传染性造血器官坏死病进境风险分析
为评估传染性造血器官坏死病病毒(infectious haematopoietic necrosis virus,IHNV)随国际贸易传入我国的风险,按照世界动物卫生组织(WOAH)动物卫生风险评估框架,从危害识别、风险评估及风险管理3个方面开展风险分析。结果显示:IHNV随活易感鱼类(包括亲鱼、鱼卵和鱼苗)和鲜活饵料鱼类(野杂鱼)传入的风险为“高”;随非易感鱼类及运输活鱼的水、包装、运输工具和用具等传入的风险为“很低”;随食用易感鱼类(包括活的、冷冻的、冰鲜的以及鱼肉)和易感鱼加工产品传入的风险为“可忽略”。根据以上风险评估结果提出相应风险管理措施:不从疫区进口高风险产品,低风险产品可以自由贸易,对来自疫区的非易感鱼类和运输活鱼的水、包装、运输工具和用具实施消毒。Analysis on the Entry Risk of Infectious Haematopoietic NecrosisIn order to evaluate the entry risk of infectious haematopoietic necrosis virus(IHNV)into China with international trade,hazard identification,risk assessment and risk management concerning the disease were analyzed according to WOAH entry risk assessment framework. The results showed that the entry risk of IHNV accompanying with live susceptible fish(including parent fish,fish eggs and fries)and live fish for baits(wild miscellaneous fish)was“high”;that with non-susceptible fish as well as water,packaging,means of transport and appliances for transporting live fish was“very low”;and that with susceptible fish for human consumption(including live,frozen or chilled fish and fish meat)and processed products of susceptible fish was “negligible”. Based on the results of above risk assessment,corresponding risk management measures were put forward,such as,except the products at low risk,those at high risk should not be imported from IHNV infected zones,all non-susceptible fish from infected zones as well as the water,packaging,means of transport and utensils for transporting live fish should be disinfected.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTODAY&filename=ZGDW202208008&uniplatform=NZKPT&v=vPzqR5W2eDBPW01NTND6jUQA36Q1Ax3VbNRx1a07JPqR0POzVCFHQWPyX6ID1mgz
2022-09-21
2021年浙江省宁波市南美白对虾养殖期EHP和DIV1病原监测
为了解浙江省宁波市南美白对虾主养区虾肝肠胞虫(EHP)、十足目虹彩病毒1(DIV1)的流行规律,2021年3—9月,在宁波市鄞州、象山、宁海、奉化等地区的15个养殖场共采集119批次南美白对虾养成期样本,采用PCR方法检测EHP和DIV1。结果显示:EHP批次阳性率为26.9%(32/119),DIV1批次阳性率为10.9%(13/119),EHP+DIV1混合感染批次阳性率为2.5%(3/119);EHP批次阳性率在各个养殖区域之间差异不显著(P>0.05),象山的DIV1批次阳性率最高,为30.4%(7/23),显著高于奉化(P<0.05),但与其他两地差异不显著(P>0.05);EHP批次阳性率在体长3 cm以上的虾样中显著高于小于3 cm的虾样(P<0.05),而DIV1批次阳性率在不同体长对虾中均无显著差异(P>0.05);EHP批次阳性率4—5月显著低于6—9月(P<0.05),DIV1批次阳性率7—8月显著高于其他月份(P<0.05);EHP在体表发红症状的批次中未检出,在其余症状的批次中均有检出,DIV1在有体表发红症状的批次中阳性率较高,为91.0%(10/11)。结果表明:EHP在宁波市流行严重,主要流行于体长大于3 cm的养殖中后期对虾,前期感染症状不明显;DIV1流行得到一定的控制,现主要流行于体长3~6 cm的对虾,体表发红是DIV1感染的重要病症;两种病原在夏季都有较强的流行趋势,需针对性加强防控。本监测初步掌握了宁波市南美白对虾中EHP和DIV1的流行规律,为宁波市南美白对虾病害防控提供了参考。Etiological Surveillance for EHP and DIV1 in Penaeus vannamei in Ningbo City of Zhejiang Province in 2021In order to find out the prevalence rules of Enterocytozoon hepatopenaei(EHP)and decapod iridescent virus1(DIV1)in Penaeus vannamei in the main breeding area in Ningbo City,from March to September 2021,119 batches of Penaeus vannamei samples were collected from 15 farms in Yinzhou,Xiangshan,Ninghai and Fenghua in Ningbo City to detect EHP and DIV1 by PCR. The results showed that the batch positive rate of EHP was 26.9%(32/119),the batch positive rate of DIV1 was 10.9%(13/119),and that of mixed infection with EHP+DIV1 was 2.5%(3/119);that of EHP was not significantly different among each area(P>0.05)and that of DIV1 was highest in Xiangshan,which was 30.4%(7/23)and higher than that in Fenghua(P<0.05),but slightly different from the other two regions(P>0.05);the positive rate of EHP was significantly higher in shrimp samples with the body length>3 cm than in those<3 cm(P<0.05),while that of DIV1 was not significantly different in those with different body lengths;that of EHP from April to May was significantly lower than that from June to September(P<0.05),and that of DIV1 from July to August was significantly higher than other months(P<0.05);except the batches with the symptom of reddening on body surface,EHP was detected from those with other symptoms,and the positive rate of DIV1 was higher in those with the symptom of reddening on body surface,which was 91.0%(10/11). In conclusion,EHP was seriously prevalent in Ningbo City,especially in the shrimps with the body length > 3 cm,but with slightly infection sympoms at early stage;DIV1 was controlled to certain extent,and now mainly in the shrimps with body length ranging from 3 to 6 cm,with main symptom of reddening on body surface;both pathogens were strongly prevalent in summer,which should be targetedly prevented and controlled. The prevalence rules of EHP and DIV1 in Penaeus vannamei were primarily investigated,which provided a reference for disease prevention and control of Penaeus vannamei in Ningbo City.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTODAY&filename=ZGDW202208007&uniplatform=NZKPT&v=vPzqR5W2eDBmoUOTyz34-l1e5KVMeeM2-O448Ocd7pL4ZBYBJRKHkyKcF9jBmJ1-
2022-09-21
我国近年来禽蛋产品主要药物风险因素分析及控制
摘要:通过收集近年来国家市场监督管理总局发布的禽蛋产品监督抽检的监测数据,结合国内有关畜禽产品质量安全检测评估机构开展禽蛋产品检测研究获得的数据,发现鲜鸡蛋、土鸡蛋、乌鸡蛋、鹅蛋等禽蛋产品中,氟苯尼考(胺)、恩诺沙星(以恩诺沙星与环丙沙星之和计)、氧氟沙星、甲砜霉素、氯霉素、磺胺类药物(总量)、甲氧苄啶、甲硝唑、地美硝唑、多西环素、呋喃唑酮代谢物[3-氨基-2-噁唑烷基酮(AOZ)]、金刚烷胺等药物存在残留安全风险。针对这些主要药物风险因素进行分析,提出有关控制对策建议:加强对国家法律、法规、公告的宣贯和培训;倡导建立集约化、标准化的蛋禽养殖场;建立蛋禽场良好生物安全体系,落实《全国兽用抗菌药使用减量化行动方案》;增强禽蛋产品生产主体的责任意识,切实落实好食用农产品承诺达标合格证制度;加强对养禽过程中药物使用的监管,强化养殖环节的监督检查和产品抽检;建立禽蛋产品跨省、跨地区流通监管机制,强化禽蛋产品市场准入和市场流通监管等。通过收集近几年国家市场监督管理总局(以下简称“市场监管总局”)发布的有关禽蛋产品监督抽检和风险监测数据,以及近年来开展的禽蛋产品质量安全风险评估检测研究中获得的检测研究数据,发现当前我国禽蛋的主要药物风险因素为酰胺醇类等7大类13种(类)药物。其中:抗菌药物6大类12种(类),包括酰胺醇类药物——氟苯尼考(胺)、甲砜霉素、氯霉素,氟喹诺酮类药物——恩诺沙星(以恩诺沙星与环丙沙星之和计)、氧氟沙星,磺胺类药物——磺胺类(总量)、甲氧苄啶,硝基咪唑类药物——甲硝唑、地美硝唑,四环素类药物——多西环素,呋喃唑酮代谢物——3-氨基-2-噁唑烷基酮(AOZ);抗病毒药物1大类1种,为金刚烷胺。通过对这些主要药物风险因素进行分析,提出相应的控制对策,以期为我国制定禽蛋产品质量安全监管措施提供参考。数据收集国家市场监管总局近年来发布的禽蛋产品不合格信息从国家市场监管总局网站收集2018年6月—2021年12月食用农产品监督抽检鲜禽蛋不合格产品信息,包括鲜鸡蛋、土鸡蛋、乌鸡蛋、鹅蛋等不合格鲜禽蛋产品118批次。主要不合格药物参数124批次(个别样品同时有2种药物超标),包括氟苯尼考67批次、恩诺沙星(以恩诺沙星与环丙沙星之和计)43批次、氧氟沙星9批次、甲砜霉素1批次、氯霉素1批次、磺胺类(总量)1批次、地美硝唑1批次、金刚烷胺1批次。2018年6月—2021年12月的鲜禽蛋产品不合格信息见表1。国家市场监管总局及部分省市市场监督管理局通报的2021年鲜禽蛋产品不合格信息2021年度国家市场监管总局、山东省市场监督管理局、浙江省市场监督管理局和北京市市场监督管理局通报的300批次监督抽检鲜禽蛋不合格数据显示,主要不合格药物参数包括氟苯尼考、恩诺沙星、磺胺类、甲硝唑、呋喃唑酮代谢物[3-氨基-2-噁唑烷基酮(AOZ)]、金刚烷胺、氧氟沙星、地美硝唑、甲砜霉素、多西环素、诺氟沙星、氯霉素、沙拉沙星等13种药物。2021年国家市场监管总局和山东省等三省市市场监督管理局通报的鲜禽蛋抽检不合格项目信息见图1。近年来对禽蛋产品质量安全风险评估检测研究情况通过农业农村部畜禽产品质量安全风险评估实验室(南昌)等风险评估机构近几年开展的禽蛋产品质量安全风险评估检测研究发现,近几年禽蛋产品质量安全的主要药物风险因素包括氟苯尼考(胺)、恩诺沙星(以恩诺沙星与环丙沙星之和计)、氧氟沙星、甲硝唑、磺胺类药物(总量,主指磺胺间甲氧嘧啶、磺胺甲噁唑、磺胺二甲嘧啶)、甲氧苄啶、甲砜霉素、氯霉素、多西环素、金霉素、土霉素、金刚烷胺、地美硝唑、诺氟沙星、洛美沙星、培氟沙星、喹乙醇、呋喃唑酮代谢物等,其中氟苯尼考(胺)、恩诺沙星(以恩诺沙星与环丙沙星之和计)、氧氟沙星和甲硝唑具有较大残留超标风险。这4类药物近年来在禽蛋产品中出现残留超标的概率非常高,成为禽蛋产品最重要的药物风险因素。其他有关药物风险因素与国家市场监管总局在网上发布的数据也较为吻合。主要风险因素按照收集到的禽蛋产品药物残留风险因素出现频次或样品数量判断其风险程度,对7大类药物进行以下排序,总体风险程度由高到低依次为酰胺醇类药物、氟喹诺酮类药物、磺胺类药物、硝基咪唑类药物、四环素类药物、呋喃唑酮代谢物、抗病毒药物。同时按国家有关法规、标准和公告等进行数据风险分析。酰胺醇类药物在国家标准《食品安全国家标准 食品中兽药最大残留限量》(GB 31650—2019)中,氟苯尼考(以氟苯尼考与氟苯尼考胺之和计)和甲砜霉素是产蛋期严禁使用的药物,实际检测值中最高残留量分别为930.0 μg/kg和4.5 μg/kg,说明我国养禽生产过程中,仍然存在违规使用氟苯尼考和甲砜霉素的现象,导致禽蛋中残留超标。氯霉素的毒副作用较强,农业农村部第250号公告《食品动物中禁止使用的药品及其他化合物清单》(以下简称250号公告)明确规定在食品动物中禁止使用氯霉素,但实际检测中却时有检出,检出值最高达185.0 μg/kg。氟苯尼考残留超标导致禽蛋不合格的批次数高居市场监管总局和有关风险检测数据榜首,是目前我国禽蛋产品最主要的药物风险因素。氟喹诺酮类药物近年来,恩诺沙星(以恩诺沙星与环丙沙星之和计)是我国禽蛋产品重要的风险因素之一,出现不合格的批次数位居市场监管总局监测数据第二名。国家标准GB 31650—2019规定恩诺沙星为产蛋期禁用药物。而实际检测结果中最高残留量为5 827.6 μg/kg,说明在家禽养殖生产过程中,存在违规使用该种药物,致使禽蛋出现残留超标的情况。氧氟沙星是人专用药物,《兽药管理条例》规定禁止将其用于动物,同时农业部第2292号公告也明确规定停止将这种药物用于食品动物。但在实际检测结果中,氧氟沙星在禽蛋产品中的最高残留量为623.3 μg/kg。在畜禽养殖过程中违法使用此类人用药物,可能导致畜禽产品存在较大质量安全风险。磺胺类药物国家标准GB 31650—2019明确规定各种磺胺类药物(总量)和磺胺增效剂甲氧苄啶(TMP)均为产蛋期禁止使用的药物。在国家市场监管总局抽检和风险监测评估结果中均有较多批次的超标现象,实际检测的磺胺类(总量)最高残留量为9.2 μg/kg。目前家禽养殖产蛋期仍然存在违规使用此类药物的情况,这将会大大影响我国禽蛋产品的质量安全。硝基咪唑类抗菌药物标准GB 31650—2019明确规定甲硝唑和地美硝唑允许用作动物治疗,但不得在动物源性食品中检出,所以在禽蛋中应为不得检出。但市场监管总局发布的检测结果中,地美硝唑的最高残留量为4.1 μg/kg;在有关检测研究中,甲硝唑的最高残留量为56.8 μg/kg。检测结果表明我国在养禽过程中存在违法使用硝基咪唑类抗菌药物的情况,可能造成较大质量安全风险。四环素类药物标准GB 31650—2019规定四环素类药物土霉素、金霉素、四环素在禽蛋中的最大残留限量为400 μg/kg,但多西环素在产蛋期禁止使用。在有关检测研究中,多西环素的最高残留量为159.0 μg/kg。综合分析国家市场监管总局抽检监测和有关风险监测评估结果,发现多西环素是禽蛋产品较为重要的药物风险因素。硝基呋喃类代谢物有关数据显示,目前禽蛋产品中存在较大风险的硝基呋喃类药物为呋喃唑酮代谢物[3-氨基-2-噁唑烷基酮(AOZ)]。