江西省赣州市蜱携带立克次体和埃立克体的调研

目的 了解江西省赣州市蜱的种类及其携带的病原体,为蜱传疾病的防控提供科学依据方法 在野外用布旗法和在动物体表采集蜱,进行种类鉴定。用PCR法扩增立克次体(Rickettsia sp.)gltA基因和埃立克体(Ehrlichia sp.)16S rRNA基因片段并测序,进行系统进化分析结果 江西省赣州市4县采集的395只蜱的种类包括2属4种,分别为血蜱属的长角血蜱(Haemaphysalislongicornis)、嗜群血蜱(H. concinna)、具角血蜱(H. cornigera)和扇头蜱属的微小扇头蜱(Rhipicephalus microplus)。395只蜱分为43批检测立克次体和埃立克体,共有18批阳性。系统进化分析显示,龙南县22批蜱中检测到16批阳性,来源于具角血蜱的LN1615株与扇头蜱立克次体(R. rhipicephali)处于同一分支,来源于微小扇头蜱的LN1620株与马赛立克次体(R. massiliae)处于同一分支,其余的12株来源于具角血蜱和2株来源于微小扇头蜱,与日本立克次体(R. japonica)处于同一分支。崇义县CY1602株来源于嗜群血蜱与R. raoultii处于同一分支。于都县YD1606株为来源于长角血蜱的埃立克体,与2010年Yonaguni206(HQ697589)、Yonaguni138(HQ697588)和2009年HLAE178(GU075695)处于同一分支。安远县微小扇头蜱检测均为阴性结论 本文对江西省赣州市采集的蜱进行了鉴定,首次在江西省赣州市的蜱中检测到日本立克次体、扇头蜱立克次体、马赛立克次体、R. raoultii和埃立克体,为江西省蜱种类的调查及其传播疾病的预防控制提供根据。     

滇西横断山区家畜体表蜱类调查及鉴定

目的 调查滇西横断山区家畜体表蜱的种类。方法 采集家畜体表寄生的蜱虫,经形态学鉴定后,用PCR法扩增蜱虫样本的16S rRNA、12S rRNA、COI、ITS2的基因片断,测序后进行序列分析。结果 共采集成虫蜱样本1 874只,经形态学鉴定为1科、1属(扇头蜱属Rhipicephalus)、4种,其中微小扇头蜱(R. microplus)1 637只(占87.35%)),镰形扇头蜱(R. haemaphysaloides)218只(11.63%),短小扇头蜱(R. pumilio)11只(0.59%),血红扇头蜱(R. sanguineus)8只(0.43%)。样品分子鉴定结果与形态学鉴定结果一致。系统发育树分析显示,微小扇头蜱Y2 16S rRNA、12S rRNA、COI、ITS2的基因序列分别与来自印度(EU918188)、贵州(KC503259)、马来西亚(KM246873)、贵州(KC503274)的微小扇头蜱在同一分支上,而与以往云南发现的微小扇头蜱不在同一分支;镰形扇头蜱Y5的 16S rRNA、12S rRNA和COI基因序列分别与来自泰国(KC170743)、台湾(DQ003005)和湖南(KM083593)的镰形扇头蜱在同一分支上;短小扇头蜱Y6和Y01 的ITS2基因序列与来自澳大利亚的短小扇头蜱(AF271282)在同一分支上。结论 滇西横断山区家畜体表蜱以微小扇头蜱为优势种,短小扇头蜱为云南境内首次发现。     

