The integrity of host lymphocyte plasmalemma during its invasion by Theileria annulata sporozoites as demonstrated by ruthenium red staining

The integrity of host lymphocyte plasma membrane during its invasion by Theileria annulata sporozoites was examined in an in vitro system using ruthenium red staining. It was demonstrated that during interiorisation of the sporozoites, the dye was completely excluded from the intracellular milieu, indicating that the continuity of the host-cell plasmalemma was not disrupted throughout the process of penetration, and confirmed a previous observation that the fragmentation of the host lymphocyte membrane only occurs later, after the parasite is intracellular.     

Reduction of economic losses caused by mycoplasmal pneumonia of pigs by vaccination with Respisure and by Tiamutin treatment

The possibilities and economic benefits of controlling mycoplasmal pneumonia of pigs caused by Mycoplasma hyopneumoniae by immunisation with Respisure and by Tiamutin treatment were studied. The experiment was carried out in a herd comprising 1000 sows which was free of PRRS, Aujeszky's disease, swine dysentery and leptospirosis, and the prevalence of mycoplasmal pneumonia was low because the farm had recently been restocked. Groups C1 and C2 served as untreated controls, while Groups R1 and R2 received a prestarter diet containing 100 ppm Tiamutin from the time of weaning. Piglets of Group R1 were vaccinated with Respisure vaccine once on day 69, while those of Group R2 twice, on days 65 and 80. Piglets of Groups ST1 and ST2 were fed 100 ppm Tiamutin in the diet for 7 days at the time of weaning and then at 4 months of age, while pigs of Group ST2 received such treatment also in the 6th month of life. The efficacy of treatment was analysed on the basis of the number of animals that died, were emergency slaughtered or were retarded in growth in the different groups, the body weight of animals at weaning, at 94 and 148 days of age and at the time of slaughter, their daily body weight gain, the lung lesions found in animals slaughtered from the different groups, the costs of medication and vaccination, and the cost-benefit calculations of the results. The mortality and emergency slaughter rate was 2.88% and 4.62% in Groups ST2 and ST1, respectively, 4.23% and 4.62% in Groups R2 and R1, respectively, and 8.39% and 9.44% in the control groups (C2 and C1, respectively). The rate of growth retardation was 0.48% and 2.12% in Groups R1 and R2, respectively, 1.59% and 3.46% in Groups ST1 and ST2, respectively, as compared to 8.03% and 6.55% in the control groups (C1 and C2, respectively). The severity score of lung lesions was 1.82 and 1.46 in Groups R1 and R2, 2.18 and 2.93 in Groups ST1 and ST2, and 3.83 and 4.02 in the control groups C1 and C2, respectively. The mean finishing weight of pigs was 102.4-107.8 kg and 95.2-106.6 kg in the treated groups and 94.5-98.6 kg in the control groups. The classification of pigs according to the EUROP categories showed a shift to the E and U categories in the treated groups. The average feed cost per one kg of liveweight was 77.89-82.64 Forints in the treated groups and 85.66 Forints in the control groups.     

结缕草属植物种间关系和遗传多样性的SRAP标记分析

 通过ＳＲＡＰ标记技术对结缕草属植物５种１变种共９６份种源进行遗传多样性分析。结果表明,１）结缕草属种质间存在丰富的遗传多样性,５４对ＳＲＡＰ引物共扩增出３６２条清晰的用于多样性分析的谱带,其中多态性条带３３７条,多态性比率（ＰＰＢ）为９３．０９％,Ｎｅｉ’ｓ基因多样性指数（犎）为０．２４０９,Ｓｈａｎｎｏｎ信息指数（犐）为０．３７４６。２）应用Ｎｅｉ－Ｌｉ相似系数法估算了９６份材料间的遗传相似系数（ＧＳ）,其ＧＳ为０．５９３９～０．９８３４,平均为０．７５８８。不同种之间,结缕草与中华结缕草、沟叶结缕草与细叶结缕草中的部分材料遗传相似系数较高,遗传距离较近。大穗结缕草Ｚ０１０和长花结缕草Ｚ１２２与其他结缕草的遗传相似系数都相对较低。同一个种内,结缕草、中华结缕草和沟叶结缕草种内遗传变异均较大,ＧＳ分别为０．５９９４～０．９８３４,０．６２４３～０．９８０７和０．６６３０～０．９４７５。３）通过ＵＰＧＭＡ 分子系统聚类法,将９６份种源分为７个大的类群,其中第１大类和第２大类均包含结缕草、中华结缕草和少量的沟叶结缕草种源;第３大类群主要包括４份美国引进的材料;第４大类主要包括沟叶结缕草和细叶结缕草;大穗结缕草Ｚ０１０、长花结缕草Ｚ１２２和结缕草Ｚ１１５都单独聚为一类。从聚类结果可以看出,结缕草、中华结缕草和沟叶结缕草均有交叉聚类现象,并不是同一个种的材料完全相聚,个别种源自行一类,遗传基础与其他材料差异较大,从遗传聚类图可以很明确地看出９６份种源间的遗传距离及亲缘关系。     

