过问卷调查发现,无害化处理中心因厂区布局、管理制度、操作措施等方面问题,存在终端产物被病原二次污染或病原随产物扩散至场外的风险。因此,要规范无害化处理企业建设,加强企业日常监管和无害化处理产物监管,降低病原传出风险。Investigation on the Pathogen Inactivation by Bio-safety Disposal Centers in ChinaIn order to investigate the effect of pathogen inactivation by bio-safety disposal centers for dead livestock and poultry in China,52 centers in 11 provinces/autonomous regions were sampled,tested and investigated by questionnaire in 2020. It was found that,through detection of viral nucleic acid and pathogenic activity of viral nucleic acid positive samples,African swine fever virus(ASFV),classical swine fever virus(CSFV),foot-and-mouth disease virus(FMDV)and porcine reproductive and respiratory syndrome virus(PRRSV)could be inactivated by rendering,fermentation,carbonization and acidic hydrolysis. Based on the results of questionnaire investigation,due to the problems including site layout,management system,operation measures and other aspects applied in the centers,there was potential risk of secondary contamination in terminal products by pathogens or spreading pathogens to the premises outside the centers with products. Therefore,it was necessary to standardize the construction of bio-safety disposal enterprises,and to strengthen daily supervision for the enterprises and supervision for the products under bio-safety disposal to reduce potential risk of spreading any pathogens.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202204005&uniplatform=NZKPT&v=vPzqR5W2eDA9hDQ3FavBVDxGNgkytV5qGdI1SMOEpserDBq88MVh6tZHhfoFv-Rh
2022-04-20
2019—2021年我国29个省级行政区鸡传染性支气管炎流行病学调查
为了解鸡传染性支气管炎病毒(IBV)在我国的流行规律,通过RT-PCR方法,对2019—2021年从我国29个省级行政区送检的38 442份疑似IBV感染样品进行病原检测和鉴定,对检出的阳性样品进行S1基因测序分型,然后对检测结果进行时间、空间和群间统计分析。结果显示:共检出6 436份IBV阳性样本,阳性检出率为16.7%。2019—2021年的IBV阳性检出率分别为12.5%、16.4%、21.0%,呈逐年增长趋势:阳性检出率呈现一定的季节性变化特点,7—9月检出率(11.3%~15.4%)较低,而3—6月(17.3%~19.3%)和10—12月(17.5%~19.0%)较高。全国29个省级行政区中有27个检出阳性样品,其中东部和中部家禽养殖密集区阳性检出率较高,而西部和北部地区较低。白羽肉鸡阳性检出率最高(28.9%),肉种鸡阳性检出率最低(5.0%),0~6周龄阶段IBV感染较为严重。共检出5种基因型,其中QX型(66.5%)、GVI型(27.7%)占比较高,为当前流行的优势基因型;不同品种鸡群中流行的基因型存在一定差异,白羽肉鸡群中以QX和GVI型为主,而其他鸡群中流行的基因型较为复杂;QX型0~3周龄(33.2%)、GVI型3~6周龄(66.4%)阳性检出数量占比较高,6周龄以后占比均较低(<14.0%)。结果表明:我国鸡群中IBV感染普遍,尤其是家禽养殖密集区,且流行呈逐年加重趋势;冬春或秋冬季节多发,小日龄鸡群感染严重;流行基因型复杂,以QX型和GVI型多见。结果提示,我国的IB防控面临较大压力与挑战,需要加强优势基因型疫苗的研发,重点做好小日龄鸡群的IB防控。Epidemiological Investigation on Avian Infectious Bronchitis in 29 Provincial Administrative Regions of China from 2019 to 2021In order to identify the prevalence rule of avian infectious bronchitis virus(IBV)in China,38 442 samples with suspected IBV infection submitted by 29 regions at provincial levels from 2019 to 2021 were detected and identified by RT-PCR. The S1 genes of positive samples were sequenced and typed,and then the results were statistically analyzed from the aspects of time,space and intergroup. The results showed that 6 436 IBV positive samples were detected,with the positive detection rate of 16.7%.The positive detection rates of IBV for the three years were 12.5%,16.4% and 21.0% respectively,tending to increase year by year:the positive detection rate changed with seasons to certain extent,which was lower from July to September(11.3% to 15.4%),and higher from March to June(17.3% to 19.3%)and October to December(17.5% to 19.0%). Positive samples were detected from 27 out of 29 regions,the detection rates were higher in intensive poultry areas