250号公告明确规定呋喃唑酮、呋喃它酮、呋喃西林、呋喃妥因和呋喃苯烯酸钠在食品动物中禁止使用,因此在禽蛋中应为不得检出,但在有关检测研究中,呋喃唑酮代谢物(AOZ)的最高残留量为1 331.2 μg/kg,所以此类药物仍然存在质量安全风险。抗病毒药物金刚烷胺是人专用抗病毒药物,《兽药管理条例》明确规定禁止将人用药品用于动物。金刚烷胺等人用抗病毒药物移作兽用,缺乏科学规范、安全有效的实验数据,用于动物病毒性疫病不但给动物疫病控制带来不良后果,还影响国家动物疫病防控政策的实施。在有关检测研究中,金刚烷胺最高残留量为657.0 μg/kg,表明若在养禽过程中违法使用,可能会导致禽蛋产品存在质量安全风险。对策建议禽蛋产品的质量安全风险因素除疫病和致病微生物等生物性风险因素以外,还存在药物残留超标风险。因此,应加强对相关药物风险因素的监管和控制,从国家到地方实施综合性管控措施。通过加强宣传教育和知识培训,提高人民群众对食用农产品质量安全的认知,增强蛋禽产品生产和加工企业主体责任意识,不断推进落实食用农产品承诺达标合格证制度,强化蛋禽场养殖环节监管,完善市场准入和流通监管机制等措施,为广大人民群众提供更多更好的禽蛋产品,提高我国禽蛋产品的质量安全水平。加强对家禽养殖和禽蛋产品生产者的法律法规、标准、公告的宣贯和培训加强对《中华人民共和国农产品质量安全法》《中华人民共和国畜牧法》《中华人民共和国动物防疫法》《兽药管理条例》以及《中华人民共和国兽药典》、《食品安全国家标准 食品中兽药最大残留限量》(GB 31650—2019)、《食品动物中禁止使用的药品及其他化合物清单》(农业农村部公告第250号)、《关于停止生产、进口、经营、使用部分药物饲料添加剂》(农业农村部公告第194号)等法律规范的宣贯和培训。对产蛋期家禽禁用药物、限用药物品种和安全用药间隔期、休药期规定等进行大力宣贯,将有关政策规定落实到家禽养殖和禽蛋产品加工经营主体及相关人员,提高他们绿色养殖和守法养殖的自觉性。倡导建立集约化、标准化的蛋禽养殖场,实现蛋禽养殖生产标准化和规范化目前我国部分大型蛋禽养殖加工企业实现了集约化、标准化和规范化生产,机械化和自动化程度高,养殖环境好,疫病防控好,药物残留风险低。有条件的企业还建立了检测实验室,开展饲料、兽药和禽蛋产品的质量安全检测,通过开展禽蛋产品质量自控,确保禽蛋产品质量安全,满足出口和内销要求。但大多数蛋禽养殖场(户)未实现集约化和标准化生产,规模小,饲养管理较差,养殖环境差,家禽疫病发生概率高,药物使用较为频繁,增加了兽药残留风险,也难以做到禽蛋产品质量自控。因此,倡导建立集约化、标准化的蛋禽养殖场,实现家禽养殖生产标准化和规范化,严格按照有关法规和规范要求进行生产,加强禽蛋产品质量自控,从根本上减少或杜绝药物残留超标风险,确保禽蛋产品的质量安全。养禽场建立良好生物安全体系,减少疫病发生,落实《全国兽用抗菌药使用减量化行动方案》养禽场要建立良好的生物安全体系,建立人员和生物安全体系管理制度。加强饲养管理,提高家禽自身免疫保护力,强化疫病防疫控制,建立并实施适合本场的防疫程序和消毒程序,确保不发生禽流感等禽类重大疫病,确保较少发生或不发生呼吸道疾病和大肠杆菌病、球虫病等消化道疾病。在进行治疗性用药时,严格按照国家标准GB 31650—2019以及农业农村部第250号公告和第194号公告等规定合理使用药物,不使用禁用药和促生长的药物饲料添加剂。落实好《全国兽用抗菌药使用减量化行动方案》,养禽场应树立健康养殖、预防为主、综合治理的理念,从“养、防、规、慎、替”五个方面,建立完善管理制度,采取有效管控措施,实现减抗目标,提高饲养管理和生物安全防护水平。增强养禽场和禽蛋产品生产主体的责任意识,切实落实好食用农产品承诺达标合格证制度2021年中央1号文件要求,加强农产品质量和食品安全监管,发展绿色农产品、有机农产品和地理标志农产品,试行食用农产品达标合格证制度。2021年11月4日农业农村部发布的《农业农村部办公厅关于加快推进承诺达标合格证制度试行工作的通知》指出,自2019年农业农村部在全国试行食用农产品合格证制度以来,各地农业农村部门积极推进,压实了生产主体责任,促进了产管衔接,进一步完善了农产品质量安全监管措施,取得了阶段性成效。2022年中央1号文件要求,开展农业品种培优、品质提升、品牌打造和标准化生产提升行动,推进食用农产品承诺达标合格证制度,完善全产业链质量安全追溯体系。应积极开展新“三品一标”提升行动,通过标准化生产,培优品种,打造食用农产品品牌,提升食用农产品质量安全水平;通过推进食用农产品承诺达标合格证制度,不断强化养禽场和禽蛋产品生产企业的主体责任意识,加强家禽养殖和禽蛋产品全过程质量安全控制和管理,不断完善全产业链质量安全追溯体系,坚决不使用违禁药物及其他违禁投入品,减少甚至杜绝药物使用风险,确保禽蛋产品质量安全。农业农村主管部门应加强对家禽养殖过程使用药物的监管,强化养殖环节的监督检查和产品抽检各地农业农村部门除完成国家和省级层面下达的禽蛋产品质量安全监管、监督检查和产品抽检任务外,还应自行不定期开展对属地蛋禽养殖场的监督检查和督导,检查养殖档案以及防疫和用药等生产记录,增强养禽场(户)的安全用药意识,不定期抽取养禽场的禽蛋样品开展主要药物风险因素的检测评估,并及时向上级部门报告有关主要药物风险的动态信息;加大对禽蛋产品中氟苯尼考(胺)、恩诺沙星(以恩诺沙星与环丙沙星之和计)、氧氟沙星、甲硝唑、金刚烷胺等主要药物风险因素的监督抽检和风险监测,获取我国禽蛋产品质量安全真实检测数据,为农业农村主管部门制定禽蛋产品质量安全监管措施提供依据。建立禽蛋产品跨省、跨地区流通监管机制,强化禽蛋产品市场准入和市场流通监管目前,我国鲜禽蛋产品跨省、跨地区流通情况较为普遍。此类产品在常温下保质期较长,便于长途运输,小包装的品牌禽蛋可进行质量安全追溯,但不注明外包装的散装禽蛋由经纪人或收货人收货后,直接进入跨省、跨地区流通销售环节,难以进行质量安全追溯。这些散装禽蛋产品一般不进行药物残留检测,直接流向市场,可能会出现质量安全问题,因而禽蛋产品跨省、跨地区流通存在一定的监管漏洞。因此应建立禽蛋产品跨省、跨地区流通监管信息共享互认机制,建议各地积极开展禽蛋产品主要药物风险因素上市流通前检测,根据检测结果出具合格证明,同时结合蛋禽企业的食用农产品质量安全承诺达标合格证,方可允许进入到本地市场进行流通和销售。通过建立跨省、跨地区监管和市场准入机制,提升我国的禽蛋质量安全监管水平。
2022-09-21
mRNA疫苗免疫学机制研究进展
摘要: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。疫苗技术分为全病毒灭活疫苗、减毒活疫苗、病毒载体嵌合疫苗、基因工程亚单位疫苗、核酸疫苗等多条技术路线。第一代灭活和减毒活疫苗的生产应用已然成熟,第二代基因工程疫苗也先后有产品问世。而信使核糖核酸(mRNA)疫苗属于第三代疫苗技术,具有制备工艺简单、易规模化生产和针对病原体变异有效性高等技术优势。灭活疫苗、亚单位疫苗安全性高,但免疫原性差,诱导细胞免疫的能力有限;弱毒疫苗、载体疫苗免疫原性强,能够诱导较强的体液免疫与细胞免疫,但安全性较差,存在核酸整合进入宿主基因组的风险,其中弱毒疫苗还存在毒力返强风险;核酸疫苗中,DNA疫苗能够同时诱导体液免疫与细胞免疫反应,但其保护效率通常较低,且也存在核酸整合进入宿主基因的风险。相关研究表明,有的mRNA本身可作为疫苗佐剂,其作用机制是通过刺激免疫系统产生多种细胞因子,从而提高机体免疫力,大大缩减免疫应答时间,增强产生和释放抗体的能力,具有极大应用价值。mRNA疫苗的主要组成部分是人工合成的mRNA分子,其由5'端帽、5'非转录区、编码抗原的开放阅读框、3'UTR和多腺嘌呤尾5个部分组成。mRNA分子可指导细胞合成抗原,激发免疫反应。由于mRNA能够以快速、直接的方式进行反应合成,因此mRNA疫苗在面对突发性传染病流行时,能够成为理想的候选疫苗类型。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展进行综述,旨在为疫苗研发人员选择mRNA疫苗特异高效递送系统,降低mRNA疫苗副反应,降低mRNA疫苗成本,提高mRNA疫苗稳定性等技术方面提供参考。mRNA疫苗分类mRNA 疫苗包括非复制型mRNA(non-replicating mRNA)疫苗与自扩增型mRNA(self-amplifying mRNA,SAM mRNA)疫苗。两种mRNA疫苗都可以通过cDNA、线性化质粒DNA体外转录而成,经呈递系统转导进入细胞,表达目的抗原。与非复制型mRNA疫苗相比,SAM mRNA疫苗诱导的抗原产量显著提升,抗原持续时间、免疫应答时间大大延长。同样是编码H1N1 HA蛋白的mRNA,1.25 μg SAM mRNA疫苗即可达到与80 μg非复制型mRNA疫苗相同的效果。非复制型mRNA疫苗仅编码抗原蛋白,具有结构简单的优点,但需要成熟的优化工艺才能以较低的剂量诱发有效的免疫应答。SAM mRNA疫苗利用了病毒的非结构蛋白基因,用外源靶蛋白基因(抗原基因)替换病毒的结构基因,因而可以在转染细胞内扩增,使其编码的抗原基因大量表达,且因结构蛋白基因缺失,使病毒不具有原有的感染性和毒性,具有较好的安全性。mRNA疫苗技术优势mRNA疫苗具有诸多优势:抗原表达效率高,因无需进入细胞核即可完成翻译,其翻译效率是DNA疫苗的数倍;安全性高,生产过程中不使用病原及抗生素,且不存在整合进入宿主基因组的风险,因而提高了生物安全性;免疫原性强,能够同时激活体液免疫与细胞免疫,满足抵御各类病原体的需要;可编译性强,能够以设想方式编码目的抗原,从而实现高效表达。当机体接种mRNA疫苗后,其将进入细胞内并能够在细胞质中进行翻译,从而成功激活体内的免疫应答。mRNA疫苗不进入细胞核即可进行反应,而DNA疫苗只有到达细胞核才能发挥效果,因此mRNA疫苗不存在整合机体基因组的风险,不会导致基因整合突变,即不存在转基因生物安全风险,理论上比DNA核酸疫苗安全性更高。同时,mRNA疫苗生产不需要用细菌或细胞作为培养基,因此病原微生物污染风险较低。mRNA分子还具有免疫佐剂效用,可以有效激活机体的免疫应答,作为佐剂时以被Toll样受体识别方式来刺激机体免疫细胞分泌产生肿瘤坏死因子(TNF-α)和干扰素(IFN-γ)等细胞因子,从而调节机体免疫应答。mRNA疫苗的制备生产采用全合成制备技术,不同品种mRNA疫苗使用的生产工艺和仪器设备均是相同的,因此研发周期较短,成本较低,易于标准化和规模化生产。此外,在mRNA疫苗的研发制备生产过程中,即使发现或寻找到新的病原体抗原蛋白,也不需要调整规模化生产过程,不需要更改生产设施、设备及其他工艺条件,仅需调整mRNA表达序列,因此mRNA疫苗的生产具有较高的灵活性和效率。mRNA疫苗区别于其他疫苗的另一个技术优势是其可引发机体主要组织相容性复合体(major histocompatibility complex,MHC)Ⅰ类免疫通路和MHC Ⅱ类免疫通路的呈现,可引发机体细胞毒性T淋巴细胞反应。mRNA分子能够在机体细胞质中瞬时表达抗原蛋白,这些被瞬时表达的抗原蛋白大量积聚,被加工成抗原多肽,装载至MHC Ⅰ类免疫通路中。mRNA分子也可在MHC Ⅱ类免疫通路中作为抗原蛋白来源,在mRNA分子瞬时表达抗原蛋白分泌和循环后,直接从细胞质穿梭至溶酶体。此外,机体细胞浆中少量的mRNA分子即可将大量的抗原蛋白递呈至细胞毒性T淋巴细胞。mRNA疫苗递送系统mRNA在机体外的高效合成技术以及在机体内的高效递送技术是现阶段开发和应用mRNA疫苗的两大核心技术。在体内环境中,mRNA半衰期短、稳定性差,直接进入机体容易被体内广泛存在的RNA酶降解。而合适的载体材料可确保mRNA疫苗具有极高的稳定性和可控的安全性,可将mRNA高效递送到机体细胞内。mRNA疫苗只有进入到细胞质中,才能发挥抗原效应,这是其发挥疫苗关键效力的重要基础。相关研究表明,只有小于1 000 Da的分子才可进行被动转运,转运一般是在细胞膜上进行。mRNA相对分子质量较大时,携带负电荷,且由磷脂双分子层结构组成的细胞膜同样携带负电荷,因此mRNA分子可被包裹形成纳米微粒,在载体帮助下进入细胞内。抗原呈递细胞将mRNA分子转运至机体内的靶细胞时需要避免酶的干扰,避免其发生降解。mRNA疫苗成功表达的关键是避免mRNA酶的降解,从而保证其完整性。采用纳米载体包裹的mRNA疫苗可通过静脉注射方式的原因是其能够很好抵御酶的降解。对于mRNA疫苗来说,递送系统的选择至关重要。递送系统分为非靶向递送系统和靶向递送系统。非靶向递送是指运输进入机体的mRNA非特异性地进入各类细胞或组织,通常使用脂质纳米颗粒来完成;靶向递送则是指通过结合抗体或核酸适配体等方式,将mRNA靶向递送到特定的细胞或组织。靶向递送系统主要有抗原抗体特异性结合和核酸适配体及其受体特异性结合两种模式,其原理是在运载mRNA的纳米颗粒中加入靶向特定细胞表面分子的抗体或者核酸适配体,通过抗原-抗体作用或核酸适配体-受体的高亲和力结合,来实现mRNA向目的细胞的特异性运输。非靶向递送系统包括脂质纳米颗粒(LNP)、多聚体纳米颗粒和蛋白衍生物-mRNA复合体。LNP通常由4个部分组成,分别是阳离子脂质、脂质连接的聚乙二醇(PEG)、胆固醇和天然磷脂。阳离子脂质能够与mRNA一起组装成病毒大小的颗粒,并协助mRNA在细胞质中的释放;PEG可延长制剂的半衰期;胆固醇主要起稳定剂的作用;而天然磷脂则构建起脂质单层结构,将阳离子脂质-mRNA包裹于其中。脂质载体对mRNA分子的包封率高,对机体细胞的靶向性强、亲和性好,生物相容性高。同时,有一部分脂质载体可以将mRNA疫苗,以非侵入性方式在机体内进行靶向递送。基于脂质载体的递送系统能够包裹mRNA分子,凭借其包封率高的特点,保护mRNA分子免受mRNA酶降解的干扰。目前,能够进行mRNA疫苗递送的另外一种非病毒载体材料主要有多聚物、阳离子脂质、细胞穿透肽、树形分子及其衍生物、阳离子脂质聚合纳米颗粒、多聚腺苷酸结合蛋白等。但mRNA疫苗递送系统的自身稳定性差,对机体细胞有毒副作用,载体对mRNA包封率低等一系列问题还有待进一步解决。mRNA疫苗免疫学机制mRNA 疫苗基于“中心法则”,将含有编码特定抗原的mRNA序列进行优化、化学修饰以及基因纯化加工,通过接种进入机体,在机体细胞中翻译产生编码蛋白,从而诱导免疫反应,补充接种机体的蛋白含量,产生机体的免疫反应,从而预防传染病。mRNA疫苗可经MHC Ⅰ类以及MHC Ⅱ类2种抗原提呈途径,引发体液免疫与细胞免疫反应。mRNA疫苗经注射进入机体后,可被抗原递呈细胞捕获,先启动机体先天免疫应答,后启动机体适应性免疫应答,从而全面激活体液免疫与细胞免疫。mRNA疫苗可在抗原递呈细胞中表达抗原蛋白,当抗原蛋白经溶酶体处理为抗原肽后,这些肽段又被MHC递呈给CD4+、CD8+ T细胞或者通过释放被B细胞识别,从而激活细胞免疫与体液免疫。mRNA疫苗在机体细胞内翻译产生的蛋白质可模拟病毒感染,从而引起机体的体液免疫和细胞免疫。不同的RNA序列可编码不同的蛋白质,因而确定主要抗原蛋白是研发mRNA疫苗的核心环节。向mRNA分子中添加修饰过的核苷酸,可提高翻译效率和自身稳定性,延长半衰期。mRNA疫苗的接种途径可分为肌肉注射、皮下注射、静脉注射、鼻内喷雾等不同方式。mRNA疫苗进入机体后,编码的蛋白质将被翻译并呈递给免疫系统。该过程类似于RNA病毒感染的自然过程及其连续诱导的保护性免疫应答。外源 mRNA 进入细胞质后会发生与内源性mRNA相似的反应。mRNA在细胞质中被翻译成蛋白质,蛋白质经过翻译后修饰,通过靶向序列或跨膜结构域进入亚细胞间隔,比如分泌途径、细胞膜、细胞核、线粒体或过氧化物酶体。体外转录后再加帽、加尾是mRNA疫苗公认的生产方法。它类似于真核细胞胞浆中自然加工和成熟的mRNA。当被接种疫苗部位的细胞吸收后,mRNA被运输到细胞质;接着,通过核糖体合成 mRNA 编码的蛋白质,然后进行翻译后修饰,产生正确折叠的功能蛋白质。mRNA 疫苗可以使其编码的蛋白或肽瞬时表达,并持续几天或几周,使得 mRNA 更容易被控制。不同的接种途径对于mRNA接触的细胞类型和激发免疫应答的能力起着重要作用,相对于皮下注射,未经修饰的裸mRNA疫苗经淋巴结注射,其诱导T细胞免疫的效力可以大幅度增高。讨论mRNA疫苗集众多优点于一身,如安全性高、免疫原性强、可编译性强、设计速度快、产量大、成本低、易于储存等,在新冠疫情防控中被视作一种革命性的疫苗技术。自新冠疫情暴发以来,英国紧急批准使用辉瑞和BioNTech公司联合研发的mRNA疫苗(BNT162b2),从而成为首个批准紧急使用mRNA疫苗的国家;美国食品药品监督管理局批准了针对新型冠状病毒(SARS-CoV-2)的mRNA 疫苗,临床试验证明,mRNA 疫苗具有良好的安全性和有效性。除疫病防控外,mRNA疫苗正在被越来越多地用于医疗领域,如肿瘤、罕见疾病的治疗等。mRNA是一个包含负电荷的大分子,它无法穿过由阴离子脂质构成的细胞膜,而且在体内,它会被先天免疫系统的细胞吞噬,或者被核酸酶降解,因此需要创新递送载体。在保证安全性的前提下,为将mRNA疫苗更好地应用于临床,聚焦于进一步增强mRNA疫苗稳定性,适当降低mRNA疫苗过高的免疫原性,优化和完善其递送系统。随着mRNA技术和LNP递送技术的不断完善,这一新型疫苗技术将有助于解决传统小分子和抗体疗法无法解决的问题,为癌症、罕见疾病、神经系统疾病等疾病提供更有效、更持久的治疗技术选择。相信mRNA疫苗技术将会具有更广泛的适用空间,成为人类对抗众多疾病的有力武器。
2022-09-21
陕西省延长县猪炭疽病疫情紧急流行病学调查
