新疆石河子地区犬埃立克体感染的流行病学调查

为了解石河子地区犬埃立克体的流行状况,本研究从石河子市宠物医院及周边地区采集犬血液和体表寄生蜱,利用间接ELISA对采集的血清样品进行血清学调查,并通过PCR扩增犬埃立克体16S rRNA基因和及系统进化分析进行其分子流行病学调查。血清学检测结果显示,犬埃立克体抗体阳性率为22.40%,表明石河子地区犬中存在埃立克体的感染。从犬体表蜱样本中扩增出埃立克体452 bp特异片段,测序和比对结果证实这些片段为犬埃立克体;遗传进化分析显示,犬源埃立克体石河子流行株,与Fujian、Yonaguni206、Yunnan、Ehrlichia muris(AY587608.2)、Ehrlichia chaffeensis(NR_074500.1)等流行株具有较近的亲缘关系,首次证实石河子地区存在犬埃立克体的感染和流行,为埃立克体病的防控提供了流行病学资料。     

湖南省蜱及5种蜱传病原研究

蜱传病呈全球分布，危害人类和动物健康。为了研究湖南省娄底市现存蜱媒病原体，于2021—2022年在湖南省娄底市采集1 395只微小牛蜱样本，提取蜱样品基因组DNA。选取蜱线粒体COI基因扩增特异性的基因片段，对微小牛蜱进行鉴定。为了对该蜱携带的病原进行检测，采用PCR方法对立克次体ompA和gltA基因，无形体groEL和23S rRNA基因，埃立克体groEL和16S rRNA基因，螺旋体16S rRNA和23S rRNA基因进行扩增，对阳性产物进行克隆测序，测序获得的基因序列进行系统发育分析来确定病原的基因型。结果显示，从蜱样本中检测出5种蜱传细菌病原，包括敬信立克次体(Candidatus Rickettsia jingxinensis)、中央无形体(Anaplasma centrale)、扁平无形体(Anaplasma platys)、米氏埃立克体(Ehrlichia minasensis)和宫本疏螺旋体(Borrelia miyamotoi)。其中敬信立克次体、米氏埃立克体和宫本疏螺旋体阳性率均为2.16%,扁平无形体阳性率为0.30%,中央无形体阳性率为5.79%。本研究利...     

古尔班通古特沙漠南缘蜱携带无形体的调查

为了解古尔班通古特沙漠南缘蜱携带无形体的状况,在该地域3个不同生境区域11个地点采集家畜寄生蜱标本,进行分类鉴定;运用套式PCR筛选无形体阳性蜱样本,并用半套式PCR扩增无形体科16SrRNA基因5′端高变区,进行克隆测序;将所获得的DNA序列与GenBank收录的序列作比对,并用Mega 5.0软件构建系统发育树,鉴定蜱携带无形体的种类。结果共采集708只蜱,鉴定为4个属8个种。在分类后的236份蜱样本中,检测出无形体阳性25份,阳性率为10.59%。序列比较发现,在亚洲璃眼蜱、血红扇头蜱、残缘璃眼蜱、长角血蜱中分别存在查菲埃立克体（Ehrlichia chaffeensis）、犬埃立克体（Ehrlichia canis）、边缘无形体（Anaplasma marginale）和绵羊无形体（Anaplasma ovis）的16SrRNA基因片段。研究结果证实在古尔班通古特沙漠南缘家畜寄生蜱中携带无形体,提示该地域可能是无形体病的自然疫源地。     

