蛋类禽流感病毒检测报告

了解丽水市禽蛋标本禽流感病毒的感染状况。方法 对随机抽样的690只鸡、鸭、鸽蛋及126份农贸市场外环境对照标本采用荧光定量PCR方法检测禽流感病毒H7N9、H5和H9亚型核酸。结果 690只禽蛋标本H7N9、H5及H9亚型禽流感病毒核酸检测均为阴性,126份外环境对照标本H7N9亚型禽流感病毒核酸检测均为阴性,H5和H9亚型阳性标本各2份,阳性率为3.17%。结论 禽蛋中H7N9、H5及H9亚型禽流感病毒污染率低,但丽水市禽间存在H5和H9亚型禽流感的传播。各有关部门应加强合作,采取切实有效措施,防止人感染禽流感。     

Inactivation of avian influenza virus by heat and high hydrostatic pressure

Avian influenza viruses threaten the life of domestic terrestrial poultry and contaminate poultry meat and eggs. Recently, these viruses rarely infected humans but had a high mortality rate in Southeast Asia, the Middle East, and Egypt. Thereby, these viruses caused high economic costs for production of poultry and health protection. We inactivated a highly pathogenic avian influenza A virus of subtype H7N7 in cell culture medium and chicken meat by heat and high hydrostatic pressure. Because heat and pressure inactivation curves of the H7N7 virus showed deviations from first-order kinetics, a reaction order of 1.1 had to be selected. A mathematical inactivation model has been developed that is valid between 10 and 60 degrees C and up to 500 MPa, allowing the prediction of the reduction in virus titer in response to pressure, temperature, and treatment time. Incubation at 63 degrees C for 2 min and 500 MPa at 15 degrees C for 15 s inactivated more than 10(5) PFU/ml, respectively. Thus, we suggest high-pressure treatment of poultry and its products to avoid the possible health threat by highly pathogenic avian influenza viruses.     

A(H1N1)流感病毒及抗病毒新药的筛选

A(H1N1)流感病毒是2009年3~4月在美国和墨西哥发现的一种流感病毒变异的新病毒株。这类流感疫情的蔓延引起了世界各国和世界卫生组织的严重关注。本文介绍了A(H1N1)流感新病毒株及感染这种病毒患者的症状,A(H1N1)流感病毒的致命力和传播,流感病毒变异对抗病毒药的抗药性,以及1918年流感大流行病毒聚合酶特性,人流感病毒和禽流感病毒聚合酶的结晶结构及其在感染中的作用。据此,提出了抗流感病毒药的筛选思路和研究方向,为抗流感病毒新药的设计和开发提供有益的参考。     

A(H1N1)流感病毒及抗病毒新药的筛选

A(H1N1)流感病毒是2009年3～4月在美国和墨西哥发现的一种流感病毒变异的新病毒株.这类流感疫情的蔓延引起了世界各国和世界卫生组织的严重关注.本文介绍了A(H1N1)流感新病毒株及感染这种病毒患者的症状,A(H1N1)流感病毒的致命力和传播,流感病毒变异对抗病毒药的抗药性,以及1918年流感大流行病毒聚合酶特性,人流感病毒和禽流感病毒聚合酶的结晶结构及其在感染中的作用.据此,提出了抗流感病毒药的筛选思路和研究方向,为抗流感病毒新药的设计和开发提供有益的参考.     

甲型H1N1流感病毒三维空间结构预测

采用从头计算思想,用改良的遗传算法对甲型H1N1流感病毒的蛋白质空间结构进行预测研究。基于蛋白质空间结构的HP模型,构建甲型H1N1流感病毒蛋白质空间结构的3DHP模型,并利用改良的遗传算法找到最小自由能结构,从而预测得到甲型H1N1流感病毒蛋白质三维空间结构。利用蛋白质空间结构数据建立距离矩阵,通过相关性分析和显著性检验,表明预测结构与已知结构存在高度的一致性。该模型提供了一种快速预测甲型H1N1流感病毒结构的方法。     

Control of aerosol contaminants in indoor air: combining the particle concentration reduction with microbial inactivation