2022年2月,陕西省延长县一养殖户饲养的21只猪先后发生不明原因死亡,经陕西省动物疫病预防控制中心及市县实验室联合诊断,证实此次疫情是由炭疽杆菌引起的猪炭疽病。为查明病菌来源,摸清感染路径,按照重大动物疫病流行病学调查相关流程,省、市、县相关部门组建专项工作组赴现场开展流行病学调查,分析疫情来源和传播途径,估测疫情扩散风险,指导开展疫情处置工作。综合流行病学特征及临床症状、实验室镜检结果,推测本次疫情很可能是历史疫源地炭疽杆菌意外暴露,通过人员、草料、交通工具传播引起的。本次疫情警示,对于历史疫源地要控制土壤的随意开挖,做好范围内养殖场的生物安全管理,加强包括猪、牛、羊在内所有炭疽易感家畜的炭疽防控。Emergency Epidemiological Investigation on the Outbreak of Swine Anthrax in Yanchang County of Shaanxi ProvinceIn February 2022,21 pigs successively died of unknown causes in a household in Yanchang Country of Shaanxi Province,which was confirmed to be an outbreak of anthrax as joint diagnosed by Shaanxi Center for Animal Disease Prevention and Control together with laboratories at city/county level. In order to find out the sources of the pathogen and identify all infection routes,a special working team was organized by relevant authorities at the provincial,municipal and county levels according to relevant procedures of epidemiological investigation on major animal diseases to analyze any possible sources and routes,evaluate the risk of spreading,and guide the disposal of the outbreak. It was speculated that,based on the epidemiological characteristics,clinical symptoms and laboratory microscopic examination results,the outbreak was likely to be caused by accidental exposure of anthrax bacteria in the historical infected zones then spreading via personnel,forage and vehicles. It was therefore recommended that random excavation of soil should be controlled in the historical infected zones where biosafety management should be well done in all farms,and the anthrax prevention and control of all susceptible livestock including pigs,cattle and sheep should be strengthened.信息来源:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTODAY&filename=ZGDW202208006&uniplatform=NZKPT&v=vPzqR5W2eDC_jizwrjxxXeQIn07jIq12ZB49DrTMPHAzvXC_dKGHX50ckdIYI8VN
2022-08-24
陕西省榆林市猪伪狂犬病流行病学调查与净化示范
为系统评估榆林市猪伪狂犬病(PR)防控成效,2014—2015年采用问卷调查与采样检测相结合的方法,对榆林市猪伪狂犬病病毒(PRV)疫苗免疫及感染情况进行了调查。结果显示:榆林市散养户基本不进行PRV疫苗免疫,PRV-gE抗体阳性率高达47.50%;规模猪场中免疫场占比仅为43.94%,PRV-gE抗体阳性率为15.40%;用PRV gE基因缺失疫苗免疫过的猪群中依然能检测到PRV-gE抗体,gE抗体阳性率为8.46%,且仔猪和育肥猪群中gE抗体阳性率较高,分别为34.36%和20.95%。结果表明,2014—2015年榆林市的PRV疫苗免疫效果较差,野毒感染较为严重。为探索科学的PR净化方案,2016—2020年选取能真实反映榆林市平均流行水平的某县进行PR净化示范建设,通过临床调查、实验室检测,划分场群类型,分类实施不同净化和免疫方案,取得了较好的净化效果。至2020年,规模场PRV-gE抗体阳性全部降为0,平均免疫抗体(gB抗体)阳性率达到90%;散养户PRV-gE平均抗体阳性降为3.20%,gB抗体阳性率达到75.00%;产死胎、木乃伊胎及弱仔数与净化前相比下降90%以上。结果表明,该县的PR净化示范工作取得了成功,净化经验可向全市推广,以最终实现全市PR净化目标。Epidemiological Investigation and Purification Demonstration of Porcine Pseudorabies in Yulin City,Shaanxi ProvinceIn order to systematically evaluate the effectiveness of prevention and control of porcine pseudorabies(PR)in Yulin City,from 2014 to 2015,the vaccination and infection of PR in the city were investigated by a questionnaire in combination with sampling detection. The results showed that no vaccination against porcine pseudorabies virus(PRV)was implemented by free-range households in general,and the positive rate of PRV-gE antibody was 47.50%;for intensive farms,those with vaccination accounted for 43.94%,and the positive rate of PRV-gE antibody was 15.40%;PRV-gE antibody could still be detected in pigs vaccinated with PRV gE gene deletion vaccines,with a positive rate of 8.46%,and the positive rates of PRV-gE antibody were higher in piglets and fattening pigs,up to 34.36% and 20.95% respectively. In conclusion,the immunization produced by PRV vaccine was poor in the period in the city,and infection with field viruses was serious. In order to develop a scientific PR purification plan,from 2016 to 2020,a county where the average prevalence level of the city could be truly reflected was selected to study the construction of PR purification demonstration. The farm tupes were classified through clinical investigation and laboratory test,and different purification and immunization programs were implemented,which achieved good purification effects. By 2020,the positive rate of PRV-gE antibody was reduced to 0 in all intensive farms where the average positive rate of immune antibody(gB antibody)reached 90%;the average positive rate of PRV gE antibody decreased to 3.20% in free-range households where the positive rate of gB antibody was up to 75.00%;and the number of stillbirths,mummified or weak fetuses decreased by above 90% compared to that prior to purification. It was concluded that the demonstration of PR purification was successful in the county,from which its experience might be popularized to other regions to reach the final goal of PR purification across the city.信息来源:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTODAY&filename=ZGDW202208005&uniplatform=NZKPT&v=vPzqR5W2eDA0GZm-qK1jv0J9ykMFCRjz__ulS66gc19y60HHsjuPyYH-QTBZD81c
2022-08-24
2020年我国部分地区猪繁殖与呼吸综合征分子流行病学调查
为了解我国猪繁殖与呼吸综合征病毒(porcine reproductive and respiratory syndrome virus,PRRSV)的流行及遗传变异情况,2020年对来自7个省的570份疑似PRRSV感染样品进行RT-PCR检测,并对60个PRRSV阳性样品进行ORF5基因测序及分析比较。RT-PCR检测结果显示,2020年送检样品中,PRRSV阳性检出率为23.68%(135/570),其中保育猪病料的阳性检出率最高,为32.24%(108/335)。同源性对比及遗传进化分析结果显示,60个PRRSV均为PRRSV2(美洲株),主要属于谱系1和谱系8,占比分别为51.67%和43.33%。氨基酸分析结果显示,60个PRRSV的GP5蛋白氨基酸以点突变为主,其中10个PRRSV的GP5蛋白氨基酸出现缺失突变,且非中和表位、中和表位、潜在毒力位点及N-糖基化位点均发生不同程度的变异。结果表明,保育猪群为PRRSV高发病群体,谱系1 PRRSV或已成为国内流行优势毒株,且PRRSV不断发生变异,这或许会影响现有疫苗的免疫保护效果。因此,针对PRRS需要综合防控,除选用安全有效的PRRSV弱毒活疫苗进行免疫外,加强猪场生物安全及饲养管理也极其重要。Molecular Epidemiological Investigation on PRRS in 2020 in Some Regions of ChinaIn order to investigate the prevalence and molecular genetic variation of porcine reproductive and respiratory syndrome virus(PRRSV)in some regions of China in 2020,570 suspected PRRSV infected samples collected from 7 provinces were detected by RT-PCR,and the ORF5 gene of 60 PRRSV positive samples were sequenced and analyzed. The results showed that,by RT-PCR,the positive rate of PRRSV was 23.68%(135/570),and highest in nursing pigs,which was 32.24%(108/335). It was shown that,by the results of homology comparison and genetic evolution analysis,all the 60 PRRSV were PRRSV2(American strains)and mainly belonged to lineages 1 and 8,accounting for 51.67% and 43.33%,respectively. It was shown that,by the results of amino acid analysis,point mutations were dominant in the GP5 protein amino acid of all the 60 PRRSV,deletion mutations were observed in 10 PRRSV thereof,and variations were observed in non-neutralizing epitopes,neutralizing epitopes,potential virulence sites and N-glycosylation sites to different extent. In conclusion,nursing pigs were highly susceptible to PRRSV. Lineages 1 PRRSV might have become a dominant strain in China,and the immune protection effect of current vaccines might be affected by constantly variation of the virus. Therefore,in addition to vaccination with safe and effective attenuated live vaccines,biosafety and feeding management on farms had also played an important role in prevention and control of PRRSV.信息来源:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTODAY&filename=ZGDW202208004&uniplatform=NZKPT&v=vPzqR5W2eDDVSt9xTwFQ1fbt01ZqKPfZQuJbak8V5-EVnc4Am-uU0kSpoHpAbjRk
2022-08-24
福建省部分养殖场鸡圆圈病毒3型病原检测及VP2基因分析
为了解福建省鸡场圆圈病毒3型(GyV3)的流行及其VP2基因变异情况,2021年在南平市、龙岩市和福州市的36个鸡场,采集365份疑似GyV3感染病鸡的腺胃样品,通过PCR进行GyV3核酸检测。结果显示:共检出GyV3核酸阳性55份,阳性检出率为15.06%。对5份GyV3阳性样品进行VP2基因序列分析发现,5份样品的VP2基因核苷酸和推导氨基酸序列相似性分别为98.6%~99.9%和98.3%~100%,与参考株山东肉鸡分离株SDAU-1和巴西家鸡分离株核苷酸和推导氨基酸序列的相似性分别为98.3%~99.2%和97.5%~99.2%,均属于Group A分支中的GyV3小分支。结果表明:福建省鸡场存在GyV3流行;其VP2基因遗传序列稳定,可作为GyV3感染流行病学监测的首选基因。本研究为GyV3的后续研究提供了理论依据。Etiological Detection of GyV3 in Some Farms of Fujian Province and Analysis on Its VP2 GeneIn order to investigate the prevalence and VP2 gene variation of gyrovirus 3(GyV3)in chicken farms in Fujian Province in 2021,365 suspected samples of glandular stomach infected with GyV3 were collected from 36 farms in Nanping,Longyan and Fuzhou cities to detect GyV3 nucleic acid by PCR. The results showed that 55 positive samples were detected,with a positive rate of 15.06%. It was found that,by sequence analysis of VP2 gene in 5 GyV3 positive samples,their homology of nucleotide and deduced amino acid sequence of VP2 gene were from 98.6% to 99.9% and 98.3% to 100%,respectively,from 98.3% to 99.2% and 97.5% to 99.2% with those of the reference Shandong broiler strain SDAU-1 and Brazil domestic chicken strain,respectively,all of which belonged to the small branch of GyV3 in group A. In conclusion,GyV3 was prevalent in the farms across the province,and stable genetic sequence was observed in its VP2 gene,which could be used as the first choice for epidemiological surveillance over GyV3 infection. A theoretical basis was thereby provided for future researches on GyV3.信息来源:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTODAY&filename=ZGDW202208003&uniplatform=NZKPT&v=vPzqR5W2eDACMu4nN2FrbQUNCucSQCAXG47vSQCRm6GDYHaWc6NGTJAAmXG6Wq6u
