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。     

云南省禽流感、新城疫与3种免疫抑制性病原共感染的检测

为调查云南省禽流感病毒、新城疫病毒与免疫抑制性病毒混合感染的情况,对云南省2007年1月～2009年10月期间145份禽流感阳性及30份新城疫阳性样品进行禽网状内皮增生病病毒(REV)、J亚群禽白血病病毒(ALV-J)及鸡传染性贫血病毒(CIAV)的检测。禽流感阳性样品中ALV-J的感染阳性率为15.9%,REV的感染阳性率为22.8%,CIAV的感染阳性率为26.9%;新城疫阳性样品中ALV-J的感染阳性率为13.3%,REV的感染阳性率为23.3%,CIAV的感染阳性率为26.7%;共有30份样品发生多重感染,多重感染率为17.1%。对不同区域的4份禽白血病病毒阳性样品、10份禽网状内皮增生病病毒阳性样品、10份禽传染性贫血病毒阳性样品进行了序列比对和系统发育分析。结果表明,云南ALV-J毒株gp85基因与国内外毒株核苷酸及氨基酸同源性分别介于80.4%～96.7%、85.2%～94.5%;REV毒株env基因核苷酸及氨基酸之间的同源性为98.8%～99.8%、97.7%～99.5%;CIAV毒株vp2基因核苷酸及氨基酸之间的同源性为92.4%～100.0%、93.7%～100.0%。     

中国部分地区鸡传染性贫血流行病学调查及病原分离鉴定

为了调查近年来鸡传染性贫血病(CIA)在我国发病鸡群中的流行特点、分布及其危害,本研究于2016年1月～2019年9月,从黑龙江、北京、山东等13个省市的381个疑似CIA发病鸡群中采集肝脏样品1 677份,PCR检出鸡传染性贫血病毒(CAV)阳性样品共242份,分布于85个鸡群,阳性样品检出率为14.43%(242/1 677),阳性鸡群率为22.31%(85/381)。CAV与鸡马立克氏病病毒、鸡白血病病毒等免疫抑制病病毒混合感染在检测鸡群中普遍存在,占CAV感染总量的52.94%(45/85)。将来自山东临沂某CAV阳性鸡场的病鸡肝脏样品处理后接种MDCC-MSB 1细胞,连续传代6次,经PCR及间接免疫荧光鉴定,确定分离到一株CAV细胞适应病毒株,命名为CAV-SD19/4604。对分离株VP1基因测序并与GenBank中19株CAV参考株VP1基因序列比对,显示同源性为95.00%～98.80%,遗传进化树表明CAV-SD19/4604与多数亚洲病毒株位于同一分支。本研究为CAV感染的研究和疾病防控提供了数据支持。     

云南省土杂鸡呼吸系统疫病病因分析

为了分析云南省土杂鸡呼吸系统疫病病因,分别在云南省楚雄、安宁和石林等地采集出现呼吸系统疫病土杂鸡的喉气管、肺脏、脾脏等组织样品57份,采用RT-PCR或PCR方法对采集的样品进行新城疫病毒、禽流感病毒、鸡传染性支气管炎病毒、鸡传染性喉气管炎病毒、鼻气管鸟杆菌、副鸡嗜血杆菌和支原体等传染性疫病病原核酸检测。结果表明:有3份样品检测显示新城疫病毒核酸呈阳性,阳性率为5.26%;4份样品检测显示禽流感病毒核酸呈阳性,阳性率为7.02%;1份样品检测显示鸡传染性支气管炎病毒核酸呈阳性,阳性率为1.75%;11份样品检测显示鸡传染性喉气管炎病毒核酸呈阳性,阳性率为19.30%;19份样品检测显示鼻气管鸟杆菌核酸呈阳性,阳性率为33.33%;28份样品检测显示副鸡嗜血杆菌核酸呈阳性,阳性率为49.12%;48份样品检测显示支原体核酸呈阳性,阳性率为84.21%;9份样品未检测到上述病原核酸,占检测总数的15.79%。说明云南省土杂鸡呼吸系统疫病由多种病原引起,其中以支原体和副鸡嗜血杆菌感染为主。     

猪细小病毒PCR检测与分离研究

根据猪细小病毒(PPV)结构蛋白VP2基因序列,设计合成1对引物,建立了检测PPV的PCR方法。检测14份临床组织,检出阳性11份,阳性检出率为79.5%。阳性样品扩增产物用EcoRⅠ酶切得到了预期的结果,对PCR产物进行测序,测序结果与已发表的PPV基因核苷酸序列比较,同源性达99%~100%,所编码的氨基酸同源性为93%~100%。从PCR检测阳性的一份病料组织中分离出1株PPV。试验证明,建立的PPVPCR检测方法特异性强、敏感性高,适用于临床样品的快速检测。     