in the eastern and central regions,and lower in the western and northern regions. The detection rate of white feather broilers was highest(28.9%),and that of broiler breeders was lowest(5.0%). The infection with IBV was more serious in chickens at the age of 0~6 weeks. Five genotypes were detected,especially QX(66.5%)and GVI(27.7%)that were dominant genotypes;the prevalent genotypes were different in different breeds,QX and GVI were the main genotypes in white feather broiler flocks,while the prevalent genotypes were complex in other flocks;the positive rates of QX and GVI were higher in the flocks at 0 to 3 weeks old(33.2%)and 3 to 6 weeks old(66.4%),and lower in those at more than 6 weeks old(<14.0%). In conclusion,IBV was widely distributed in chicken flocks in China,especially in intensive areas where the prevalence tended to increase year by year;it occurred frequently in winter,spring or autumn,and was serious in the flocks at young day old;the prevalent genotypes were complex,especially QX and GVI were common. In conclusion,there was a huge pressure and challenge to prevent and control IB in China,thus it was necessary to strengthen the development of vaccines of dominant virus genotypes,and a priority should be given to IB control of chicken flocks at young day old.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202204020&uniplatform=NZKPT&v=vPzqR5W2eDDGd3nEvemc-sUjGnikySnGZY31xk2TX3Em9TINuFTei5CTHVW7jzwJ
2022-04-20
PRRS嵌合病毒活疫苗(PC株)和灭活疫苗联合免疫母猪应用试验
为验证猪繁殖与呼吸综合征(PRRS)嵌合病毒活疫苗(PC株)和灭活疫苗联合应用于母猪的免疫效果,在天津市某PRRS阳性猪场,对部分母猪实施了两种疫苗联合免疫试验,利用RT-PCR和间接ELISA方法进行病毒和免疫抗体检测。结果显示:接种疫苗后,试验母猪精神、食欲和体温均正常,猪肛拭子和饲养环境样品中均未检测到病毒;免疫后14~70 d,试验母猪PRRS抗体阳性率均为100%;免疫后42 d,试验母猪的抗体IRPC平均值仍维持在较高水平,且免疫后14 d,2个试验组变异系数分别下降31和44个百分点;试验母猪所产仔猪的均匀度、活泼程度均高于对照组。结果表明,PRRS嵌合病毒活疫苗(PC株)和灭活苗联合免疫安全有效,不仅可以很好地诱导机体产生正常的免疫反应,而且还可以提高猪群抗体的整齐度且无排毒风险,免疫保护期较长。本研究为阳性猪场的PRRS防控提供了有效免疫方案。Application Test of Combined Vaccination of Live Chimeric Virus Vaccine(PRRSV PC Strain)and Inactivated Vaccine in SowsIn order to verify the immune effect of combined vaccination of chimeric virus vaccine(PC strain)and inactivated vaccine of porcine reproductive and respiratory syndrome(PRRS)applied in sows,some sows in a PRRS positive farm in Tianjin City were simultaneously vaccinated with the two kinds of vaccines,and related samples were collected and detected for virus nucleic acids and antibodies by RT-PCR and indirect ELISA,respectively. The results showed that the experimental sows were with normal spirit,appetite and body temperature,and no virus was detected in their samples of anal swabs and feeding environment;the positive rate was 100% in 14 to 70 days after vaccination;the average IRPC of antibodies remained at a relatively high level in 42 days after vaccination,and the variation coefficient of the two experimental groups decreased by 31% and 44% respectively in 14 days after vaccination;the evenness and liveliness of piglets produced by the experimental sows were higher than those by control group. In conclusion,combined vaccination of chimeric virus vaccine(PC strain)and inactivated vaccine of PRRS was safe and effective,which not only induced normal immune response in the body,but also improved the uniformity of antibodies in pigs without any risk of detoxification,and provided a long immune protection period. An alternative and effective choice for PRRS prevention and control was thereby provided for PRRS-positive farms. 全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202112020&uniplatform=NZKPT&v=2vpJqQNi66Gty71SN-LVre9WQUkbzyJK5jmc8ScN4F2kIS-3eCAgsmu3ksgfgayl