Diversity among isolates of Actinobacillus equuli and related organisms as revealed by ribotyping

Objective The objective of this work was to examine the diversity within Australian isolates of Actinobacillus equuli and related organisms by the genotypic method of ribotyping.
Design Ribotyping, performed using the enzyme Hae III, was used to examine the diversity in 12 field isolates of A equuli (five being capable of fermenting L-arabinose), one field isolate of Pasteurella caballi and two unclassifiable field isolates. Isolates were obtained from Australian horses, except for three isolates of A equuli (one L-arabinose positive and two L-arabinose negative) which were obtained from horses and a pig in Africa. In addition, the type strains for A equuli and P caballi and a reference strain for Bisgaard Taxon 9 were included in the study.
Results The ribotype patterns were analysed by computerised cluster analysis, yielding five clusters (A to E). All five of the L-arabinose positive A equuli were assigned to cluster A, with all the other seven A equuli isolates (all L-arabinose negative) and the type strain being assigned to cluster B. One of the two unclassified isolates formed cluster C along with the reference strain for Bisgaard Taxon 9. The remaining unclassified isolate formed cluster D. Cluster E consisted of the field isolate and reference strain of P caballi .
Conclusion The results of this study indicate that A equuli is a diverse species, with L-arabinose positive isolates of A equuli being quite distinct from typical L-arabinose negative isolates. Ribotyping appears to be a useful tool in confirming the identity of A equuli -like organisms from horses.     

猪支原体和巴氏杆菌混合感染的诊断及防制

1999年 1 1月以来 ,北京郊区某规模化养猪场发生以咳嗽、气喘、体温升高、消瘦为主要症状的疾病。该病的发病率、死亡率均较高 ,经病理剖检、细菌学及血清学检验诊断为支原体和巴氏杆菌混合感染 ,临床采取组织灭活苗紧急接种 ,结合泰乐菌素、支原净等药物治疗使病情得到了有效的控制。1　发病情况　发病猪群在 35～ 60日龄之间 ,病猪气喘、咳嗽、呼吸困难 ,呈腹式呼吸 ,口鼻流出泡沫样液体 ,尤以清晨和夜间症状严重 ,病猪耳根、腹侧和四肢内侧的皮肤出现红斑 ,可视粘膜发绀 ,病初食欲正常 ,随着病情的发展食欲减退至废绝 ,某些育肥猪往往不…     

Goat flea (order Siphonaptera) as a possible vector for the transmission of caprine mycoplasmal polyarthritis with septicaemia

Goat fleas of the order Siphonaptera were collected from the body surfaces of naturally infected polyarthritic goat kids with septicaemia. These fleas and the infected kids were positive for Mycoplasma mycoides subsp. mycoides (large colony type) identified by cultural, morphological, biochemical and growth inhibition tests. Blood from the infected fleas contained 1 × 10²−1 × 10⁵ viable subsp. mycoides ml⁻¹. Experimental transmission of the disease to other kids was established by placing 120 infected fleas on each kid's body surfaces. All experimentally infected kids developed characteristic clinical signs and showed leucopenia with neutropenia, an increased amount of fibrinogen and mortality with lesions of suppurative polyarthritis associated with septicaemia. The organisms were also recovered in high numbers from heart blood, body fluids, and infected organs and joints. The results suggested that fleas of the order Siphonaptera acted as vectors for the transmission of the spontaneous disease in kids.     

Heterogeneity of fibronectin reactivity among streptococci as revealed by binding of fibronectin fragments

