内蒙古包头市牛场寄生蜱的调查

蜱类刺吸家畜的血液,除了传播多种病原体外,还会引起牛的产奶量、产肉量下降。调查内蒙古包头地区17家牛场蜱虫的感染情况、蜱虫染蜱率、染蜱指数、体表寄生蜱的分布及蜱的季节消长规律,结果显示包头地区牛场蜱虫感染率偏低,仅有1家肉牛场有微小牛蜱感染。肉牛体表寄生此蜱主要集中在腹部鬃毛密集处,颈部肉垂处,次为两前腿和两后腿区间,占总数的85%以上。该蜱活动时间4~11月,高峰期是5月上旬、8月上旬和9月下旬。并针对蜱虫成虫活动高峰时间应采取防治措施,用1%敌百虫溶液、0.02%蜱虱敌溶液对牛体表及畜舍寄生的蜱进行喷洒杀灭,两种药物均可有效地杀灭微小牛蜱,动物健康也未见异常,可用于包头地区动物体表及圈舍蜱的杀灭药物。     

南宁某警犬基地蜱虫及病原体感染调查

目的了解广西南宁某警犬养殖训练基地蜱虫及病原体携带情况。方法 2013年7月在广西南宁某警犬养殖训练基地,采用逆毛式检蜱法采集犬体表以及犬舍墙壁的蜱虫,用巴贝虫属18S rRNA通用引物的巢式PCR、原核生物16S rRNA及真核生物线粒体16S rRNA通用引物的PCR和序列测定方法,鉴定蜱虫体内的病原体感染情况和蜱虫种类。结果从警犬体表及犬舍墙壁共计采集5只饱血蜱和13只饥饿蜱;经PCR鉴定均为血红扇头蜱(Rhipicephalus sanguineus)。蜱虫体内扩增到田鼠巴贝虫(Babesia microti)、伯纳特氏立克次氏体(Coxiella burnetii)、假单胞球菌(Pseudomonas sp.)、甲基杆菌(Methylobacterium sp.)DNA序列,阳性率分别为27.8%(5/18)、22.2%(4/18)、11.1%(2/18)、11.1%(2/18)。结论南宁某警犬养殖训练基地蜱虫存在一定比例的田鼠巴贝虫、伯纳特氏立克次氏体、假单胞球菌、甲基杆菌感染阳性率,对接触人员、及其他牲畜有潜在感染的风险,应加强预防和控制。     

Efficacy of Rhipicephalus (Boophilus) microplus Bm86 against Hyalomma dromedarii and Amblyomma cajennense tick infestations in camels and cattle

The recombinant Bm86-based tick vaccines have shown their efficacy for the control of cattle ticks, Rhipicephalus (Boophilus) microplus and R. annulatus infestations. However, cattle ticks often co-exist with multi-host ticks such as Hyalomma and Amblyomma species, thus requiring the control of multiple tick infestations for cattle and other hosts. Vaccination trials using a R. microplus recombinant Bm86-based vaccine were conducted in cattle and camels against Hyalomma dromedarii and in cattle against Amblyomma cajennense immature and adult ticks. The results showed an 89% reduction in the number of H. dromedarii nymphs engorging on vaccinated cattle, and a further 32% reduction in the weight of the surviving adult ticks. In vaccinated camels, a reduction of 27% and 31% of tick engorgement and egg mass weight, respectively was shown, while egg hatching was reduced by 39%. However, cattle vaccination with Bm86 did not have an effect on A. cajennense tick infestations. These results showed that Bm86 vaccines are effective against R. microplus and other tick species but improved vaccines containing new antigens are required to control multiple tick infestations.     

Immune responses of cattle to biochemically modified antigens from the midgut of the cattle tick, Boophilus microplus

Treatment of membrane antigens of the midgut (GM) of the cattle tick, Boophilus microplus with sodium metaperiodate (periodate), pronase and lipase significantly inhibited the reactivity of the GM with antibodies in the sera of 57 cattle vaccinated with GM. Treatment of GM with periodate only removed the correlation between antibody reactivity of sera and protection against infestation with ticks. A monoclonal antibody (MoAb QU13), which recognises protective antigens solubilized from GM (Lee + Opdebeeck 1991), did not react with GM treated with periodate. Cattle vaccinated with GM extracts were significantly protected against infestation with cattle ticks (P less than 0.05), whereas cattle vaccinated with either GM extracts treated with periodate or with antigens precipitated from GM extracts with MoAb QU13 and also treated with periodate, were not protected against infestation. These studies provide preliminary evidence that protective antigens in the tick midgut membrane either are carbohydrate or are dependent on carbohydrate for their specificity.     

长角血蜱和微小扇头蜱的形态与分子生物学鉴定

目的 建立鉴定长角血蜱和微小扇头蜱的形态学和分子生物学相结合的方法.方法 采集自湖北和河南省布尼亚新病毒疫区家养动物体表寄生的蜱及草丛、灌木中的蜱;先以形态学鉴定,后用PCR方法扩增得到蜱的12S rDNA,测序后进行同源性和系统进化分析.结果 形态学方法鉴定采集到两种蜱:长角血蜱(Haemaphysalis longicornis)和微小扇头蜱(Rhipicephalus microplus).蜱的12S rDNA经克隆、测序,用PAUP 4.0软件构建系统发生树,湖北、河南省两种蜱的12S rDNA序列分别与长角血蜱和微小扇头蜱聚类,与形态学鉴定结果一致.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.

