Mite-borne virus isolates from cultivated Allium species,and their classification into two new rymoviruses in the family Potyviridae

While testing several samples of onion and of vegetatively propagated garlic, sand leek and shallot from a number of countries, virus isolates with unusually flexuous particles were obtained by mite (Aceria tulipae) or sap transmissions. No aphid-borne poty-or carlavirus was transmitted by mites, and mite-borne virus isolates could not be transmitted by aphids. The mite-borne isolates did not react with antisera to aphid-borne potyviruses ofAllium spp. or with the Agdia potyvirus group monoclonal. In contrast to the mite-borne onion and garlic mosaic viruses reported in the literature, our mite-borne isolates induced no visible or only very mild symptoms inAllium spp., except isolates from shallot ‘Santé’ which caused diffuse striping. Heavily mite-infested test plants or plant samples showed streaking and malformation due to mite feeding (tangle-top). The mite-borne virus isolates could be classified with test plants and a discriminating antiserum into three groups, representing two viruses and a strain of one of them. They are tentatively named onion mite-borne latent virus (OMbLV), garlic strain of this virus (OMbLV-G), and shallot mite-borne latent virus (SMbLV). Mite transmission, length of virus particles (ca. 700 to 800 nm), and the presence of granular inclusion bodies in infected tissue indicate that the viruses belong to the mite-borne genusRymovirus of the familyPotyviridae. OMbLV from shallot and onion, and OMbLV-G from garlic and sand leek, can be assayed onChenopodium murale but differ in their natural hosts. They are very common. SMbLV, to whichC. murale does not react, was isolated from shallot originating from Asia and Russia.     

Seroprevalence for norovirus genogroups GII and GIV in captive non‐human primates

Noroviruses (NoVs) are a major cause of epidemic gastroenteritis in children and adults. Several pieces of evidence suggest that viruses genetically and antigenically closely related to human NoVs might infect animals, raising public health concerns about potential cross‐species transmission. The natural susceptibility of non‐human primates (NPHs) to human NoV infections has already been reported, but a limited amount of data is currently available. In order to start filling this gap, we screened a total of 86 serum samples of seven different species of NPHs housed at the Zoological Garden (Bioparco) of Rome (Italy), collected between 2001 and 2017, using an enzyme‐linked immunosorbent assay (ELISA) based on virus‐like particles (VLPs) of human GII.4 and GIV.1 NoVs. Antibodies specific for both genotypes were detected with an overall prevalence of 32.6%. In detail, IgG antibodies against GII.4 NoVs were found in 18 Japanese macaques (29.0%, 18/62), a mandrill (10.0%, 1/10), a white‐crowned mangabey (16.6%, 1/6) and in an orangutan (33.3%, 1/3). Twelve macaques (19.3%, 12/62), five mandrills (50.0%, 5/10), two chimpanzees (100%, 2/2) and a white‐crowned mangabey (16.6%, 1/6) showed antibodies for GIV.1 NoVs. The findings of this study confirm the natural susceptibility of captive NHPs to GII NoV infections. In addition, IgG antibodies against GIV.1 were detected, suggesting that NHPs are exposed to GIV NoVs or to antigenically related NoV strains.     

日粮高铜对雏鸡血清免疫球蛋白含量的影响

选用1日龄艾维茵肉鸡健雏420只,随机分为7组,分别喂以对照日粮(Cu11mg/kg)和高铜日粮(Cu100mg/kg,高铜Ⅰ组;Cu200mg/kg,高铜Ⅱ组;Cu300mg/kg,高铜Ⅲ组;Cu400mg/kg,高铜Ⅳ组;Cu500mg/kg,高铜Ⅴ组;Cu600mg/kg,高铜Ⅵ组)6周。结果显示,高铜Ⅰ、Ⅱ、Ⅲ组雏鸡血清免疫球蛋白含量与对照组比较差异不显著(P>0.05);高铜Ⅳ、Ⅴ、Ⅵ组雏鸡血清免疫球蛋白含量显著降低(P<0.05或P<0.01),并与日粮含铜量呈负相关。结果表明,日粮铜含量在400mg/kg及其以上可抑制免疫球蛋白的合成,导致雏鸡体液免疫功能受损。     

犬感染犬瘟热病毒后抗体的产生规律及检测方法

由犬瘟热病毒引起的犬瘟热(Canine distemper,CD)疾病,是造成犬及部分食肉目动物的一种具有高度传染性和高死亡率的疾病。犬瘟热病毒感染犬产生抗体的规律在临床上具有非常重要的意义。幼犬在出生后约35 d就失去了母源抗体的保护,需要人工对其进行预防免疫,以获得针对该病毒的特异性抗体。犬瘟热病毒在进入机体后,引起以胸腺依赖性的B2细胞所介导的体液免疫为主,初次免疫应答产生的Ig M稍多于Ig G,再次免疫应答时记忆性B细胞发挥着主要的作用,在很短时间内使得特异性Ig G抗体达到较高水平,且在机体内维持很久的时间。通过掌握Ig M和Ig G抗体产生的量及变化规律,可以诊断疾病发生的过程,为疾病的治疗和预防提供诊断依据。     

