Establishment of High-sensitivity Rapid Fluorescence Quantitative Detection Method for Antibody against Peste des Petits Ruminants Virus

[Objectives]This study was conducted to establish a rapid quantitative method for detecting antibody against Peste des Petits Ruminants Virus(PPR V)in sheep serum.[Methods]Soluble N protein and NH fusion protein were obtained in Escherichia coli prokaryotic expression system by optimizing codons and expression conditions of E.coli.Furthermore,based on the purified soluble N protein and NH fusion protein,a high-sensitivity fluorescence immunoassay kit for detecting the antibody against PPR V was established.[Results]The method could quickly and quantitatively detect PPR V antibody in sheep serum,with high sensitivity and specificity,without any cross reaction to other related sheep pathogens.The intra-batch and inter-batch coefficients of variation were less than 10%and 15%,respectively,and the method had good repeatability.Through detection on 292 clinical serum samples,it was compared with the French IDVET competitive ELISA kit,and the coincidence rate of the two methods reached 93.84%.Compared with the serum neutralization test,the detected titer value of the high-sensitivity rapid fluorescence quantitative detection method was basically consistent with the tilter value obtained by the neutralization test on the standard positive serum(provided by the WOAH Brucellosis Reference Laboratory of France).[Conclusions]This method can realize rapid quantitative detection of PPR V antibody on site,and has high practical value and popularization value.

Absolute quantitative detection of genetically modified soybean MON87708×MON89788 with stacked traits by digital polymerase chain reaction

The main advantage of digital PCR(dPCR) is that it facilitates absolute quantification of the target without reference to the standard/calibration curve.Crystal droplet dPCR has a three-color staining detection function,which enables multiplex PCR reaction.In this study,this technique was used to establish triple dPCR detection for the genetically modified soybean MON87708 × MON89788 with stacked traits.Specific absolute quantitative detection was accomplished for the genomic DNA extracted from the homogenized seeds of GM stack MON87708× MON89788 soybean.Our results can serve as a reference for the absolute quantitative detection of stacked events of genetically modified crops.

Preliminary Investigation and Analysis of Alien Pests at Panjin Port

[Objective] The paper was to understand the current situation of alien species at Panjin port,and provide the reference basis for the de-velopment,construction and management of Panjin port.[Method] The species,life forms and habitats,place of origin and invasion mode of alien pests at Panjin port were studied by the way of route survey,combined with literatures and molecular biology methods.[Result] A total of 137 species of weeds and insects were preliminarily identified at Panjin port.There were 84 species of weeds belonging to 25 families,39 of which were alien species and 3 were quarantine weeds.There were 56 species of insects belonging to 30 families,all of which were native to China.(i) There were 29 species of Compositae weeds,accounting for 35.8% of the total.(ii) Weeds were mainly annual and biennial.(iii) There were 24 species of weeds native to America,accounting for 61.5% of the total;followed by those native to Europe,with a total of 12 species,accounting for 30.8%.(iv) Weeds had poor growth,so there was no invasion,and they can be eradicated once discovered.[Conclusion] In the newly opened grain berths at Panjin port,it is suggested that all departments strictly check the pass,strengthen supervision and monitoring,scientifically introduce seeds,strengthen public education,raise public awareness,and improve the control system of alien pests.

Risk Analysis on Spring Viraemia of Carp from Imported Cyprinidae

Spring Viraemia of Carp (SVC), also known as catfish infectious ascites, is an acute, hemorrhagic infectious septicaemia. The disease can harm salmon, catfish, Carassius auratus, Hypophthalmichthys molitrix, Aristichthys nobilis, etc., and is popular in both Europe and Asia. SVC is the first type of quarantine target for fish port quarantine. The World Organization for Animal Health (OIE) lists SVC as a disease that needs to be declared, and China’s Ministry of Agriculture defines it as a class of animal disease. In order to avoid the risk of introduction of IHN due to the introduction of fingerlings, and provide decision-making departments with scientific decision-making data, this paper conducts a systematic risk analysis of SVC from risk assessment, risk management, and risk communication.

