2003～2007年中国风疹病毒基因特征分析

本研究用Vero细胞或Vero/SLAM细胞从我国10个省(直辖市、自治区,下同)2003～2007年风疹暴发和散发病例的咽拭子标本中分离到57株风疹病毒,用RT-PCR方法扩增了57株风疹病毒E1基因1 107个核苷酸的片段,并对该PCR产物进行序列测定和分析.结果提示,在基于WHO基因定型靶序列739个核苷酸片段构建的基因亲缘关系树上,其中55株风疹病毒株属于1E基因型,相对于其他国家的1E基因型,形成一个独立分支;另外2株风疹病毒属于2B基因型.57株风疹病毒大部分核苷酸的突变为无义突变,氨基酸序列高度保守,除了2株风疹病毒在E1蛋白血凝抑制和中和位点区域第212位氨基酸由Thr变为Ser,其他病毒株均无重要抗原位点的改变;所有我国已分离到的1E基因型风疹病毒在E1蛋白第338位氨基酸共享突变位点(Leu338→Phe338),而其他基因型以及其他国家的1E基因型风疹病毒在该位点均未发生突变,提示该氨基酸(Phe338)可能是我国1E基因型风疹病毒所特有.2003～2007年在我国10个省均分离到1E基因型,而2B基因型只在2006年从四川省的越南输入病例中分离到,提示1E为绝对优势基因型,2B基因型为输入基因型.与1979～1984年和1999～2002年我国流行的风疹基因型不同,发生了基因型的更替,近年我国风疹的流行是由1E基因型为主的风疹野病毒的多个传播链引起.     

Epidemiology and Genotypic Diversity of Eurasian Avian-Like H1N1 Swine Influenza Viruses in China

Eurasian avian-like H1 N1(EA H1 N1) swine influenza virus(SIV) outside European countries was first detected in Hong Kong Special Administrative Region(Hong Kong, SAR) of China in 2001. Afterwards, EA H1 N1 SIVs have become predominant in pig population in this country. However, the epidemiology and genotypic diversity of EA H1 N1 SIVs in China are still unknown. Here, we collected the EA H1 N1 SIVs sequences from China between 2001 and 2018 and analyzed the epidemic and phylogenic features, and key molecular markers of these EA H1 N1 SIVs. Our results showed that EA H1 N1 SIVs distributed in nineteen provinces/municipalities of China. After a long-time evolution and transmission, EA H1 N1 SIVs were continuously reassorted with other co-circulated influenza viruses, including 2009 pandemic H1 N1(A(H1 N1)pdm09), and triple reassortment H1 N2(TR H1 N2) influenza viruses, generated 11 genotypes. Genotype 3 and 5, both of which were the reassortments among EA H1 N1, A(H1 N1)pdm09 and TR H1 N2 viruses with different origins of M genes, have become predominant in pig population. Furthermore, key molecular signatures were identified in EA H1 N1 SIVs. Our study has drawn a genotypic diversity image of EA H1 N1 viruses, and could help to evaluate the potential risk of EA H1 N1 for pandemic preparedness and response.     

1968−2014年中国甲型H3N2流感病毒PB1基因进化分析

【目的】分析季节性H3N2流感病毒PB1基因序列的变异情况,揭示H3N2流感病毒PB1基因的分子特征与进化趋势。【方法】对1968?2014年中国地区82株人H3N2毒株、2012?2014年江苏省分离的81株甲型H3N2流感病毒、6株SIV和4株AIV H3N2亚型PB1、PB1-F2基因进行分子进化分析。【结果】1968?2014年中国H3N2流感毒株PB1核苷酸和氨基酸相似性分别为90.91%?100%和96.91%?100%。系统进化树分析,1968?2014年共173株H3N2流感病毒总体上分为4个分支,2002?2014年分离毒株位于第IV分支上,1968?1994年分离毒株位于第II和III分支;猪源H3N2亚型分布于第I、II、IV分支上;分子特征显示PB1氨基酸52、113、179、216、576、586、619、621、709位在2002年以后发生适应性改变,替换了原来的氨基酸;PB1-F2基因编码截断型蛋白长度有52、34、25、24、11 aa (猪源),PB1-F2蛋白毒力关键位点上未出现高致病性特征突变。【结论】自1968年起H3N2亚型PB1基因变异逐步趋于稳定,且PB1-F2截断型毒株正逐渐成为一类新的进化特征,但PB1基因与其他亚型之间发生重配以及关键毒力位点的变异仍应是监测的重点。     

Detection of Oseltamivir-Resistant Pandemic Influenza A(H1N1)pdm2009 in Brazil: Can Community Transmission Be Ruled Out?