兔抗鸡IgG荧光抗体的制备及应用

本试验通过提取鸡的免疫球蛋白(IgG),与弗氏完全佐剂按照1:1的比例免疫兔子3次,然后提取兔的IgG并经过异硫氰酸荧光素染色。经检测,制备出的兔抗鸡IgG荧光抗体敏感性高、特异性强,是比较理想的检测试剂。     

血红素铁对断奶仔猪生长性能和血液指标的影响

选取120头28日龄断奶仔猪,随机分成4个处理组,即1个对照组和3个试验组,每组3个重复,每个重复10头。对照组饲喂基础日粮,试验1、2、3组分别饲喂基础日粮中血红素铁净添加量为27.5、55.0、85.0 mg/kg的3种试验日粮,研究日粮中添加血红素铁对断奶仔猪的生长性能、血液指标(血红蛋白浓度、免疫球蛋白浓度)的影响。试验正试期13 d。结果表明,血红素铁各添加量组均能够提高仔猪的生长性能,日粮中血红素铁添加量为55 mg/kg时,仔猪平均日增重、饲料转化率较对照组分别提高12.02%和10.27%(P<0.05)。血红素铁对断奶仔猪有良好的促生长作用,也在一定程度上提高了仔猪血液中血红蛋白和IgG浓度。     

Maternal stress during late gestation has moderate but long-lasting effects on the immune system of the piglets

Events acting prenatally on developing foetuses are important determinants for disorders later in life. Prenatal stress (PNS) is one of these events. The purpose of this study was to determine the consequences of a repeated social stress applied during late gestation of the pregnant gilt on the immune system and hypothalamo-pituitary-adrenal (HPA) axis activity of the piglets from birth to two months of age. Pregnant gilts were submitted to repeated social stress which was induced by housing unfamiliar gilts in pairs modified twice a week during 4 weeks between days 77 and 105 of gestation (S group, n = 18). Control gilts were housed in stable pairs during the same period (C group, n = 18). Blood cortisol, haptoglobin and IgG levels, immune cell counts, mitogen-induced whole-blood proliferation and TNF-α production were evaluated in piglets at 4 days of age (D4), before and after weaning (D26 and 28) and before and after relocation to a new building (D60 and 62). We found that PNS did not affect growth rate of the progeny. It decreased the relative weight of adrenal glands on D4 (P < 0.05) but plasma cortisol levels were similar in both groups at all ages. IgG levels in colostrum and in the serum of piglets were not affected. PNS decreased the total numbers of white blood cells, lymphocytes and granulocytes from D26 to D60 (P < 0.05), the CD4⁺/CD8⁺ T cell ratio on D4 (P < 0.05), and LPS induced-TNF-α production on D60 (P < 0.05). PNS increased the ConA-induced lymphocyte proliferation on D4 and D60 and the PWM-induced proliferation on D60 (P < 0.05). Our results demonstrate that a repeated social stress applied to pregnant sows during late gestation can induce long-lasting effects on several parameters of the immune function of the offspring. These effects are not due to modifications of the HPA axis activity and may impair the abilities of the piglets to efficiently react against infections during the suckling period and around weaning.     

Caprine herpesvirus-1-specific IgG subclasses in naturally and experimentally infected goats

Enzyme-linked immunosorbent assays (ELISAs) were developed to detect caprine herpervirus-1 (CpHV-1)-specific IgG1 and IgG2 in sera from 43 naturally infected goats. The analysis of the IgG subclasses showed a dual pattern of distribution in seropositive goats with a major group of animals (36 out of 43) exhibiting significantly higher levels of IgG2 over IgG1 and a minor group (7 out of 43) possessing equal levels of IgG1 and IgG2. Four goats were experimentally infected with a virulent CpHV-1 Ba.1 strain by the intranasal or the intravaginal route and the kinetics of appearance of CpHV-1-specific IgG, IgG1 and IgG2 in the serum were studied. Two weeks following infection, both IgG1 and IgG2 levels increased although convalescent sera (i.e., collected 5–8 weeks post-infection) showed a clear prevalence of the IgG2 subclass. To determine the contribution of the different IgG subclasses to herpesvirus immunity, serum neutralization (SN) assays were performed in both naturally and experimentally infected goats. The kinetics of SN showed that neutralization activity was mainly associated to the IgG1 subclass and this was also confirmed in naturally infected goats. The results are discussed from the standpoint that the profile of the IgG subclasses is instrumental to study immune responses to CpHV-1 and that vaccination strategies may benefit from this information.     

水牛初乳粉加工技术的研究

以水牛产后72h内分泌的乳汁为原料，通过脱脂、杀菌、真空冷冻干燥制成水牛初乳粉；采用正交试验方法，分析水牛初乳中初始lgG活性质量浓度、热处理温度、初乳粉的储存条件对初乳粉产品中lgG活性质量浓度的影响。结果表明：采用奶水牛产后第1天的初乳为原料，65％杀菌20min，初乳粉在4℃下储藏时，产品中活性lgG的回收率最高。