鸭流感病毒4/2004-H6N2亚型毒株的血凝素基因全序列克隆与分析

2004初从正常鸭群中分离到一株鸭源禽流感病毒，命名为A／Duck／HN／4／2004(H6N2)。经对血凝素基因(HA)序列分析发现HA基因全长为1744bp，共编码566个氨基酸，在裂解位点仅含一个碱性氨基酸-精氨酸(R)，符合LPAIV的标准。将所得基因序列与已发表的同一亚型参考序列分析表明，与H6亚型流感HA基因同源性为89．2％-97．1％，经分子遗传演化分析表明本次分离株与香港分离株A／Duck／Hong Kong／3600／99(H6N2)、A／Duck／Hong Kong／3600／99(H6N2)最近。     

Effect of rifaximin on gut-lung axis in mice infected with influenza A virus

Gut-lung axis injury is a common finding in patients with respiratory diseases as well as in animal model of influenza virus infection. Influenza virus damages the intestinal microecology while affecting the lungs. Rifaximin, a non-absorbable derivative of rifamycin, is an effective antibiotic that acts by inhibiting bacterial RNA synthesis. This study aimed to determine whether rifaximin-perturbation of the intestinal microbiome leads to protective effects against influenza infection, via the gut-lung axis. Our results showed that influenza virus infection caused inflammation of and damage to the lungs. The expression of tight junction proteins in the lung and colon of H1N1 infected mice decreased significantly, attesting that the barrier structure of the lung and colon was damaged. Due to this perturbation in the gut-lung axis, the intestinal microbiota became imbalanced as Escherichia coli bacteria replicated opportunistically, causing intestinal injury. When influenza infection was treated with rifamixin, qPCR results from the gut showed significant increases in Lactobacillus and Bifidobacterium populations, while Escherichia coli populations markedly decreased. Furthermore, pathology sections and western blotting results illustrated that rifaximin treatment strengthened the physical barriers of the lung-gut axis through increased expression of tight junction protein in the colon and lungs. These results indicated that rifaximin ameliorated lung and intestine injury induced by influenza virus infection. The mechanisms identified were the regulation of gut flora balance and intestinal and lung permeability, which might be related to the regulation of the gut-lung axis. Rifaximin might be useful as a co-treatment drug for the prevention of influenza virus infection.     

Effects of ganmao shuangjie heji on the inflammatory damage in the lungs of mice infected by IV FM1

AIM: To establish the influenza infected mouse model and study the anti-inflammatory effect of ganmao shuangjie heji. METHODS: IV FM1 infected mice were used as the animal model. The changes of pathology and the cytokine TNF-α, IFN-γ and IL-10 in the lung were observed by HE staining and ELISA (double antibody sandwich enzyme linked immunosorbent assay) after ganmao shuangjie heji treatment. RESULTS: After infected by influenza virus, severe interstitial pneumonia was induced in the model group. Mild interstitial pneumonia was observed in ganmao shuangjie heji treated group. The protein expressions of cytokine TNF-α, IFN-γ and IL-10 were higher in model group than those in the control group. The protein expressions of TNF-α and IFN-γ in ganmao shuangjie heji treated group decreased and IL-10 expression increased significantly compared with model group. CONCLUSION: Ganmao shuangjie heji decreases the expressions of TNF-α and IFN-γ, and increases the expression of IL-10, thus, alleviates inflammatory injury. The clinical application of this medicine can shorten the course of disease.     

大青叶中4（3H）喹唑酮体外抗H1N1型流感病毒的作用研究

目的：探讨大青叶中4（3H）喹唑酮体外抗H1N1型流感病毒的作用。方法：用MTT染色法测定大青叶中4（3H）喹唑酮通过不同加药方式对H1N1型流感病毒的体外抑制作用。结果：大青叶中4（3H）喹唑酮对H1N1型流感病毒具有明显的阻断作用和对细胞内病毒有抑制作用。结论：大青叶中4（3H）喹唑酮具有明显的体外阻止H1N1型流感病毒吸附到靶细胞和抑制H1N1型流感病毒增殖的作用。     