2021-12-23
小反刍兽疫病毒芯片式数字PCR检测方法的建立及应用
为建立一种准确、快速、敏感性更高的小反刍兽疫病毒(peste des petits ruminants virus,PPRV)检测方法,建立了一种芯片式数字PCR(cdPCR)检测方法。根据GenBank中公布的PPRV Nigeria75 /1疫苗株N基因序列设计1对引物,PCR扩增大小为166 bp片段,构建pMDTM18-N标准质粒并优化反应条件,建立了PPRV N基因cdPCR检测方法,并与实时荧光定量 PCR(RT-qPCR)检测方法的灵敏性、重复性、特异性和临床样品检测做了比较分析。结果显示:当质粒标准品浓度在1.22×(105~102)copies/μL范围时,cdPCR检测方法比普通RT-PCR灵敏度高1 000倍,且稳定性好,特异性强;当标准品浓度在1.22×(105~10-3)copies/μL范围时,cdPCR与RT-qPCR相比具有相同的特异性,但灵敏性比RT-qPCR高100倍;与RT-qPCR 测定结果(13.29±6.74)copies/μL相比,cdPCR的最低检测限更低,约为(0.44±0.14)copies/μL;cdPCR对47份临床样本的PPRV核酸阳性检出率(25.5%)高于RT-qPCR(17.0%)。结果表明,建立的cdPCR方法特异性强、灵敏度高、重复性好,为预防PPR早期流行提供了一种快速有效的诊断和定量检测方法。Development and Application of a Chip Digital PCR Assay for PPRVIn order to establish an accurate、rapid and sensitive method to detect peste des petits ruminants virus(PPRV),a chip digital PCR(cdPCR)assay was developed. A pair of primers was designed based on the N gene sequence of PPRV Nigeria75/1 vaccine strain registered in GenBank. The fragment with the size of 166 bp was amplified by PCR to construct pMDTM18-N standard plasmid,followed by optimization of reaction conditions,then a cdPCR assay for PPRV N gene was established,its sensitivity,repeatability,specificity and clinical sample detection capacity were compared and analyzed with those of RT-qPCR. The results showed that cdPCR was with good stability and specificity,and its sensitivity was 1 000 times higher than that of RT-PCR when the concentration of plasmid standard ranged 1.22×(105~102)copies/μL;cdPCR was with the same specificity as RT-qPCR,but its sensitivity was 100 times higher than that of RT-qPCR when the concentration was 1.22×(105~10-3)copies/μL;the lowest detection limit of cdPCR(0.44±0.14)copies/μL was lower compared to that of RT-qPCR(13.29±6.74)copies/μL;and for 47 clinical samples,the detection rate of PPRV nucleic acid by cdPCR(25.5%)was higher than that by RT-qPCR(17.0%). In conclusion,the established cdPCR was with good specificity,sensitivity and repeatability,which could support to prevent any early prevalence of PPRV as a rapid and effective diagnostic and quantitative method.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202112018&uniplatform=NZKPT&v=2vpJqQNi66Hsx9rFNbOw9lXSp6DdAn_4kxzLwL3L4Iwsw1LBwHwJUAFQCpEGvGIW
2021-12-23
天然免疫RIG-I样受体LGP2在抗病毒免疫中的作用
RIG-I样受体(RLRs)是细胞质中重要的模式识别受体(PRRs),LGP2是其重要的家族成员之一。LGP2在抗病毒天然免疫应答中具有特殊功能,能够双向调控RIG-I、MDA5介导的I型干扰素(IFNs)信号通路。在不同病毒感染宿主的过程中,LGP2也表现出明显的功能差异。在双链DNA病毒中,LGP2在RIG-I介导的信号传导过程中起正向调节作用;在单链DNA病毒中,LGP2能够促进CARDs区失活的RIG-I与非典型泛素链结合,从而诱导I型IFNs产生;在双链RNA病毒中,正常表达可增强RIG-I、MDA5对dsRNA的识别能力;在正义单链RNA病毒中,LGP2参与对正义单链RNA病毒的识别过程;在负义单链RNA病毒中,LGP2有时可作为IFNs的诱导剂。另外,LGP2在适应性免疫应答中也发挥着重要作用,能够通过不同途径调控T细胞存活与凋亡。目前在调控RIG-I、MDA5介导的信号通路与抗病毒免疫应答中,尚不清楚LGP2发挥的确切功能和其作用机制,未来可进一步加深LGP2在细胞免疫应答中的作用及机制研究。本文就近年来LGP2在RLRs介导的信号通路和抗病毒免疫应答中发挥的作用作综述,以期为LGP2的进一步研究和机体抵御病毒感染新机制提供参考。