流式病毒检测法的应用进展

流式病毒检测法(flow virometry,FVM)是一种利用流式细胞仪检测单个病毒颗粒及其特征的前沿技术。通过FVM,可以精确测量样本中完整病毒颗粒的浓度、表面靶抗原的丰富度以及相对直径等关键参数,进而实现对单个病毒颗粒的高效分析和表征。随着仪器设备、荧光染料和标记策略的不断发展和优化,FVM得到了广泛的应用和研究。该方法不仅被用于实现对单个病毒颗粒的精确分析,还被用于细胞外泌体和微囊泡的检测。本文总结了FVM的发展历程以及病毒等微颗粒的常用标记方法和应用领域,旨在为FVM在病毒学、免疫学、生物医学等研究领域的进一步应用提供参考和借鉴。

澳洲研发新型艾滋病病毒检测方法快速简便

澳大利亚卫生部长近日宣布，澳药物管理局已批准一种新的艾滋病病毒检测法投入市场，新检测法具有快速简便的优点。据介绍，这一初步检测法仅需取指端血样放置在测试卡上，测试卡将在20到30分钟内检验出血液中是否存在艾滋病病毒抗原和抗体。除快速外，新检测法还操作简便，不像以前仅限于医学专业人员操作。希望这种快速简便的初步检测法可以鼓励那些感染风险较高的人能够更多地参与定期检测，并积极配合治疗。数据统计显示，自1985年至2011年，澳大利亚共报告艾滋病病毒携带者31645人，其中艾滋病患者10797例。2011年，澳大利亚新发现艾滋病病毒携带者1137人，比上年增长8．3％。

Comparative Studies on Detection of Antibodies against Infectious Bursal Disease Virus with Test Strips and Agar Gel Immunodiffusion Method

[Objective] This study aimed to compare the detection results of antibodies against infectious bursal disease virus with test strips and agar gel immunodiffusion method. [Method] Antibodies against infectious bursal disease virus in chicken serum were detected using test strips developed in our laboratory, and the results were comparad^with that using traditional agar diffusion method. [Result] The comparative study of the two methods showed that the sensitivity of test strips was eight times over agar gel immunodiffusion; test strips showed higher detection rate in the deter- mination test of 216 clinical samples, with high specificity, easy preservation, and simple and rapid operation, thereby being more suitable for the monitoring of clinical antibodies. [Conclusion] Test strips could replace the existing serological methods, having great promotion and application value in antibody monitoring.

Establishment of an ELISA to Detect Kaposi's Sarcoma-associated Herpesvirus Using Recombinant ORF73

Kaposi's sarcoma-associated herpesvirus (KSHV) is causally related to Kaposi's sarcoma (KS), primary effusion lymphoma (PEL) and a proportion of cases of multicentric Castleman's disease (MCD). The ORF73 protein was cloned into pQE80L-orf73 and expressed in E.coli and purified. The expressed recombinant ORF73 was identified by sodium dodecyl sulfatepolyacrylamide gel electrophoresis (SDS-PAGE). A protein of about 27 kDa was expressed as expected. Western Blotting showed that the purified recombinant ORF73 reacted with KSHV positive serum. The immunogenicity of the recombinant ORF73 was further analysed by ELISA and the optimal conditions were determined. The ORF73 ELISA was used to compare the KSHV seroprevalence between Hubei and Xinjiang Han people. The Han people in Xinjiang have significantly higher KSHV seroprevalence than their counterparts in Hubei (6.7% vs 2.9%, P = 0.005).

Laboratory Detection and Diagnosis of Filoviruses

Ebola virus(EBOV) and Marburg virus(MARV),belonging to the Filoviridae family,emerged four decades ago and caused severe viral hemorrhagic fever in human and other primates.As high as 50-90% mortality,filoviruses can cause significant threats to public health.However,so far no specific and efficient vaccine has been available,nor have other treatment methods proved to be effective.It is of great importance to detect these pathogens specific,rapidly and sensitively in order to control future filovirus outbreaks.Here,recent progresses in the development of detection and diagnosis methods for EBOV and MARV are summarized.