A Universal Real-Time Fluorescence qPCR Method for Identifying Epidemic Strains of African Swine Fever Virus

Objective Establishing a highly sensitive real-time fluorescence quantitative PCR (qPCR) method for universal testing of epidemic African swine fever virus (ASFV) strains. Methods The ASFV p72 gene was targeted to design primer probes covering 24 p72 genotypes. The optimal amount of dimethylsulphoxide (DMSO) for qPCR amplification was determined, Various sensitivity and limit of detection (LOD) tests were performed, and clinical samples from China and imported goods were tested. Results The optimal primer-probe combination could specifically detect ASFV, 1.5% DMSO was optimal for qPCR, and LOD reached 3.2 copies/μL with good reproducibility (n = 20, p = 0.369). The method was employed to test 142 clinically suspected samples, of which 30 pig blood and 37 pig tissue samples were ASFV-positive. Moreover, the positive testing rate for ASFV was higher than for the standard qPCR method recommended by the Office International Des Epizooties (OIE), and for the commercially available kit. Thus, our method is superior for testing weakly positive samples with low virus titre, and epidemic strains present in imported goods. Conclusion Our method could be employed for universal testing of epidemic ASFV strains worldwide, ensuring wider coverage of hosts and ASFV strains/endemic strains, reducing false negatives, and benefitting early diagnosis.

Establishment of Real-Time Fluorescent PCR Method for Detection of D Epizootic Hemorrhagic Disease of Deer

Epizootie hemorrhagic disease of deer virus (EHDV), is a member of the family Reoviridae virus (Orbi virus), and a double-stranded RNA virus from arthropods (mainly Culicoides), which is very similar in morphology and structure to Blue tongue virus (BTV). Serologically, there is a clear cross between the blue tongue virus and EHDV. EHD (caused by EHDV) is a seasonal, non-contact viral infectious disease. Under natural conditions, EHDV can cause infection of cattle, sheep and other domestic animals as well as many domesticated and wild ruminants such as white tail deer, Mi, large horned antelope and so on. The virus has been isolated from white-tailed deer, black-tailed deer, sheep, goats, cattle, bison and Culicoides. White tail deer infection is the most serious, and clinical characteristics are transient elevated body temperature, symptoms of shock, mucosal, serous bleeding and death in a coma [1]. At present, there is no effective vaccine and treatment for this disease. To control and eliminate EHD, it is necessary to spend a lot of manpower and material resources. Export trade is restricted, which brings great economic losses to the countries with EHD epidemic. Moreover, because of the complexity of antigen structure and the diversity of clinical symptoms of EHDV, it is difficult to diagnose in laboratory. Therefore, developing a quick and precise laboratory diagnostic method becomes more and more significant among researchers.

A Brief Talk on How to Promote China Health and Quarantine at Points of Entry in the Framework of Global Health

Global health concerns about the health of the global population and the concepts of global health are gradually being accepted by all of the countries in the world.China health and quarantine at points of entry(POEs) is an integral part of global health,and its duty of prevention and control of the communicable diseases in POEs is consistent with the duty of global health to promote the health of global population.Under the principle of "prevention first",health and quarantine organ carries out the work of disease prevention and control and international travel health care,the reinforcement of core capacity at POEs,and focuses on human rights protection.All the same,there are some gaps with the requirements of global health,such as the inadequate of health promotion planning capacity,ethics awareness and legal protection.The future work of health and quarantine should change ideas on communicable diseases prevention at POEs,focus more on ethical consideration,and should optimize system architecture and human resources,strengthen cooperation,maintain core capacity at POEs,thus to build points of entry public health system with Chinese characteristics,meanwhile to apply the concepts of global health deeply into every aspects of health and quarantine at POEs.