2022-08-24
2020—2021年我国部分省份禽呼肠孤病毒分子流行病学调查
近年来,禽呼肠孤病毒(ARV)在我国白羽肉鸡群中的感染率呈上升趋势,流行范围较广,给我国肉鸡养殖企业带来了较大经济损失。ARV易变异重组,因此全面了解其分子流行病学特征具有十分重要的意义。为了解我国白羽肉鸡群中ARV的遗传变异特点,2020—2021年从山东、河北、福建、安徽、辽宁、江苏等6个省份收集疑似ARV感染样品,采用RT-PCR方法筛选阳性样本,然后对阳性样本进行σC基因(1 088 bp)测序,根据测序结果分析ARV不同基因型分布规律及占比。结果显示:2020—2021年,从6个省份中,经RT-PCR检测,检出ARV阳性样品157份,总阳性检出率为62.1%,不同省份的阳性检出率为44.4%~77.3%。157份阳性样品可分为6个基因型,其中基因1型61份(38.85%)、基因2型41份(26.11%)、基因3型15份(9.56%)、基因4型9份(5.73%),基因5型30份(19.11%),基因6型1份(0.64%);61份基因1型样品中,38份与标准ARV疫苗株(S1133)属于同一亚分支,另外23份与4599参考株处于单独的另一亚分支。结果表明:我国肉鸡群中存在一定程度的ARV流行;流行的ARV基因型较为复杂,且存在基因1型变异毒株,当前的疫苗株已不能对其提供足够的保护。结果提示,今后需要进一步开展ARV感染监测,评估其流行及变异情况,调整免疫策略,加快新疫苗等防疫技术及产品研发。本研究初步了解了我国部分省份的ARV分子流行病学特征,对我国ARV感染的防控具有重要意义,也为变异株新型疫苗研发提供了依据。Molecular Epidemiological Investigation on Avian Reovirus in Some Provinces of China from 2020 to 2021In recent years,avian reovirus(ARV)has been increasingly and widely prevalent in white feather broilers in China,bringing great economic losses to broiler breeding enterprises in China. As ARV is prone to mutation and recombination,it would be of great significance to comprehensively investigate its molecular epidemiological characteristics. In order to investigate the genetic variation characteristics of ARV in white feather broilers in China from 2020 to 2021,253 suspected ARV infected samples were collected from Shandong,Hebei,Fujian,Anhui,Liaoning and Jiangsu provinces to detect positive samples by RT-PCR,followed by σC gene(1 088 bp)sequencing,against which,the distribution and proportion of different ARV genotypes were analyzed. The results showed that 157 positive samples were detected by RT-PCR,with a total positive detection rate of 62.1%,and that in each province was from 44.4% to 77.3%. All the 157 positive samples were divided into 6 genotypes,including 61 genotype 1(38.85%),41 genotype 2(26.11%),15 genotype 3(9.56%),9 genotype 4(5.73%),30 genotype 5(19.11%),and 1 genotype 6(0.64%);38 out of 61 genotype 1 samples belonged to the same sub-branch as the standard ARV vaccine strain(S1133),and the other 23 fell into a separate sub-branch with 4599 reference strain. In conclusion,ARV was prevalent in broilers in China to certain extent;the prevalent ARV genotypes were complex,and there were genotype 1 variant strains,so sufficient protection could not be provided by current vaccine strains anymore,which indicated that surveillance for ARV infection should be further strengthened,its prevalence and variation should be evaluated,immunization strategies should be adjusted,and research and development of disease prevention technologies and products such as new vaccines should be accelerated. The above study on the molecular epidemiological characteristics of ARV in some provinces of China supported the prevention and control of ARV infection in China,and provided a basis for the research and development of novel vaccines against any variant strains.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTODAY&filename=ZGDW202208002&uniplatform=NZKPT&v=vPzqR5W2eDCKEuOpxiM-wmxdYfXcu3OP23QUUDr9_kAdYcR0KBOQB90icqbypN2o
2022-08-17
2021年安徽省屠宰及流通环节禽群主要呼吸道病毒感染情况调查
为了解安徽省禽群呼吸道病毒感染情况,2021年3—11月从12个县(市、区)17个家禽屠宰点和1个农贸市场收集472份喉头气管组织样本,运用荧光定量RT-PCR方法,对诱发家禽呼吸道疾病的主要病毒性病原进行检测。结果显示:除未检出高致病性禽流感病毒(AIV-H5、AIV-H7)核酸阳性外,新城疫病毒(NDV)、禽传染性支气管炎病毒(IBV)、禽传染性喉气管炎病毒(ILTV)、禽偏肺病毒(aMPV)均有核酸阳性被检出,平均阳性率分别为9.96%、27.54%、1.06%、5.51%;NDV、IBV、aMPV的春季阳性率高于其他季节,夏季检出病原种类最多;皖南、皖中和皖北区域均有NDV阳性被检出,皖南区域的IBV阳性率最高,皖南、皖中区域均检出aMPV阳性,而ILTV阳性仅在皖北区域被检出;鸡群中的NDV、IBV、ILTV、aMPV阳性率高于鸭群。病毒感染以单一感染为主,占比为86.89%;单一感染中,IBV单一感染占比最高,为66.67%;混合感染中,IBV+NDV和IBV+aMPV双重感染占比较高,分别为45.83%和50.00%,仅检出1份三重感染样本(NDV+IBV+aMPV)。结果表明:安徽省家禽禽流感防控效果较好,但存在不同程度的NDV、IBV、ILTV、aMPV流行,其中IBV最为严重,且这些病原存在一定的季节和区域流行特征。因此,安徽省不同区域应根据不同病原流行特点,采取各有侧重的防控策略,完善疫病监测机制,在重点区域和高发季节加强疫病防控。Investigation on the Infection with Major Respiratory Viruses in Poultry during Slaughtering and Circulation in Anhui Province in 2021In order to identify the infection with respiratory viruses in poultry in Anhui Province,from March to November 2021,472 samples of laryngeal and trachea tissues were collected from 17 poultry slaughterhouses and 1 farmers' market in 12 counties(cities/districts)to detect major pathogens leading to respiratory diseases by fluorescence quantitative RT-PCR. The results showed that,except of highly pathogenic avian influenza virus(AIV-H5 and AIV-H7),Newcastle disease virus(NDV),infectious bronchitis virus(IBV),infectious laryngotracheitis virus(ILTV)and avian metapulmonary virus(aMPV)nucleic acids were all detected,with average positive rate of 9.96%,27.54%,1.06% and 5.51%,respectively. The positive rate of NDV,IBV and aMPV in spring were higher than that in other seasons,and most pathogens species were detected in summer. NDV positive was detected from southern Anhui,central Anhui and northern Anhui,the positive rate of IBV was highest in southern Anhui,aMPV was detected from southern Anhui and central Anhui,while ILTV only from northern Anhui;the positive rates of NDV,IBV,ILTV and aMPV in chickens were higher than those in ducks. Single infection was prominent,accounting for 86.89%,most of which was IBV infection,accounting for 66.67%;most mixed infection was the dual infection with IBV+NDV or IBV+aMPV,accounting for 45.83% and 50.00%,respectively,and only 1 sample with triple infection(NDV+IBV+aMPV)was detected. In conclusion,avian influenza(AI)in poultry was well prevented and controlled in Anhui Province,although NDV,IBV,ILTV and aMPV were prevalent to different extent,especially IBV,all of which were with certain characteristics of seasonal and regional prevalence. Therefore,the prevention and control strategies with different emphasis should be applied in different regions according to the prevalence characteristics of pathogens,so as to improve the monitoring mechanism,and strengthen the prevention and control of diseases in key regions and seasons with high incidence.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTODAY&filename=ZGDW202208001&uniplatform=NZKPT&v=vPzqR5W2eDCOtBWCUVzo_HSusxkB8gEKvb0dp2-P1Uc2c5jG2wJuv7lwgIvtbSeN
2022-08-17
宁夏彭阳县肉牛布鲁氏菌病风险因素病例对照研究