革蜱携带微生物多样性的二代测序技术分析

为了解黑龙江省尚志市某林区革蜱携带微生物种类的特点,试验采集游离蜱,随机取雌雄革蜱各96只,提取蜱足和其他部位的DNA样品分成雌蜱、雄蜱和蜱足3组,分别扩增16S r DNA基因V3~V4区,应用Illumina Hi Seq 2500测序平台进行深度测序,并对微生物多样性进行生物信息学分析。蜱足组代表外环境微生物群,在去除蜱足组所携带微生物的有效序列后,对雌蜱和雄蜱两组革蜱体内的微生物进行具体分析。结果表明:雌蜱和雄蜱两组样品共获得60 954条有效序列,平均序列长度为423 bp,包括651个分类操作单元(OTU),共192个科,309个属;其中检测到25类致病微生物,分别包括布鲁氏菌科、巴斯德氏菌科和分支杆菌属等常见人兽共患病菌,以及考克斯氏体属、立克次氏体属、无形体属、疏螺旋体属和埃立克体属5类蜱传病原;分析发现雌蜱和雄蜱携带的病原种类和丰度均不同,其中雌蜱中蜱传病原的种类多于雄蜱。说明采自尚志市某林区森林革蜱体内的微生物群结构具有多样性和复杂性,雌蜱和雄蜱微生物群的多态性存在差异。     

规模化山羊养殖场暴发绵羊无浆体病的诊断检测

正无浆体病(Anaplasmosis)是由各种无浆体(Anaplasma spp)(又称无形体,旧称边虫)寄生于牛、羊、鹿等反刍动物红细胞内,由蜱媒传播而引起的疾病,亦称无形体病,旧称边虫病,以发热、贫血、黄疸、衰弱和渐进性消瘦为特征。病原为无浆体,隶属于立克次氏体目(Rickettsiales)无浆体科(Anaplasmataceae)无浆体属(Anaplasma)。无浆体呈圆点状、球状,直径为0.3~1.0μm,只有1个     

吸血行为对草原革蜱和森林革蜱中肠菌群结构的影响

本研究旨在探明随吸血时间的延长,草原革蜱和森林革蜱中肠菌群结构的特征及变化。从内蒙古呼伦贝尔和宁夏固原绵羊体表分别采集半饱血、饱血草原革蜱和半饱血、饱血森林革蜱,无菌条件下收集蜱中肠内容物,提取细菌总DNA,扩增细菌16SrDNA V3-V4区,IonS5~(TM)XL高通量测序,对比分析各样本菌群结构的特征。结果显示,森林革蜱半饱血中肠内的细菌多样性最高,草原革蜱饱血和半饱血中肠内的细菌多样性次之,森林革蜱饱血中肠内的细菌多样性最低;变形菌门为4个样品的优势菌门;无形体属、立克次体属、寡养单胞菌属和柯克斯体属为4个样品的优势菌属,其中无形体属在草原革蜱和森林革蜱饱血中肠内的含量高于2种蜱半饱血中肠,立克次体属和柯克斯体属在2种蜱半饱血中肠内的含量明显大于饱血中肠;边缘无形体、弯曲假单胞菌和柯克斯体科RFE02菌为4个样品的优势菌种,其中边缘无形体的分布特点与无形体属在2种蜱中肠内的分布特点相一致。结果表明,草原革蜱和森林革蜱中肠菌群结构易受到吸血行为的影响,共有菌属和菌种在不同蜱种和不同饱血状态下的相对丰度变化较大。     

吸血行为对草原革蜱和森林革蜱中肠菌群结构的影响

本研究旨在探明随吸血时间的延长,草原革蜱和森林革蜱中肠菌群结构的特征及变化。从内蒙古呼伦贝尔和宁夏固原绵羊体表分别采集半饱血、饱血草原革蜱和半饱血、饱血森林革蜱,无菌条件下收集蜱中肠内容物,提取细菌总DNA,扩增细菌16S rDNA V3-V4区,IonS5^TMXL高通量测序,对比分析各样本菌群结构的特征。结果显示,森林革蜱半饱血中肠内的细菌多样性最高,草原革蜱饱血和半饱血中肠内的细菌多样性次之,森林革蜱饱血中肠内的细菌多样性最低;变形菌门为4个样品的优势菌门;无形体属、立克次体属、寡养单胞菌属和柯克斯体属为4个样品的优势菌属,其中无形体属在草原革蜱和森林革蜱饱血中肠内的含量高于2种蜱半饱血中肠,立克次体属和柯克斯体属在2种蜱半饱血中肠内的含量明显大于饱血中肠;边缘无形体、弯曲假单胞菌和柯克斯体科RFE02菌为4个样品的优势菌种,其中边缘无形体的分布特点与无形体属在2种蜱中肠内的分布特点相一致。结果表明,草原革蜱和森林革蜱中肠菌群结构易受到吸血行为的影响,共有菌属和菌种在不同蜱种和不同饱血状态下的相对丰度变化较大。     