COI基因DNA条形码技术在福建省蜱类鉴定中的应用

目的 探讨基于线粒体细胞色素C氧化酶亚基I(COI)基因的DNA条形码技术应用于福建省蜱类鉴定的可行性。方法 蜱标本经形态学鉴定后提取基因组DNA,PCR扩增COI基因片段,并进行测序和比对,用Kimura-2-parameter模型计算种内及种间遗传距离,以邻接法构建系统发育树。结果 经形态学鉴定,97只蜱隶属于5属12种,遗传距离计算结果显示,种间遗传距离(14.65%~26.79%)显著大于种内遗传距离(0~7.14%);BLAST同源性比对发现GenBank数据库中尚无越原血蜱(Haemophysalis Yeni)与基刺硬蜱(Ixodes spinicoxalis)的COI基因序列,褐黄血蜱(H.flava)、台岛血蜱(H.formosensis)、豪猪血蜱(H.hystricis)、粒形硬蜱(I.granulatus)、微小扇头蜱(Rhipicephalus microplus)与血红扇头蜱(R.sanguineus)的形态学鉴定与DNA条形码鉴定结果一致,但是,龟形花蜱(Amblyomma testudinarium)、台湾革蜱(Dermacentor taiwanensis)、中华硬蜱(I.sinensis)的形态学鉴定与COI基因DNA条形码鉴定结果不一致;系统发育树显示,同一物种的不同个体均形成高支持率的单系,种间分支很明显。结论 COI基因DNA条形码测定是一种快速准确的蜱类鉴定新兴技术,但现阶段,COI基因DNA条形码技术尚不能完全脱离传统的形态学鉴定而独立进行,两者应有机结合。     

塞罕坝自然保护区硬蜱调查及分子鉴定

目的掌握河北省承德市塞罕坝自然保护区内硬蜱种类及其分子特征,明确该地区蜱类的分类地位,为相关蜱媒传染病的防控制提供参考。方法 2018年4-9月间,采用布旗法捕捉该地区森林、草地、灌丛3种生境内自由生活的蜱类;提取蜱基因组,PCR扩增2种硬蜱的线粒体16S rDNA和COⅠ基因片段,并进行同源性分析。基于邻接法和最大简约法,用Mega 7.0软件分别构建系统发生树,进行遗传进化分析。结果在植被上共采集蜱231头,分为1科2属2种,其中全沟硬蜱212头,嗜群血蜱19头。PCR扩增嗜群血蜱标本(QS11)16S rDNA和COⅠ扩增基因片段长度分别是434 bp和712 bp,全沟硬蜱标本(QG13)16S rDNA、COⅠ基因片段长度是445 bp、735 bp。嗜群血蜱标本和全沟硬蜱标本的16S rDNA序列、COⅠ序列与GenBank中已登录的2种硬蜱对应基因聚类,且在一个进化分支上;嗜群血蜱标本16S rDNA、COⅠ序列与已登录嗜群血蜱相同基因序列的同源性分别为98.2%和98.1%,遗传距离分别为0.035和0.028;全沟硬蜱2个基因与已登录基因的同源性分别为98.3%和97.4%,遗传距离分别为0.067和0.104。结论塞罕坝自然保护区内优势蜱种是全沟硬蜱且存在嗜群血蜱。两蜱种16S rDNA、COⅠ与序列存在多样性和地域差异性。     

云南临沧地区蜱种分子生物学鉴定及埃立克体基因序列分析

目的 了解云南临沧地区蜱虫种类及其自然感染埃立克体的情况。方法 采集耕牛体表寄生的蜱虫,经形态学鉴定和分组后,从蜱虫中提取DNA,应用PCR扩增蜱虫COI基因以及埃立克体16S rRNA和groEL基因,并测序分析。结果 共采集到蜱虫42只,其中微小牛蜱38只占90.48%、血蜱4只占9.52%。将每种蜱的2只为1组,在21组样本中,检出COI片断21份(检出率100%);在相同的4组样本中均检出埃立克体16S rRNA片断和groEL片断4份(检出率19.05%)。基因序列分析,检出的COI片断序列中有2份与澳大利亚pava血蜱(JX573136)的同源性最高(89.3%),其余19份序列与马来西亚微小牛蜱B3的同源性最高(99.5%);检出的4份16S rRNA片断序列完全一致,与美国查菲埃立克体Arkansas和埃文埃立克体Aa2FT349及中国北京查菲埃立克体BY-YQ-HME-O18株的同源性均为100%;检出的4份groEL片断序列也完全一致,与日本埃立克体Yonaguni206 株的同源性最高均为93.9%。结论 经分子检测证实云南临沧地区耕牛体表微小牛蜱中存在一种类似日本Yonaguni206株的埃立克体感染,耕牛体表还可能寄生一种新的血蜱。     

