HCV E2和HBV preS融合蛋白真核表达载体的构建及在哺乳动物细胞中的表达

目的:构建丙型肝炎病毒(HCV)E2和乙型肝炎病毒(HBV)preS融合蛋白的真核表达载体.方法:用PCR方法扩增HBV preS和HCV E2蛋白基因,并将二者克隆到真核表达载体pcDNA3中,用脂质体转染试剂将其转入COS7细胞,通过免疫荧光检测细胞瞬时表达的融合蛋白.结果:E2-preS融合蛋白基因包括了全长的HBV preS和HCV E2蛋白基因,嵌合基因长度约1.6 kb.表达载体在COS7细胞表达出了E2-preS融合蛋白.结论:构建的E2-preS融合蛋白表达载体能在哺乳动物细胞中表达融合蛋白,为获得真核表达的融合蛋白及研究此蛋白的免疫原性打下基础.     

Novel Amdoparvovirus Infecting Farmed Raccoon Dogs and Arctic Foxes

A new amdoparvovirus, named raccoon dog and fox amdoparvovirus (RFAV), was identified in farmed sick raccoon dogs and arctic foxes. Phylogenetic analyses showed that RFAV belongs to a new species within the genus Amdoparvovirus of the family Parvoviridae. An RFAV strain was isolated in Crandell feline kidney cell culture.     

运城市2006年流行性乙型脑炎疫情调查分析

目的了解山西省运城市2006年流行性乙型脑炎(乙脑)疫情的流行病学特点,探讨乙脑发病的年龄特征,为预防控制乙脑提供基础资料。方法分析法定传染病报告系统数据及现场流行病学调查资料,现场快速评估乙脑疫苗接种率,乙脑病毒IgM抗体采用酶联免疫吸附试验捕获法检测。结果运城市2006年7～8月乙脑报告发病率为1.87/10万,病死率为16.1%。≥30岁乙脑病例占总病例数的84.9%,年龄别发病率分为<4岁及≥30岁两个高峰,成人及老年人发病率高于小年龄组儿童发病率。结论运城市2006年乙脑疫情特点为成人病例构成比、发病率及病死率均较高。     

Circulating coxsackievirus A16 identified as recombinant type A human enterovirus, China

To determine the relationship of coxsackievirus A16 (CA16) to prototype CA16-G10, we conducted a phylogenetic analysis of circulating CA16 strains in China. Complex recombinant forms of CA16-related viruses involving multiple human enteroviruses, subgroup A (CA4, CA16, and enterovirus 71), are prevalent among patients with hand, foot, and mouth disease.     

中国2000～2004年流行性乙型脑炎流行病学特征分析

目的了解中国2000~2004年流行性乙型脑炎(乙脑)流行情况,为乙脑预防控制提供流行病学依据。方法利用法定传染病报告数据进行乙脑描述流行病学分析。结果中国2000~2004年乙脑报告发病率分别为0.948 9/10万、0.770 7/10万、0.654 8/10万、0.582 9/10万、0.402 1/10万,报告病例主要集中在贵州、重庆、四川、河南、云南、陕西省(直辖市);报告病例中90%为<15岁儿童。结论中国2000~2004年乙脑报告发病率逐年下降,表明乙脑预防控制取得了显著成效。     

Targeted Virome Sequencing Enhances Unbiased Detection and Genome Assembly of Known and Emerging Viruses—The Example of SARS-CoV-2

Targeted virome enrichment and sequencing (VirCapSeq-VERT) utilizes a pool of oligos (baits) to enrich all known—up to 2015—vertebrate-infecting viruses, increasing their detection sensitivity. The hybridisation of the baits to the target sequences can be partial, thus enabling the detection and genomic reconstruction of novel pathogens with <40% genetic diversity compared to the strains used for the baits’ design. In this study, we deploy this method in multiplexed mixes of viral extracts, and we assess its performance in the unbiased detection of DNA and RNA viruses after cDNA synthesis. We further assess its efficiency in depleting various background genomic material. Finally, as a proof-of-concept, we explore the potential usage of the method for the characterization of unknown, emerging human viruses, such as SARS-CoV-2, which may not be included in the baits’ panel. We mixed positive samples of equimolar DNA/RNA viral extracts from SARS-CoV-2, coronavirus OC43, cytomegalovirus, influenza A virus H3N2, parvovirus B19, respiratory syncytial virus, adenovirus C and coxsackievirus A16. Targeted virome enrichment was performed on a dsDNA mix, followed by sequencing on the NextSeq500 (Illumina) and the portable MinION sequencer, to evaluate its usability as a point-of-care (PoC) application. Genome mapping assembly was performed using viral reference sequences. The untargeted libraries contained less than 1% of total reads mapped on most viral genomes, while RNA viruses remained undetected. In the targeted libraries, the percentage of viral-mapped reads were substantially increased, allowing full genome assembly in most cases. Targeted virome sequencing can enrich a broad range of viruses, potentially enabling the discovery of emerging viruses.     

Multisystem Inflammatory Syndrome after Breakthrough SARS-CoV-2 Infection in 2 Immunized Adolescents,United States

Eight weeks after having laboratory-confirmed SARS-CoV-2 breakthrough infections, 2 otherwise healthy, fully immunized adolescent patients in the United States who were experiencing related signs and symptoms were diagnosed with multisystem inflammatory syndrome in children. Our findings indicate that COVID-19 vaccination does not completely protect adolescents against multisystem inflammatory syndrome.     

Effect of Agroecosystems on Seroprevalence of St. Louis Encephalitis and West Nile Viruses in Birds,La Pampa,Argentina, 2017–2019

In Argentina, the Pampa ecoregion has been almost completely transformed into agroecosystems. To evaluate the environmental (agricultural area, tree coverage, distance to the nearest water body and urban site) and biological (dove, cowbird, and sparrow abundance) effects on free-ranging bird exposure to St. Louis encephalitis virus (SLEV) and West Nile virus (WNV), we used generalized linear mixed models. For 1,019 birds sampled during 2017–2019, neutralizing antibodies were found against SLEV in samples from 60 (5.8%) birds and against WNV for 21 (2.1%). The best variable for explaining SLEV seroprevalence was agricultural area, which had a positive effect; however, for WNV, no model was conclusive. Our results suggest that agroecosystems in the La Pampa ecoregion increase the exposure of avian hosts to SLEV, thus potentially increasing virus activity.     

Deaths from Tick-Borne Encephalitis,Sweden

We assessed standardized mortality ratio in tick-borne encephalitis (TBE) in Sweden, 2004–2017. Standardized mortality ratio for TBE was 3.96 (95% CI 2.55–5.90); no cases in patients <40 years of age were fatal. These results underscore the need for further vaccination efforts in populations at risk for TBE.