为探索宁夏回族自治区彭阳县肉牛感染布鲁氏菌的风险因素,采用匹配设计的病例对照研究方法,对76个检出肉牛布鲁氏菌感染抗体阳性的养殖场户,按照肉牛养殖场户同在一个行政村,和/或相似养殖规模以及养牛时间差异在±3年内的原则,以1:2比例匹配肉牛布鲁氏菌感染抗体阴性场户,通过问卷形式收集数据,采用条件Logistic回归进行分析。结果显示:通过肉牛经纪人买牛的场户,其肉牛的布鲁氏菌感染风险增大(OR = 5.05,95%CI = 1.50~17.01);养牛场同时养羊且母羊近两年有流产史的场户,所养肉牛感染布鲁氏菌风险增大(OR = 1.86,95%CI = 0.92~3.75)。由此可见,彭阳县肉牛交易方式与当地肉牛布鲁氏菌感染存在密切关联。建议加强牛经纪人管理,提高其布病防控意识,进一步调查当地羊群布鲁氏菌病流行状况。本研究为当地肉牛布鲁氏菌病防控策略制定提供了依据。A Case-Control Study on Risk Factors for Brucellosis in Beef Cattle in Pengyang County in NingxiaIn order to identify the risk factors for Brucella infection in beef cattle in Pengyang County,Ningxia Hui Autonomous Region,a matched case-control study method was used to collect data from 76 positive farms/households by questionnaires and analyzed by conditional logistic regression. The study was based on the principles that farms/households located in the same administrative village,and/or similar breeding scale and the difference in breeding period was within ± 3 years,and a ratio of 1:2 was used to match negative farms.. The results showed that the risk of Brucella infection in beef cattle increased(OR = 5.05,95%CI = 1.50-17.01)in the farms/households who bought cattle via brokers;so did the farms(OR = 1.86,95%CI = 0.92-3.75)where sheep were also kept and history of abortion in ewes was available in the past two years. It was concluded that the transaction mode of beef cattle was closely related to local infection in the county. Therefore,it was recommended to strengthen the management of cattle brokers,improve their awareness concerning brucellosis prevention and control,and further investigate the prevalence of the disease in local sheep. A basis was thereby provided for future development of control strategies for brucellosis in local beef cattle.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202207008&uniplatform=NZKPT&v=vPzqR5W2eDACrmVfSirtvT5YphANZXm6U75wjmFC182LlceXbSG6lkUzrHLWGKPS
2022-07-28
厦门市宠物犬猫中布鲁氏菌、弓形虫、A型流感病毒及巴尔通体的流行病学调查
为初步了解厦门市宠物犬猫中布鲁氏菌、弓形虫、A型流感病毒及巴尔通体的流行情况,采用荧光PCR、ELISA及血凝抑制等检测方法,对2021年从厦门市32家动物诊疗机构中采集的304份宠物犬猫血清及对应的全血样品进行抗体及核酸检测。结果显示:宠物犬猫中,布鲁氏菌(光滑型及粗糙型)表观流行率为2.0%,真实流行率为0.5%(95%CI:0~1.3%);弓形虫表观流行率为3.3%,真实流行率为0.8%(95%CI:0~1.8%);A型流感病毒表观流行率为8.6%,真实流行率为7.7%(95%CI:4.7%~10.7%),检出H9亚型抗体阳性样品19份(抗体滴度为4log2~6log2),未检出H5亚型及H7亚型抗体阳性样品(抗体滴度<1log2)。未检出布鲁氏菌、弓形虫、巴尔通体及A型流感病毒核酸阳性样品。结果表明,厦门市宠物犬猫中存在一定的A型低致病性流感病毒传播风险,其他病原流行风险较低,但这些病原均具有感染人和其他动物的潜在风险,需要继续加强监测,做好个人防护。本研究为本地犬猫人兽共患病防治提供了依据。Epidemiological Investigation on Brucella,Toxoplasma gondii,Influenza Virus A and Bartonella in Pet Dogs and Cats in Xiamen CityIn order to primarily identify the prevalence of Brucella,Toxoplasma Gondii(T. gondii),influenza virus A and Bartonella in pet dogs and cats in Xiamen City,304 serum samples and corresponding whole blood samples collected from 32 animal clinics in the city in 2021 were detected by fluorescence PCR,ELISA and HI. The results showed that the apparent prevalence rates of Brucella(both smooth and rough),T. gondii and influenza virus A were 2.0%,3.3% and 8.6%,respectively,and their true prevalence rates were 0.5%(95%CI:0-1.3%),0.8%(95%CI:0-1.8%)and 7.7%(95%CI:4.7%-10.7%)respectively. 19 H9 subtype positive samples were detected(antibody titer from 4log2 to 6log2),and neither H5 nor H7 subtypes was detected (antibody titer<1log2). No nucleic acids of Brucella,T. gondii,Bartonella and influenza virus A were detected. In conclusion,certain risk of a low pathogenic influenza virus A was available in dogs and cats in Xiamen City,and that of other pathogens were low. All of these pathogens posed a potential risk to persons and other animals,which should be further monitored with good protection of persons. This study provides a basis for the further prevention and control of canine feline zoonoses in Xiamen City .原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202207007&uniplatform=NZKPT&v=vPzqR5W2eDCE-zk0jrbnYzA0KT7A5i964N4l0LogK--oPtyMbqGvvdwhL5tY5p2_
2022-07-28
新疆北疆部分地区鼠类伯氏疏螺旋体携带情况调查
为了解新疆北疆地区鼠类伯氏疏螺旋体携带情况及其基因型分布特征,2021年1—9月在新疆昌吉州吉木萨尔县、伊犁哈萨克自治州新源县、塔城地区乌苏市巴音沟,采集147只野生鼠类的肾脏和膀胱组织样本,采用实时荧光定量PCR和巢式PCR方法,检测鼠类中的伯氏疏螺旋体携带情况;以伯氏疏螺旋体5S—23S基因间隔区进行巢式 PCR检测,对检出的阳性样本进行基因测序及序列分析,确定伯氏疏螺旋体基因型,构建系统发育树。结果显示:在147份鼠类样本中,经实时荧光定量PCR和巢式PCR方法检测,分别检出伯氏疏螺旋体阳性样本11份和13份,阳性率分别为7.48%和8.84%;13份巢式PCR阳性样本中,吉木萨尔县检出1份,新源县检出1份,乌苏市检出11份,通过序列同源性分析确定Borreliella garinii、Borreliella bavariensis为主要致病基因型。结果表明,北疆地区鼠类中存在伯氏疏螺旋体的自然感染,有传播给家畜及人群的风险,应加强该病原体检测和莱姆病防控。Investigation on Borrelia burgdorferi in Rodents in Some Areas in Northern XinjiangIn order to identify the prevalence and genotype distribution of Borrelia burgdorferi in rodents in Northern Xinjiang,from January to September 2021,the kidney and bladder tissue samples were collected from 147 wild rodents in Jimusar County of Changji Prefecture,Xinyuan County of Ili Kazak Autonomous Prefecture,Wusu City(Bayingou) of Tacheng Prefecture to detect Borrelia burgdorferi by real time fluorescent quantitative PCR and nested PCR;the positive samples detected by nested PCR with the Borrelia burgdorferi 5S-23S gene spacer region were subject to gene sequencing and polygenetic tree analysis to determine the genotype of Borrelia burgdorferi.. The results showed that 11 and 13 positive samples were respectively detected by real-time PCR and nested PCR,with the positive rates of 7.48% and 8.84%,respectively;for 13 positive samples by nested PCR,one was detected each from Jimsar and Xinyuan,and 11 from Wusu. Borreliella garinii and Borreliella bavariensis were identified as the main pathogenic genotypes by sequence homology analysis. In conclusion,natural infection with Borrelia burgdorferi was available in rodents,which posed a risk to livestock and persons,indicating that the pathogen of the disease should be monitored and Lyme disease should be strictly controlled.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202207006&uniplatform=NZKPT&v=vPzqR5W2eDCRJjwGHPGlsbVJG413UF2kJhjX54OYyJs2EoqrLHgD6Ep99sBb99Cf
2022-07-28
一起肉牛黄曲霉等毒素中毒事件的紧急流行病学调查
2021年10月25日,四川省宣汉县某肉牛场发生肉牛猝死事件。为了解事件状况和发生原因,并尽可能采取措施减少养殖场的经济损失,赴现场开展了流行病学调查。调查发现,该牛场3天内共死亡22头牛,累积死亡率为46.8%(22/47)。综合流行病学调查信息、病牛临床症状、剖检变化,初步推测肉牛猝死的原因是饲喂霉变饲料导致黄曲霉等毒素中毒。通过暂停饲喂原饲料,增加饮水量,更换饲草饲料并添加蒙脱石脱霉剂,肉牛发病情况得到有效控制。该起肉牛猝死事件提示,养殖场人员应加强饲养管理和疫病防控知识的学习,增强责任心,提高饲养管理能力。An Emergency Epidemiological Investigation on a Poisoning Event with Aflatoxin and Other Toxins in Beef CattleOn October 25,2021,some beef cattle suddenly died in a farm in Xuanhan County,Sichuan Province. In order to investigate the event and find out all the causes leading to the death,and to take measures to reduce economic loss of the farm as far as possible,an epidemiological investigation was carried out on the farm. It was investigated that a total of 22 cattle died within three days,with a cumulative mortality rate of 46.8%(22/47). It was preliminarily speculated that,based on the information of movement,clinical symptoms and changes under autopsy,the cattle died of aflatoxin poisoning due to feeding with moldy feed. The disease was effectively controlled after stopping feeding the previous feed,increasing the amount of drinking water,changing forage and adding montmorillonite. It was suggested that the farm staff should learn the knowledge about breeding management and disease prevention and control,strengthen their sense of responsibility and improve their ability for feeding and management.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202207005&uniplatform=NZKPT&v=vPzqR5W2eDD1sLpdEZ2oUCW1MIb5Q4Fccvo3-S6QIJ5B6hBPbp1-9kyFb4c9Wgs_
2022-07-27
新疆南疆地区部分集约化肉牛繁育场主要临床病症和生物安全调查