基于16S rDNA和COⅠ基因的3种血蜱分子生物学鉴定

目的利用16S rDNA基因及线粒体DNA细胞色素氧化酶亚基Ⅰ(cytochrome oxidase subunitⅠgene,COⅠ)基因建立3种形态学特征相近的血蜱属蜱类-长角血蜱、褐黄血蜱及铃头血蜱的分子生物学鉴定方法,探讨它们的系统发生关系。方法在上海市动物体表采集寄生蜱,在解剖显微镜下进行形态学鉴定后,提取蜱样本基因组DNA,采用PCR方法从蜱基因组中扩增16S rDNA及COⅠ基因,测序后进行同源性分析,用Mega 6.0软件分别构建系统发生树并进行系统进化分析。结果3种血蜱中长角血蜱的16S rDNA序列和COⅠ序列与GenBank中的长角血蜱的16S rDNA序列和COⅠ序列同源性分别为96.0%~97.2%,96.9%~98.8%;褐黄血蜱的16S rDNA序列和COⅠ序列与GenBank中的褐黄血蜱的16S rDNA序列和COⅠ序列同源性分别为95.9%~98.3%、87.1%~91.9%;铃头血蜱的16S rDNA序列与GenBank中来自日本的铃头血蜱(AB819170)的16S rDNA序列同源性为97.5%;3种血蜱16S rDNA基因之间的同源性分别为88.0%、87.0%、86.9%,COⅠ基因之间的同源性分别为80.4%、80.8%、82.8%。用16S rDNA及COⅠ基因构建系统发生树中,长角血蜱、褐黄血蜱分别与已知的长角血蜱和褐黄血蜱聚在一起,长角血蜱、褐黄血蜱均形成独立的分支。结论在传统形态学分类的基础上结合分子生物学鉴定方法能更准确地鉴定蜱的种类,并能更好地了解其系统发育进化关系。     

河南省信阳地区家畜寄生蜱感染巴贝虫的分子流行病学调查

目的 了解河南省信阳地区家畜寄生蜱感染巴贝虫的情况。方法 2022年6—8月在河南省信阳市光山县和商城县采集家畜动物体表寄生蜱,采用形态学和PCR扩增蜱虫16S rDNA鉴定蜱虫种类。提取蜱虫基因组DNA,采用巢式PCR扩增巴贝虫18S rRNA基因。目的条带经测序后,进行BLAST比对分析,采用邻接法构建系统进化树,采用MEGA7.0软件进行同源性分析。结果 共釆集335只蜱,形态学和PCR扩增鉴定结果显示,长角血蜱49只、微小扇头蜱208只、褐黄血蜱1只、具环扇头蜱34只、刻点血蜱43只。PCR扩增结果显示,335份蜱虫样品中有2份样品扩增出巴贝虫400 bp大小的目的条带,蜱虫巴贝虫总阳性率为0.6%。BLAST比对分析结果显示,1份样品扩增出的18S rRNA序列与GenBank中来自美国（MK609547）、泰国（MG199181）、中国（KU204794）的田鼠巴贝虫序列相似性均达99.26%;另1份样品扩增出的18S rRNA序列与GenBank中来自美国（MH620203）、印度（MN161136）和中国（KP666166）的吉氏巴贝虫序列相似性均达100%。系统进化树...     

上海市犬体表媒介蜱寄生情况初步调查

目的初步了解上海市犬体表蜱虫寄生情况。方法2011年3-12月,在上海市18个区(县)采用动物体表采集法捕获犬体表蜱类样本,将蜱虫样本带回实验室,在解剖显微镜下观察成蜱形态,通过形态学鉴定蜱种类。结果在上海市18个区(县)共调查犬1 950只,其中在嘉定、闵行、浦东、松江、黄浦、金山6个区的犬体表共捕获蜱虫328只,经实验室鉴定分为2属2种;宠物犬体表寄生的蜱种为血红扇头蜱和长角血蜱,实验犬和警犬体表寄生的蜱种为血红扇头蜱。结论血红扇头蜱是上海市犬体表寄生的优势蜱种,长角血蜱是新发现的寄生于上海市犬体表的硬蜱蜱种;应加强对媒介蜱的防控。     