Abstract：

Objective To establish a method combined morphology and molecular marker for identifying Haemaphysalis longicomis and Rhipicephalus microplus. Methods Ticks were collected from domestic animals and wild environment in epidemic area of Hubei and Henan provinces where cases of fever with thrombocytopenia syndrome were prevalent. We classified the ticks by morphology characteristics before 12S rDNA of ticks were amplified by PCR and subsequently sequenced. Phylogenetic tree was constructed by PAUP4.0. Results The ticks belonged to Haemaphysalis longicomis and Rhipicephalus microplus through observation and analysed by the morphological characteristics of the ticks. 12S rDNA was cloned and sequenced while data confirmed the morphological identification of the results. Conclusion The method based on morphology that combined with molecular marker seemed a good method for the identificaton of ticks.     

In-Vitro Assessment of the Acaricidal Properties of Artemisia annua and Zataria multiflora Essential Oils to Control Cattle Ticks

Background

The aim of this study was to investigate the ‘acaricidal effect’ of Zataria multiflora and Artemisia annua essential oils on Rhipicephalus (Boophilus) annulatus.

Methods

This study was carried out in 2009 in the Laboratory of Parasitology of the Faculty of Veterinary Medicine of Shahrekord University, west central Iran. Six dilutions (5, 10, 20, 40, 60 and 80 µL/cm³) of both essential oils were used against engorged female R. (Boophilus) annulatus ticks using an in vitro immersion method. The mortality rates for each treatment were recorded 6, 15 and 24 hours post inoculation (hpi). Mortality rate was analyzed using Repeated Measures Analysis of Variance, and comparison of means was carried out using General Linear Models Procedure.

Results

The mortality rate caused by different dilutions of Z. multiflora essential oil ranged from 26.6% (using 10 µL/cm³) to 100% (using 40 µL/cm³) and for A. annua essential oil it was 33.2 to 100% (using 20 and 80 µL/cm³, respectively) by the end of the experiment (36 hpi). No mortality was recorded for the non-treated control group or for dilutions less than 5 and 10 µL/cm³ using Zataria and Artemisia essential oils, respectively. For Z. multiflora mortality peaked at 15 hpi for all concentrations other than 20 µL/cm³ and took 24 h to achieve its maximum effect while for A. annua the two highest concentrations needed 24 hpi to reach their full effect. In addition, essential oils applied at more than 20 and 60 µL/cm³ caused 100% egg-laying failure in engorged female ticks by Zataria and Artemisia, respectively while no failure was observed for the non-treated control group. The mortality rate in both botanical acaricides was dose-dependent.

Conclusion

Both these medicinal plants have high potential acaricidal effects on the engorged stage of R. (Boophilus) annulatus in vitro.     

Cell Death in Salivary Glands of Rhipicephalus (Boophilus) microplus (Canestrini, 1887) (Acari: Ixodidae) Females at Semi-engorged Feeding Stage

The ultrastructure of the salivary glands of Rhipicephalus (Boophilus) microplus females is described during feeding. In beginning of feeding, individuals show acini I with many mitochondria and wide basal labyrinth in peripheral cells; glycoprotein granules only in b and c₃ cells (acini II); and epithelial interstitial cells with developed basal labyrinth between f cells (acini III). Semi-engorged females show cells in degeneration, with autophagic vacuoles, lysosomes, myelin figures, and irregular, condensed, and/or fragmented nuclei, in addition to apoptotic bodies. R. B. microplus points to apoptosis in these organs before the detachment from the host, in contrast to others tick species.     

Action of the chemical agent fipronil on the reproductive process of semi-engorged females of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae). Ultrastructural evaluation of ovary cells

The ovary of the tick Rhipicephalus sanguineus consists of a wall of epithelial cells and a large number of oocytes in five different developmental stages (I–V), which are attached to the wall by a pedicel. The present study provides ultrastructural information on the effects (dose–response) of the acaricide fipronil (Frontline^®) on ovaries of semi-engorged females of R. sanguineus, as well as it demonstrates some possible defense mechanisms used by oocytes to protect themselves against this chemical agent. Individuals were divided into four groups. Group I was used as control while groups II, III and IV were treated with fipronil at the concentrations of 1, 5 and 10 ppm, respectively. Fipronil at the concentration of 10 ppm had the strongest effect on the development of oocytes. At this concentration, even oocytes that reached the final developmental stage exhibited damaged cell structures. Moreover, the observation in fipronil-treated R. sanguineus ticks of damaged cellular components such as plasmic membrane, mitochondria and protein granules (due to alteration in the protein synthesis), and cellular defense mechanisms such as increase in the amount of cytoplasmic microtubules and large amounts of digestive vacuoles and myelin figures, were only possible by means of ultrastructure.     

Evaluation of cytotoxic effects of fipronil on ovaries of semi-engorged Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) tick female

The ovary of the Rhipicephalus sanguineus dog tick female is structurally formed by oocytes in five different stages of development (from I to V) and attached to the gonad by the pedicel. The present study evaluated possible toxic effects of the acaricide fipronil (Frontline) on ovaries of semi-engorged ticks. Sixty partially fed females of R. sanguineus tick were distributed into four groups of 15 specimens each: I--non-treated; II, III and IV--treated with 1, 5 and 10 ppm of fipronil, respectively. The acaricide induced structural changes in the oocytes of individuals of the different treated groups ranging from the presence of a few small vacuoles to cellular death. In conclusion, germinative cells of semi-engorged R. sanguineus tick female are affected by different concentrations of fipronil leading to the reduction of tick fertility.     

Severe Fever with Thrombocytopenia Syndrome Virus in Ticks Collected from Humans,South Korea, 2013

We investigated the infection rate for severe fever with thrombocytopenia syndrome virus (SFTSV) among ticks collected from humans during May–October 2013 in South Korea. Haemaphysalis longicornis ticks have been considered the SFTSV vector. However, we detected the virus in H. longicornis, Amblyomma testudinarium, and Ixodes nipponensis ticks, indicating additional potential SFTSV vectors.