Studies on the Roles of Innate Immune RIG-I-like Receptor LGP2 in Antiviral ImmunityRIG-I-like receptors(RLRs)are the key pattern recognition receptors(PRRs)in cytoplasm,and LGP2 is one of its important family members. LGP2 functions specially in antiviral innate immune response,and could regulate the type-I interferon(IFNs)signaling mediated by RIG-I and MDA5 bidirectional. Functional differences are also obviously present in LGP2 during the process of infection with different viruses in hosts.LGP2 positively regulates the progress of signaling mediated by RIG-I in double-stranded DNA(dsDNA)viruses,induces type-I IFNs through supporting the binding of inactivated RIG-I located in CARDs region with atypical ubiquitin chainin single-stranded DNA(ssDNA)viruses,increases the capacity of RIG-I and MDA5 to recognize dsRNA through normal expression in double-stranded RNA(dsRNA)viruses,participates in the process of recognition for positive-sense single-stranded RNA(+ssRNA)viruses,and is sometimes used as an inducer for IFNs in negative-sense single-stranded RNA(-ssRNA)viruses. In addition,LGP2 also plays an important role in adaptive immune response,regulating the survival and apoptosis of T cells through different ways. Currently,its specific functions and mechanisms for regulation of signaling mediated by RIG-I and MDA5 and for antiviral immune response are still unclear,which should be further studied in the future. In the paper,the studies on the roles of LGP2 in signaling mediated by RLRs and antiviral immune response in recent years were reviewed,with a view to providing a reference for further study on LGP2 and new mechanisms of resistance to viral infection.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202112017&uniplatform=NZKPT&v=2vpJqQNi66ErScKeXzQGj8VwgZo-gA4TnGAGyZxXqhRCxps7PW9rE1W-DEjpWRzf
2021-12-23
全球基因I型非洲猪瘟病毒流行与疫苗研究进展
非洲猪瘟病毒已在我国定殖并形成较大污染面,国内样品中发现基因I型非洲猪瘟病毒,提示当前临床中实际流行的病毒种群更加复杂。基因I型毒株从1957年传入葡萄牙后,研究人员就开始对其进行研究。多年来,国外对基因I型毒株的流行分布情况特别是弱毒疫苗进行了大量研究,但国内目前尚无这方面的分析讨论。为此,作者就基因I型非洲猪瘟病毒流行与疫苗研究现状进行综述,以期为我国非洲猪瘟的科学防控提供参考。Global Epidemic and Vaccine Research Status of African Swine Fever Virus Genotype I StrainThe African swine fever virus has been introduced into China and contaminated certain areas. Genotype I strains have been found in domestic pig samples,suggesting that the virus populations actually circulating in clinical samples are more complicated. Research on genotype I strains began after it was introduced to Portugal in 1957. After years of research accumulation,a large number of studies on the prevalence and distribution of genotype I strain,especially the development of live-attenuated vaccines based on genotype I strains,have been largely documented and developed in foreign countries,but there is no description in this regard in China. Therefore,the author reviewed the current status of the African swine fever virus genotype I strains and vaccine research developement,hoping to provide a reference for the scientific prevention and control of African swine fever in China.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202112015&uniplatform=NZKPT&v=2vpJqQNi66Hby1pq3vTe20KOauu52mR6F-LqVPN6BLcUOMbZmSw5vpffiQkl1Ono
2021-12-22
云南省野猪源猪瘟病毒E2及5'NTR基因序列测定分析