An indoor air purification technique, which combines unipolar ion emission and photocatalytic oxidation (promoted by a specially designed RCI cell), was investigated in two test chambers, 2.75 m3 and 24.3 m3, using nonbiological and biological challenge aerosols. The reduction in particle concentration was measured size selectively in real-time, and the Air Cleaning Factor and the Clean Air Delivery Rate (CADR) were determined. While testing with virions and bacteria, bioaerosol samples were collected and analyzed, and the microorganism survival rate was determined as a function of exposure time. We observed that the aerosol concentration decreased approximately 10 to approximately 100 times more rapidly when the purifier operated as compared to the natural decay. The data suggest that the tested portable unit operating in approximately 25 m3 non-ventilated room is capable to provide CADR-values more than twice as great than the conventional closed-loop HVAC system with a rating 8 filter. The particle removal occurred due to unipolar ion emission, while the inactivation of viable airborne microorganisms was associated with photocatalytic oxidation. Approximately 90% of initially viable MS2 viruses were inactivated resulting from 10 to 60 min exposure to the photocatalytic oxidation. Approximately 75% of viable B. subtilis spores were inactivated in 10 min, and about 90% or greater after 30 min. The biological and chemical mechanisms that led to the inactivation of stress-resistant airborne viruses and bacterial spores were reviewed.     

Label-free chemiresistive immunosensors for viruses

We report development, characterization, and testing of chemiresistive immunosensors based on single polypyrrole (Ppy) nanowire for highly sensitive, specific, label free, and direct detection of viruses. Bacteriophages T7 and MS2 were used as safe models for viruses for demonstration. Ppy nanowires were electrochemically polymerized into alumina template, and single nanowire based devices were assembled on a pair of gold electrodes by ac dielectrophoretic alignment and anchored using maskless electrodeposition. Anti-T7 or anti-MS2 antibodies were immobilized on single Ppy nanowire using EDC-NHS chemistry to fabricate nanobiosensor for the detection of corresponding bacteriophage. The biosensors showed excellent sensitivity with a lower detection limit of 10(-3) plaque forming unit (PFU) in 10 mM phosphate buffer, wide dynamic range and excellent selectivity. The immunosensors were successfully applied for the detection of phages in spiked untreated urban runoff water samples. The results show the potential of these sensors in health care, environmental monitoring, food safety and homeland security for sensitive, specific, rapid, and affordable detection of bioagents/pathogens.     

新疆琐琐葡萄提取物抗流感病毒A(H1N1)亚型作用研究

目的对新疆琐琐葡萄提取物抗流感病毒A(H1N1)亚型作用进行研究。方法1.采用狗肾传代细胞培养法和MTT法研究新疆琐琐葡萄多糖、琐琐葡萄总黄酮、琐琐葡萄总三萜对抗流感病毒A(H1N1)型作用。2.采用Read-muench法计算流感病毒A(H1N1)型在狗肾传代细胞中的半数感染量。3.通过观察细胞病变(CPE)、计算细胞病变CPE抑制率、MTT法测定药物对细胞的保护率等来评价琐琐葡萄多糖、总黄酮、总三萜的抗流感病毒效果。结果琐琐葡萄总黄酮的最大无毒作用浓度(TC0)为20μg/ml,琐琐葡萄总三萜的TC0为1500μg/ml。体外细胞试验中,琐琐葡萄黄酮、多糖提取物表现出对病毒的直接抑制作用,但是琐琐葡萄三萜提取物和利巴韦林(阳性对照)此作用不明显。体外细胞试验中,琐琐葡萄黄酮、多糖、三萜提取物均表现出对感染细胞后病毒的抑制作用,三萜的抑制效果要强于黄酮和多糖,利巴韦林的抑制作用强于黄酮、多糖、三萜。结论新疆特色植物资源—琐琐葡萄提取物抗流感病毒A(H1N1)亚型的作用是多途径的,琐琐葡萄总黄酮、琐琐葡萄多酚、琐琐葡萄三萜分别表现出对流感病毒A(H1N1)亚型感染细胞前、感染细胞后的抑制作用,以及直接抑制作用...     