四川石渠县牦牛源蜱感染斑点热群立克次体分子流行病学调查

目的 了解四川省石渠县牦牛体表寄生蜱的种类及其斑点热群立克次体的感染情况。方法 采集牦牛体表的蜱,经形态学初步鉴定后,提取蜱总DNA,PCR扩增蜱16S rRNA基因及斑点热群立克次体ompA、ompB基因,并对扩得阳性产物进行测序和构建进化树分析,从而确定蜱及其携带斑点热群立克次体的种类。结果 在石渠县4个乡共采集到蜱818只,其中西藏革蜱占78.97%(646/818)、青海血蜱占21.03%(172/818)。在818只蜱中有408只扩得斑点热群立克次体ompA、ompB基因,总阳性率为49.8%。经比对分析, ompA基因总共得到4条序列(uncultured Rickettsia sp.shiqu1、R.raoultii.shiqu2、R.raoultii.shiqu3和R.raoultii.shiqu4),ompB基因也得到4条序列(uncultured Rickettsia sp.shiqu1、R.raoultii.shiqu2、R.raoultii.shiqu3和R.raoultii.shiqu4)。经遗传进化分析显示ompA基因的uncultured Rickettsia sp.shiqu1与我国青海未定种的Uncultured Rickettsia sp.(MG228270)亲缘关系最近;ompB基因的uncultured Rickettsia sp.shiqu1与韩国未定种的Rickettsia sp.(KC888953)和Candidatus Rickettsia longicornii(MG906675)亲缘关系最近;ompA和ompB基因的R.raoultii.shiqu2-4与对人有致病性的劳氏立克次体(R.raoultii)的亲缘关系最近。结论 首次在牦牛体表寄生的西藏革蜱中检出劳氏立克次体。石渠县存在西藏革蜱和青海血蜱,蜱传劳氏立克次体感染率较高并且具有感染人的风险。     

内蒙古部分地区草原革蜱携带无形体检测与进化分析

目的 探究内蒙古地区草原革蜱无形体感染情况,鉴定蜱传无形体种属并进行系统进化分析。方法 基于无形体16S rRNA基因、groEL基因和MSP4基因合成特异引物,对内蒙古地区采集的蜱虫标本进行PCR扩增,将阳性样本进行测序和分析并构建系统发育进化树。结果 将采集的905只蜱虫经形态学鉴定后将168只饱血蜱与737只未饱血蜱分为220个蜱虫混合样本,经检测有41个无形体阳性样本均来自于单只饱血蜱样本,总阳性检出率为4.53%(41/905),其中呼伦贝尔地区阳性率为1.03%(3/292);赤峰地区阳性率为3.13%(17/543);鄂尔多斯地区阳性率为30%(21/70),Blast比对分析结果显示与绵羊无形体同源性高达99%以上。系统发育进化树和同源性比对分析结果显示内蒙古地区16S rRNA基因的序列与新疆绵羊无形体xjmns03(JN400674)同源性最高,为99.49%;groEL基因序列与苏丹青尼罗州绵羊无形体G-BN-40(MG383903)同源性最高,为98.77%;MSP4基因序列与与陕西绵羊无形体D/SX786(MN307493)同源性最高,为100.00%。结论 内蒙古地区存在蜱传绵羊无形体,鄂尔多斯地区阳性率最高,为避免蜱传疾病对动物及人类健康造成危害,应重点对鄂尔多斯地区进行科学防控。     

A survey of ticks on farm animals in Libya.

Thirteen species of ixodid ticks and two species of argasid ticks were collected during a three-year survey of 58 farms in Libya. These included Boophilus annulatus, B. microplus, B. decoloratus, seven species of Hyalomma, Rhipicephalus sanguineus, Rh. evertsi, Rh. bursa, Argas persicus and Ornithodoros foleyi. This is the first recording of B. microplus, B. decoloratus and Rh. bursa in Libya. Of 20,391 animals examined by random sampling, 2020 (9.6%) had ticks; particularly common were Hy. dromedarii on camels, Hy. impeltatum on sheep and Hy. excavatum on cattle. The tick found most frequently overall was Hy. dromedarii.     

