山羊捻转血矛线虫ITS基因序列分析

为了解不同年份山羊源捻转血矛线虫内转录间隔区(internal transcribed spacer,ITS)基因的遗传变异情况,提取2015年-2020年间陕西省咸阳地区44株山羊源捻转血矛线虫的核糖体DNA(rDNA),对其ITS基因进行扩增、测序与分析.结果显示,44株捻转血矛线虫的ITS-1序列长度为400 b...     

论捻转血矛线虫对山羊的危害及防治

捻转血矛线虫属直接发育型的寄生虫,不需要中间缩主,成虫排卵量大,严重污染草地和水源,因此山羊感染率高,影响山羊的生长发育,甚至引起成批死亡.应当引起养羊场和养羊专业户高度重视,采取积极地预防和治疗措施,控制该寄生虫病的发生.     

山羊捻转血矛线虫病的诊断与防制

山羊捻转血矛线虫病主要引起羊群持续消瘦、贫血,直至死亡.是当前养羊业面临的重要寄生虫病,造成危害很大.通过早发现、早治疗和定期驱虫等措施可有效防止该病的发生.     

山羊捻转血矛线虫病的诊治

山羊捻转血矛线虫病的诊治滕碧珠（广西兽医研究所５３０００１）近几年来，随着农村产业结构的调整，通过实践，部分山区贫困县的农民群众认识到发展山羊养殖，是一条脱贫致富的好途径。因此，群众养殖山羊的积极性进一步高涨，使广西的养羊业生产获得了大发展。在发展生...     

捻转血矛线虫冷冻保藏研究

用人工感染捻转血矛线虫单一种试验羊粪便培养收集感染性幼虫。经０．０６％和０．０８％次氯酸钠脱鞘，脱鞘率可达９０％以上，慢速致冷后幼虫的存活率为６４．５％。加入冷冻保护剂不能提高冷冻感染性幼虫的存活率。用正常的感染性幼虫感染试验羊后第１７ｄ即可查到虫卵，剖杀后成虫的回收率为２．６％，而相同数量的冷冻保藏的感染性幼虫感染后第２１ｄ才查到虫卵，成虫回收率为０．８％。表明冷冻保藏后的感染性幼虫发育受阻，成     

怀化三县山羊捻转血矛线虫感染情况调查

用剖检法对怀化溆浦、通道、会同三县的山羊捻转血矛线虫的感染情况进行了调查。结果显示,64头被检测的山羊中有42头被感染捻转血矛线虫,感染率为65.6%,其中溆浦县、会同县、通道县的山羊捻转血矛线虫感染率分别为56.5%、66.7%、75%。     

Effects of condensed tannins on goats experimentally infected with Haemonchus contortus

Although the use of tanniferous plants or condensed tannins as an alternative to anthelmintics to control gastrointestinal nematodes has been largely documented in sheep, studies remain scarce in goats. The objective of this study was therefore to assess the possible impact of condensed tannins in goats infected with adult Haemonchus contortus. Two groups of cull goats were experimentally infected with 10.000 L3 of H. contortus. After 4 weeks, quebracho extracts, representing 5% of the diet DM, were administered for 8 days to one of the two groups. Goats of the second group remained as controls. One week after the end of quebracho administration, the goats were euthanised. Individual egg excretion and pathophysiological parameters were measured weekly during the study. At the end of the study, worm counts were assessed and histological samples from the abomasa were taken to count the numbers of mucosal mast cells, globule leukocytes and eosinophils. The administration of tannins was associated with a significant decrease in egg excretion, which persisted until the end of experiment. This reduction was not associated with any difference in worm number but with a significant decrease in female fecundity. No significant changes in the mucosal density of the three inflammatory cell types were detected between the two groups. These results indicate that the major consequence of tannin consumption in goats is a reduction in worm fecundity and egg output, which does not seem related to significant changes in the local mucosal response.     

