Examination of possible transmission of sheep scab mitePsoroptes ovis between host species

Examination of possible transmission of the Irish strain of the sheep scab mite (Psoroptes ovis) of ovine origin between host species involved calves and goats being placed with infected sheep and also directly challenged with live mites. Although mites remained on recipient species for up to a week, they failed to produce disease in either of these species. Calves and goats that had live mites placed on them likewise failed to infect sheep with which they were housed.     

Haematology and blood biochemistry during the course of psoroptic scabies in sheep

Haematology and blood biochemistry were monitored during the development and regression of psoroptic scabies in sheep. There were rises in numbers of neutrophils and eosinophils and in the fibrinogen concentrations, with lowered haemoglobin concentrations any lymphocyte numbers. The only biochemical parameters that were affected were the estimated serum globulin concentration, which rose during the disease process, and the serum albumin concentration, which fell. All of these changes reverted to normal soon after treatment.Abbreviations CK creatine kinase - Diff WBC differential white blood cell - E eosinophils - GOT asparate aminotransferase - GT glutamyl transferase - Hb haemoglobin - Ly lymphocytes - M monocytes - N neutrophils - WBC white blood cell count     

Stimulation of the <Emphasis Type="Italic">In Vitro</Emphasis> Migration of Ovine Eosinophils by Factors Derived from the Sheep Scab Mite, <Emphasis Type="Italic">Psoroptes ovis</Emphasis>

The ectoparasitic astigmatid mite Psoroptes ovis causes sheep scab, a highly contagious, severe allergic dermatitis associated with damage to the fleece and hide, loss of condition and occasional mortality. The scab lesion is characterized by a massive infiltration of eosinophils that begins very rapidly after infection. This paper reports the finding that mite-derived factors directly enhance the migration of ovine eosinophils in vitro. Significant (p < 0.01) and dose-dependent (r = 0.972 ± 0.018 (SD)) activity was initially identified in whole mite extracts, by comparison with medium controls in an assay based on modified Boyden chambers and ovine bone marrow target cells. Similar pro-migratory activity (p < 0.005; r = 0.928 ± 0.069 (SD)) was detected in washes containing mite excretory/secretory material. By direct comparison with migration ratios (n = 3) for defined chemotactic (rmeotaxin = 3.430 ± 0.360 (SD)) and chemokinetic (rminterleukin-5 = 0.982 ± 0.112 (SD)) stimuli it was determined that the activity in both mite extracts (0.992 ± 0.038 (SD)) and mite washes (0.969 ± 0.071 (SD)) was chemokinetic. Subsequent experiments (n = 3) in which live mites were incorporated directly into the in vitro assay system indicated that they produced factors that significantly (p < 0.001) enhanced eosinophil migration to a degree directly related to mite numbers (r = 0.993 ± 0.005 (SD)). The identity of the factor(s) responsible is uncertain, but their presence suggests that mites may be capable of directly activating eosinophils in vivo, and raises the possibility that mites could directly influence, perhaps even initiate, the rapid early tissue eosinophilic response observed in experimental sheep scab infections.     

Sheep psoroptic mange: An update

Psoroptic mange is one of the most severe skin conditions of sheep. This highly contagious disease is responsible for huge economical losses in many sheep-raising countries. It is also a significant welfare concern. Our understanding of the biology of Psoroptes ovis and of the host-parasite relationship during psoroptic mange made remarkable progress during the last decade. These data combined with the availability of powerful molecular tools have opened new avenues of research. Clearly, there is still a long way to go before a vaccine becomes a reality. Additionally, other diagnostic tools and control methods should be further investigated such as breeding for genetic resistance and the use of biocontrol agents.     

Looking for prognosticators in ovine anaplasmosis: discriminant analysis of clinical and haematological parameters in lambs belonging to differently susceptible breeds experimentally infected with Anaplasma ovis

Background

A study was carried out to evaluate the response of different native sheep breeds to experimental infection with Anaplasma ovis, the most prevalent sheep tick-borne pathogen in Apulia (Southern Italy). Thirty-four lambs belonging to a Northern European breed (Suffolk) and two Southern Italian breeds (Comisana and Altamurana) were infected. Eleven clinical as well as haematological parameters were monitored at different temporal resolutions on the same subjects before and after the infection, resulting in a data set of 435 observations. The present work, aiming to further the research, presents the results of a multivariate analysis carried out to identify which parameters out of the eleven considered are the most reliable parameters to be considered as markers of the disease phenotype as well as prognosticators of practical clinical importance.