猪瘟(CSF)是由猪瘟病毒(CSFV)感染猪引起的一种急性、热性、接触性传染病,严重危害我国养猪业健康稳定发展。本研究采用RT-PCR方法,对从云南省宁洱县2头病死野猪体内分离到的2株CSFV毒株进行了E2及5'NTR基因扩增、克隆及序列测定;采用DNAMAN、MEGA6等分子生物学软件,对测得的序列与国内外参考毒株进行了同源性分析及系统发育分析。结果显示:2株野猪源CSFV株E2、5'NTR基因同源性分别为87.2%、100%,与国内外参考毒株同源性分别为81.0%~97.6%、93.6%~98.5%,与我国强毒株Shimen株的同源性分别为81.0%~81.2%、95.6%;2株野猪源CSFV毒株E2基因属于基因2.1亚型,5'NTR基因属于基因2.3亚型。氨基酸序列分析显示:其中一株分离毒株的E2基因有6个氨基酸具有2.1d分子变异特征,另一株兼有2.1d和2.1b亚型分支特征,可能是2.1b和2.1d亚型的过渡毒株。结果表明,云南省野猪源CSFV虽存在一定的遗传衍化,但总体比较稳定。本研究为云南省CSF防控提供了分子流行病学依据,为进一步做好分子变异等研究奠定了基础。Sequencing and Analysis of E2 and 5'NTR Genes of CSFV Derived from Wild Boars in Yunnan ProvinceClassical swine fever(CSF)is an acute,febrile and contact infectious disease caused by classical swine fever virus(CSFV),which has seriously endangered the healthy and stable development of pig industry in China. In this study,E2 and 5'NTR genes of two CSFV strains isolated from two dead wild boars in Ning'er County of Yunnan Province were amplified,cloned and sequenced by RT-PCR;the homology and phylogeny of the obtained sequences and the reference strains were analyzed and compared by DNAMAN,MEGA6.0 and other molecular biology software. The results showed that the homology of E2 and 5'NTR gene of the two strains were 87.2% and 100%,respectively,which were 81.0% to 97.6% and 93.6% to 98.5% respectively with the reference strains,81.0% to 81.2% and 95.6% respectively with Shimen virulent strains in China;for the two strains,E2 gene and 5'NTR gene belonged to subtype 2.1 and subtype 2.3,respectively. As indicated by amino acid sequence analysis,6 amino acids with molecular variation characteristics of 2.1d subtype were observed in one strain,characteristics of both 2.1d and 2.1b subtypes were in another strain,which might be a transitional strain of the two subtypes. In conclusion,the CSFV prevalent in wild boars in Yunnan Province was generally steady although a certain genetic evolution was detected. A molecular epidemiological basis was provided for prevention and control of CSF in Yunnan Province,and a foundation was also laid for further studies on molecular variation.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202112007&uniplatform=NZKPT&v=2vpJqQNi66ERRxmGNP7wH4P5HUgI2p6-yUNyfAIzjEJR1xJdu5Cvr13hDIdzEpPA
2021-12-22
5株湖南猪圆环病毒1型全基因组测序与遗传进化分析
为了解湖南猪群猪圆环病毒1型(PCV1)的遗传变异情况,以PCV1阳性DNA为模板,使用PCR方法分两段扩增PCV1全基因序列并进行拼接。结果共获得5个PCV1全基因组,其中3株全基因大小为1759 bp,另外2株分别为1758 bp和1760 bp。5株全基因组同源性为98.4%~99.7%,与国内外的PCV1全基因组同源性为98.1%~99.7%;ORF2序列同源性为97.6%~99.6%,与国内外的PCV1 ORF2同源性为96.1%~99.9%。系统发育树显示,5株PCV1均属于同一分支,并显示出一定的地理差异,但差异较小。结果表明,湖南省流行的PCV1毒株基因较为稳定,分离株间差异较小。本研究为湖南省猪圆环病毒病防控及相关研究奠定了基础。Whole Genome Sequencing of Five Strains of PCV1 in Hunan Province and Analysis on Their Genetic EvolutionIn order to identify the genetic variation of porcine circovirus type 1(PCV1)in pigs in Hunan Province,taking PCV1 positive DNA as a template,two sections of PCV1 gene sequence were amplified by PCR and then spliced together to form the whole genome. Five strains of whole genomes were obtained,in which,three were 1759 bp,and two were 1758 bp and 1760 bp,respectively. The homology of the whole genome was 98.4% to 99.7%,which shared the homology of 98.1% to 99.7% with other whole genomes of PCV1;the homology of ORF2 sequence was 97.6% to 99.6%,which shared the homology of 96.1% to 99.9% with other PCV1 ORF2. As indicated by the phylogenetic tree,all the five strains belonged to the same branch with slightly geographical difference. In conclusion,the strains were steadily prevalent in Hunan Province with little difference. A foundation was thereby provided for future prevention and control of PCV in Hunan and for relevant studies.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202112006&uniplatform=NZKPT&v=2vpJqQNi66HqJDejgO5KLs0EGxQ8L9WhpUhacoszGiKxaCrkOSuJB1p4Dd7-SVjr