Microassay for measuring thermal inactivation of H5N1 high pathogenicity avian influenza virus in naturally infected chicken meat

A precise, reproducible microassay was developed to measure thermal inactivation of high pathogenicity avian influenza (HPAI) virus in chicken meat. Small pieces of breast or thigh meat (0.05 g) from chickens infected with A/chicken/Pennsylvania/1370/1983 (H5N2) (PA/83) or A/chicken/Korea/ES/2003 (H5N1) (Korea/03) HPAI viruses were tested for inactivation in the heating block of a thermocycler. Korea/03 infected thigh and breast meat had higher virus concentrations (10(6.8) and 10(5.6) mean embryo infectious doses [EID(50)]/g, respectively) compared to PA/83 infected thigh and breast meat (10(2.8) and 10(2.3) EID(50)/g, respectively). The samples were ran through a ramp-up cycle from 25 to 70 degrees C, and meat samples were removed and examined for virus infectivity at 30, 40, 50, 60 and 70 degrees C, and after treatment for 1, 5, 10, 30 and 60 s at 70 degrees C. The reduction in virus infectivity titers was dependent on virus concentration and no HPAI virus was isolated after 1 s of treatment at 70 degrees C. A change in coloration from pink-tan to white was associated with a loss in recovery of infectious virus. The microassay provided a predictable and reproducible method to measure thermal inactivation of HPAI virus in chicken meat.     

Short communication: Antiviral activity of subcritical water extract of Brassica juncea against influenza virus A/H1N1 in nonfat milk

Subcritical water extract (SWE) of Brassica juncea was studied for antiviral effects against influenza virus A/H1N1 and for the possibility of application as a nonfat milk supplement for use as an “antiviral food.” At maximum nontoxic concentrations, SWE had higher antiviral activity against influenza virus A/H1N1 than n-hexane, ethanol, or hot water (80°C) extracts. Addition of 0.5 mg/mL of B. juncea SWE to culture medium led to 50.35% cell viability (% antiviral activity) for Madin-Darby canine kidney cells infected with influenza virus A/H1N1. Nonfat milk supplemented with 0.28 mg/mL of B. juncea SWE showed 39.62% antiviral activity against influenza virus A/H1N1. Thus, the use of B. juncea SWE as a food supplement might aid in protection from influenza viral infection.     

常温乙炔敏感振荡元件研究

报道了一种新型乙炔气体敏感元件。这种元件以Ｓｎｏ２为基体材料，工作在室温条件，对低浓度Ｃ２Ｈ２气体非常敏惑，对１０００ｐｐｍＨ２几乎没有气敏响应；其输出特性与一般加热元件明显不同，呈现为规律性极强的振荡波形，并对这种元件的气敏振荡机理进行了讨论．     

Characteristic features of InfA-15 monoclonal antibody recognizing H1, H3, and H5 subtypes of hemagglutinin of influenza virus A type

Hemagglutinin molecule is an envelope protein of influenza virus and plays an important role in the infection to human cells. Many mutations are observed in the molecule, which generates sixteen subtypes (H1–H16) of the hemagglutinin molecule for influenza virus A type. The subtypes such as H1, H2, H3, and H5 out of the sixteen are underlined molecules, which are responsible to Spain, Asia, Hong Kong, and Avian Flu, respectively. Based on the sequence analysis, three short sequences, which are highly conserved in the subtypes of influenza virus A type, were extracted. The sequence peptides were chemically synthesized and conjugated with BSA for immunization into Balb/c mice. A sequence GMVDGWYG located at the domain of fusion protein in the hemagglutinin molecule exhibited a high immuno-response, resulting in the production of a monoclonal antibody (mAb; InfA-15). The unique features of InfA-15 mAb were investigated from the viewpoint of immunological reaction, the binding affinity, the steric conformation, etc. The InfA-15 mAb could react with the H1, H3, and H5 subtype of hemagglutinin molecule of influenza virus A type. ELISAs using InfA-15 mAb suggested a wide reaction spectrum for the hemagglutinin of many important influenza viruses A type.     

Effects of yogurt containing probiotics on respiratory virus infections: Influenza H1N1 and SARS-CoV-2

Respiratory virus infections are an escalating issue and have become common worldwide. Influenza and COVID-19 are typical infectious respiratory diseases, and they sometimes lead to various complications. In a situation in which no established drug or treatment exists, consumption of proper food might be beneficial in maintaining health against external infections. We studied the potential effects of mixtures of probiotic strains on various viral infections. The purpose of this study was to assess the ability of yogurt containing probiotics to reduce the risk of respiratory viruses such as influenza H1N1 and SARS-CoV-2 infection. First, we performed in vitro tests using infected Madin-Darby canine kidney (MDCK) and Vero E6 cells, to evaluate the potential effects of yogurt containing high-dose probiotics against influenza H1N1 and SARS-CoV-2 infection. The yogurt significantly reduced plaque formation in the virus-infected cells. We also performed in vivo tests using influenza H1N1-infected C57BL/6 mice and SARS-CoV-2-infected Syrian golden hamsters, to evaluate the potential effects of yogurt. Yogurt was administered orally once daily during the experimental period. Yogurt was also administered orally as pretreatment once daily for 3 wk before viral infection. Regarding influenza H1N1, it was found that yogurt caused an increase in the survival rate, body weight, and IFN-γ, IgG1, and IL-10 levels against viral infection and a decrease in the inflammatory cytokines TNF-α and IL-6. Although the SARS-CoV-2 copy number was not significantly reduced in the lungs of yogurt-treated SARS-CoV-2-infected hamsters, the body weights and histopathological findings of the lungs were improved in the yogurt-treated group. In conclusion, we suggest that consumption of yogurt containing probiotics can lead to beneficial effects to prevent respiratory viral infections.     

