Application of recombinase polymerase amplification method for rapid detection of infectious laryngotracheitis virus

Infectious laryngotracheitis is a significant respiratory disease of chickens that causes huge economic losses due to high morbidity and mortality and reduced egg production. A real-time recombinase polymerase amplification (RPA) assay was developed to accurately detect ILTV. The specific probe and primer sets were carefully designed and screened. The real-time RPA assay was carried out at 39 °C for 30 min, and results were obtained within 15 min. The results of the specificity assay showed no fluorescence signals with other avian-related viruses. The sensitivity of the assay was 1 × 10² copies/μL. The low CV value showed that the assay was reproducible. A total of 115 clinical samples were tested using the real-time RPA assay and the real-time PCR assay in parallel; the coincidence rates of the two detection methods were 100%. The results indicated that the real-time RPA assay is a specific, sensitive, rapid, and useful tool for epidemiological studies and clinical diagnosis, especially in the field and in resource-poor areas.     

美白化妆品卫生安全及功效评价

美白化妆品越来越被人们所重视,其安全性和功效性评价已成为消费者和生产厂家所关注的重点。本文从科学角度介绍了美白化妆品的美白原理,美白成分及其卫生安全评价,以及国内外对美白化妆品功效评价的进展情况,包括美白活性成分的仪器分析法、功效评价的体外细胞法、动物试验法和人体皮肤试验仪器测试法等。同时展望了美白化妆品的未来发展趋势,为我国美白化妆品事业的发展提供参考。     

化妆品过敏的检测和评价

随着化妆品的广泛使用,化妆品过敏的现象也越来越普遍,受到人们的高度关注。作者对化妆品过敏的原因、化妆品过敏的分类和特点做了简要介绍,而对国内外化妆品过敏的非动物检测和评价方法做了重点介绍,主要包括皮肤斑贴试验、体外皮肤模型试验、角质层水分含量试验、皮肤屏障功能试验、皮肤红斑指数测试、皮肤其它生理指数测试等,并针对化妆品过敏的种种现象,对我国化妆品过敏防治的未来发展趋势做了展望,为我国化妆品事业的健康发展提供技术参考。     

“一带一路”广西云南重点口岸蚊类监测分析

目的通过“一带一路”重点口岸蚊虫专项监测,了解西南口岸蚊虫种群构成及变化,为口岸蚊媒传染病防控提供科学依据。方法分别在2018年、2019年夏季于广西东兴、云南瑞丽和磨憨3个口岸,采用灯诱法、吸蚊器法采集成蚊,形态鉴定后,记录蚊种和数量。结果2018年、2019年3个口岸共捕获成蚊90156只,经鉴定隶属3亚科7属31种:按蚊属11种共9645只,占10.70%;库蚊属10种共71312只,占79.10%;伊蚊属6种共4597只,占5.10%;阿蚊属1种共1852只,占2.05%;曼蚊属1种2658只,占2.95%;轲蚊属1种2只,占0.002%;巨蚊属1种90只,占0.10%。3个口岸的蚊种为:东兴16种、瑞丽13种、磨憨23种。2018年共捕获成蚊7属28种,2019年共捕获成蚊6属19种,但黑点库蚊(磨憨1只)、埃及伊蚊(瑞丽1只)、多斑按蚊(磨憨30只)只在2019年监测到。三带喙库蚊在东兴口岸占78.29%(17300只),瑞丽口岸占94.24%(36310只),磨憨口岸占52.43%(15481只)。结论应将蚊虫专项监测与本底监测相结合,防止乙脑、疟疾、登革热等蚊媒传染病的跨境传播。     

Exposure assessment of 3-monochloropropane-1, 2-diol esters from edible oils and fats in China

3-monochoropropane-1, 2-diol (3-MCPD) esters from edible oils are considered to be a possible risk factor for adverse effects in human. In the present study, the exposure assessment of 3-MCPD esters to Chinese population was performed. A total of 143 edible oil and fat samples collected from Chinese markets were determined for the concentrations of 3-MCPD esters. The concentration data together with the data of fats consumed were analyzed by the point evaluation and probabilistic assessment for the exposure assessment. The point evaluation showed that the mean daily intake (DI) of 3-MCPD esters were lower than the value of provisional maximum tolerable daily intake (PMTDI) of 3-MCPD (2 µg/kg BW/d). The mean DI values in different age groups obtained from probabilistic assessment were similar to the results of the point evaluation. However, in high percentiles (95th, 97.5th, 99th), the DI values in all age groups were undesirably higher than the value of PMTDI. Overall, the children and adolescents exposed more to 3-MCPD esters than the adults. Uncertainty was also analyzed for the exposure assessment. Decreasing the level of 3-MCPD esters in edible oils and consuming less oil were top priority to minimize the risk of 3-MCPD esters.     