2021-12-22
2017—2020年广西部分猪场送检血清猪伪狂犬病抗体检测
为了解广西猪场伪狂犬病毒(PRV)感染和免疫状况,2017年1月—2020年12月,对部分猪场随机采样送检的血清样品,应用ELISA方法开展PRV血清抗体检测,并对检测结果进行不同年份、不同季节、不同地区、不同生长阶段猪群的统计分析。结果显示:从时间分布上看,2018年PRV gE抗体场阳性率(57.71%)和个体阳性率(24.75%)均最高,此后呈逐年下降趋势,其中个体阳性率下降明显(P<0.05),2020年下降至6.14%;各年间的PRV gB抗体场合格率差异不显著(P>0.05),均在90%以上,而2019年的个体阳性率(88.71%)最低,与其他年份差异显著(P<0.05)。冬季PRV gE和gB抗体个体阳性率最低,分别为14.96%和89.35%,与其他季节差异明显(P<0.05);冬季gE抗体场阳性率(42.97%)最低,与春季、秋季差异不显著(P>0.05),但显著低于夏季(P<0.05),而gB抗体场合格率一年四季差异不显著(P>0.05),均在95%以上。从空间分布上看,广西14个地市猪场均存在不同程度的PRV野毒感染,其中玉林市最严重,场阳性率和个体阳性率分别为69.51%和35.86%,而钦州市最轻,分别为16.67%和4.07%;PRV gB抗体个体合格率普遍较高,均在84%以上。从不同生长阶段猪群上看,后备母猪、育肥猪PRV gE和gB抗体个体阳性率均显著低于其他生长阶段猪群(P<0.05),其中gE抗体个体阳性率在13%以下,而gB抗体个体阳性率不足80%。结果表明,近年广西规模猪场PRV野毒感染率较高,而疫苗免疫并不能完全阻止野毒株感染。建议通过PRV净化和提高规模猪场生物安全水平等措施来控制其流行。本研究为制定合理的猪伪狂犬病防控与净化策略提供了依据。Detection of Antibodies against PRV in Serum Samples Delivered by Some Swine Farms in Guangxi from 2017 to 2020 In order to investigate the status of infection and immune of porcine pseudorabies virus(PRV)in swine farms in Guangxi,serum samples randomly collected from some farms during January 2017 to December 2020 were detected for antibodies against PRV by ELISA,the results were summarized and analyzed according to different years,seasons,regions and pig populations at different ages. The results showed that the positive rates of antibodies against PRV gE at farm level(57.71%)and individual level(24.75%)were highest in 2018,then trended to decrease year by year,especially the individual one that even decreased to 6.14% in 2020(P<0.05);the qualification rates of antibodies against PRV gB at farm level were above 90% and the difference was not significant in all these years(P>0.05),but the positive rate at the individual level was lowest in 2019(88.71%),and significantly different from those in other years(P<0.05). The individual positive rates of antibodies against PRV gE and gB were 14.96% and 89.35% respectively,lowest in winter,and obviously different from those in other seasons(P<0.05);the positive rates of antibodies against gE at farm level were lowest in winter(42.97%),and not significantly different from those in spring and fall(P>0.05),but significantly lower than those in summer(P<0.05),while those of antibodies against gB were above 95% and the difference throughout the year was not significant(P>0.05). For spatial distribution,PRV wild virus was present in all the farms to different extent,most serious in Yulin City where the positive rates at farm and individual level were 69.51% and 35.86%,respectively,and lightest in Qinzhou City where were 16.67% and 4.07%,respectively;The individual qualification rates of antibodies against gB were all above 84% and generally higher. For pig populations at different ages,the individual positive rates of antibodies against gE and gB in reserved sows and finishing pigs were significantly lower than those at other stages(P<0.05),specifically,the individual positive rate of antibodies against gE was less than 13%,while that of antibodies against gB was less than 80%. In conclusion,the infection rate of PRV wild virus was relatively high in large-scale farms in Guangxi,which could not be fully controlled by vaccination,so PRV purification and improvement of bio-safety level in the farms were recommended. A basis was thereby provided for developing reasonable measures for PRV prevention,control and purification.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202112002&uniplatform=NZKPT&v=2vpJqQNi66G6HrjqIrUp6YtHMbKZogQ0_UBQjYj2DaI3GF0Mz3ac3ErTgp8mhlAW