A hard tick relapsing fever group spirochete in a Brazilian Rhipicephalus (Boophilus) microplus

Tick-borne diseases usually comprise a complex epidemiological and ecological network connecting the vector, pathogen, and a group of host species. Symptoms associated with Lyme disease have been reported in Brazil, but no Borrelia sp. has been definitively related to these events. Here we have identified a B. lonestari/B. theileri-related spirochete DNA in the cattle tick Rhipicephalus (Boophilus) microplus from Brazil. Four hundred R. microplus and 80 Amblyomma cajennense ticks were screened, and only 1 horse-fed R. microplus was infected. A Borrelia sp. 16S rDNA sequence was amplified by polymerase chain reaction (PCR) from the total tick DNA with 99% similarity to B. theileri and B. lonestari. Partial flaB sequence was also obtained, demonstrating 96% similarity to the B. lonestari flagellin gene, and the resultant putative amino acid sequence demonstrated 97% identity to B. lonestari flagellin. Moreover, partial glpQ sequence demonstrated 92% similarity to the B. lonestari gene, with a putative amino acid sequence 90% identical to the B. lonestari glycerophosphodiester phosphodiesterase. Phylogenetic analyses clearly include this Brazilian Borrelia sp., denoted "Borrelia," sp-BR in a group of spirochetes aligned with B. theileri and B. lonestari. Thus, hard tick relapsing fever group spirochetes represent a clade of widespread bacteria and herein we describe the first molecular identification of a Borrelia sp. in South America.     

Identification of Ehrlichia chaffeensis,Anaplasma phagocytophilum,and A. bovis in Haemaphysalis longicornis and Ixodes persulcatus ticks from Korea

A total of 1,467 tick (1,463 of Haemaphysalis longicornis, three of Ixodes persulcatus and one of I. turdus) collected from nine provinces of Korea were examined by TaqMan real-time PCR for the presence of Ehrlichia and Anaplasma species. One set of primers and a probe were designed for detection of all of the Ehrlichia and Anaplasma species. Template DNAs (total 803) were prepared either from pools of larvae, nymphs, adult males and females, or from the salivary gland and midgut of adult ticks. Only DNAs positive in TaqMan PCR were examined for A. phagocytophilum with nested PCR and for E. chaffeensis with PCR. Four A. phagocytophilum 16S rRNA gene PCR products were sequenced for comparison with sequences previously reported. Amplification of a 16S rRNA gene fragment of Ehrlichia and Anaplasma species was observed in 364 tick DNAs (45.3% of the total). Of these 364 positive ticks, species-specific PCRs confirmed that 35 H. longicornis and one I. persulcatus were positive for A. phagocytophilum and one I. persulcatus was positive in E. chaffeensis. Except for one (AB-GGHL, GenBank accession number [GAN] AF470698), three of the four 16S rRNA gene fragment sequences of the A. phagocytophilum-positive samples were similar or identical to the sequences of variants of A. phagocytophilum deposited in GenBank. The 16S rRNA gene fragment sequence of AB-GGHL was similar to that of Anaplasma (Ehrlichia) bovis 16S rRNA (GAN U03775). The identities of the Anaplasmataceae genus and species DNA in the 327 ticks that could not be confirmed infected with either E. chaffeensis, A. phagocytophilum, or A. bovis are not known. This study is the first to demonstrate the presence of E. chaffeensis, A. phagocytophilum and A. bovis in Korean ticks.     

