猪轮状病毒与猪传染性胃肠炎病毒混合感染的实验室诊断

[目的]对海南省某猪场腹泻病死仔猪病原进行实验室诊断。[方法]通过临床症状观察与病理剖检,结合RT-PCR方法和病毒的分离培养进行病原鉴定。[结果]经过RT-PCR扩增,获得了PRV和TGEV阳性目的片段;应用MA-104细胞与PK-15细胞分别进行PRV与TGEV的分离培养后,可见典型的细胞病变,经过RT-PCR进一步鉴定最终确诊为PRV和TEGV混合感染。[结论]通过采用紧急接种和保守治疗等综合防治措施,获得了较好的防控效果。     

Recommendations for designing and conducting veterinary clinical pathology biologic variation studies

The recent creation of a veterinary clinical pathology biologic variation website has highlighted the need to provide recommendations for future studies of biologic variation in animals in order to help standardize and improve the quality of published information and to facilitate review and selection of publications as standard references. The following recommendations are provided in the format and order commonly found in veterinary publications. A checklist is provided to aid in planning, implementing, and evaluating veterinary studies on biologic variation (Appendix  S1 ). These recommendations provide a valuable resource for clinicians, laboratorians, and researchers interested in conducting studies of biologic variation and in determining the quality of studies of biologic variation in veterinary laboratory testing.     

A new lean no time test baking method with improved discriminating power

In response to customer concerns related to gluten strength in commercial baking, the Canadian Grain Commission assessed whether the Canadian Short Process (CSP) test bake method was generating useful data related to intrinsic strength of wheat varieties. Assessment of CSP loaf volume data for Canadian variety trials spanning 2003 to 2013 showed very little correlation with dough strength parameters as measured by farinograph and extensigraph. A lean no time (LNT) test baking method was developed that can better discriminate genotypes and provide objective indicators of the effect of intrinsic dough strength on baking quality. From early method development, through method validation and verification using diverse sets of samples targeting different Canadian wheat classes and grown in three different crop years, results showed the LNT method to be more discriminating and easily adopted by other laboratories. In 2015, the LNT method was adopted as the method of choice in future Canadian variety registration trials. The LNT method is fast, simple and well-suited to high throughput test baking conditions encountered in the evaluation of large numbers of breeder lines. A new objective parameter, loaf top ratio, was also introduced and found to correlate well with dough strength and dough handling properties.     

激光共聚焦显微镜技术进展

激光共聚焦显微镜技术发展迅速,新技术主要集中于从提高分辨率、降低光毒性、提高扫描速度、活体观察等方面提升激光共聚焦显微镜的功能,各种新技术带来更多的生物学应用潜力,因此有必要梳理分析各项新技术的原理。本研究归纳分析了光门控、白激光、Ga As P光谱检测器、超高分辨率、活细胞工作站、光片成像系统、多光子、相干反斯托克斯拉曼散射、激光捕获显微切割等技术的原理和应用潜力。并指出了现有技术在扫描速度、兼容性、样品适用性等方面的不足,展望了下一步的研究方向。该论文供研究人员在熟悉和了解新技术的基础上更加清晰的获知"基于什么样的技术能够达到什么样的生物学功能",进而获得更多的实验思路。     

African Horse Sickness Fever in Vaccinated Horses: Short Communication

Our investigation has shown that multiple vaccinations with inactivated African horse sickness (AHS) vaccines containing all 9 serotypes and produced at the Central Veterinary Research Laboratory in Dubai, UAE, protect horses from AHS. However, the immunization did not prevent African horse sickness fever (AHSF) in approximately 10% of the vaccinated horses despite high enzyme-linked immunosorbent assay and virus neutralizing antibodies. African horse sickness fever is a very mild form of AHS with similar clinical signs. From all 6 horses which had developed AHSF, no virus was isolated from EDTA blood withdrawn during the acute phase of infection. Despite high neutralizing antibodies, serotype 9 was detected by polymerase chain reaction in 4 of them. All 6 horses recovered within 72 hours, after they developed mild clinical signs of AHS.     

Tuberculosis vaccination sequence effect on protection in wild boar

The Eurasian wild boar (Sus scrofa) is a reservoir for tuberculosis (TB) in which vaccination is a valuable tool for control. We evaluated the protection and immune response achieved by homologous and heterologous regimes administering BCG and heat-inactivated Mycobacterium bovis (IV). Twenty-one wild boar piglets were randomly allocated in five groups: Control, homologous BCG, homologous IV, heterologous IV-BCG, heterologous BCG-IV. Significant 67% and 66% total lesion score reductions were detected in homologous IV (IVx2) and heterologous IV-BCG groups when compared with Control group (F_4,16 = 6.393, p = 0.003; Bonferroni _{Control vs IVx2} p = 0.026, Tukey _{Control vs IV-BCG} p = 0.021). No significant differences were found for homologous BCG (although a 48% reduction in total lesion score was recorded) and BCG-IV (3% reduction). Heterologous regimes did not improve protection over homologous regimes in the wild boar model and showed variable results from no protection to similar protection as homologous regimes. Therefore, homologous regimes remain the best option to vaccinate wild boar against TB. Moreover, vaccine sequence dramatically influenced the outcome underlining the relevance of studying the effects of prior sensitization in the outcome of vaccination.     

非洲凤仙茎基腐病病原学及药剂敏感性1）

对非洲凤仙（Impatiens wallerana Hook．f．）茎基腐病的症状进行了描述，结合病原形态特征、培养特性及rDNA－ITS序列分析结果，确定该病害由Rhizoctonia solani Kühn AG4－HG－Ⅰ融合群引起。病菌的生物学特性研究表明：菌丝较适生长温度为25～30℃；菌丝生长较佳的培养基为OA和PSA，较佳的碳源为D－（＋）麦芽糖、α－乳糖和可溶性淀粉，较佳的氮源为硝酸钾和硝酸钠；pH＝7时菌丝生长最好；光照条件对菌丝生长无影响；菌丝致死条件为51℃、10 min。采用生长速率法测定了病菌对30种杀菌剂的敏感性，结果表明，病菌对≥300亿个· g－1内生芽孢杆菌WP、1000亿个· g－1枯草芽孢杆菌WP、25％肟菌·50％戊唑醇WG、40％氟硅唑EC敏感性较高，对其EC50＜1．0 mg· L－1，可以作为田间防治非洲凤仙茎基腐病的首选杀菌剂。     

甘蔗褐条病病原菌分离鉴定及其室内毒力的测定

针对海南省不同植蔗区甘蔗褐条病的典型病斑进行分离培养、单孢纯化、形态学观察、致病性检测以及结合r DNA-ITS序列分析鉴定病原菌。分离到的5株病原菌,经回接实验表明,病原菌HT-4致病性最强,能引起与田间病害一致的症状,将菌株HT-4的r DNA-ITS序列在NCBI上进行BLAST比对。结果表明:菌株HT-4与离蠕孢属(Bipolaris)相似性达到99%,结合形态学分析确定该菌是甘蔗褐条病的病原菌。室内毒力实验表明:在7种供试药剂中,50%咪鲜胺锰盐和10%苯醚甲环唑对病原菌抑制效果最好,EC50值分别为4.400 6 mg/L和9.421 1 mg/L。结果为甘蔗褐条病的防控提供科学参考。     

高等农业院校实验教学体系改革探讨

对高等农业院校加强实验室管理、实验教学改革等方面进行了探讨,旨为高等院校的实验教学体系改革提供一些建设性建议。