Identification of newly isolated Babesia parasites from cattle in Korea by using the Bo-RBC-SCID mice

Attempts were made to isolate and identify Korean bovine Babesia parasite. Blood samples were collected from Holstein cows in Korea, and Babesia parasites were propagated in SCID mice with circulating bovine red blood cells for isolation. The isolate was then antigenically and genotypically compared with several Japanese isolates. The Korean parasite was found to be nearly identical to the Oshima strain isolated from Japanese cattle, which was recently designated as Babesia ovata oshimensis n. var. Haemaphysalis longicornis was the most probable tick species that transmitted the parasite.     

Cloning and characterization of a ribosomal protein L23a from Haemaphysalis qinghaiensis eggs by immuno screening of a cDNA expression library

A primary cDNA library with a size of 1.34 × 10⁶ PFU was constructed from Haemaphysalis qinghaiensis eggs and was immunoscreened with rabbit anti-H. qinghaiensis serum. One clone (Hq22, named following those clones obtained from adult Haemaphysalis qinghaiensis cDNA library which we constructed before) screened from the cDNA library was selected randomly for sequencing. The entire sequence of the clone was subsequently obtained using rapid amplification of the cDNA ends (RACE). A search of the cloned sequence against GenBank revealed that it related to ribosomal protein L23a (Rpl23a) and had a high percentage similarity to this protein from different species. Conserved domains for Rpl23a were also identified in the cloned sequence. Expression analysis by RT-PCR showed that this gene is expressed in salivary glands, midguts, other tissues and different developmental stages of H. qinghaiensis. Based on the H. qinghaiensis Rpl23a sequence, open reading frames (ORF) of Rpl23a of Heamaphysalis longicornis and Boophilus microplus were also cloned and were performed for comparison with Rpl23a of H. qinghaiensis and other organisms as well. Vaccine based on Rpl23a recombinant protein cannot protect sheep against H. qinghaiensis.     

Influence of biotope on the distribution and peak activity of questing ixodid ticks in Hungary

Abstract In order to update the occurrence of hard tick species in Hungary, 3442 questing ticks were collected from the vegetation by the dragging/flagging method in 37 different places in the country, between March and June of 2007. Ixodes ricinus (L.) turned out to be ubiquitous. Dermacentor marginatus (Schulzer) was absent from sampling sites in the southwestern part of the country, but in most places was concomitant and contemporaneous with Dermacentor reticulatus (Fabricius). These two species, as well as I. ricinus, occurred up to an altitude of 900–1000 m a.s.l. Haemaphysalis inermis (Birula) and Haemaphysalis concinna (Koch) were not confined to any parts of the country, unlike Haemaphysalis punctata (Canestrini & Fanzago) which was found in only one region. The local prevalence of the latter species was also significantly lower than those of the former two in the same habitat (fringes of meadows, paths in forests). Dermacentor spp. and H. inermis were represented only by adults. In most species females were collected more frequently than males, except in H. concinna and H. punctata. Temporal differences between the peak activity of I. ricinus and Dermacentor spp. on dry pastures appeared to equalize on meadows in mountain forests, and a similar phenomenon was observed for the three Haemaphysalis spp. when collected along forest paths with fresh, green vegetation.     

Hyalomma aegyptium as dominant tick in tortoises of the genus Testudo in Balkan countries, with notes on its host preferences

Collection of 1327 ticks sampled throughout Greece, Bulgaria, Romania and Croatia, from 211 tortoises belonging to three species, Testudo marginata Schoepff, T. graeca Linnaeus, and T. hermanni Gmelin, revealed the presence of four species of ixodid ticks, namely Hyalomma aegyptium (Linnaeus), Haemaphysalis sulcata Canestrini and Fanzago, H. inermis Birula and Rhipicephalus sanguineus (Latreille). Study confirmed the strong dominance of all life stages of H. aegyptium among ticks parasitizing west Palaearctic tortoises of genus Testudo Linnaeus. Furthermore, a considerable portion of ticks collected from tortoises in southwestern Bulgaria represent larvae and nymphs of H. sulcata. At the same area we collected as exception one larva and one nymph of H. inermis from a single specimen of T. hermanni. Our findings of four adults of R. sanguineus is the first record of this species from reptilian host. According to our results achieved on localities with syntopic occurrence of two tortoise species, T. marginata and T. graeca represent in the Balkans the principal hosts of H. aegyptium, whereas T. hermanni serves only as an alternative host in the areas close to range of either T. marginata or T. graeca.     