2021-12-22
固相萃取-超高效液相色谱法同时测定猪肉中22种磺胺类药物残留
为探索一次性检测猪肉中多种磺胺类药物残留的检测方法,建立了同时测定猪肉中22种磺胺类药物残留的固相萃取-超高效液相色谱方法。样品用3%乙酸乙腈提取,MCX固相萃取柱净化,水和甲醇淋洗,5%氨化甲醇洗脱,氮气吹至近干,0.1%甲酸-乙腈(9:1,V/V)溶液复溶,二极管阵列检测器270 nm检测。结果显示:该方法对22种磺胺类药物检测的线性关系良好(R2>0.999),定量限为2.5~10.0 μg/kg,检测限为1.0~4.0 μg/kg;各药物平均回收率为83.2%~96.6%,批内和批间变异系数分别为1.1%~3.5%和3.6%~13.4%。结果表明,该方法灵敏度高、重复性好、成本低廉,且操作简单、快速,可用于猪肉样品中多种磺胺类药物残留的同时检测。Simultaneous Determination of 22 Kinds of Sulfonamide Residues in Pork by SPE-UPLCIn order to develop a method for simultaneously detecting various sulfonamide residues in pork,a solid-phase extraction-ultra-high performance liquid chromatography(SPE-UPLC)method for detecting 22 kinds of sulfonamide residues in pork was established. Samples were extracted by 3% acetic acid acetonitrile,purified by MCX solid phase extraction column,rinsed by water and methanol,eluted by 5% ammoniated methanol,dried by blowing with nitrogen,and redissolved by 0.1% formic acid-acetonitrile(9:1,V/V)solution,and then detected by a diode array detector at 270 nm. The results showed that the linear relationship was good(R2>0.999)for detection of the 22 kinds of sulfonamides by the method,with the limit of quantification of 2.5 to 10.0 μg/kg,the detection limit of 1.0 to 4.0 μg/kg;the average recovery rate of each drug ranged 83.2% to 96.6%,and the variable coefficients within and between batches were 1.1% to 3.5% and 3.6% to 13.4%,respectively. It was concluded that various sulfonamide residues in pork could be simultaneously detected by the established method due to its advantages of high sensitivity,good repeatability,low cost,simple and rapid operation.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202107022&v=2vpJqQNi66HJ2q0ogrDg58x2dhwKSEOa%25mmd2F2c9kdBYouetCkjtg4e8xbu7QrTxlq1b
2021-07-26
不同非洲猪瘟病毒荧光PCR检测试剂盒在检测猪肉及猪肉制品中的比较
为了解不同非洲猪瘟病毒荧光PCR检测试剂盒在检测猪肉及猪肉制品中的特征,采用国内外6种商品化非洲猪瘟病毒实时荧光PCR检测试剂盒,分别对同一样本开展稳定性试验,对相同非洲猪瘟强阳性、中阳性及弱阳性样本开展敏感性试验。结果显示:6种试剂盒扩增稳定性良好;对强阳性样本,所有商品化试剂盒均能检出;对中阳性及弱阳性样本,特别是弱阳性样本,不同试剂盒的检出情况不尽相同。因此在实际应用中,应根据具体需求选择合适检测试剂盒。本试验为一线工作者选择使用不同商品化非洲猪瘟检测试剂盒提供了一定参考。Comparison of Different Fluorescent PCR Kits for Detection of ASFV in Pork and Its ProductsIn order to identify the characteristics of different fluorescent PCR kits for detection of African swine fever virus(ASFV)in pork and its products,stability test was conducted for the same samples by 6 domestic and foreign PCR kits and sensitivity test for the samples with strong,medium and weak positive ASFV. The results showed that all the 6 kits were with good stability;for sensitivity test,the strong positive samples could be detected out by all 6 kits,but medium positive and weak positive samples,especially the latter,the results were quite different depending on different kits. Therefore,an appropriate kit should be selected according to specific need in practice. Some reference was thereby provided for field workers to select various kits.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202107021&v=2vpJqQNi66HdeB%25mmd2FairmIkTp%25mmd2BpTLac8IKAFG3c7tBG4r%25mmd2Bbxzu3K5KmKJj971CGEDq
2021-07-26
猪场紫外消毒技术研究进展