Streptococci belonging to serological groups A, B, C, G, L and U were studied for their interaction with 125I-labelled fibronectin and its fragments. Fibronectin purified from humans plasma by affinity chromatography on gelatin-agarose and heparin-agarose was cleaved by thrombin into a 29,000 Dalton and a 210,000 Dalton fragments. Terminal analysis of purified fragments indicated that 29,000 fragment was from amino-terminal and 210,000 fragment from carboxyl-terminal domain of fibronectin. Binding of fibronectin was observed in all streptococci except those of group B. Streptococci of groups A, G, L, U and S. equisimilis reacted only with 29,000 Dalton fragment whereas S. dysgalactiae, S. zooepidermicus and S. equi reacted only with 210,000 Dalton fragment. The streptococcal binding sites for these two fragments were distinct from each other. Fibrinogen blocked the binding of 210,000 Dalton fragment but not of 29,000 Dalton fragment. Trypsinization of streptococci did not affect their binding sites for 210,000 Dalton fragment but destroyed those for 29,000 Dalton fragment. The results indicate that the streptococci of group A and G as well as S. equisimilis which are mainly pathogenic in humans bind amino-terminal fragment of fibronectin. This may facilitate the adherence of these pathogens. On the other hand, the streptococci isolated from animal infections had different binding sites recognized only by carboxyl-terminal part of fibronectin.     

基于叶绿体atpB-rbcL序列探讨猬草属和赖草属植物的系统发育和母系起源

对小麦族猬草属、赖草属(NsXm)、披碱草属(StH)及含不同染色体组(St、H、Ns、E^b、E^e、P、F 、V、W)的近缘二倍体属共46个类群的叶绿体基因间隔区atpB-rbcL序列进行系统发育分析,探讨猬草属和赖草属植物系统发育关系及母系起源。结果显示,1)猬草属模式种H. patula与拟鹅观草属和披碱草属物种聚为一支,表明H. patula与披碱草属植物亲缘关系近,其母本来源为含St染色体组的拟鹅观草属物种;2)猬草、长芒猬草、4个新麦草属物种及滨麦和所有欧亚分布的赖草属物种聚在一支,说明猬草、长芒猬草与欧亚赖草亲缘关系较近,其母本供体来自含Ns染色体组的新麦草属物种;3)高丽猬草和东北猬草与北美赖草及冰草属、旱麦草属、大麦属物种处于同一分支,表明高丽猬草和东北猬草与北美赖草具有较近亲缘关系,其母本供体为未知来源的Xm染色体组。研究结果支持将H. patula组合到披碱草属中,猬草、长芒猬草、高丽猬草和东北猬草应组合到赖草属中。     

Efficacy of slow-release albendazole capsules in controlling lungworms and gastro-intestinal nematodes in red deer (Cervus elaphus)

One hundred and fifteen young red deer (Cervus elaphus), heavily infected with lungworm (Dictyocaulus viviparus) and lightly infected with gastro-intestinal nematodes, were divided into three groups. One group of 50 animals was treated with one adult sheep dose of a slow-release albendazole capsule, another group of 50 was dosed orally five times with liquid albendazole and 15 were left as untreated controls. The capsule eliminated faecal lungworm larvae during the 103-day trial period There was a highly significant difference in faecal larval counts between the capsule-treated and control group. Over the trial period, the mean body weight gain of the untreated, liquid albendazole and capsule-treated animals was 0.1 kg, 4.5 kg and 7.8 kg respectively.     

Efficacy of slow-release albendazole capsules in controlling lungworms and gastro-intestinal nematodes in red deer (Cervus elaphus)

One hundred and fifteen young red deer (Cervus elaphus), heavily infected with lungworm (Dictyocaulus viviparus) and lightly infected with gastro-intestinal nematodes, were divided into three groups. One group of 50 animals was treated with one adult sheep dose of a slow-release albendazole capsule, another group of 50 was dosed orally five times with liquid albendazole and 15 were left as untreated controls. The capsule eliminated faecal lungworm larvae during the 103-day trial period. There was a highly significant difference in faecal larval counts between the capsule-treated and control group. Over the trial period, the mean body weight gain of the untreated, liquid albendazole and capsule-treated animals was 0.1 kg, 4.5 kg and 7.8 kg respectively.     

Attachment of Moraxella bovis to calf corneal cells and inhibition by antiserum

An in vitro assay was developed using calf corneal cells to assess the importance of fimbriae in the colonisation of the bovine ocular surface by Moraxella bovis, and the role of fimbrial antibodies in the bovine immune response and resistance to infectious bovine keratoconjunctivitis (IBK). Fimbriae promoted adherence of M. bovis to calf corneal cells in culture; 15 fimbriate isolates, representative of 6 fimbrial serogroups of M. bovis, adhered to the cells whereas 4 non-fimbriate isolates failed to do so. Fimbrial antibodies in hyperimmune rabbit serum inhibited attachment of all fimbriate strains of the homologous fimbrial serogroup but not those of 5 heterologous serogroups. The relevance of these results to the use of a polyvalent fimbrial vaccine in the control of IBK is discussed.     