Cloning and characterization of a selenium-independent glutathione peroxidase (HC29) from adult Haemonchus contortus

The complete coding sequence of Haemonchus (H.) contortus HC29 cDNA was generated by rapid amplification of cDNA ends in combination with PCR using primers targeting the 5''- and 3''-ends of the partial mRNA sequence. The cloned HC29 cDNA was shown to be 1,113 bp in size with an open reading frame of 507 bp, encoding a protein of 168 amino acid with a calculated molecular mass of 18.9 kDa. Amino acid sequence analysis revealed that the cloned HC29 cDNA contained the conserved catalytic triad and dimer interface of selenium-independent glutathione peroxidase (GPX). Alignment of the predicted amino acid sequences demonstrated that the protein shared 44.7~80.4% similarity with GPX homologues in the thioredoxin-like family. Phylogenetic analysis revealed close evolutionary proximity of the GPX sequence to the counterpart sequences. These results suggest that HC29 cDNA is a GPX, a member of the thioredoxin-like family. Alignment of the nucleic acid and amino acid sequences of HC29 with those of the reported selenium-independent GPX of H. contortus showed that HC29 contained different types of spliced leader sequences as well as dimer interface sites, although the active sites of both were identical. Enzymatic analysis of recombinant prokaryotic HC29 protein showed activity for the hydrolysis of H₂O₂. These findings indicate that HC29 is a selenium-independent GPX of H. contortus.     

巨型艾美耳球虫抗原Em8对鸡外周血单核细胞功能的影响

探讨了巨型艾美耳球虫抗原Em8体外对鸡外周血单核细胞(PBMCs)功能的影响。选取抗原基因Em TFP250中具有较好免疫保护性的Em8基因片段,并对其进行原核表达纯化出重组蛋白。无菌采集未被鸡球虫感染的鸡的外周血,分离出单核细胞,加入终浓度为5μg/m L的Em8重组蛋白进行体外培养,通过免疫荧光抗体技术观察重组蛋白与单核细胞的结合情况;Em8重组蛋白不同浓度体外刺激鸡外周血单核细胞,用q PCR技术测定各实验组单核细胞中IL-4、IL-17D、IFN-γ、TGF-β4的mRNA转录水平;采用CCK-8法测定细胞的增殖情况;Em8重组蛋白不同浓度(低、中、高浓度)体外与巨噬细胞共培养,测定巨噬细胞吞噬和NO分泌功能。结果表明:重组蛋白Em8是巨型艾美耳球虫的重要抗原,发挥广泛而重要的免疫作用。其中,重组蛋白Em8能够与外周血单核细胞结合并能刺激细胞因子IL-17D和IFN-γ的表达水平显著提高(P0.01),能够引起单核细胞增值(P0.01),巨噬细胞吞噬作用增强(P0.01)且NO分泌增加(P0.01)。     

捻转血矛线虫重组H11抗原山羊免疫保护性试验

以重组H11-1、H11-2及H11-1与H11-2混合物分别免疫山羊后,ELISA检测发现血清抗体均在首次免疫后14 d达到较高水平,在第2次免疫后10 d达到高峰。用10 000只捻转血矛线虫第3期幼虫攻击山羊后,对不同免疫组山羊排出虫卵数、虫卵孵化率和成虫数的统计分析结果表明,免疫组与对照组间差异不显著,但免疫组雌虫数显著少于对照组,这对防治捻转血矛线虫病可能会起一定的作用。     

绵阳地区山羊粪便中捻转血矛线虫的分子鉴定

为鉴定绵阳地区山羊粪便中疑似血矛属线虫虫卵的虫种,本研究提取绵阳地区三个县山羊粪便中疑似血矛属线虫的虫卵DNA 60份,采用PCR技术扩增其核糖体第二内转录间隔区(rDNA ITS-2)基因序列,并与GenBank上公布的捻转血矛线虫同源序列进行比较分析。结果显示:60份疑似血矛属线虫的虫卵DNA样品均得到191bp的ITS-2片段;60条ITS-2序列共形成15条不同的序列,含有17个单变异位点,与GenBank中多株捻转血矛线虫的同源性达95.8%~100%;ML系统发育树显示,本研究得到的15种类型ITS-2序列与已报道的捻转血矛线虫(Haemonchus contortus)聚类形成一个分支。综上可得,60份来自山羊的血矛属线虫均为捻转血矛线虫。     

