A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for human enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) infection was further evaluated. The one step reaction was perfor...A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for human enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) infection was further evaluated. The one step reaction was performed in a single tube at 65?C for 45 min for EV71 and 35 min for CVA16. The detection limits of RT-LAMP assays for both EV71 and CVA16 were 0.1 of a 50% tissue culture infective dose (TCID50) per reaction, based on 10—Fold dilutions of a titrated EV71 or CVA16 strain. The specific assay showed there were no cross-reactions with Coxsackievirus A (CVA) viruses (CVA 2, 4, 5, 7, 9, 10, 14, and 25), Coxsackievirus B (CVB) viruses (CVB 1, 2, 3, 4, and 5) or ECHO viruses (ECHO 3, 6, 11, and 19). In parallel with commercial quantitative real-time polymerase chain reaction (qRT-PCR) diagnostic kits for EV71 and CVA16, the RT-LAMP assay was evaluated with 515 clinical specimens, the results showed the RT-LAMP assay and the qRT-PCR assay were in complete agreement for 513/515 (99.6%) of the specimens. Two samples with discrepant results from two methods were further verified by nested reverse transcription polymerase chain reaction (nRT-PCR) assay and sequencing to be true positives for CVA16. In conclusion, RT-LAMP assay is demonstrated to be a sensitive and specific assay and have a great potential for the rapid and visual screening of EV71 and CVA16 in China, especially in those resource-limited hospitals and rural clinics of provincial and municipal regions.展开更多
目的:对比分析15~24个月及2~5岁CA16感染的普通型与危重症手足口病(hand,foot and mouth disease,HFMD)患者外周血中CD8^+T细胞的表达情况,寻找发现与CA16致病有关的免疫病理因素。方法:收集2014年5-8月间昆明市儿童医院感染科确诊的儿...目的:对比分析15~24个月及2~5岁CA16感染的普通型与危重症手足口病(hand,foot and mouth disease,HFMD)患者外周血中CD8^+T细胞的表达情况,寻找发现与CA16致病有关的免疫病理因素。方法:收集2014年5-8月间昆明市儿童医院感染科确诊的儿童HFMD病例外周血标本共72例,其中普通型32例,危重症40例,采用流式细胞术对患者外周血CD8^+T淋巴细胞亚群进行检测分析。结果:15~24个月普通型HFMD患者外周血CD8^+T淋巴细胞百分比略高于正常健康儿童参考值,而危重症患者CD8^+T细胞略低于正常参考值。此外,与正常参考值相比,2~5岁普通型及危重症患者外周血中CD8^+T淋巴细胞百分比均减低,其中危重症患者略低于普通型患者。结论:CA16感染后,不同年龄、不同病情的HFMD患者外周血中CD8^+T细胞的表达变化不太明显,说明CA16感染后,患者体内的CD8^+T细胞基本能够发挥正常的抗病毒免疫效应。而在危重症时,两个年龄段患者CD8^+T细胞百分比略低或减低,说明CA16的持续性感染可能对机体CD8^+T细胞的表达产生了影响,使其杀伤病毒效应减低,这可能是CA16感染诱导神经系统并发症发生的免疫病理因素之一。展开更多
In 2008,China launched a national surveillance system for hand‐foot‐and‐mouth disease(HFMD).Several million cases of HFMD are reported every year,coxsackievirus A16(CVA16)was the leading cause of HFMD epidemic in Y...In 2008,China launched a national surveillance system for hand‐foot‐and‐mouth disease(HFMD).Several million cases of HFMD are reported every year,coxsackievirus A16(CVA16)was the leading cause of HFMD epidemic in Yantai city,China in recent years,but the information of epidemiology and molecular characterization of CVA16 in Yantai is limited.The aim of this study is to investigate the epidemiological characteristics and pathogenic spectrum of HFMD,and most importantly,the molecular characterization of CVA16 in Yantai from 2018 to 2021.A total of 2,000 clinical samples were collected in Yantai city from 2018 to 2021 and the enterovirus typing was performed using real‐time reverse transcriptase–polymerase chain reaction(qRT‐PCR).VP1 coding regions of 41 CVA16 isolates were amplified and Sanger sequenced,and phylogenetic analysis was performed.During the study period,HFMD became prevalent from May to August each year.It peaked in June and declined in September.The incidence was highest in children aged 1 to 5 years,while more common in males than females.1,617 out of 2,000 clinical collection of samples were tested positive for enterovirus.Among them,614 were identified as CVA16,45 were enterovirus A71(EV A17),and 958 were other enterovirus serotypes.All 41 CVA16 strains belonged to the Bla and B1b genotypes.Homology analysis showed that 41 CVA16 isolates shared 83.2%–100%nucleotide and 93.7%–100%amino acid similarity among themselves.The results of this study update molecular epidemiology of CVA16 and provide a reference for HFMD prevention and control.展开更多