Ixodid ticks on domestic animals in Samut Prakan Province,Thailand

The prevalence of tick-harboring domestic animals, tick density, and the species of ticks were studied throughout the year 2000, in Muang Samut Prakan, Bang Phli and Phra Pradaeng districts of Samut Prakan Province. The animals examined were Canis lupus familiaris (450), Bos indicus (cross-bred) (189), Bos taurus (30), Bubalus bubalis (171) and Sus scrofa domestica (450). The total number of collected ticks was 1,491. The pigs did not harbor ticks. The stages of ticks collected were larvae, nymphs and adults. The prevalence rates of tick-harboring were 46% (Canis lupus familiaris), 42.86% (Bos indicus, cross-bred), 33.33% (Bos taurus) and 9.35% (Bubalus bubalis). The tick densities were 2.22 (Bos indicus, cross-bred), 2.16 (Canis lupus familiaris), 1.16 (Bos taurus) and 0.36 (Bubalus bubalis). Only 2 species of ixodid ticks, Boophilus microplus and Rhipicephalus sanguineus, were found. R. sanguineus was the dominant species of tick. The percentage of R. sanguineus was 65.2% and B. microplus was 34.8%. In Muang district, R. sanguineus was the dominant species in C. lupus familiaris; in Bang Phli district, B. microplus was the dominant species in Bos indicus (cross-bred). The density of B. microplus was high in the summer season; the density of R. sanguineus was high in the winter season. The number of ticks depended on the geographic location, animal host and season.     

Immunologic relations between cattle and ticks, specifically between cattle and Boophilus microplus]

In the present investigation, it has been demonstrated that cattle become resistant to ticks after several heavy infestations, particularly with B. microplus. During development of the infestations, antibodies against salivary glands of B. microplus were detected using 2 techniques: indirect immunofluorescence and immunoelectrophoresis. There is a positive causal relationship between antibody titer and resistance development. Two precipitating systems against B. microplus in infested cattle and 7 systems in immunized rabbits were studied. The systems 1 and 2 are similar in cattle and rabbits, but system 2 does not show any specificity, as it has been detected in cattle completely lacking tick infestations. Two one-day calves were treated with the antigen of B. microplus by injection of salivary glands and repeated infestations with a small number of larvae. They developed a pronounced resistance to the usual subsequent infestations by the ticks of the same species. Specific antibodies were found before the first usual infestation. This suggests that they might be responsible for resistance.     

Crimean-Congo hemorrhagic fever virus in ticks collected from humans, livestock, and picnic sites in the hyperendemic region of Turkey

During June and July 2007, about 3125 adult ticks were collected from humans, animals, and vegetation in a hyperendemic region (Sivas and Tokat) of Turkey. A total of 2193 ticks were pooled in 225 pools and screened for the Crimean Congo hemorrhagic fever virus (CCHFV) presence by antigen-capture enzyme-linked immunosorbent assay. Infection rates were calculated as the maximum likelihood estimation with 95% confidence intervals (CI). The dominant tick species was found to be Hyalomma marginatum with the following infestation rates in human, cattle and sheep, respectively: 47.43%, 66.07%, and 30.12%. Maximum likelihood estimation values of CCHFV in H. marginatum ticks collected from human, cattle, and sheep were 0.91% (CI 0.05-4.42), 2.10% (CI 1.12-3.64), and 3.11% (CI 1.18-6.87), respectively. CCHFV antigens were also demonstrated in Hyalomma excavatum, Haemaphysalis parva, and Boophilus annulatus ticks collected from cattle and Rhipicephalus bursa ticks from sheep. Our results suggest that the studied area might maintain its endemic properties in the near future unless effective tick control measures are implemented.     

Anaplasma phagocytophilum infection in domestic animals in ten provinces/cities of China

A nationwide epidemiologic investigation of domestic animal infections has been conducted in nine provinces and one city during 2007-2010. Serum samples from a total of 707 goats, 433 cattle, and 219 dogs were collected for detecting Anaplasma phagocytophilum IgG antibody by immunofluorescence assays and the average seroprevalences were 10.05% for dogs, 3.82% for goats, and 0.69% for cattle, respectively. A total of 472 goats, 201 cattle, 102 dog blood clots, and 1,580 ticks were collected for polymerase chain reaction (PCR) amplifying A. phagocytophilum 16S rRNA genes and the PCR-positive rates were 26.69% for goats, 23.38% for cattle, and 10.89% for dogs. Six species were identified and the average PCR-positive rates were 58.3% for Dermacentor silvarum, 43.9% for Haemaphysalis longicornis, 12.5% for Ixodes persulcatus, 7.5% (3 of 40) for Boophilus microplus, and 5.2% for Rhipicephalus sanguineus, respectively. The evidence in the study indicated the zoonotic Rickettsia is highly prevalent in China.