塔里木盆地三种扇头蜱的鉴别要点

目的 澄清三种扇头蜱的存在,列出3种扇头蜱的鉴别要点.方法 从不同自然景观和家、野生动物体上采集蜱类进行分类鉴定.结果 共获得蜱类18 000余只.经鉴定隶属2科5属10种.结论 其中优势蜱种为璃眼蜱属Hyalomma中的种类.其次是扇头蜱属Rhipicephalus、革蜱属Dermacentor、血蜱属Haemaphysalis和钝缘蜱属Ornithodoros的种类.     

Detection of Bm86 antigen in different strains of Boophilus microplus and effectiveness of immunization with recombinant Bm86

The control of tick populations by using conventional strategies poses several problems, including the appearance of organophosphate resistant strains, among others. The possibility of using alternative strategies such as vaccination with tick antigens has been suggested by several authors. One particular antigen (Bm86) has been described and shown to be able to induce a protective immunity against the cattle tick Boophilus microplus. In this paper we demonstrate by means of immunohistochemical staining that this antigen is conserved among several strains of this species. These results correlate with those showing that animals vaccinated with a preparation of recombinant Bm86 were protected against challenge with the four different strains tested, including one resistant to organophosphates. These results favour the immunization with recombinant Bm86 for the control of the cattle tick B. microplus.     

Frequency and Distribution of Rickettsiae,Borreliae, and Ehrlichiae Detected in Human-Parasitizing Ticks,Texas, USA

To describe the presence and distribution of tickborne bacteria and their vectors in Texas, USA, we screened ticks collected from humans during 2008–2014 for Rickettsia, Borrelia, and Ehrlichia spp. Thirteen tick species were identified, and 23% of ticks carried bacterial DNA from at least 1 of the 3 genera tested.     

Permethrin-induced morphological changes in oocytes of Rhipicephalus sanguineus (Acari: Ixodidae) semi-engorged females

The permethrin, active ingredient of the Advantage® Max3 – Bayer, has been widely used in the chemical control of ticks. These ectoparasites are one of the most important animal groups that cause serious damage to their hosts. This study evaluated the toxic effects of permethrin in oocytes of Rhipicephalus sanguineus semi-engorged females subjected to four treatments: group I (control – distilled water), group II (206 ppm of permethrin), group III (1031 ppm of permethrin) and group IV (2062 ppm of permethrin). Results demonstrated that permethrin is a potent chemical agent causing major structural changes in oocytes, such as emergence of large vacuolated cytoplasm regions, reducing the amount of yolk granules and decreasing the size of oocytes, culminating with cell death. As reported in the literature, these oocytes changes, besides affect the tick nervous system, also drastically reduce or prevent the reproduction process in females of R. sanguineus ticks subjected to this compound.     

A Potential Role for Ixodid (Hard) Tick Vectors in the Transmission of Lumpy Skin Disease Virus in Cattle

Lumpy skin disease (LSD) is an economically important cattle disease. The disease is endemic in many African countries, but outbreaks have also been reported in Madagascar and the Middle East. The aim of this study was to investigate the potential role of ixodid (hard) ticks in the transmission of the disease. Cattle were infected with a virulent, South African field isolate of lumpy skin disease virus (LSDV). Three common African tick species (genera Rhipicephalus, Amblyomma and Rhipicephalus (Boophilus)) in different life cycle stages were fed on the infected animals during the viraemic stage and on skin lesions. Post‐feeding, the partially fed male ticks were transferred to the skin of non‐infected ‘recipient’ animals, while females were allowed to lay eggs that were then tested using the polymerase chain reaction (PCR) method and virus isolation. Nymphs were allowed to develop for 2–3 weeks after which time they were tested. The non‐infected ‘recipient’ cattle were closely monitored, both skin and blood samples were tested using PCR and virus isolation, and serum samples were tested by the serum neutralization test. This is the first report showing molecular evidence of potential transmission of LSDV by ixodid ticks. The study showed evidence of transstadial and transovarial transmission of LSDV by R. (B.) decoloratus ticks and mechanical or intrastadial transmission by R. appendiculatus and A. hebraeum ticks.     

PARTICIPATION OF TICKS IN THE INFECTIOUS CYCLE OF CANINE VISCERAL LEISHMANIASIS,IN TERESINA,PIAUí, BRAZIL

In this study, we detected Leishmania spp. infection in R. sanguineus collected from dogs that were naturally infected with L. (L.) infantum. We examined 35 dogs of both sexes and unknown ages. The infected dogs were serologically positive by the immunofluorescence antibody test (IFAT), enzyme-linked immunosorbent assay (ELISA), and Quick Test-DPP (Dual Path Platform), as well as parasitological examination of a positive skin biopsy or sternal bone marrow aspiration. Ten negative dogs were included as controls. The ticks that infested these dogs were collected in pools of 10 adult females per animal. The PCR was performed with specific primers for Leishmania spp., which amplified a 720-bp fragment. Of the 35 analyzed samples, a product was observed in eight samples (8/35; 22.9%). We conclude that the presence of parasite DNA suggests that ticks participate in the zoonotic cycle of canine visceral leishmaniasis, in the city of Teresina, Piauí.     

Efficacy of Hyalomma scupense (Hd86) antigen against Hyalomma excavatum and H. scupense tick infestations in cattle

The Rhipicephalus microplus recombinant Bm86-based tick vaccines have shown their efficacy for the control of several Hyalomma cattle ticks genera, namely H. dromedarii and H. anatolicum. However, H. scupense species, the most important tick in North Africa has never been studied. Vaccination trials using either a recombinant Bm86-based vaccine or a recombinant Hd86-based vaccine (the Bm86 ortholog in H. scupense) were conducted in cattle against immature and adult H. scupense ticks and adult H. excavatum ticks. The results showed a 59.19% reduction in the number of scupense nymphs engorging on Hd86 vaccinated cattle. However, cattle vaccination with Bm86 or Hd86 did not have an effect on H. scupense or H. excavatum adult ticks infestations. These results showed that Hd86 vaccines are selectively effective against H. scupense immature instars and emphasize on an integrated anti-tick vaccine control in North Africa.