An Efficient Method of Noroviruses Recovery from Oysters and Clams

Noroviruses (NoVs) are widespread causes of nonbacterial gastroenteritis. Outbreaks of NoVs caused diseases are commonly ascribed to the consumption of contaminated shellfish. The concentration and RNA extraction of NoVs are crucial steps of detecting NoVs in shellfish. This study aimed to select a simple, rapid and highly efficient recovery method of NoVs detection with real-time RT-PCR. Four methods of recovering GI.3 and GII.4 NoVs from spiked digestive tissues of oysters and clams, respectively, were compared, of them, the method involving proteinase K and PEG 8000 was found the most efficient. With this method, 9.3% and 13.1% of GI.3 and GII.4 NoVs were recovered from oysters and 9.6% and 12.3% of GI.3 and GII.4 NoVs were recovered from clams, respectively. This method was further used to detect NoVs in 84 oysters (Crassostrea gigas) and 86 clams (Ruditapes philippinarum) collected from 10 coastal cities in China from Jan. 2011 to Feb. 2012. The NoVs isolation rates were 10.47% of clams (9/86) and 7.14% of oysters (6/84). All the detected NoVs belonged to genotype GII. The NoVs recovery method selected is efficient for NoVs detection in oysters and clams.

An Improved Culture System for Virus Isolation and Detection

Cell culture plays an important role in virology. It provides a platform for the detection and isolation of viruses as well as for the biochemistry and molecular biology based studies of viruses. In the present work, a new system that could permits multiple (different) cell lines to be simultaneously cultured in one dish was developed. In the system, each cell line was cultured in an isolated zone in the same dish or well and the system is therefore called an isolated co-culture system. The usefulness of this novel approach for virus isolation was demonstrated using a model system based on adenovirus.

Unusual colonoscopy finding:Taenia saginata proglottid

Infection with tapeworms is a major problem in many parts of the world. Patients may be asymptomatic or have a significant morbidity depending on the species. Infection with Taenia species is sometimes found by expulsion of eggs or proglottids in stool. Species specific diagnosis of Taenia is difficult,but possible. We present a case of Taenia saginata incidentally discovered,and risk factors for transmission,diagnosis,symptoms,and treatment.

Orf in Goats in China： Prevalence and Risk Factors

Orf is an important viral disease that affects goats and sheep and results in large economic losses. The aim of this study was to investigate the prevalence of off and identify the potential risk factors of this disease in the main breeding areas of China. Among 1,241 blood samples collected from goats without clinical signs of off, 433 samples （34.89%） were positive for off virus infection, which was detected by polymerase chain reaction （PCR） targeting a partial B2L sequence of the viral genome. Moreover, a total of 874 buceal swab samples were collected, of which 64 samples （7.32%） were positive for the orf virus on the basis of PCR detection. According to logistic regression, all of the variables, including age, breed, location and farm management, had significant impacts on the prevalence of orf. Lambs under intensive management in Yunnan province were more susceptible to off virus infection than animals in other groups. Anglo-Nubian goats were at more risk of off positivity than other breeds, whereas Saanen dairy goats were at significantly less risk. In summary, as the first epidemiological study of off in China, this investigation suggested that off is a neglected disease that requires more attention in the future.

Micro-droplet Digital Polymerase Chain Reaction and Real-Time Quantitative Polymerase Chain Reaction Technologies Provide Highly Sensitive and Accurate Detection of Zika Virus

The establishment of highly sensitive diagnostic methods is critical in the early diagnosis and control of Zika virus(ZIKV)and in preventing serious neurological complications of ZIKV infection. In this study, we established micro-droplet digital polymerase chain reaction(ddPCR) and real-time quantitative PCR(RT-qPCR) protocols for the detection of ZIKV based on the amplification of the NS5 gene. For the ZIKV standard plasmid, the RT-qPCR results showed that the cycle threshold(Ct) value was linear from 10~1 to 10~8 copy/l L, with a standard curve R^2 of 0.999 and amplification efficiency of 92.203%;however, a concentration as low as 1 copy/l L could not be detected. In comparison with RT-qPCR, the dd PCR method resulted in a linear range of 10~1–10~4 copy/l L and was able to detect concentrations as low as 1 copy/l L. Thus, for detecting ZIKV from clinical samples, RT-qPCR is a better choice for high-concentration samples(above 10~1 copy/l L),while ddPCR has excellent accuracy and sensitivity for low-concentration samples. These results indicate that the ddPCR method should be of considerable use in the early diagnosis, laboratory study, and monitoring of ZIKV.