近年来,新疆南疆地区开始引进国外安格斯肉牛养殖。为了解该地区集约化安格斯肉牛繁育场的主要疫病流行现状和存在的生物安全问题,采用现场调查、问卷调查和实验室检测相结合的方式,对新疆喀什地区4个大中型集约化安格斯肉牛繁育场进行了调查。结果显示:4个牧场安格斯肉牛表现的临床症状主要是腹泻,其次是肺炎;导致犊牛腹泻的病毒性病原主要是牛冠状病毒(BCV)、牛诺如病毒(BNoV),阳性检出率分别为19.93%、15.20%,导致肺炎的主要是牛传染性鼻气管炎病毒(IBRV)、牛腺病毒3型(BAV-3),阳性检出率分别为28.24%、14.12%。4个牧场在防疫设施设备建设、消毒制度落实、人流物流管控、规章制度建设以及饲养管理、鼠害蝇害防控和无害化处理等生物安全方面均存在不同程度的隐患。结果提示,南疆地区安格斯肉牛繁育场要加强BCV、BNoV、IBRV、BAV-3等病毒感染的防控,通过加强免疫,降低牛群腹泻和肺炎的发病率,通过严格生物安全控制,防止外部病原传入。本调查为南疆地区国外引进安格斯肉牛的动物疫病防控提供了依据。Investigation on Major Clinical Symptoms and Biosafety in Some Intensive Beef Cattle Farms in Southern XinjiangIn recent years,Angus beef cattle have been imported into Southern Xinjiang for breeding. In order to identify the epidemic status of major animal diseases and current biosafety problems in intensive farms in the region,four large and medium-sized intensive farms in Kashi region were investigated by means of field interview,questionnaire investigation and laboratory test. The results showed that the main clinical symptoms of the cattle included diarrhea,followed by pneumonia;the main viral pathogens causing calves diarrhea were bovine coronavirus(BCV)and bovine norovirus(BNoV),with positive detection rates of 19.93% and 15.20% respectively. Pneumonia was mainly caused by bovine infectious rhinotracheitis virus(IBRV)and bovine adenovirus type 3(BAV-3),with positive detection rates of 28.24% and 14.12% respectively. Potential dangers to different extent were found in the construction of disease prevention facilities and equipment,implementation of disinfection system,management and movement control of persons and materials,development of rules and regulations,feeding management,prevention and control of rodents and flies as well as biosafety disposal in the four farms. In conclusion,BCV,BNoV,IBRV,BAV-3 and other viruses should be strictly controlled in the farms,the incidence rate of diarrhea and pneumonia should be reduced by strengthening immunization,and any external pathogens should be avoided by strict biological safety control. A basis was thus provided for future prevention and control of animal diseases of Angus beef cattle imported to the region.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202207004&uniplatform=NZKPT&v=vPzqR5W2eDBafzb_SLZRVrOMLizAG7aZVgeA0LwmQEDRc0ZoWVX7i6-l2wla1KN5
2022-07-27
山东省部分规模化驴场主要病原感染情况调查
目前关于规模化驴场主要病原的流行数据极为有限。为了解山东省驴养殖密集区的主要病原流行情况,2019—2021年,从聊城、德州、滨州等地的9个规模化驴场(繁育母驴100头以上),无菌采集表现不同临床症状病死驴(驹)的心、肝、脾、肺、肠、肾等不同脏器病料共计742份,采用PCR与病原分离方法进行常见马属动物病原检测;采集296份临床健康驴血液样品,采用虎红平板凝集试验进行布鲁氏菌感染抗体检测。结果显示:在腹泻症状样品中,大肠杆菌检出率最高,为48.89%(132/270);在肺炎症状样品中,大肠杆菌检出率为24.10%(80/332),肺炎克雷伯氏菌检出率为29.82%(99/332),马链球菌检出率为22.29%(74/332);在流产症状样品中,沙门氏菌检出率最高,为44.29%(62/140);在临床健康驴血液样品中,未检出布鲁氏菌感染抗体。结果表明,导致规模驴场发生腹泻、肺炎和流产的主要是条件性致病菌,其中导致腹泻的主要是大肠杆菌,肺炎的主要是大肠杆菌、肺炎克雷伯氏菌和马链球菌,流产的主要是沙门氏菌。因此,规模化驴场应通过加强饲养管理,提高养殖圈舍卫生水平,科学使用抗生素等措施,控制细菌性疫病流行。Investigation on Major Pathogens in Large-scale Donkey Farms in Shandong ProvinceAs there had been very limited data on the prevalence of major pathogens in large-scale donkey farms,in order to identify the infection status in the intensive breeding areas in Shandong Province,from 2019 to 2021,a total of 742 samples of lesions including hearts,livers,spleens,lungs,intestines,kidneys and other organs of dead donkeys(foals)with different clinical symptoms were aseptically collected from 9 farms(with above 100 female donkeys)in Liaocheng,Dezhou,Binzhou and other regions to detect common equine pathogens by PCR and pathogen isolation method;and 296 samples from clinical healthy donkeys to detect the antibody against Brucella by RBT. The results showed that,for the samples with diarrhea symptoms,the detection rate of Escherichia coli was highest,which was 48.89%(132/270);for those with pneumonia symptoms,the detection rates of Escherichia coli,Klebsiella pneumoniae and Streptococcus equi were 24.10%(80/332),29.82%(99/332)and 22.29%(74/332),respectively;for those with abortion symptoms,the detection rate of Salmonella was highest,which was 44.29%(62/140);and no antibody against Brucella was detected in the blood samples of clinical healthy donkeys. In conclusion,the diarrhea,pneumonia and abortion occurred in the farms were mainly caused by conditional pathogens,specifically,diarrhea was mainly caused by Escherichia coli,while pneumonia by Escherichia coli,Klebsiella pneumoniae and Streptococcus equi,and abortion by Salmonella. Therefore,bacterial diseases should be prevented and controlled through strengthening feeding management,improving the health level of pens,using antibiotics scientifically and other measures.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202207003&uniplatform=NZKPT&v=vPzqR5W2eDCGo3YX4kD_3sPeFGe-h0sxMZl3we1DIqMxO6suBsN6jri-rIBasOSC
2022-07-27
云南省边境地区牛阿卡斑病毒血清学调查
为掌握云南省边境地区牛群中的阿卡斑病毒(Akabane virus,AKAV)流行情况和分布特征,采用竞争ELISA检测方法,对2019—2020年采自云南省边境地区10个县市的牛群血清样品进行AKAV抗体检测与分析。结果显示:在采集的4 437份牛血清样品中,检出抗体阳性样品1 367份,平均抗体阳性率为30.81%;2019年抗体阳性率为27.88%,2020年为32.14%,差异不显著(P>0.05);入境牛抗体阳性率显著高于本地牛(P<0.05);养殖场抗体阳性率略高于散养户和交易市场,但三者间差异不显著(P>0.05);舍饲牛群的抗体阳性率显著高于半放牧半舍饲和系牧饲养(P<0.05),黄牛的抗体阳性率明显高于水牛(P<0.05)。结果表明,云南省边境地区存在一定程度的AKAV感染且有加重趋势,入境牛感染风险较高,需持续开展血清学调查和监测,加强境外牛的检疫和移动控制,降低AKAV向内地扩散的风险。本研究摸清了云南省边境地区牛群中的AKAV流行本底,为今后该病毒流行控制策略的研究与制定提供了参考。Serological Investigation on Akabane Virus in Border Areas of Yunnan ProvienceIn order to investigate the prevalence and distribution of Akabane virus in cattle in border areas of Yunnan Province,the serum samples of cattle were collected from 10 counties/cities in the border areas from 2019 to 2020 for antibody detection by using competitive ELISA. The results showed that 1 367 out of 4 437 samples were positive,with an average positive rate of 30.81%,which tended to increase year by year;the positive rate was significantly higher in imported cattle compared to that in local cattle(P<0.05);slightly higher in farms compared to that in free-range households and trading markets with no signifcant difference between them(P>0.05);significantly higher in house-fed cattle compared to that in semi-house-fed and grazing ones(P<0.05),significantly higher in yellow cattle compared to that of buffalo(P<0.05). In conclusion,to some extent,the Akabane virus was increasingly spread in the border areas of Yunnan Province,especially in imported cattle,which calls for the conduction of serological investigation and monitoring,strengthen the quarantine and movement control of imported cattle in order to reduce any risk of virus spreading to the mainland. The prevalence situation of the Akabane virus in cattle in the border areas of Yunnan Provience were identified in the paper,which provided a reference for future considerations and development of relevant control strategies.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202207002&uniplatform=NZKPT&v=vPzqR5W2eDAnfqBwfYDVye-XM4gEgAncl8BY4-RR7KSu7XbMkdMuLSO3eTmADXpE
2022-07-19
2021年河南省O型口蹄疫免疫效果评估
为了解河南省O型口蹄疫(FMD)的免疫抗体水平,评估其免疫效果,2021年在河南省规模场、屠宰场与散养户,随机采集785场次22 879份血清样品,采用ELISA方法检测O型FMD免疫抗体,并对检测结果进行不同畜种、不同场点类型、不同季节、不同行政区域的统计分析。结果显示:2021年全省O型FMD抗体免疫合格率为80.30%,其中猪、牛、羊抗体免疫合格率分别为79.09%、92.48%、72.26%。猪场中,种猪场、商品代场、屠宰场O型FMD抗体免疫合格率分别为85.24%、82.57%、65.56%;牛场中,种牛场、商品代场、屠宰场、散养户O型FMD抗体免疫合格率分别为96.72%、91.75%、94.17%、100%;羊场中,种羊场、商品代场、散养户O型FMD抗体免疫合格率分别为78.63%、72.37%、69.46%。春、夏、秋、冬季的O型FMD抗体免疫合格率分别为79.42%、79.00%、80.58%、86.12%。18个地市中,有2个地市O型FMD抗体免疫合格率低于70%。结果表明:河南省O型口蹄疫整体免疫效果较好,但羊场免疫效果相对较差,尤其是散养户,免疫抗体合格率未达到70%,存在疫情发生风险。结果提示,需重点加强羊饲养场尤其是散养户的O型FMD免疫工作。Evaluation on the Immune Effects of FMD-O Vaccine in Henan Province in 2021In order to identify the immune status of foot-and-mouth disease subtype O(FMD-O)in Henan Province and to evaluate its immune effects,22 879 serum samples were randomly collected from 785 premises/times in intensive farms,slaughter houses and free-range households in 2021 to detect antibody against FMDV by ELISA,then the test results were analyzed based on animal species,types of premises,different seasons and administrative regions. The results showed that the immunization rate of FMD-O was 80.30% across the province,specifically,79.09%,92.48% and 72.26% respectively in pigs,cattle and sheep;for swine farms,85.24%,82.57% and 65.56% respectively in breeding farms,commercial farms and slaughter houses;for cattle farms,96.72%,91.75%,94.17% and 100% respectively in breeding farms,commercial farms,slaughter houses and free-range households;for sheep farms,78.63%,72.37% and 69.46% respectively in breeding farms,commercial farms and free-range households;79.42%,79.00%,80.58% and 86.12% respectively in spring,summer,autumn and winter;and below 70% in two of 18 cities. In conclusion,the immune status of FMD-O was generally well in Henan Province,and the immunization rate exceeded the national standard(70%),but poor in sheep farms,especially free-range households(<70%)where a risk of disease occurrence was available. Therefore,it was necessary to strengthen immunization against FMD-O in sheep farms especially free-range households.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202207024&uniplatform=NZKPT&v=vPzqR5W2eDADPsj4ka7FchIPK_0CF2S-N95xt5aimaYiBcPEq5-a23sCvcb5iGXM