Although surveillance efforts that monitor the emergence of drug-resistant strains of influenza are critical, systematic analysis is overlooked in most developing countries. We report on the occurrence of strains of pandemic influenza A(H1N1)pdm09 with resistance and decreased susceptibility to oseltamivir (OST) in Brazil in 2009, 2011 and 2012. We found 7 mutant viruses, 2 with the mutation S247N and other 5 with the mutation H275Y. Most of these viruses were from samples concentrated in the southern region of Brazil. Some of these resistant viruses were detected prior to the initiation of OST treatment, suggesting that community transmission of mutant viruses may exist. Moreover, we show that one of these OST-resistant (H275Y) strains of A(H1N1)pdm09 was discovered in the tri-border region between Brazil, Argentina and Paraguay, highlighting that this strain could also be found in other Latin American countries. Our findings reinforce the importance of enhanced antiviral resistance surveillance in Brazil and in other Latin American countries to confirm or rule out the community transmission of OST-resistant strains of A(H1N1)pdm09.     

Genetic characterization of swine influenza viruses isolated in Japan between 2009 and 2012

Eleven swine influenza viruses (SIVs) isolated from pigs in Japanese institutions between 2009 and 2012 were genetically characterized. Seven H1N1 were shown to have originated from A(H1N1)pdm09 viruses. Two H1N2 viruses contained H1 and N2 genes of Japanese H1N2 SIV origin together with internal genes of A(H1N1)pdm09 viruses. Two H3N2 viruses isolated during animal quarantine were identified as triple reassortant H3N2 viruses maintained among pigs in North America. This study shows that A(H1N1)pdm09 viruses and their reassortant strains are already present in domestic pigs in Japan and that novel SIVs are possibly being imported from abroad.     

Reassortant swine influenza viruses isolated in Japan contain genes from pandemic A(H1N1) 2009

In 2013, three reassortant swine influenza viruses (SIVs)—two H1N2 and one H3N2—were isolated from symptomatic pigs in Japan; each contained genes from the pandemic A(H1N1) 2009 virus and endemic SIVs. Phylogenetic analysis revealed that the two H1N2 viruses, A/swine/Gunma/1/2013 and A/swine/Ibaraki/1/2013, were reassortants that contain genes from the following three distinct lineages: (i) H1 and nucleoprotein (NP) genes derived from a classical swine H1 HA lineage uniquely circulating among Japanese SIVs; (ii) neuraminidase (NA) genes from human‐like H1N2 swine viruses; and (iii) other genes from pandemic A(H1N1) 2009 viruses. The H3N2 virus, A/swine/Miyazaki/2/2013, comprised genes from two sources: (i) hemagglutinin (HA) and NA genes derived from human and human‐like H3N2 swine viruses and (ii) other genes from pandemic A(H1N1) 2009 viruses. Phylogenetic analysis also indicated that each of the reassortants may have arisen independently in Japanese pigs. A/swine/Miyazaki/2/2013 were found to have strong antigenic reactivities with antisera generated for some seasonal human‐lineage viruses isolated during or before 2003, whereas A/swine/Miyazaki/2/2013 reactivities with antisera against viruses isolated after 2004 were clearly weaker. In addition, antisera against some strains of seasonal human‐lineage H1 viruses did not react with either A/swine/Gunma/1/2013 or A/swine/Ibaraki/1/2013. These findings indicate that emergence and spread of these reassortant SIVs is a potential public health risk.     

Isolation and genetic characterization of avian-like H1N1 and novel ressortant H1N2 influenza viruses from pigs in China

As pigs are susceptible to both human and avian influenza viruses, they have been proposed to be intermediate hosts or mixing vessels for the generation of pandemic influenza viruses through reassortment or adaptation to the mammalian host. In this study, we reported avian-like H1N1 and novel ressortant H1N2 influenza viruses from pigs in China. Homology and phylogenetic analyses showed that the H1N1 virus (A/swine/Zhejiang/1/07) was closely to avian-like H1N1 viruses and seemed to be derived from the European swine H1N1 viruses, which was for the first time reported in China; and the two H1N2 viruses (A/swine/Shanghai/1/07 and A/swine/Guangxi/13/06) were novel ressortant H1N2 influenza viruses containing genes from the classical swine (HA, NP, M and NS), human (NA and PB1) and avian (PB2 and PA) lineages, which indicted that the reassortment among human, avian, and swine influenza viruses had taken place in pigs in China and resulted in the generation of new viruses. The isolation of avian-like H1N1 influenza virus originated from the European swine H1N1 viruses, especially the emergence of two novel ressortant H1N2 influenza viruses provides further evidence that pigs serve as intermediate hosts or “mixing vessels”, and swine influenza virus surveillance in China should be given a high priority.     