禽流感研究进展

近年来禽流感的大范围流行,造成了巨大的经济损失并严重威胁着人类健康,因此禽流感的研究越来越被人们重视。本文就目前禽流感流行状况、检测方法进行综述。     

Immune characterization of long pentraxin 3 in pigs infected with influenza virus

Long pentraxin 3 (PTX3) is a conserved pattern-recognition secreted protein and a host-defence-related component of the humoral innate immune system. The aim of the present study was to characterize swine PTX3 (SwPTX3) protein expression in influenza virus infected pigs. First, we performed in silico studies to evaluate the cross-reactivity of PTX3 human antibodies against SwPTX3. Secondly, we used in vitro analysis to detect SwPTX3 presence in swine bone marrow dendritic cells (SwBMDC) upon stimulation with different agents by Western blot and immunofluorescence. Finally, the levels of SwPTX3 were assessed in experimental infection of pigs with different strains of influenza virus. This is a novel study where the expression of SwPTX3 was evaluated in the context of a pathogen infection. The initial characterization of SwPTX3 in influenza virus infected pigs contributes to understand the role of PTX proteins in the immune response.     

Genomic analysis of influenza A virus from captive wild boars in Brazil reveals a human-like H1N2 influenza virus

Influenza is a viral disease that affects human and several animal species. In Brazil, H1N1, H3N2 and 2009 pandemic H1N1 A(H1N1)pdm09 influenza A viruses (IAV) circulate in domestic swine herds. Wild boars are also susceptible to IAV infection but in Brazil until this moment there are no reports of IAV infection in wild boars or in captive wild boars populations. Herein the occurrence of IAV in captive wild boars with the presence of lung consolidation lesions during slaughter was investigated. Lung samples were screened by RT-PCR for IAV detection. IAV positive samples were further analyzed by quantitative real-time PCR (qRRT-PCR), virus isolation, genomic sequencing, histopathology and immunohistochemistry (IHC). Eleven out of 60 lungs (18.3%) were positive for IAV by RT-PCR and seven out of the eleven were also positive for A(H1N1)pdm09 by qRRT-PCR. Chronic diffuse bronchopneumonia was observed in all samples and IHC analysis was negative for influenza A antigen. Full genes segments of H1N2 IAV were sequenced using Illumina's genome analyzer platform (MiSeq). The genomic analysis revealed that the HA and NA genes clustered with IAVs of the human lineage and the six internal genes were derived from the H1N1pdm09 IAV. This is the first report of a reassortant human-like H1N2 influenza virus infection in captive wild boars in Brazil and indicates the need to monitor IAV evolution in Suidae populations.     

Putative human and avian risk factors for avian influenza virus infections in backyard poultry in Egypt

Highly pathogenic influenza A virus subtype H5N1 causes significant poultry mortality in the six countries where it is endemic and can also infect humans. Egypt has reported the third highest number of poultry outbreaks (n = 1084) globally. The objective of this cross-sectional study was to identify putative risk factors for H5N1 infections in backyard poultry in 16 villages in Damietta, El Gharbia, Fayoum, and Menofia governorates from 2010–2012. Cloacal and tracheal swabs and serum samples from domestic (n = 1242) and wild birds (n = 807) were tested for H5N1 via RT-PCR and hemagglutination inhibition, respectively. We measured poultry rearing practices with questionnaires (n = 306 households) and contact rates among domestic and wild bird species with scan sampling. Domestic birds (chickens, ducks, and geese, n = 51) in three governorates tested positive for H5N1 by PCR or serology. A regression model identified a significant correlation between H5N1 in poultry and the practice of disposing of dead poultry and poultry feces in the garbage (F = 15.7, p < 0.0001). In addition, contact between domestic and wild birds was more frequent in villages where we detected H5N1 in backyard flocks (F = 29.5, p < 0.0001).     

流感病毒的变异及其研究现状

2013年3月,我国首次出现了人感染H7N9的禽流感疫情,给我国卫生、动物疫病防治与经济健康发展带来了严峻挑战.基于近年来禽流感等流感病毒造成的严重危害,从流感病毒的病原学、分类命名、致病性、变异特性、培养特性、临床诊断、疫苗和药物防治研究进展等方面进行了综述,以期为流感病毒的深入研究和防治提供参考.