2022-07-19
羊布鲁氏菌病直接经济损失与防控成本效益分析方法构建及实证研究
为了解我国布鲁氏菌病(以下简称“布病”)一类地区羊布病造成的直接经济损失及防控投入合理性,构建了羊布病直接经济损失指标体系和防控成本效益评估方法,并对我国羊主产区4省份17市县的防疫部门和319个养羊场户进行实地走访与问卷调查。共回收防疫部门问卷21份,场户有效问卷301份,涉及124个布病羊场和177个无布病羊场。运用Excel、SPSS等软件,对问卷数据进行统计分析。结果显示:2020年单只布病羊直接经济损失平均为4 557元(不含奶羊),各省份羊布病损失为 1.8亿~20.4 亿元,其中养羊场户损失占比较高,占总损失的 73.0%~81.0%;各省份政府的布病防控效益成本比为5:1~38:1。结果表明,羊布病导致的经济损失严重,对其防控可取得显著经济效益。建议养殖户及政府进一步加大布病防控投入,而且政府应提高预防性投入比重。本研究为优化布病防控政策提供了技术支撑。Establishment of an Analytical Method for Direct Economic Loss Caused by Sheep Brucellosis and Cost-effectiveness of Its Control with Empirical ResearchIn order to identify the direct economic loss caused by sheep brucellosis in class I area of China and the financial rationality in its prevention and control,an index system of direct economic loss caused by the disease and a cost-benefit evaluation method of its prevention and control were established. A field visit and questionnaire investigation were conducted in 319 farms/households and the disease prevention departments in 17 cities/counties in 4 provinces which are the main sheep production area. 21 questionnaires from the disease prevention departments and 301 from farms/households were collected,covering 124 brucellosis infected farms and 177 brucellosis free farms. The questionnaire data were statistically analyzed by using Excel,SPSS and other software. The results showed that,in 2020,the average direct economic loss of each infected sheep was 4 557 yuan(excluding dairy sheep),and the loss in each province was from 0.18 to 2.04 billion yuan,especially in farms/households,accounting for 73.0%-81.0% of the total loss;the benefit-cost ratio of each government at province level for the disease control was about 5:1-38:1. It was concluded that serious economic loss was caused by the brucellosis which should be controlled to achieve significant economic benefits. Therefore,farmers and governments should increase their investment in the disease control,especially governments should improve their proportion of preventive inputs.原文链接:https://kns.cnki.net/kcms/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202207001&uniplatform=NZKPT&v=vPzqR5W2eDC7pHNo-8K7HXCsEcM6lBbo9jXo2_KGxGvH30QX4qCADsT1Nkc3oqp0
2022-07-15
云南省江城县山羊地方性鼻内肿瘤病毒检测及序列分析
为了解云南省山羊群中的地方性鼻内肿瘤病毒(enzootic nasal tumor virus,ENTV)感染情况,2017年在云南省南部边境地区江城县采集山羊血分离血浆,采用随机PCR(random PCR)进行扩增、克隆,结果从20份血浆中获得与ENTV 2型(ENTV-2)同源性较高的2条序列;根据ENTV-2 CHN1(KU258870)毒株序列设计一套半巢式引物,对采集的20份血浆进行核酸检测,结果4份为阳性。序列分析发现,检测到的4条序列与四川、福建等地流行的ENTV-2位于同一个进化分支,它们之间的核苷酸同源性为96.3%~99.5%,氨基酸同源性为95.3%~99.0%,提示江城县羊群中流行的ENV-2可能与四川省、福建省流行毒株相关;位点分析结果显示,江城县的这4份ENTV-2核酸阳性样品在env蛋白186和204位发生了独特的“G→E”氨基酸位点突变,其中1份在178位还发生了“T→P”的氨基酸位点突变。结果表明,江城县山羊群中存在ENTV-2感染,且流行的ENTV-2呈现一些特有的分子特征。因此,云南省需要加强ENTV监测,了解其在山羊群中的流行情况及其演变规律。本研究为进一步开展ENTV感染调查和山羊呼吸道疾病的诊断和预防提供了依据。Detection and Sequence Analysis of Goat Enzootic Nasal Tumor Virus in Jiangcheng County,Yunnan ProvinceIn order to investigate the infection of enzootic nasal tumor virus(ENTV)in goats in Yunnan Province,goat blood was collected in 2017 to isolate plasma in Jiangcheng County,the southern border area of Yunnan Province,followed by amplification by random PCR and clone,then two sequences with high homology with ENTV-2 were obtained from 20 plasma samples;a set of semi-nested primers were designed based on the sequence of ENTV-2 CHN1(KU258870)to detect the nucleic acid of 20 plasma samples,in which four were positive. It was found that,by sequence analysis,the four sequences were located in the same evolutionary clade as ENTV-2 prevalent in Sichuan and Fujian provinces,with nucleotide homology of 96.3% to 99.5% and amino acid homology of 95.3% to 99.0%,which indicated that ENTV-2 prevalent in goats in the county might be related to those in Sichuan and Fujian provinces;by site analysis,a unique“G→E”amino acid mutation was observed in the four strains when they were located at the positions of 186 and 204 of env protein,and“T→P”in one strain at the position of 178. In conclusion,goats in the county were infected with ENTV-2 that showed some unique molecular characteristics. Therefore,ENTV should be strictly monitored to identify its prevalence and rule of evolution in goats in the province,and then to provide a basis for further efforts against the disease.原文链接:https://chn.oversea.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202206009&uniplatform=OVERSEAS_CHS&v=vPzqR5W2eDCZvASTWiM59wn_jgjssTDzGgIlUMsP_isU4kenVwLuGwzR50YssfdA
2022-06-27
云南省某养鸡场鼻气管鸟杆菌核酸检测及其16S rDNA基因序列分析
为确定云南省易门县某养鸡场大量肉鸡出现流鼻涕、打喷嚏、面部肿胀、食欲下降的原因,采集病死肉鸡鼻腔黏液及肺、气管等组织,处理后提取病原核酸,通过RT-PCR/PCR方法分别检测禽流感病毒(AIV)、传染性喉气管炎病毒(ILTV)、鼻气管鸟杆菌(ORT)、鸡副嗜血杆菌(ICV)。结果显示,仅ORT为核酸阳性,其他病原均为阴性。对检出的ORT阳性样品16S rDNA基因进行序列分析发现,阳性样品与伊朗分离株和土耳其/匈牙利分离株的同源性均在99.7%以上,都处于同一分支内,与国内2014年的报道一致,说明云南省流行的ORT变异较少,仅具有相对短的进化史。本研究对于指导该地区鸡群细菌病防控具有参考意义。Nucleic Acid Detection and 16S rDNA Gene Sequence Analysis of Ornithobacterium rhinotracheale in a Chicken Farm in Yunnan ProvinveIn order to determine the causes of runny nose,sneezing,facial swelling and loss of appetite in a large number of broiler chickens in a farm in Yimen County,Yunnan Province,tissues such as nasal mucus,lungs and trachea of dead broiler chickens were collected to extract the nucleic acid of the pathogen after disposal,then to detect avian influenza virus(AIV),infectious laryngotracheitis virus(ILTV),Ornithobacterium rhinotracheale(ORT)and Haemophilus paragallinium(ICV),respectively by RT-PCR/PCR. The results showed that positive nucleic acid was observed only in ORT,and negative in all other pathogens. The sequence of 16S rDNA gene of the detected ORT positive samples was analyzed,and it was found that the 16S rDNA gene had more than 99.7% homology with the Iranian and Turkey/Hungary isolates,all of which were located in the same branch,which was similar to the information reported in China in 2014,indicating fewer pathogenic variations of ORT prevalent in Yunnan Province and a relatively short evolutionary history. Therefore,the study was of reference significance to guide the prevention and control of bacterial diseases in chicken flocks in the region.原文链接:https://chn.oversea.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202206008&uniplatform=OVERSEAS_CHS&v=vPzqR5W2eDCB7zxSyNxSO9bq9SIk0rOPqGDBEQqPmEGsEQzh_VFZyzZRTA0uLKmR
2022-06-27
禽网状内皮组织增生症病毒山东SD2101株的分离鉴定及全基因组序列和致病性分析