Results

Data were analysed by discriminant analysis. Out of the eleven considered variables (red blood cells, packed cell volume, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin content, haemoglobin concentration, white blood cells, neutrophils, leukocytes, platelets, rectal temperature), only seven were included in the step-wise model since significantly increasing the Mahlanobis distance between the two closest groups. Both discriminant functions resulted to be highly significant (P < 0.0001) and the percentage of variation accounted for by the first discriminant function was 63.6% of the variance in the grouping variable.

Conclusions

Taken together, the observed results stress the marked differentiation among the three breeds in terms of physio-pathological phenotypes indicating packed cell volume and red blood cell count as the most informative parameters in the routine clinical practice for A. ovis infection in sheep.     

山西黄土高原地区羊鼻蝇蛆病流行病学调查和病理学观察

通过对山西黄土高原区域羊鼻蝇蛆感染情况调查和病理学研究,以明确该地区羊鼻蝇蛆的感染率和该病的病理变化。春秋两个季节对羊鼻蝇蛆感染情况进行调查,对307例绵羊进行羊头剖检,检查羊鼻蝇蛆病的各龄幼虫感染情况,同时观察病理变化,并采取感染羊的鼻黏膜、咽后淋巴结、脑和肺组织进行病理组织学检查。春季检查157例,鼻蝇蛆感染患羊34例,感染率达22%;秋季检查150例,感染患羊70例,感染率达47%;春秋两季平均感染率为34%。病理变化主要表现为:鼻黏膜出现不同损伤和增生性炎,咽后淋巴结炎性细胞浸润,有的病例出现肺气肿,脑组织水肿。免疫组织化学染色结果表明,检出虫体的羊与未检出虫体羊比较,咽后淋巴结IgA分泌细胞和IgG分泌细胞呈增高趋势,尤其是淋巴结髓质中IgA分泌细胞和IgG分泌细胞明显增多。     

Characterization of pathogen-specific expression of host immune response genes in Anaplasma and Mycobacterium species infected ruminants

Anaplasma and Mycobacterium species are among the most prevalent bacterial pathogens in European red deer (Cervus elaphus) in south-central Spain and are known to modify gene expression in ruminants. In this study, we used microarray hybridization and real-time RT-PCR analyses to characterize global gene expression profiles in red deer in response to Anaplasma ovis and A. ovis/Mycobacterium bovis/Mycobacterium avium sub. paratuberculosis (MAP) infections, compare the expression of immune response genes between red deer infected with A. ovis, M. bovis and A. ovis/M. bovis/MAP, and characterize the differential expression of immune response genes identified in red deer in cattle infected with M. bovis and Anaplasma marginale. Global gene differential expression in A. ovis- and A. ovis/M. bovis/MAP-infected deer resulted in the modification of common and pathogen-specific cellular biological processes. The differential expression of host immune response genes showed pathogen and host-specific signatures and the effect of infection with multiple pathogens on deer immune response. These results suggested that intracellular bacteria from Anaplasma and Mycobacterium genera produce similar genes expression patterns in infected ruminants. However, pathogen and host-specific differences could contribute to disease diagnosis and treatment in ruminants.     

Effects of inactive parapoxvirus ovis on cytokine levels in rats

The aim of this study is to determine the effects of iPPOV on pro-inflammatoryand anti-inflammatory cytokine levels in rats. iPPOV (1 ml/rat) wasadministered intraperitoneal route to 49 rats, except for 7 rats (Control, 0 group). Serumsamples were collected from 7 rats at 1st, 2nd, 4th, 8th, 12th, 16th and 24th hr aftertreatments. Levels of TNF-α, IL-6, IL-12 and IL-10 were determined using ELISA.Administration of iPPOV stimulated TNF-α (16th and 24th hr) and IL-6 (12th, 16th and 24thhr) synthesis and caused fluctuations in IL-10 and IL-12 concentrations. In conclusion,increased cytokine levels could be attributed to immunomodulatory activity of iPPOV,however, detailed studies are required to fully understand effects of iPPOV on immunesystem.     

羊附红细胞体解离方法的比较研究

本试验为建立一种高效的羊附红细胞体解离方法,采集红细胞感染率大于90%的阳性抗凝血,分别应用水浴法和药物体外驱虫法对羊附红细胞体进行解离,观察分离前后附红细胞体感染率、红细胞感染强度、附红细胞体数、杂质含量和附红细胞体的运动性5项指标;提取附红细胞体抗原,制备全蛋白悬液,测定蛋白质含量,比较解离效果。将两种方法制备的羊附红细胞体抗原全蛋白进行SDS-PAGE试验,观察条带是否一致。结果显示,200 mL血液中加入1 mL双向红莲灭,4℃作用36 h,即可达到较好分离效果。与水浴法相比,解离后,红细胞感染率和感染强度明显下降,蛋白含量增加,收率高,纯度好。SDS-PAGE结果显示,体外驱虫法所制的羊附红细胞体抗原全蛋白悬液,其抗原蛋白带与水浴法相同,因此可用于粗制羊附红细胞体抗原。     

