猪繁殖与呼吸综合征病毒、圆环病毒2型和衣原体混合感染引起母猪流产的诊断与防治

2018年10月,甘肃省某规模猪场存栏900头不同胎次母猪,在产仔高峰期内突然出现大量流产现象,临产母猪主要表现为产死胎、木乃伊胎、弱仔、畸形胎,平均产生率为26.92%(365/1 356),乳猪平均死淘率高达16.55%(164/991)。为确定病因,采集5头猪病料,包括木乃伊胎1头、死胎1头、流产胎儿2头、7日龄自然死亡弱仔1头,进行猪常见疫病病原学检测。检测结果显示:5头猪的猪繁殖与呼吸综合征病毒和猪圆环病毒2型核酸检测均为阳性,4头的衣原体核酸检测为阳性,猪瘟病毒、细小病毒、乙型脑炎病毒、伪狂犬病毒核酸检测均为阴性。结果表明,猪繁殖与呼吸综合征病毒、圆环病毒2型和猪衣原体混合感染是导致该规模场母猪流产的主要原因,因此需要加强混合感染的控制。     

H9亚型禽流感病毒实时荧光RT-PCR检测方法的建立与应用

为建立一种快速准确检测H9亚型禽流感病毒基因的检测方法,根据GenBank中H9亚型禽流感病毒血凝素编码基因进行荧光检测引物和探针设计,建立了一种针对H9亚型禽流感病毒的荧光RT-PCR检测方法。利用该方法进行灵敏度和特异性检测,并用本方法和国家标准中的荧光RT-PCR检测方法,同时对临床样本进行检测。结果显示,仅H9亚型禽流感病毒出现了正常荧光检测曲线,而其他病毒及阴性对照均未出现;检测灵敏度为RNA终浓度10~(-4) ng/μL(1.30×10~4 copies/μL);临床样本检测结果与国标方法一致,符合率为100%。结果表明,该方法特异性强、灵敏度高,可用于H9亚型禽流感病毒检测。     

50％乙·嗪乳油防除马铃薯田杂草试验

50%乙·嗪乳油通过土壤处理可有效地防除马铃薯田杂草 ,在所设3个剂量处理中 ,最低剂量100/667m2 除草效果达97%以上。     

Generation of RUNX3 knockout pigs using CRISPR/Cas9‐mediated gene targeting

Pigs are an attractive animal model to study the progression of cancer because of their anatomical and physiological similarities to human. However, the use of pig models for cancer research has been limited by availability of genetically engineered pigs which can recapitulate human cancer progression. Utilizing genome editing technologies such as CRISPR/Cas9 system allows us to generate genetically engineered pigs at a higher efficiency. In this study, specific CRISPR/Cas9 systems were used to target RUNX3, a known tumour suppressor gene, to generate a pig model that can induce gastric cancer in human. First, RUNX3 knockout cell lines carrying genetic modification (monoallelic or biallelic) of RUNX3 were generated by introducing engineered CRISPR/Cas9 system specific to RUNX3 into foetal fibroblast cells. Then, the genetically modified foetal fibroblast cells were used as donor cells for somatic cell nuclear transfer, followed by embryo transfer. We successfully obtained four live RUNX3 knockout piglets from two surrogates. The piglets showed the lack of RUNX3 protein in their internal organ system. Our results demonstrate that the CRISPR/Cas9 system is effective in inducing mutations on a specific locus of genome and the RUNX3 knockout pigs can be useful resources for human cancer research and to develop novel cancer therapies.     

新疆牛群中鹿流行性出血热血清学调查

本研究采用鹿流行性出血热(EHD) cELISA诊断试剂盒分别对2014年和2015年6、7月份从新疆10个地(州、市)随机采集的662份牛血清进行了EHD检测。结果检出阳性48份,阳性率为7.25%;检出地区有:哈密市、巴里坤县、伊吾县、尉犁县、岳普湖县,其中哈密市和岳普湖县的阳性率较高,在20%左右。这是首次对新疆部分地区进行EHD血清学调查,检测结果为今后新疆地区的EHD研究,特别是病原学方面研究提供了科学依据。     

我国长三角与珠三角地区2014年肉鸡卫生状况调查

为掌握我国长三角和珠三角地区肉鸡养殖卫生状况,调研组联合江苏、安徽等5省（市）相关兽医技术支撑部门开展了肉鸡卫生状况调查。调查发现：两地78.6%的出栏肉鸡来自“公司+农户”或公司;72.9%的养殖场户采取全进全出方式饲养,且不同类型养殖场户饲养方式存在明显差别;10个生物安全防护措施指标平均得分56.2,生物防护安全水平随着规模化程度的提高而上升;H5亚型禽流感、新城疫和传染性法氏囊的场户免疫率超过95%;2%的场户以丢弃、出售或饲喂其他动物的方式处理病死禽。5省（市）肉鸡生长周期内的平均死淘率为7.23%（95%CI：4.24%~11.49%）;平均每只肉鸡防疫投入0.99元,其中疫苗和兽药费用占比大于88%。调查结果显示,长三角和珠三角地区进一步提升动物疫病防控水平,需要逐步淘汰防疫条件较差的养殖场户,减少活禽调运,杜绝随意丢弃或出售病死禽类的现象。     