Induction of oestrus by administering Inhibin antiserum along with equine chorionic gonadotropin in anoestrous bitches

As dogs experience oestrus only once or twice a year, it is necessary to establish an effective method of oestrous induction for efficient breeding. In the present study, we evaluated inhibin antiserum (IAS) on oestrous induction in anoestrous females. Bitches were administered 0.5 ml/kg IAS or a mixture of 50 IU/kg equine chorionic gonadotropin (eCG) and 0.5 ml/kg IAS and 500 IU human chorionic gonadotropin (hCG) administered 7 days after the mixture injection. As a control, bitches received 50 IU/kg eCG, with 500 IU hCG administered 7 days after eCG injection. Blood-tinged vaginal discharge, vulvar swelling, plasma progesterone concentrations and ovarian follicular development were assessed from day 0 to day 14. IAS alone injection did not induce oestrus in bitches at the anoestrous stage. Conversely, vulvar swelling, blood-tinged vaginal discharge and an estimated luteinizing hormone (LH) surge appeared on days 3–7, days 3–6 and days 7–9 after the IAS+eCG mixture injection, respectively, in all five bitches at the anoestrous stage. The average number of developing and ovulated follicles in bitches administered IAS+eCG was 8.8 and 9.6 respectively. A single eCG injection followed by hCG induced oestrous signs, with an average of 8.3 developing follicles and 4.5 ovulated follicles. This study revealed that IAS alone did not induce oestrus, but when IAS was used in combination with eCG, it induced oestrus and promoted a considerable number of ovulations in anoestrous dogs.     

The morphology of the normal end-plate in lambs as revealed by silver impregnation and light microscopy.

A technique employing silver impregnation can be used on frozen formalin-fixed material for demonstrating ovine motor end-plates. The morphology of ovine motor end-plates is variable but broadly similar to that described in other species. The end-plates are oval with approximate dimensions of 33 X 17 micrometer. The distal ramifications of the nerve fibre show terminal and sub-terminal vesicles. The endings are flimsy or robust and the latter have single, dual or multiple terminations.     

The associations of viral and mycoplasmal antibody titers with respiratory disease and weight gain in feedlot calves

Blood samples from 32 groups of calves (n = 700) were taken on arrival and after 28-35 days at the feedlot. Eleven groups were housed in feedlots in Ontario, and 21 groups in feedlots in Alberta. Serum antibody titers to bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), parainfluenza virus type 3 (PIV-3), infectious bovine rhinotracheitis virus (IBRV), Mycoplasma dispar and M. bovis, plus data on bovine corona virus (BCV) from a previous study were investigated for their association with the risk of bovine respiratory disease (BRD), and with 28-day weight change, both before and after controlling for titers to Pasteurella haemolytica and Haemophilus somnus. Exposure to IBRV and M. bovis was infrequent, and although exposure to PIV-3 was more common, none of these agents had important associations with BRD. Higher titers to BVDV, BRSV, and BCV on arrival were associated with reduced risks of BRD and increased weight gains. However, there was some variation in these relationships and higher arrival titers to BVDV and BRSV in a subset of the calves were associated with increased risks of BRD. Titer increases to BVDV were associated with a higher risk of BRD and lower weight gains. Titer increases to BRSV were not usually associated with the occurrence of BRD, but titer increases to BRSV in a subset of calves that were vaccinated against BRSV, on arrival, were associated with an elevated risk of BRD. Of all the agents studied, BVDV had the most consistent associations with elevated risk of BRD and lower weight gains. Higher BRSV arrival titers were related to lower risk of BRD and higher weight gains; in some instances titer increases to BRSV were associated with higher BRD risk. Higher titers to BCV on arrival were related to reduced risks of BRD. Practical ways of adequately preventing the negative effects of these agents are still needed.     

使用荧光染色和流式细胞术检测山羊精子

分别使用PI(碘化丙碇),FITC-PSA(异硫氰酸荧光素络合豌豆凝集素)和RH123(罗丹明)对山羊冷冻精子进行染色,再使用流式细胞仪进行检测、分析。试验发现,对于山羊的冷冻精子,PI染色阴性的为质膜完整的精子;FITC-PSA染色阴性的可能为顶体完整的精子,染色FITC-PSA+和FITC-PSA++,可能分别为顶体反应中的精子和顶体破损精子;RH123+应为线粒体无活性精子,有绿色荧光可能是因为染料残留在细胞膜上导致,而RH123++可能应为线粒体有活性的活精子。不同个体羊的精子对于低温敏感度不一样。不同个体羊之间的冻精顶体完整率、质膜完整率、线粒体有活性的精子比率之间差异显著,据此应选择合适的山羊个体进行精液冷冻。