羊附红细胞体双抗体夹心ELISA诊断方法的建立

为快速准确诊断和检测羊附红细胞体病,及时采取防治措施,建立了检测羊附红细胞体抗原的双抗夹心ELISA诊断方法。选取规模化养殖场羊,镜检附红细胞体红细胞感染率> 90%,无菌采取血液,分离羊附红细胞体抗原,制备纯化兔抗羊附红细胞体抗体,应用辣根过氧化物酶标记抗体,进行双抗体夹心ELISA试验。试验结果表明,双抗体夹心ELISA方法的最佳工作条件为:抗体最佳包被量为82.91 μg/mL,酶标抗体最适工作浓度为1∶400,抗原最低检出量为7.81 μg/mL;而且与支原体、大肠杆菌、葡萄球菌以及牛、猪、兔附红细胞体均不出现交叉反应,表明该方法具有良好的特异性,可用于羊附红细胞体病的诊断和群体检测。     

The distribution pattern of Sarcocystis species,their transmission and pathogenesis in sheep in Fars Province of Iran

Of 1362 sheep examined during two years in Fars Province of Iran, 786 (57.7%) were positive for Sarcocystis spp. The prevalence was significantly higher (p<0.05) in animals owned by nomadic Assyrians (67.95%) than in those owned by local people (41.86%). More of the animals above 2 years age were infected (69.98%) than young ones (30.02%). Females had a higher prevalence of infection (61.07%) than males (38.93%) but most of the males were younger. There was no variation in the infection rate during spring, summer or autumn, but it was low in winter. The species observed were Sarcocystis gigantea, predominantly in oesophagus, S. medusiformis, mainly in diaphragm, S. tenella in the oesophagus, diaphragm, tongue and heart, and S. arieticanis in the oesophagus, tongue and occasionally in the diaphragm. In transmission studies, the prepatent period for S. gigantea and S. medusiformis and for the two microscopic species was 11–13, 10 and 8–12 days, respectively. The infection could not be transmitted to hamsters and guinea-pigs. The macroscopic species were almost non-pathogenic but were responsible for economic losses because of rejection of carcases or parts thereof at slaughter. The microscopic species caused tissue damage to the affected organs, resulting in haemorrhages, mononuclear infiltration and necrotic changes.Abbreviations DPI days post infection     

羊毛尾线虫线粒体nad4基因的序列变异分析

本研究旨在阐明中国羊毛尾线虫(Trichuris ovis)广东分离株线粒体NADH脱氢酶亚单位4(nad4)基因部分序列(pnad4)的遗传变异情况, 并用pnad4序列构建其与其他鞭虫的进化关系。应用PCR扩增羊鞭虫虫株的pnad4,将所获得的序列应用ClustalX 1.81程序进行比对,然后用Mega 5.0程序NJ法绘制种系发育树。本试验扩增所获得的pnad4序列长度一致,均为827 bp,种内变异在0~1.5%之间。种系发育分析结果表明,12个羊鞭虫分离株位于同一分支。由于羊鞭虫nad4序列种内相对保守,种间差异较大(37.8%~45.6%), 故可作为种间鉴定检测研究的遗传标记, 本研究结果为进一步研究羊鞭虫的群体遗传结构奠定了基础。     

Effects of immunization of Pelibuey lambs with Oestrus ovis digestive tract protein extracts on larval establishment and development

Larval midgut proteins of hematophagous parasites contain strong antigens that can be used for host immunization. This concept has been applied for immunization of Pelibuey sheep against Oestrus ovis L. (Diptera: Oestridae). The aim of this study was to examine the effect of immunization on larval establishment (LE) and development. Immunized lambs (I, n = 6) received two injections of crude gut membrane protein extracts (GMPE) from third instar larvae with Freund's incomplete adjuvant (FIA) on days 0 (Day of first immunization) and 21 (0.4 and 0.45 mg GMPE/lamb, respectively). The control group (C, n = 5) received physiological saline with FIA. Lambs were challenged with first instars on Day 29 (20 larvae) and Day 43 (25 larvae). Blood samples were collected biweekly and IgG titers were analyzed by ELISA. All lambs were slaughtered on Day 90 and number of larvae recovered, larval stage and larval weight were recorded at necropsy. No significant effect of immunization on LE (C = 28.9%; I = 31.0% P > 0.05) was observed. Antibody titers were higher in the immunized group on Day 28 (P < 0.05), but subsequently similar in both groups. Larval physiological age and weight were also significantly (P < 0.05) affected by immunization. Immunization of Pelibuey lambs with GMPE did not affect LE but did delay O. ovis larval development.     