低温加热状态下烤烟气溶胶释放量及其影响因素

为考察烟草在低温加热状态下气溶胶释放特性,采用自制稳态热解装置和烟密度计联用测试系统(SSTF-SDG)建立了可定量表征气溶胶释放量的烟草质量光密度(D_m)测试方法,考察了全国不同产区、品种、部位共34种烤烟样品在低温加热状态下的D_m,并对D_m与烤烟主要元素及常规化学成分的关系进行了统计分析。结果表明:①基于SSTF-SDG,该方法可分析低温加热状态下烟草D_m。②D_m与烟草中碳、氢、氮、烟碱均在0.01水平显著正相关,与钾硫比、钾氮比、(碳+氢)/氧以及糖碱比均在0.01水平显著负相关。③D_m各影响因素重要性排序依次为:碳 > 烟碱 > 钾硫比 > 氮 > 钾氮比 > 氢 > (碳+氢)/氧 > 糖碱比 > 硫 > 钾 > 总糖 > 氧 > 还原糖 > 氯 > 钾氯比。④由碳、氮和钾硫比为自变量的回归方程可较好地评价烤烟烟叶低温加热状态下气溶胶释放量。      

A Chromatographic Strip for Rapid Semi-quantitative Detection of H5 Subtype Avian Influenza Viruses in Poultry

An immunochromatographic strip was developed for rapid semi-quantitative of the H5 subtype of avian influenza viruses (H5 AIVs) in poultry. A specific monoclonal antibody 1C4 for H5 AIV hemagglutinin (HA) was produced and conjugated with colloidal gold as the detecting probes for the immunochromatographic strips, and a polyclonal antibody against H5N1 was used to firm the test line. Different from the traditional strips, four test lines with a same capture complex of different concentrations were designed on the nitrocellulose membrane. By contrast with the HA tests and the simulated infection experiment, the immune strip was proved to be specific for the detection of H5 AIV within 10 min and had the character to reflect the viruses infection degree in different organs of the infected poultry. It should be useful for diagnosing and semi-quantitative analysis of the H5 subtype of AIV.     

Bactericidal effects of negative air ions on airborne and surface Salmonella enteritidis from an artificially generated aerosol

The bactericidal effect of high levels of negative ions was studied using a custom-built electrostatic space charge device. To investigate whether the ion-enriched air exerted a bactericidal effect, an aerosol containing Salmonella Enteritidis (SE) was pumped into a sealed plastic chamber. Plates of XLT4 agar were attached to the walls, top, and bottom of the chamber and exposed to the aerosol for 3 h with and without the ionizer treatment. The plates were then removed from the chamber, incubated at 37 degrees C for 24 h, and colonies were counted. An average of greater than 10(3) CFU/plate were observed on plates exposed to the aerosol without the ionizer treatment (control) compared with an average of less than 53 CFU/plate on the ionizer-treated plates. In another series of experiments, the SE aerosol was pumped for 3 h into an empty chamber containing only the ionizer and allowed to collect on the internal surfaces. The inside surfaces of the chamber were then rinsed with 100 ml phosphate-buffered saline that was then plated onto XLT4 plates. While the rinse from the control chamber contained colony counts greater than 400 CFU/ml of wash, no colonies were found in the rinse from the ionizer-treatment chamber. These results indicate that high levels of negative air ions can have a significant impact on the airborne microbial load, and that most of this effect is through direct killing of the organisms. This technology, which also causes significant reduction in airborne dust, has already been successfully applied for poultry hatching cabinets and caged layer rooms. Other potential applications include any enclosed space such as food processing areas, medical institutions, the workplace, and the home, where reduction of airborne and surface pathogens is desired.     

