诺如病毒感染性腹泻患者的IL-2、IL-6和IL-23水平检测及临床意义

目的研究诺如病毒感染性腹泻患者的血清白细胞介素-2(IL-2)、白细胞介素-2(IL-6)和白细胞介素-23(IL-23)的水平检测及临床意义。方法采用ELISA法对47例诺如病毒感染性腹泻患者和100例健康人的血清IL-2、IL-6和IL-23水平进行测定。结果诺如病毒感染性腹泻患者的血清IL-2、IL-6和IL-23均高于健康对照组(P<0.05)。结论血清IL-2、IL-6和IL-23水平检测在诺如病毒感染性腹泻的诊断和临床对症治疗中具有重要意义。     

Terminal modifications of norovirus P domain resulted in a new type of subviral particles, the small P particles

The protruding (P) domain of norovirus VP1 is responsible for immune recognition and host receptor interaction. Our previous studies have demonstrated that a modification of the ends of the P domain affects the conformation and/or function of the P protein. An expression of the P domain with or without the hinge, or with an additional cysteine at either ends of the P protein resulted in P dimers and/or P particles. Here we report a new type of subviral particle, the small P particles, through a further modification, either an addition of the flag tag or a change of the arginine cluster, at the C-terminus of the cysteine-containing P domain. Gel filtration and cryo-EM studies showed that the small P particles are tetrahedrons formed by 6 P dimers or 12 P monomers that is half-size of the P particles. Fitting of the crystal structure of the P domain into the cryo-EM density map of the particle indicated similar conformations of the P dimers as those in P particles. The small P particles bind human HBGAs and are antigenically reactive similar to their parental VLPs and P particles. These data suggest that the C-terminus of the P domain is an important factor in the formation of the P particles. Further elucidation of the mechanism of these modifications in the P particle formation would be important in structure biology and morphogenesis of noroviruses. The small P particles may also be a useful alternative in study of norovirus-host interaction and vaccine development for noroviruses.     

The effect of pre-treatment and sonication of centrifugal ultrafiltration devices on virus recovery

Enteric viruses such as norovirus (NV) and hepatitis A (HAV) are responsible for a large proportion of food and water-borne illnesses. Most human pathogenic enteric viruses cannot be cultured so they must be detected by molecular techniques. Male specific (F⁺) RNA coliphages, a potential surrogate for human enteric viruses, can be detected by culture and molecular assays. Numbers of viruses and F-RNA coliphages in contaminated food or water may be too low for direct detection. Ultrafiltration is a general concentration method for all virus types but there is little information on the recovery efficiency of F-RNA coliphages and enteric viruses. The recovery of F-RNA coliphage MS2 was only 25% by plaque assay in initial trials. The objective was to optimize the recovery of concentrated MS2 from Microsep 100K ultrafiltration devices. The mean recovery of MS2 increased significantly to 85% by plaque assay and 65% by real-time RT-PCR when ultrafiltration devices were treated with 1% BSA before concentration and then ultrasonicated after concentration. The method was validated with MS2, HAV, NV and feline calicivirus (FCV) in water and spinach eluate. The recovery of MS2, HAV and NV was significantly higher from concentrates obtained from water with treated devices than untreated devices but not significantly different for FCV or from spinach eluate. To our knowledge, this is the first study to use ultrasonication as a post-treatment step to increase recovery of viruses from ultrafiltration devices.     

上海口岸首例邮轮大规模诺如病毒感染爆发的应急处置

〔目的〕通过对某大型邮轮一起诺如病毒引起的急性胃肠炎疫情处置,关注国际间疫情变化,为国境口岸突发公共卫生事件快速反应提供对策依据。〔方法〕通过对来沪某大型邮轮的一起诺如病毒引起的急性胃肠炎的临床诊断、流行病学调查、实验室检测和卫生检疫措施的实施,探讨口岸突发公共卫生事件的快速反应对策。〔结果〕经过对邮轮上患者样本和食品样本的细菌学和病毒学检测,结合流行病学调查和临床表现确定为诺如病毒引起的急性胃肠炎,采取了以传染源控制和管理为重点、切断传播途径和保护易感人群等卫生检疫措施后控制了疫情的蔓延。〔结论〕国境卫生检疫应在排除检疫传染病的情况下,扩大疾病监测范围,以控制常见的、多发的、易引起突发公共卫生事件的传染病为重点。根据新的《国际卫生条例》的规定,调整国境口岸卫生检疫策略,加强口岸卫生检疫核心能力建设,建立应对突发公共卫生事件快速反应体系的新机制,为防止疾病的国际传播提供技术保障。     

Molecular characterization of three novel murine noroviruses

Murine noroviruses (MNV) comprise a group of newly recognized pathogens infecting laboratory mice. The first reported murine norovirus, murine norovirus 1 (MNV-1), produces a transient infection with a short duration of fecal shedding after infection of immunocompetent laboratory mice. Our laboratory subsequently isolated three novel murine noroviruses, murine norovirus 2 (MNV-2), murine norovirus 3 (MNV-3), and murine norovirus 4 (MNV-4), that have markedly different pathogenicity from MNV-1 by producing persistent infections and prolonged fecal shedding in infected immunocompetent mice. In this study, the nucleotide sequences and the predicted amino acid sequences of the three novel murine noroviruses were determined and compared to each other, MNV-1, and other previously described human and animal noroviruses. The three novel murine norovirus strains were shown to be related to each other and MNV-1 by sequence and phylogenetic analysis even though MNV-2, MNV-3 and MNV-4 all display markedly different biologic behavior from that of MNV-1. The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers DQ223041, DQ223042, and DQ223043.     

Gastroenteritis caused by norovirus GGII.4, The Netherlands, 1994-2005

From 1994 through 2005, gastroenteritis outbreaks caused by norovirus generally increased in the Netherlands, with 3 epidemic seasons associated with new GGII.4 strains. Increased percentages of GGII.4 strains during these epidemics, followed by a sharp decrease in their absolute and relative numbers, suggest development of immunity.