四川石渠县牦牛体表蜱携带无形体和疏螺旋体的分子检测

为了解四川省石渠县牦牛体表寄生蜱携带无形体与疏螺旋体的种类和感染情况。采集牦牛体表寄生蜱,经形态学和分子生物学鉴定,确定蜱种类。再采用巢式PCR分别扩增无形体科16S rRNA基因和疏螺旋体属的16S rRNA与flaB基因片段,并对阳性产物进行测序、比对和系统进化树构建,从而确定无形体和疏螺旋体的种类。结果显示,共采集到818只蜱,其中西藏革蜱占78.97%(646/818)、青海血蜱占21.03%(172/818)。所有蜱中有132只检出无形体,阳性率为16.14%;8只检出疏螺旋体,阳性率为0.98%;3只蜱混合感染牛无形体和疏螺旋体。经进一步分析,仅在青海血蜱中检测到牛无形体(Anaplasma bovis)、埃立克体(Ehrlichia)和疏螺旋体(Borrelia),其阳性率分别为6.98%(12/172),2.33%(4/172)和4.65%(8/172);仅在西藏革蜱中检测到绵羊无形体(Anaplasma ovis),其阳性率为17.96%(116/646)。此外,获得的疏螺旋体16S rRNA和flaB基因序列均与分离自日本大刺血蜱中的Borrelia sp.HM菌株亲缘关系最近。结果提示,四川石渠县存在牛无形体、绵羊无形体、埃立克体未定种以及疏螺旋体未定种,存在感染人的风险。     

我国犬埃立克体病研究现状

犬埃立克体病是由严格细胞内寄生的埃立克体所致的疾病。目前,我国已经发现的犬埃立克体病原有犬埃立克体(Ehrlichia)和扁平埃立克体(E.platy)两种。我国已发现的犬埃立克体病均为E.canis和E.platy的混合感染。临床症状包括发热、体重严重减轻、流鼻血和腹泻带血等;白细胞和血小板计数同时下降是我国犬埃立克体病的特点;严重的病犬常因广泛性出血或继发感染而死亡。犬埃立克体病的病原学诊断主要依靠镜检、血清学试验和PCR等。犬血清埃立克体抗体的调查结果表明,我国犬埃立克体病的流行与蜱活动密切相关。四环素类抗生素是治疗犬埃立克体病的有效药物。     

广州地区犬血清埃立克体抗体季节消长规律

为了解犬埃立克体全年消长情况，从而掌握犬埃立克体病在广州地区流行规律，以便更有效地预防和控制犬埃立克体病。以查菲埃立克体28kD重组为抗原，采用免疫印迹法，逐月检测犬血清埃立克体抗体水平。结果表明，1－3月抗体呈缓慢上升趋势，4月后急剧上升，并维持高水平至10月，之后急剧下降。其抗体消长情况与先前我们调查的犬埃立克体病的发病和流行规律相一致，与该地区蜱活动时间基本一致。     

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 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 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.

     

Heartworm in dogs in Canada in 1991

In late November 1991, 1883 clinics in Canada were sent a questionnaire to assess the status of Dirofilaria immitis in dogs in 1991 and there was a 60.0% response. There were 344,031 dogs tested for heart-worm (HW), 627 were found infected and the prevalence of HW infection was 0.18%. There were 417 dogs with HW in Ontario, 116 in Manitoba, 38 in Quebec, 53 in British Columbia, three in Alberta, and one in Nova Scotia. In British Columbia, all of the infected dogs but one were from the Okanagan valley which, as from 1991, is a new focus of infection in Canada. Most dogs with HW had not been on preventive medication in 1990, and the prevalence among dogs tested and unprotected was 0.59%. That prevalence was considerably higher in endemic areas. Companion dogs, over three years of age and maintained primarily outdoors in rural areas, were most frequently infected. One cat was diagnosed with D. immitis and 33 dogs had Dipetalonema reconditium.     

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.