Effects of Acacia nilotica and Acacia karoo diets on Haemonchus contortus infection in goats

This study was carried out to determine the effects of Acacia karoo and Acacia nilotica diets on Haemonchus contortus infections in goats. Twenty-four Boer goats of mixed sex (live weight 17-22 kg) were randomly assigned to four treatment groups, namely: A. nilotica (AN) group, A. karoo (AK) group, control infected with H. contortus (HC) group and the non-infected control (NHC) group. Animals in the AN, AK and HC groups were orally infected with a single dose of 3000 HC third stage larvae. The AN and AK groups had dried leaves of AN and AK, respectively, included in their basal diet at a rate of 40% dry matter (DM) while the HC and NHC groups had the basal diet throughout the experiment. All animals received a total feed allowance of 500 g DM per day and Katambora Rhodes grass hay ad libitum for roughage. Parameters measured included faecal egg counts and live weight. At the end of the experiment, three animals from each group were slaughtered and abomasal worm burdens were determined. A significant decrease in the faecal egg counts was recorded in animals in the AK group (P<0.05) relative to those in the AN and HC groups. The worm burdens were reduced by 34% in the AK group (P<0.05) and by 10% in the AN group (non-significant) relative to the infected control group. The study indicates that the difference in the effects of the two forages on HC infections may be related to type and concentration of tannins.     

The establishment and development of Haemonchus contortus in goats

Twelve goats were inoculated with 40,000 third-stage Haemonchus contortus larvae and two were killed on each of Days 4, 7, 11, 14, 18 and 21 after inoculation (DAI). The number of worms that established, and the site of development were recorded. More worms established in the fundic, than in the middle or pyloric thirds of the abomasum. Early development occurred within the mucosa; emergence into the lumen started between 7 and 11 days after infection. By 4 DAI, all worms had completed the third moult to the L4 stage. At 11 DAI the majority of the worms were adults. A mean of 13.2% of the female worms had eggs in their uteri at 18 DAI; by 21 DAI more than half of the female worms had eggs in their uteri. The development of H. contortus was essentially similar to that described in sheep.     

Dual oxidase 2 and glutathione peroxidase gene expression are elevated in hyperimmunized sheep challenged with Haemonchus contortus

A sequential biopsy sampling method was used to investigate oxidant and antioxidant gene responses in resistant sheep challenged with Haemonchus contortus larvae or a sham saline challenge. The expression of key sheep oxidant and antioxidant producing genes were measured in sequential samples removed from the abomasums at days 0, 1, 2, 3, 5, 7 and 28 post challenge. Gene expression levels at each time point were compared to expression at day 0, and levels of the various genes were also correlated to other markers of infection including immune cell counts and cytokine gene expression. The early response to larval challenge infection in resistant animals was marked by a divergence of two groups of host oxidant producing genes: the dual oxidase group (DUOX2/DUOXA2) showing increases in expression to day 7, while members of the phagocytic NADPH oxidase (PHOX) group showed significant decreases in expression. The change in DUOX2 expression between days zero and seven, when host resistance to infection is mediated, was negatively correlated to final worm burden suggesting NADPH oxidase expression may play a role in parasite expulsion. Expression of the DUOX group oxidants was positively correlated to expression of the Th2 cytokine IL4. Changes in host antioxidant pathways between different members of the glutathione peroxidase family (intestinal and plasma GPX) and genes involved in glutathione metabolism were also observed. This first study of the putative roles of oxidant production by the dual oxidase group, antioxidant glutathione pathways, immune cell populations, and cytokine profiles, in the development of resistance to infection by hyperimmune sheep are discussed.