Phylogentic analysis of Anaplasma ovis strains isolated from sheep and goats using groEL and mps4 genes

Evidence of Anaplasma spp. in goats and sheep in Cyprus has been demonstrated by previous research. Herein, further research was performed for the identification of the exact Anaplasma spp. resulting in the identification of Anaplasma ovis strains in all samples examined. We used a bioinformatics as well as a molecular approach (study of groEl and mps4 genes) in order to verify the validity of the results. All samples depicted the presence of A. ovis regardless of the host (goat or sheep).     

Duration of immunity, efficacy and safety in sheep of a recombinant Taenia ovis vaccine formulated with saponin or selected adjuvants

The efficacy and safety of a recombinant Taenia ovis protein was tested in sheep using 13 different adjuvant formulations, including oil adjuvants, aluminium salts, saponin, Iscoms and DEAE-dextran. The oil adjuvants, saponin and DEAE-dextran gave the highest antibody responses and greatest degree of protection against challenge infection with T. ovis eggs. Duration of immunity studies with a saponin based vaccine showed that highly significant protection (>90% reduction of cyst numbers) was achieved when sheep were challenge infected one month after immunisation. Significant protection (79%) was still present when sheep were challenged 6 months after immunisation. The optimum dose for this batch of saponin was 10 mg, which stimulated a peak antibody titre of 38,400, 4 weeks after immunisation and did not cause injection site reactions. Dialysed saponin was shown to retain its adjuvant properties and allowed an increase in dose to 30 mg without site reaction, resulting in a peak antibody titre of 51,200.     

The curative and antioxidative efficiency of doramectin and doramectin+vitamin AD3E treatment on Psoroptes cuniculi infestation in rabbits

In the present study, the efficiency of the administration of doramectin (DOR) and DOR+vitamin AD3E (VIT), and the influence of these agents on oxidative stress parameters in rabbits infested by Psoroptes cuniculi (P. cuniculi) were investigated. DOR (200 microg/kg) and DOR (200 microg/kg)+VIT AD3E were administered to infested rabbits intramuscularly (IM). The administration of DOR and DOR+VIT improved the healing of ear lesions on day seven. Increase in the plasma malondialdehyde (MDA) level and erythrocyte catalase (CAT) activity, and decrease in glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities were determined in infested rabbits. In the rabbits which were administered DOR+VIT, plasma MDA levels decreased, and erythrocyte GSH-Px and SOD activities increased on day seven. In conclusion, DOR and DOR+VIT combination were effective against P. cunuculi infestation. Infestation stimulated oxidative stress. VIT treatment resulted in antioxidant activity against oxidative stress induced by P. cuniculi infestation.     

Prevalence and seasonal incidence of larval and adult cestode infections of sheep and goats in eastern Ethiopia

A study on the prevalence and seasonal incidence of cestode parasite infections of sheep and goats was carried out in eastern Ethiopia for 2 years (May 2003-April 2005). During this period, viscera including liver, lungs, heart, kidneys and the gastro-intestinal tract were collected from 655 sheep and 632 goats slaughtered at four abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga. At the abattoirs the abdominal, thoracic and pelvic cavities as well as the muscle surfaces of all animals were visually examined for the presence of larval (cystic) stages of cestode parasites. The viscera were transported within 24 h to the parasitology laboratory of Haramaya University and were examined for larval and adult cestodes following standard procedures. The most prevalent metacestodes (larval cestodes) were Cysticercus ovis (Taenia ovis), Cysticercus tenuicollis (T. hydatigena) and hydatid cysts (Echinococcus granulosus). In sheep, the overall prevalence was 26% for C. ovis, 79% for C. tenuicollis, and 68% for hydatid cysts. Similarly, for goats, the corresponding prevalence was 22%, 53% and 65%, respectively. The difference between sheep and goats in prevalence of C. tenuicollis was significant. The high prevalence of hydatid cysts in both sheep and goats indicates that cystic echinococcosis/hydatidosis is a public health problem in these regions which requires implementation of control measures, including public health education, strict meat inspection and control of stray dogs. The results of the survey also implies that infections of small ruminants with these metacestodes are responsible for condemnation of substantial quantities of affected organs and muscles and therefore of direct economic importance. Intestinal infections with adult tapeworms of Moniezia expansa, Avitellina centripunctata and Stilesia globipunctata, and bile duct infections with Stilesia hepatica were also common in both sheep and goats. In sheep, the overall prevalence of these tapeworms were 61%, 20%, 24% and 39%, respectively. Similarly, the overall prevalence of these parasites in goats was 53%, 21%, 27% and 36%, respectively.