内蒙阿盟斑点热群立克次体Ha—91株的分离与鉴定

我们于1991年从内蒙阿盟亚东璃眼蜱分离到一株斑点热群(SFG)立克次体,命名为Ha-91株。免疫荧光法及蛋白免疫印迹分析表明Ha-91株立克次体与西伯利亚立克次体抗原性相近,但不完全相同;明显不同于其它种班点热群立克次体。这是首次证实亚东璃眼蜱为SFG立克次体的贮存宿主,也是首次从内蒙发现抗原性与西伯利亚立克次体不完全相同的SFG立克次体。     

中哈边境阿拉山口口岸亚洲璃眼蜱首次检测到Q热立克次体核酸

目的 对新疆阿拉山口口岸地区蜱类进行Q热立克次体核酸检测。方法 采集蜱样本并进行形态学和分子生物学鉴定。聚合酶链反应扩增Q热com1基因,通过Blast软件比对分析测序产物,利用Mega 6.0软件构建分子遗传进化树。结果 共采集253只蜱,其中优势蜱种为亚洲璃眼蜱,蜱类的形态学鉴定与分子生物学鉴定结果一致。阿拉山口口岸地区蜱携带Q热立克次体核酸平均阳性率为16.21%（41/253）,亚洲璃眼蜱阳性率为22.65%（41/181）,血红扇头蜱、短垫血蜱和边缘革蜱均为阴性,亚洲璃眼蜱显著高于其他蜱种。序列分析显示与Coxiella burnetii Cb175_Guyana（HG825990,圭亚那）进化关系较近,核苷酸同源性为99%。结论 阿拉山口口岸地区亚洲璃眼蜱在16S rRNA和COⅠ基因序列间存在多样性,并首次在中哈边境地区亚洲璃眼蜱中检测到Q热立克次体核酸。     

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.     

实验室条件下小亚璃眼蜱生活史观察

目的为深入研究蜱媒疾病提供充足、有效的实验材料,建立一套规范的实验室人工饲养繁殖蜱类的技术和方法。方法在实验室条件下,以新西兰白兔和绵羊为小亚璃眼蜱的供血动物,在温度28℃,相对湿度80％～85％的条件下,对该蜱的生活史周期及其生物学特性进行观察。结果小亚璃眼蜱饲喂在羊体上表现为三宿主型生活史周期,完成一个生活史周期需要84～159d（平均为121．5d）;而饲喂在兔体上表现为二宿主型生活史周期,完成一个生活史周期需要77～140d（平均为108．5d）。结论对蜱的生活周期与生活习性进行研究,是合理制订蜱及其传播疫病防治方案的重要依据,同时对实验室的活蜱保藏继代具有指导意义。     

新疆准噶尔盆地南缘地区新疆出血热病毒自然疫源地的发现

1990年4月下旬我们在准噶尔盆地古尔班通古特沙漠的南缘荒漠地区,从采集的亚洲璃眼蜱(Hyalomm asiaticum asiaticum)中分离到2株可引起乳鼠发病和在细胞培养中复制的病原。经血清学鉴定,包括交叉补体结合,间接免疫荧光和抗新疆出血热McAb(14B_7株)致敏血球的RPHA和RPHI试验证实为新疆出血热病毒。并采集了在荒漠牧场中放牧的羊群血清148份及放牧人员血清21份。用新疆出血热McAb RPHI法从羊血清中查到抗体阳性血清107份(72.3％)人群血清抗体阳性者2份(9.5％)。 上述结果首次证实了新疆北疆的准噶尔盆地南缘荒漠地带存在新疆出血热病毒的自然疫源地,该地区是北疆农牧业生产的主要地区和石油工业的新开发区,也是北疆主要的冬季牧场。     

Cloning, expression and immunoprotective efficacy of rHaa86, the homologue of the Bm86 tick vaccine antigen, from Hyalomma anatolicum anatolicum

The Bm86 homologue of Hyalomma anatolicum anatolicum Izatnagar isolate was cloned and expressed in methylotropic yeast Pichia pastoris as intracellular, glycosylated and particulated form. It was named as rHaa86, the first recombinant protein of H. a. anatolicum . Seven epidermal growth factor-like domains predicted in Haa86 were structurally similar with that of its Bm86 counterpart. The identity between the corresponding EGF like domains of Bm86 and Haa86 were ranging from 51·3% to 78·3%. The molecular weight of the rHaa86 was 120–140 kDa, with possible 50–70 kDa glycosylation. The purified rHaa86 was characterized immunologically and evaluated for its immunoprotective potential against homologous challenge infestation in three groups of cross-bred calves. The immediate rejection percentage of females of H. a. anatolicum was 36 5%, 12·4% and 10·1% fed on immunized (group 1), adjuvant control (group 2) and untreated control (group 3) calves, respectively. The percent rejection of female ticks fed on immunized calves was 24·1% and 26·4% higher than for the ticks fed on control groups 2 and 3, respectively ( P <  0·05). The reduction of number of females, mean weight of eggs, adult females and efficacy of immunogen were 58·0%, 9·0%, 5·0% and 61·6%, respectively. The mean reproductive index of females fed on group 1 calves was significantly lower ( P <  0·05) than the females fed on the control groups and 44% reduction in the number of engorged larvae was recorded from the group 1 calves. The data demonstrated that rHaa86 antigen based vaccine could serve as one of the effective components in the integrated control of H. a. anatolicum.     

Crimean congo hemorrhagic fever infection simulating thrombotic thrombocytopenic purpura

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease that may also be transmitted through person-to-person transmission by exposure to infected body fluids. Despite its wide geographic distribution in animals, CCHF virus is rarely associated with recognized human diseases. We report the first case of CCHF in Kermanshah province, Iran. Clinical presentation was characterized by fever, myalgia, and hemorrhage. The levels of liver enzymes, creatinine phosphokinase, and lactate dehydrogenase were elevated, and bleeding markers were prolonged.     

In vivo immunomodulatory effects of ixodid ticks on ovine circulating T- and B-lymphocytes

Selected aspects of the ovine immune system were examined during the course of repeated infestations with the ixodid ticks, Haemaphysalis bispinosa and Hyalomma anatolicum anatolicum that naturally infest sheep, either individually or together. By the use of flow cytometry it was shown that total T-lymphocyte numbers were significantly reduced from the sixth through the ninth days of all infestations. Gamma/delta (gammadelta+) and CD8+ T-lymphocytes were significantly depleted during tick feeding in all infested groups. CD4+ T-lymphocyte levels were significantly increased during secondary H. bispinosa and mixed species infestations. Hyalomma anatolicum anatolicum caused a significant increase in circulating B-lymphocytes over several days in both initial and secondary infestations. All infested sheep had increased CD4/CD8 and decreased T/B lymphocyte ratios during exposure to both ticks. Bromodeoxyuridine (BrdU) ELISA was used to measure in vitro proliferation of peripheral blood mononuclear cells stimulated with the T-lymphocyte mitogen Concanavalin A (Con A) after their collection from infested sheep. Significant suppression of in vitro proliferation occurred during first and secondary infestations with H. bispinosa, H. a. anatolicum and with both tick species together, beginning on the sixth day of infestation in all cases. These important tick species of sheep significantly modulate the numbers of immune effector cells and proliferation of T-lymphocytes derived from infested animals.