云南省部分猪场猪戊型肝炎的流行情况调查

为了解云南省猪群戊型肝炎感染情况,从云南省8个猪场采集166份新鲜猪粪便样品,用套式RT-PCR技术对戊型肝炎病毒(HEV)核酸进行检测,结果 21份样品阳性,阳性率为12.7%,感染率较高。通过PCR产物片段的测序分析,去除重复序列后得到11株基因序列。同源性分析结果表明,这11株毒株序列与选定的Gen Bank中基因1型、2型、3型和4型参考序列的核苷酸序列同源性分别为85.6%~87.8%,85.6%~87.8%,85.6%~95.6%和92.8%~98.9%,说明这些株毒株属于基因4型,与中国其他地区分离的毒株同源性最高,证实HEV的流行具有地理分布的特征。     

华中地区犬细小病毒流行病学调查及其VP2基因序列分析

为了解华中地区犬细小病毒2型(CPV-2)的流行趋势以及变异情况，本研究于2020年9月至2022年1月间采集华中地区的418份疑似感染犬细小病毒的粪便样品，通过PCR方法检测，利用F81细胞进行病毒分离、间接免疫荧光试验，并对分离病毒的VP2基因进行氨基酸序列及其同源性和遗传进化分析。结果显示，358份病料检测出CPV-2,阳性率为85.65%。病料接种F81细胞后，有23份阳性样品出现明显细胞病变，间接免疫荧光试验观察到明显荧光。VP2基因序列分析结果表明，分离毒株中有New-CPV-2a型12株、New-CPV-2b型5株、CPV-2c型6株。核苷酸同源性为97.9%～99.8%,氨基酸同源性为95.9%～100.0%。遗传进化分析结果显示，分离毒株与国内分离株、伊朗、巴西分离株亲缘关系较近，与意大利、日本、阿根廷分离株亲缘关系较远。本研究为华中地区犬细小病毒防控及研制高效疫苗奠定了基础。     

鸡传染性贫血病毒泰州的分离鉴定及遗传演化分析

江苏泰州某鸡场发生疑似鸡传染性贫血疫情。本试验从发病鸡采集病料,通过免疫荧光染色和病毒特异性PCR确定为鸡传染性贫血病毒(CAV);将病料组织用抗生素处理之后接种MDCC-MSB1细胞系,最终分离1株鸡传染性贫血病毒,命名CAV MY1305-30株。电镜负染结果表明,该病毒粒子呈球形、无囊膜,为典型的CAV粒子。动物回归试验表明,该病毒能够引起雏鸡发病,剖检能够看到鸡传染性贫血典型的骨髓黄化、凝血不良、胸腺萎缩等病理变化。根据Gen Bank中设计的特异性引物对泰州株进行序列测定和遗传进化分析,结果表明,泰州株MY1305-30株基因组编码区VP1基因和VP2基因全长分别为1 350和651 bp,编码区内不存在碱基插入或缺失,同源性分析表明泰州株与GenBank中收录的CAV流行株编码区同源性在96.5%~99.8%之间,VP1和VP2基因的遗传进化树表明CAV泰州株属于亚洲流行毒株。     

4株猪圆环病毒2型凉山州分离株全基因组进化分析

为了解猪圆环病毒2型(PCV2)凉山州分离株的基因型,本研究采用PCR方法对采自凉山州3个发病猪场的4个PCV2阳性样品进行全基因组序列的扩增、克隆、测序分析,并绘制遗传进化树。结果显示:4个PCV2凉山州分离株全基因组序列长度均为1767 bp,核苷酸同源性为99.4%~99.8%,与国内外101株PCV2参考毒株核苷酸同源性为93.8%~99.9%,与4个PCV2国产疫苗株核苷酸同源性为95.1%~96.0%;4个分离株ORF1和ORF2基因核苷酸同源性分别为99.3%~99.8%和99.6%~100%;构建的系统进化树显示,4个分离株均为PCV2d亚型,与YA1株(四川雅安,MH094769)的亲缘关系最近。本研究为凉山州PCV2疫苗毒株的选择提供了科学依据。     

云南猪繁殖与呼吸综合征的诊断与Nsp2基因变异分析

对2019年5月份云南省出现的流产胎儿样品进行猪繁殖与呼吸综合征病毒、猪瘟病毒、猪伪狂犬病毒和猪细小病毒核酸检测,2个猪场胎儿样品检测猪繁殖与呼吸综合征病毒核酸均为阳性,其他病原均为阴性。对核酸阳性样品通过RT-PCR扩增猪繁殖与呼吸综合征病毒Nsp2基因,并对其进行测序。序列比对及系统发育分析结果表明:2019年云南2株猪繁殖与呼吸综合征病毒Nsp2基因核苷酸序列同源性为97.5%;与VR2332、CH-1a、HUN4、JXA-1、JXAIP80、TJA-1毒株之间的核苷酸同源性为77.1%～98.3%,与JXAIP80毒株同源性最高为97.6%～98.3%,与经典北美毒株VR2332同源性最低为71.1%～71.2%,与经典毒株VR2332和CH-1a相比存在90 bp碱基缺失。     

Heartworm in dogs in Canada in 1984

In late December 1984, 1853 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1984 and 35% of them responded. Veterinarians reported that 97,794 dogs were blood-tested to check for microfilariae and 1417 dogs (1.45% of those tested) were found with heartworm. Another 34 dogs were amicrofilaremic, but were diagnosed as having heartworm disease, to give the total number diagnosed in 1984 as 1451 (1.48%). Heartworm was reported from all provinces except Prince Edward Island and Newfoundland but most (1310) of the cases were in Ontario. In Quebec, 126 cases were reported mostly from west of Montreal.

Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 27% of the cases were observed with clinical signs of heartworm disease and 72% had a history of not having left Canada. Southwestern Ontario continued to be the primary focus of the infection.

     

Heartworm in dogs in Canada in 1988

In late November 1988, 1581 small and mixed animal clinics and institutional veterinarians across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1988, and 46% of them responded. Veterinarians reported that 181,577 dogs were blood-tested for heartworm disease and 367 dogs were found with D. immitis microfilariae. Another 60 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1988 as 441 (0.24%).     

Heartworm in dogs in Canada in 1985

In late December 1985, 1485 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1985 and 44% of them responded. Veterinarians reported that 137,300 dogs were blood-tested to check for microfilariae and 1210 dogs were found with heartworm. Another 36 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number diagnosed in 1985 as 1247 (0.91%).

Heartworm was reported from all provinces except Prince Edward Island, Newfoundland and Saskatchewan but most (1126) of the cases were in Ontario. Southwestern Ontario continued to be the primary focus of the infection in Canada. From Quebec, 91 cases were reported mostly from and around Montreal. From Manitoba, 19 cases were reported from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 28% of the cases were observed with clinical signs of heartworm disease and 78% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1989

In late November 1989, 1732 clinics and institutional veterinarians were sent a questionnaire to assess the status of Dirofilaria immitis, and 51.7% responded. Of 247,716 dogs tested, 394 had D. immitis microfilariae and 51 were amicrofilaremic for a total of 445 cases and heartworm prevalence of 0.17%. Most (408) of these dogs had no preventive medication and the prevalence among dogs tested and unprotected was 1.01%. That prevalence was considerably higher in endemic areas. Thirty-seven dogs with heartworm had preventive medication. Heartworm was most frequent in companion dogs over three years of age maintained outdoors in rural areas. About 75% of the cases had never left Canada, 26% had clinical signs and 125 were not treated.

Heartworm was reported from British Columbia, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland, but 383 cases were in Ontario. South-western Ontario was the primary focus of infection. There were 33 cases in Quebec and 24 in Manitoba, mainly found in and around Metropolitan Montreal and Winnipeg respectively.

     

Heartworm in dogs in Canada in 1987

In late November 1987, 1246 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1987, and 50% of them responded. Veterinarians reported that 165,428 dogs were blood tested for heartworm disease and 511 dogs were found with D. immitis microfilariae. Another 78 dogs were amicrofilaremic but diagnosed with heartworm disease to give the total number of cases diagnosed in 1987 as 589 (0.35%).     

Heartworm in dogs in Canada in 1986

In late December 1986, 1224 institutional veterinarians and small and mixed animal clinics across Canada were sent a questionnaire in order to assess the status of Dirofilaria immitis in Canada in 1986; 46% of them responded. Veterinarians reported that 150,989 dogs were blood-tested for microfilariae and 869 dogs were found with heartworm. Another 65 dogs were amicrofilaremic but diagnosed with heartworm disease and one was found with heartworm at necropsy to give the total number diagnosed in 1986 as 935 (0.62%).

Heartworm was reported from Manitoba, New Brunswick, Ontario and Quebec, but most (810) of the cases were from Ontario. South-western Ontario continued to be the primary focus of the infection in Canada. There were 103 cases reported from Quebec, mostly from and around Montreal, and 21 cases from Manitoba, from Winnipeg and surrounding areas. Heartworm was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 33% of the cases were observed with clinical signs of heartworm disease and 81% had a history of not having left Canada.

     

Heartworm in dogs in Canada in 1983

In late December 1983, 2 800 veterinarians across Canada were sent a questionnaire in order to assess the status of heartworm disease in Canada in 1983 and 26% of them responded. Veterinarians reported that 59 504 dogs were blood-tested to check for microfilariae and 771 dogs (1.30% of those tested) were found with Dirofilaria immitis. Heartworm disease was diagnosed in all provinces except New Brunswick and Newfoundland but most (733) of the cases were in Ontario.

Heartworm disease was found most frequently in companion dogs over three years of age maintained mainly outdoors in rural areas. About 31% of the cases were observed with clinical signs of heartworm disease and 64% had a history of not having left Canada. Southwestern Ontario continues to be the focus of the infection and most of the dogs there had not left the province previously.