在养猪业发展进程中,生物安全防控一直是人们关注的焦点。紫外消毒技术以消毒效率高、使用成本低及安全性高等特点,在猪场生物安全领域开始受到关注,并取得一些进展。但是紫外消毒技术仍存在病原体灭活不完全等情况,其灭活效果是紫外消毒作业中最被关心的问题。本文就影响紫外消毒效果的因素、灭活常见猪病原体所需紫外剂量以及紫外消毒在猪场的应用分别展开论述。同时,针对研究发展中的不足之处进行了总结和思考,以期为提高猪场紫外消毒效果和效率提供参考。Research Progress on Ultraviolet Disinfection Technology in Swine FarmsBiosafety has always been a focus concerned during the development of swine industry,especially ultraviolet(UV)disinfection technology due to its high efficiency,low cost and high safety,and some results have been achieved. However,the technology could not fully inactivate pathogens sometimes,so its effect was mostly concerned during the work of UV disinfection. In the paper,the factors affecting the effect of UV disinfection,its dose required to inactivate common swine pathogens and its application in swine farms were discussed. Meanwhile,the gaps available in its development were summarized and considered with a view to providing some references to improve the effect and efficiency of UV disinfection in swine farms.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202107019&v=2vpJqQNi66Gnf%25mmd2F0V0z1tivdNkkdZxLgxO1XyItTazpPv29fsSFpDpJ0oD1Roayqf
2021-07-26
纳米抗体筛选和表达技术研究进展
纳米抗体(nanobody,Nb)是在骆驼血清中发现的一种新型抗体,具有相对分子质量小、稳定性高、亲和力高、组织渗透性强以及可识别抗原缝隙表位、进一步改造和表达等特点。Nb筛选技术分为噬菌体展示、酵母双杂交、mRNA展示以及高通量测序和质谱分析等4种,它们都能够快速筛选到特异性Nb。对具有高度亲和力的Nb,多种表达系统均可以实现高效表达。其中:原核表达最常用,其操作相对简单、产量大、生产成本低,但要去除表达出的重组蛋白内毒素;酵母表达可以直接收集培养基上清纯化,杂蛋白含量少,但可能存在过度糖基化问题;植物宿主可以大量表达Nb,但基因操作过程繁琐,且分离纯化Nb相对困难;哺乳动物细胞生产抗体也是较常用的方式,但生产成本较高。针对每一种筛选方法和表达系统目前没有统一的评价标准,在选择时,应以实验室条件为基础,充分了解筛选对象的结构、功能和用途,根据不同目的选用。本文对Nb结构特点、筛选及表达以及在动物疫病防治中的应用展开论述,可为相关领域研究提供技术支持。 Research Progress on the Screening and Expression of NanobodyNanobody(Nb),a new antibody found in camel serum,is characterized by small molecular weight,high stability,high affinity,strong tissue permeability,and recognition of antigen gap epitopes,further modification and expression. Nb screening technology includes phage display,yeast double hybridization,mRNA display and high-throughput sequencing and mass spectrometry analysis,all of which could rapidly screen specific Nb. For the Nb with high affinity,many expression systems could be used to realize an effectively expression. Specifically,prokaryotic expression is mostly used due to its simple operation,mass production and low production cost,but the output of recombinant protein endotoxin should be removed;yeast expression could be used to directly collect purification of medium supernatant,with small content of miscellaneous protein,but excessive glycosylation may be available;host plants could express Nb in large quantity,but the process of gene operation is complicated and it is difficult to isolate and purify Nb;antibody produced by cells of mammals is also usually used,but its production cost is high. No uniform evaluation standard has been developed for all the above methods and expression systems till now. A decision should be made based on laboratory conditions and according to corresponding purpose provided that the structure,function and usage of the object to be screened should be well understood. In the paper,the structure,screening and expression of Nb as well as its application in the prevention and control of animal diseases were discussed,which might technically support the study in related fields.全文下载链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202107018&v=2vpJqQNi66FLBlc73hPRRzQ%25mmd2FUx6kmo9dZRrG7i2%25mmd2By6OlS1JcLyCcNp862nq3WlZI
2021-07-26