Effects of different group B streptococci strains on platelet activation

AIM: To explore the ability of different group B streptococci (GBS) strains on inducing platelet activation. METHODS: Six strains of GBS, separated from the septic patients with thrombocytopenia, were used as the inducers. Light transmission aggregometry was used to measure platelet aggregation. Scanning electron microscopy (SEM) was performed to investigate the interaction of platelets with bacteria. The expression of platelet CD62P, Toll-like receptor 2 (TLR2) and TLR4 was determined by flow cytometry and Western blotting. Furthermore, the activity of platelet TLR2 (or TLR4) was blocked by anti-TLR2 (or anti-TLR4) monoclonal antibody, and the platelet aggregation induced by GBS was detected. RESULTS: Only 3 of 6 GBS strains isolated from the septic patients induced platelet aggregation and up-regulated the expression of CD62P and TLR2 in the platelets (P < 0.05), but not TLR4. Incubation with anti-TLR2 antibody, but not anti-TLR4 antibody, significantly blocked platelet aggregation induced by GBS.CONCLUSION: Some GBS strains from the patients are able to trigger platelet activation in vitro, and platelet TLR2 may play an important role in the interaction between GBS and platelets.     

Evaluation of four portable blood glucose meters in diabetic and non-diabetic dogs and cats

Background: Monitoring of an animal's blood glucose concentration is critical for diagnostic and therapeutic decisions. Over the past few decades, portable blood glucose meters (PBGMs) have been used to monitor blood glucose concentrations in animals. Recently, new and improved PBGMs have been made available on the market.

Objective: The purpose of this study was to evaluate four PBGMs for use in dogs and cats.

Animals and methods: A total of 155 venous blood samples of dogs and 85 venous blood samples of cats were tested using four PBGMs. Control solutions from manufacturers were used to determine the precision of each meter. The coefficient of variation was calculated to determine precision during a set of replicates. Pearson's correlation analysis, Passing–Bablok regression, and Bland–Altman analysis were used to determine the accuracy of four PBGMs against the hexokinase reference method. Error grid analysis was used to evaluate clinical relevance.

Results: All PBGMs, except CERA-PET®, were clinically acceptable for monitoring blood glucose concentrations; AlphaTrak® and VetMate® appeared to be the most accurate ones, demonstrating that to use PBGMs for glucose monitoring, it is important to understand the strengths or limitations of each meter. The difference in results between the PBGMs and the reference method increased at high glucose concentration ranges, which were also affected by the hematocrit.

Conclusions: Although readings of the PBGMs and the reference method varied across glycemic ranges (low, normal, and high glucose concentrations), most PBGMs were clinically acceptable for monitoring blood glucose concentrations in dogs and cats.     

青海省利用马铃薯抗晚疫病品种问题的商榷

青海省是我国马铃薯的重要产区之一。晚疫病在本省容易发病的地区最近十年中流行了五次(1954、1955、1958、1959、1961年)平均每两年流行一次,一般减产在20％左右。但也有经常不流行的地区可以被利用为免疫品种繁育的基地。 1.晚疫病在青海不同地区的流行规律: 晚疫病的流行与否,完全决定于当年的气候条件。由于青海省地形复杂,各地的发病条件也不一致。根据影响晚疫病流行的两大主要气候因素——相对湿度和温度,大致可以分为三类地区: 第一类地区为温度能经常满足病害流行要求。如东部农业区的川水和部分浅山地区(海拔     

Development of multiplex polymerase chain reaction assays for detecting enterotoxigenic Escherichia coli and their application to field isolates from piglets with diarrhea.

Fimbriae and enterotoxins are major virulence factors associated with enterotoxigenic Escherichia coli (ETEC). In this study, 3 sets of multiplex polymerase chain reaction (mPCR) assays targeting fimbriae, enterotoxins, and other adherence factors were developed for detecting ETEC. A total number of 188 E. coli field isolates were examined, and percentages of E. coli strains carrying each virulence factors were as follows: F4 (7.45%), F5 (29.79%), F6 (6.38%), F18 (15.43%), F41 (3.72%), STa (10.11%), STb (20.74%), LT (9.57%), Stx2e (2.13%), EAST1 (42.02%), F1 (67.55%), AIDA-I (2.66%), and pAA (7.45%). Of the 188 E. coli field isolates examined, 25.53% were found to be pathogenic ETEC, having both fimbriae and enterotoxins. However, the ratio increased to 44.68% when the presence of other adhesins was considered as criteria for virulence. Among the adherence factors, F1 was found to be the most prevalent. AIDA-I and pAA were also found with similar ratio as compared with other virulence factors. In addition, virulence patterns carrying these alternate adhesive genes with enterotoxins were detected with significant ratio. Therefore, it is desirable that alternate adhesins be considered as markers for diagnosis of ETEC.