Effect of ultraviolet germicidal irradiation on viral aerosols

Ultraviolet (UV) germicidal air disinfection is an engineering method used to control the airborne transmission of pathogenic microorganisms in high-risk settings. Despite the recent emergence of respiratory viral pathogens such as SARS and avian influenza viruses, UV disinfection of pathogenic viral aerosols has not been examined. Hence, we characterized the UV disinfection of viral aerosols using the bacteriophage MS2, adenovirus, and coronavirus. Our objectives were to characterize the effect of nebulization and air sampling on the survival of important viral pathogens, quantitatively characterize and estimate the UV susceptibility of pathogenic viral aerosols, and evaluate the effect of relative humidity (RH) on the susceptibility of viral aerosols, to 254 nm UV-C. The viruses were aerosolized into an experimental chamber using a six-jet Collison nebulizer, exposed to 254 nm UV, and sampled using an AGI-30 liquid impinger. Both the MS2 and adenovirus aerosols were very resistant to UV air disinfection, with a reduction of less than 1 logarithm in viable viral aerosols at a UV dose of 2608 microW s/cm2. The susceptibility of coronavirus aerosols was 7-10 times that of the MS2 and adenovirus aerosols. Unlike bacterial aerosols, there was no significant protective effect of high RH on UV susceptibility of the tested viral aerosols. We confirmed that the UV disinfection rate differs greatly between viral aerosols and viruses suspended in liquid.     

Thermal inactivation of avian influenza virus and Newcastle disease virus in a fat-free egg product

High-pathogenicity avian influenza (HPAI) virus, low-pathogenicity avian influenza (LPAI) virus, virulent Newcastle disease virus (vNDV) and low-virulent Newcastle disease virus (lNDV) can be present on the eggshell surface, and HPAI viruses and vNDV can be present in the internal contents of chicken eggs laid by infected hens. With the increase in global trade, egg products could present potential biosecurity problems and affect international trade in liquid and dried egg products. Therefore, the generation of survival curves to determine decimal reduction times (D(T)-values) and change in heat resistance of the viruses (z(D)-value) within fat-free egg product could provide valuable information for development of risk reduction strategies. Thermal inactivation studies using A/chicken/Pennsylvania/1370/83 (H5N2) HPAI virus resulted in D(55)-, D(56)-, D(56.7)-, D(57)-, D(58)-, and D(59)-values of 18.6, 8.5, 3.6, 2.5, 0.4, and 0.4 min, respectively. The z(D)-value was 4.4 °C. LPAI virus A/chicken/New York/13142/94 (H7N2) had D(55)-, D(56.7)-, D(57)-, D(58)-, D(59)-, and D(60)-values of 2.9, 1.4, 0.8, 0.7, 0.7, and 0.5 min, respectively, and a z-value of 0.4 °C. vNDV avian paramyxoviruses of serotype 1 (AMPV-1)/chicken/California/212676/2002 had D(55)-, D(56)-, D(56.7)-, D(57)-, D(58)-, and D(59)-values of 12.4, 9.3, 6.2, 5, 3.7, and 1.7 min, respectively. The z(D)-value was 4.7 °C. lNDV AMPV-1/chicken/United States/B1/1948 had D(55)-, D(57)-, D(58)-, D(59)-, D(61)-, and D(63)-values of 5.3, 2.2, 1.1, 0.55, 0.19, and 0.17 min, respectively, and a z(D)-value of 1.0 °C. Use of these data in developing egg pasteurization standards for AI and NDV-infected countries should allow safer trade in liquid egg products.     

Novel Sensor Fabrication for the Determination of Nanomolar Concentrations of Hg2+ in Some Foods and Water Samples Based on Multi-walled Carbon Nanotubes/Ionic Liquid and a New Schiff Base

The air and water stable room temperature ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [BMP]Tf₂N, multi-walled carbon nanotubes (MWCNTs), graphite powder and also a new synthesized Schiff base have been used to fabricate a new carbon composite electrode with very attractive sensing behavior. The new Schiff base was synthesized to apply as a selective agent in electrochemical responses of the voltammetric sensor for the determination of mercury (II) ions in aqueous solutions. The proposed sensor allowed the determination of mercury (II) in the wide linear dynamic range of 0.2–260.0 nmol l^?1. The limit of detection (LOD) was noticed to be 0.05 nmol l^?1. The prepared electrode was used for mercury (II) determination in the real samples.