秦皇岛口岸首例输入性登革热病例的分子溯源

目的对2012年秦皇岛口岸的首例登革热输入性病例进行分子溯源,确定病毒的基因型别及感染来源。方法应用ELISA方法和实时荧光RT-PCR方法对患者进行初筛,利用RT-PCR法扩增病毒的NS1基因并测序,根据获得的序列进行同源性分析、遗传距离计算及系统进化树的构建。结果从患者2份血清(QHD-01-BS1和QHD-01-BS2)中检测到Ig M抗体阳性,从QHD-01-BS1及尿液(QHD-01-US)中检测到登革热2型病毒的NS1基因。同源性分析发现QHD-01-BS1(US)与COM基因型中的印度株GWL39 INDI-01和GWL18 INDI-01同源性最高,为97.3%;QHD-01-BS1(US)的遗传距离与COM基因型遗传距离最小,为0.04;进化分析显示QHD-01-BS1(US)与GWL39 INDI-01和GWL18 INDI-01亲缘关系最近。结论分子溯源证实患者感染的登革热病毒与来源于印度的登革热2型病毒亲缘关系最近,指示其传染源极有可能在印度。     

我国食品来源金黄色葡萄球菌种群结构分析

目的了解我国食源性金黄色葡萄球菌(金葡菌)的种群结构。方法通过全基因组测序方法对2006-2020年我国16个省份收集的763株食源性金葡菌进行多位点序列分型、葡萄球菌蛋白A编码基因(spa)和葡萄球菌染色体mec基因盒(SCCmec)分型, 使用BioNumerics 7.5软件创建基于ST类型的最小生成树。国外进口食品分离到的金葡菌31株被纳入基因组系统发育树的构建。结果 763株金葡菌共鉴定出90个ST型和160个spa型别, 其中20种为新ST型别。72个(72/90, 80.0%)ST型属于22个克隆群, 其中主要型别为CC7、CC1、CC5、CC398、CC188、CC59、CC6、CC88、CC15和CC25, 占82.44%(629/763)。其中优势克隆群中ST型和spa型别随着时间的变化呈多态性变化。耐甲氧西林金葡菌(MRSA)的阳性率为7.60%, 共鉴定出7种SCCmec型别, 以ST59-t437-Ⅳa(17.24%, 10/58)、ST239-t030-Ⅲ(12.07%, 7/58)、ST59-t437-Ⅴb(8.62%, 5/58)、ST338-t437-...     

Inclusion of membrane-anchored LTB or flagellin protein in H5N1 virus-like particles enhances protective responses following intramuscular and oral immunization of mice

We previously demonstrated that intramuscular immunization with virus-like particles (VLPs) composed of the haemagglutinin (HA), neuraminidase (NA), and matrix (M1) proteins of A/meerkat/Shanghai/SH-1/2012 (clade 2.3.2.1) protected mice from lethal challenge with viruses from other H5 HPAI clades. The inclusion of additional proteins that can serve as immunological adjuvants in VLPs may enhance adaptive immune responses following vaccination, and oral vaccines may represent the safest choice. Here, we report the generation of H5N1 VLPs composed of the viral HA, NA, and M1 proteins and membrane-anchored forms of the Escherichia coli heat-labile enterotoxin B subunit protein (LTB) or the Toll-like receptor 5 ligand flagellin (Flic). Mice intramuscularly or orally immunized with VLPs containing LTB or Flic generated greater humoural and cellular immune responses than those administered H5N1 VLPs without LTB or Flic. Intramuscular immunization with VLPs protected mice from lethal challenge with homologous or heterologous H5N1 viruses irrespective of whether the VLPs additionally included LTB or Flic. In contrast, oral immunization of mice with LTB- or Flic-VLPs conferred substantial protection against lethal challenge with both homologous and heterologous H5N1 influenza viruses, whereas mice immunized orally with VLPs lacking LTB and Flic universally succumbed to infection. Mice immunized orally with LTB- or Flic-VLPs showed 10-fold higher virus-specific IgG titres than mice immunized with H5N1-VLPs lacking LTB or Flic. Collectively, these results indicate that the inclusion of immunostimulatory proteins, such as LTB and Flic, in VLP-based vaccines may represent a promising new approach for the control of current H5N1 HPAI outbreaks by eliciting higher humoural and cellular immune responses and conferring improved cross-clade protection.