昆虫病原线虫斯氏线虫和异小杆线虫对长角血蜱雌蜱的致病力

用昆虫病原线虫小卷蛾斯氏线虫（Sc BJ）、夜蛾斯氏线虫（Sf Otio）、拟双角斯氏线虫（Sc D43）、格氏斯氏线虫（Sg NC32）和嗜菌异小杆线虫（Hb E-6-7）对长角血蜱雌蜱进行感染试验,所用线虫剂量为4 000 Ijs/dish。结果表明,5种线虫均对长角血蜱雌蜱有致死效应。Hb E-6-7和Sc BJ两种线虫对雌蜱各发育期致病力最强,导致雌蜱的累积死亡率和半致死时间分别为饥饿雌蜱82.5%,9.0天和75.0%,8.8天;吸血雌蜱90.0%,8.0天和82.5%,8.0天;饱血雌蜱93.3%,7.3天和86.7%,7.3天。Sc D43对饱血雌蜱有较高的致死效应,为80.0%,但半致死时间较长,为11.7天。Sf Otio和Sg NC32对长角血蜱雌蜱的致死效应较低。饱血雌蜱较饥饿雌蜱和吸血雌蜱更易被线虫感染。     

QUANTITATIVE VARIATION OF ECDYSTEROIDS OF IXODID TICKS

Abstract  In order to explore the role of ecdysteroids in development and reproduction of ixodid ticks, we studied the quantitative variation of ecdysteroids in the hemolymph, synganglion, ovary and whole body of the female ixodid ticks, Dermacentor niveus and Haemaphysalis longicornis , before and after engorgement and oviposition by HPLC and RIA. The ecdysteroid content in eggs of these ticks was determined by HPLC. The results indicated that before engorgement the quantitative variation of ecdysteroids in the whole female body was not significant, but their levels increased rapidly after engorgement. The ecdysteroid titer in hemolymph was peaked on the 5th day after engorgement, which was one day prior to oviposition. It may be regarded as a singnal of oviposition. In the synganglion the peak of ecdysteroid level occurred also on the 5th day after engorgement. This is coincident with the secretory activity of neurosecretory cells of synganglion. From the 3rd day after engorgement until oviposition the ecdysteroid level in the ovary increased rapidly. Ecdysteroids were detected in eggs of H. longicornis too. They stem from ovary and accumulated with the process of embryonic development.     

Resistance in cattle to Haemaphysalis (Kaiseriana) longicornis

Samples of each instar of the 3-host tick, Haemaphysalis (Kaiseriana) longicornis were collected from grazing Bos taurus cattle to investigate their survival on hosts with previous exposure to the tick and on previously unexposed ‘naive’ hosts. The ticks were allocated to categories based on their size to observe at what stage of development mortality occurred. Analysis of the age structure of the ticks showed that small but variable proportions of larvae, nymphs and females matured on previously exposed hosts and larger proportions on the naive hosts. This suggests that cattle acquire and express different levels of resistance against each instar of the tick. The technique used has potential for estimating levels of resistance of hosts to 3-host ticks under field conditions.     

长角血蜱卵泡抑素相关蛋白的定性

参照GenBank中长角血蜱致病性Okayama株卵泡抑素基因的核苷酸序列(GenBank Accession No.DQ248886)设计合成一对引物,从本实验室保藏的单克隆洁净长角血蜱饥饿成蜱中快速提取总RNA,通过RT-PCR扩增出814bp的卵泡抑素基因,序列比对结果显示:与长角血蜱致病性Okayama株的核苷酸序列及氨基酸序列一致性分别为97.8%和99%,将其亚克隆到表达载体pGEX-4T-1中进行表达,GST融合重组蛋白预期分子量为57kD。表达重组蛋白经MagneGSTTM蛋白纯化系统纯化后作为抗原分别与抗不同发育阶段长角血蜱(卵、幼蜱、若蜱、成蜱)多克隆抗体作为一抗进行免疫印迹,结果表明:与长角血蜱卵制备的多克隆抗体有很强的免疫反应,而与其他发育阶段(幼蜱、若蜱、成蜱)饥饿长角血蜱制备的多克隆抗体反应性很弱。以上结果表明:长角血蜱卵泡抑素蛋白在长角血蜱产卵及卵成熟发育时期的表达水平较其他发育阶段(幼蜱、若蜱、成蜱)的蛋白表达水平高。