禽网状内皮组织增生症病毒(reticuloendotheliosis virus,REV)是一种常见的禽肿瘤性病毒,可诱发感染鸡群免疫抑制,给我国养禽业带来巨大经济损失。本试验运用DF-1细胞接种方法,在山东省某父母代白羽肉种鸡场鸡群中分离到1株REV,将其命名为SD2101株。为掌握SD2101株基因组遗传演化特征,设计合成6对引物,通过PCR扩增获得了SD2101株的前病毒全基因组序列,并与GenBank下载的参考毒株进行了序列比对和遗传进化分析。结果显示:SD2101株前病毒全基因组具有典型复制完整型逆转录病毒的基因组结构,与2011年分离自江苏省的鸡源REV野毒株HA1101同源性最高;遗传进化分析发现,SD2101株与大部分国内分离株处于同一进化支上。为了解SD2101株的致病性,将分离毒株接种于1日龄SPF鸡,通过体质量、免疫器官指数和灭活疫苗免疫应答等指标进行评价。结果显示,SD2101株对1日龄SPF鸡的生长和免疫功能具有明显的抑制作用。综上,与参考毒株相比,SD2101株基因组序列变异程度较小,具有一定致病作用,提示在生产中应加强对REV的关注和监测。本研究为REV的流行病学研究提供了信息资料。Isolation and Identification of Avian Reticuloendotheliosis Virus SD2101 Strain from Shandong Province and Analysis on Its Whole Genome Sequence and PathogenicityReticuloendotheliosis virus(REV),a common avian neoplastic virus,could induce immunosuppression in infected chickens and bring huge economic losses to poultry industry in China. In this study,a REV strain was isolated from chicken flocks in a parental farm in Shandong Province through inoculating DF-1 cells and named as SD2101. In order to investigate its genetic evolution characteristics,six pairs of primers were designed and synthesized to obtain the whole genome sequence of its provirus by using PCR amplification,followed by sequence alignment and analysis on genetic evolution with the reference strains downloaded from GenBank. The results showed that the provirus was with a typical genome structure of replication-competent retrovirus,with the highest homology with HA1101 which was isolated from chickens in Jiangsu Province in 2011. It was found that,by analysis on genetic evolution,SD2101 strain was on the same evolutionary clade as most domestic isolates. In order to identify the pathogenicity of SD2101 strain,the isolate was inoculated into one-day-old specific pathogen free(SPF)chickens,which was then evaluated by body weight,indexes of immune organs and immune response of inactivated vaccine. In conclusion,the growth and immune functions of one-day-old SPF chickens were significantly inhibited by SD2101 strain. Compared with the reference strain,a small degree of genomic sequence variation was observed in SD2101 strain,with certain pathogenicity. Scientific data was thus provided for further epidemiological research on REV,as it was suggested to focus on and monitor the virus in practice. 原文链接:https://chn.oversea.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202206007&uniplatform=OVERSEAS_CHS&v=vPzqR5W2eDDCCa8x0eUlqRwe3KUFA0bYqdbrEhm8tVlQwrLXEqbGNtRqMXLlpanp
2022-06-27
3株禽副黏病毒4型国内分离株的基因组序列及生物学特性分析
为了解我国近年来新出现的禽副黏病毒4型(APMV-4)的生物学特性,对2020年分离鉴定的3株鸭源APMV-4进行致病性分析和基因组测定。结果显示:3株APMV-4分离株F蛋白裂解位点均为116DIPQR↓F121,1日龄雏鸡脑内接种致病指数(ICPI)为0~0.23,对鸡表现为低致病力。3株分离毒株基因组长度均为15 054 nt,基因组结构顺序均为3'-N-P-M-F-HN-L-5',符合典型的副黏病毒基因组“六碱基原则”;病毒3'端具有55 nt的前导序列,5'端存在17 nt的尾随序列,各基因间有9~42 nt的基因间隔序列;3株分离毒株与APMV-4代表株同源性最高(97.2%~97.5%),与其余禽副黏病毒同源性为37.1%~47.3%,与中国香港、韩国分离株高度同源。结果表明,我国新出现的鸭源APMV-4为弱毒株,基因组序列同源性较高,关键氨基酸位点未发生变异。本研究为进一步了解APMV-4 和科学防控APMV-4感染提供了参考。Analysis on the Genome Sequence and Biological Characteristics of Three Avian Paramyxovirus-4 Isolated in ChinaIn order to investigate the biological characteristics of avian paramyxovirus type 4(APMV-4)newly emerged in China in recent years,pathogenicity and genome analysis were carried out on three APMV-4 strains isolated from ducks in 2020. The results showed that all the F protein cleavage sites of the three strains was 116DIPQR↓F121. The intracerebral pathogenicity index(ICPI)in one-day-old chickens was from 0 to 0.23,indicating low pathogenicity to chickens. The genome length of the three strains was 15 054 nt,and 3'-N-P-M-F-HN-L-5' in the order of structure,which conformed to the typical“six bases principle”of paramyxovirus genome;55 nt leading sequence was observed at 3' end of the virus,and 17 nt trailing sequence at 5' end,a gene interval sequence of 9 to 42 nt was available between each gene;the homology of the three strains with the representative strain of APMV-4 was highest(97.2% to 97.5%),37.1% to 47.3% with other APMVs,and highly closest to those isolated in Hong Kong China and Korea. In conclusion,APMV-4 was low virulent as a new duck derived strain in China,with high homology and no mutation was observed in key amino acid sites. A reference was thus provided for further research on APMV-4 and scientific prevention and control of its infection.原文链接:https://chn.oversea.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202206006&uniplatform=OVERSEAS_CHS&v=vPzqR5W2eDCNLdU1OVoTJzxU6eKV_LbCVxnU-hhyaD01yGabHAsbf86DqRiE8YKQ
2022-06-27
猪流行性腹泻病毒山东SD20BZ01株的分离鉴定及遗传进化分析
为了解山东省猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)基因组遗传演化特征,将山东省滨州市某猪场的PEDV阳性样品接种Vero E6细胞,结果成功分离到1株PEDV,将其命名为SD20BZ01株。通过RT-PCR分段扩增病毒基因组,经测序、拼接获得SD20BZ01株全基因组序列,并将其与GenBank收录的参考毒株序列进行同源性比对和遗传进化分析。全基因组序列分析结果显示,SD20BZ01株与我国2010年以来流行的GII-b亚群变异株序列同源性为97.8%~98.7%,明显高于CV777、DR13、SM98、SD-M等早期经典毒株,因此SD20BZ01属于GII-b亚群变异株。基于S基因的遗传进化关系与基于全基因组序列的遗传进化关系基本一致。与CV777株相比,SD20BZ01株S蛋白在中和抗原表位COE处有10个氨基酸突变,与近年来变异株S蛋白的氨基酸序列基本一致,说明GII-b亚群PEDV的变异规律逐渐趋于稳定。本研究为山东省PEDV流行病学研究及其流行控制策略的制定提供了理论依据。Isolation,Identification and Genetic Evolution Analysis of Porcine Epidemic Diarrhea Virus SD20BZ01 Strain in Shandong ProvinceIn order to investigate the genetic evolution characteristics of porcine epidemic diarrhea virus(PEDV)in Shandong Province,PEDV-positive samples collected from a swine farm in Binzhou City of Shandong Province were inoculated with Vero E6 cells,then a strain of PEDV was successfully isolated,then named as SD20BZ01. Viral genome fragments were amplified by RT-PCR to obtain its whole genome sequence through sequencing and splicing,then the homology and genetic evolution relationship were compared with the reference strain registered in GenBank. It was found that,by the analysis of whole genome sequence,the homology of SD20BZ01 and GII-b variants prevalent in China since 2010 was from 97.8% to 98.7%,which was significantly higher than early classical strains like CV777,DR13,SM98 and SD-M. It was determined that SD20BZ01 was belonged to GII-b subtype variants. The genetic evolutionary relationship based on S gene was generally consistent with that based on the whole genome sequence. Compared with CV777,the S protein of SD20BZ01 harbored 10 amino acid mutations in the neutralizing antigen epitope,while was basically consistent with the amino acid sequence of S protein of variants prevalent in recent years,indicating that the rules of variation of GII-b subtype PEDV tended to be stable gradually. A theoretical basis was thus provided for future epidemiological research as well as development of prevention and control strategy against PEDV in Shandong Province.全文下载链接:https://chn.oversea.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202206005&uniplatform=OVERSEAS_CHS&v=vPzqR5W2eDBD3TJuF7oWdBhvEspuPhNpB7avssGxoqjJELGx1EHO0DMNUvx3VVuN
2022-06-17
2021年全球高致病性禽流感疫情分析
为了解2021年全球高致病性禽流感疫情情况,分析其流行趋势,以有效应对疫情发生,从农业农村部(畜牧兽医局)、香港特区卫生防护中心以及台湾地区农业委员会动植物防疫检疫局等官方网站,收集2021年全球高致病性禽流感疫情信息,从时间、空间、群间三个维度进行统计分析。结果显示:2021年全球共有65个国家和地区报告发生高致病性禽流感疫情,疫情数同比增长250.64%;疫情呈现明显的季节性,1月、4—5月、11—12月疫情报告较多,其中12月为疫情高峰;1—8月主要流行H5N8亚型,9月以后H5N1成为主要流行型;欧洲报告的疫情次数最多,其次是亚洲和非洲;感染家禽和野禽种类多,病毒亚型多样。结果表明,2021年全球高致病性禽流感疫情形势十分严峻,我国应及时出台应对措施,强化监测预警,有效防控国内疫情。Analysis on Global Outbreak of Highly Pathogenic Avian Influenza in 2021In order to investigate the status of global outbreak of highly pathogenic avian influenza(HPAI)in 2021,to analyze its prevalent trend,then to effectively response to any occurrence of outbreaks,relevant information was collected from official websites of Ministry of Agriculture and Rural Affairs(Animal Husbandry and Veterinary Bureau),Hong Kong Center for Health Protection and Taiwan Council of Agriculture(Bureau of Animal and Plant Health Inspection and Quarantine),and statistically analyzed by three dimensions:time,space and inter group. The results showed that,HPAI was reported by 65 countries and regions in 2021,with a year-on-year increase of 250.64%;obvious seasonality was observed,especially in January,April-May,November-December,and in December when the outbreak peaked;H5N8 subtype was mainly prevalent during January-August,while H5N1 become more dominant after September;most outbreaks were reported in Europe,followed by Asia and Africa;a wide variety of poultry and wild birds were infected with diverse virus subtypes. In conclusion,the status of global outbreak of HPAI was very serious in 2021,countermeasures should be timely developed in China to strengthen surveillance and monitoring and to effectively prevent and control the disease.全文下载链接:https://chn.oversea.cnki.net/KCMS/detail/detail.aspx?dbcode=CJFD&dbname=CJFDAUTO&filename=ZGDW202206004&uniplatform=OVERSEAS_CHS&v=vPzqR5W2eDBkoQwPUcytqx5OAMUJsQ_FkInAbGmJarwqZ1VEJhkDyNT7n-m_PO-n
2022-06-17