Rubella epidemics and genotypic distribution of the rubella virus in shandong province, china, in 1999-2010

Background

The rubella vaccine was introduced into the immunization program in 1995 in the Shandong province, China. A series of different rubella vaccination strategies were implemented at different stages of measles control in Shandong province.

Methodology/Principal Findings

The average reported incidence rate of rubella cases remained at a low level in Shandong province after 1999. However, rubella epidemics occurred repeatedly in 2001/2002, 2006, and 2008/2009. The age of the onset of rubella cases gradually increased during 1999–2010, which showed that most cases were found among the 10 years old in 1999 and among the 17 years old in 2010. Phylogenetic analysis was performed and a phylogenetic tree was constructed based on the World Health Organization standard sequence window for rubella virus isolates. All rubella viruses isolated in Shandong province were divided into 4 genotypes: 1E, 1F, 2A, and 2B. Genotype 1E viruses accounted for the majority (79%) of all these viruses. The similarity of nucleotide and amino acid sequences among genotype 1E viruses was 98.2–100% and 99.1–100%, respectively. All Shandong genotype 1E strains, differed from international genotype 1E strains, belonged to cluster 1 and interdigitated with the viruses from other provinces in mainland China. The effective number of infections indicated by a Bayesian skyline plot remained constant from 2001 to 2009.

Conclusions/Significance

The gradual shift of disease burden to an older age group occurred after a rubella-containing vaccine was introduced into the childhood immunization schedule in 1995 in Shandong province. Four genotypes, including 1E, 1F, 2A, and 2B, were found in Shandong province during 2000–2009. Genotype 1E, rather than genotype 1F, became the predominant genotype circulating in Shandong province from 2001. All Shandong genotype 1E viruses belong to the genotype 1E/cluster 1; they have constantly circulated, and co-evolved and co-circulated, with those from other provinces.     

Sequence comparison of the capsid region of hepatitis E viruses isolated from Myanmar and China.

Hepatitis E viruses (HEVs) were isolated during epidemics, one from Myanmar (formerly called Burma) and one from China and were partially sequenced. Another HEV Myanmar strain from sporadic hepatitis was previously sequenced by us. A cDNA sequence comparison was performed among them in the 3'-terminal region, approximately 750-base long. This region contained at least two immunological epitopes and was considered to correspond to the structural protein. The nucleotide sequence identity was 97.2% between the two Myanmar strains and 93.3 and 92.5% between the two Myanmar and the China strain. The deduced amino acid sequence identity ranged from 98.4 to 100.0% among the three strains. Thus this segment was well conserved on the amino acid level among the different strains isolated from these two Asian countries, although the China strain diverged more from the Myanmar strains on the nucleotide sequence level. This data may provide important information for the development of a vaccine and for identification of the virological link between different geographical locations.     

人集落刺激因子-1(CSF-1)对常见呼吸道病毒的抑制作用

本文观察集落刺激因子-1(CSF-1)及其诱生剂:内毒素(LPS)、胞壁二肽(MDP)和干扰素(IFN-α)对下列病毒所致细胞病变的抑制,包括不同型别腺病毒5株,单疱病毒Ⅰ型和Ⅱ型,流感病毒A_3型,鼻病毒,ECHO11型各1株,在人胚肺传代细胞株上病变抑制的结果如下:对HSV-1、HSV-2、腺病毒6、11、22型,流感A_3型,鼻病毒。(CSF-1)和IFN-α,一样有明显抑毒效果,LPS MDP联合使用对以上病毒有明显增强抑毒作用。CSF-1和IFN-α的抑毒作用能分别被CSF-1和IFN-α的抗体所解除。 CSF-1在人胚肺传代细胞和人胚皮肤肌肉传代细胞上对VSV的抑毒效果在人胚肺细胞中效果比人胚皮肤肌肉细胞更明显。LPS10ng/ml作用48小时比作用24小时效果更强。LPS MDP和IFN-α对二种细胞都有同样高效的抑毒作用。