Background Enterovirus 71 （EV71） and coxsackievirus A16 （Cox A16） are major causative agents for hand, foot and mouth disease （HFMD）. Studies indicate that the frequent HFMD outbreaks result in a few hundreds ch...Background Enterovirus 71 （EV71） and coxsackievirus A16 （Cox A16） are major causative agents for hand, foot and mouth disease （HFMD）. Studies indicate that the frequent HFMD outbreaks result in a few hundreds children＇s death in China in recent years. The vaccine and other research for HFMD need to be developed urgently. The aims of our study were： to explore dynamic development of mother-source neutralizing antibodies against EV71 and Cox A16 in infants from Jiangsu Province, China, and to provide the fundamental data for further establishing of corresponding immunization course. Methods Peripheral blood samples were collected from 133 of parturient women once immediately before delivery and their infants at two and seven months of age. Method of micro-dose cytopathogenic effect was used to measure neutralizing antibodies against EV71 and Cox A16, respectively. Results Seropositive rates of anti-EV71 and anti-Cox A16 in prenatal women were 79.7% （106/133） and 92.5% （123/133）, respectively; geometric mean titers （GMTs） were 29.0 and 61.9; 75.9% （101/133） prenatal women were both positive in anti-EV71 and anti-Cox A16; seropositive rates of anti-EV71 and anti-Cox A16 were 25.6% （34/133） and 38.3% （51/133） in infants at two months of age; GMTs were 12.3 and 18.0, respectively. GMTs of anti-EV71 were significantly higher for infants at seven months （82.6） compared with that at two months （P 〈0.05）, showing infants had inapparently infected by EV71 during two to seven months. Although only one offspring （0.75%） at seven months was found having anti-Cox A16 transfered from maternal, this observation suggested no maternal antibody may remain in infants at seven months. Conclusions The prevalence of EV71 and Cox A16 were relatively high in Jiangsu Province. Bivalent vaccine against both EV71 and Cox A16 should be developed, and the ideal time point for prime immunization for infants is around 2-5 months of age.展开更多
Coxsackievirus A16(CA16) is one of the major causes of hand, foot, and mouth disease(HFMD) worldwide, which is a common illness that affects children. The frequent occurrence of HFMD outbreaks has become a serious pub...Coxsackievirus A16(CA16) is one of the major causes of hand, foot, and mouth disease(HFMD) worldwide, which is a common illness that affects children. The frequent occurrence of HFMD outbreaks has become a serious public health problem in Asia. Therefore, it is important to understand the pathogenesis and replication of CA16. In this study, a stable infectious c DNA clone of an epidemic strain of Coxsackievirus A16(CA16) was assembled, and subsequently a reporter virus(e GFP-CA16) was constructed by inserting the e GFP gene between the 5'-UTR and the N-terminus of VP4, with the addition of a 2A protease cleavage site(ITTLG) at its C-terminus. This was transfected into Vero cells to generate infectious recombinant viruses. The growth characteristics and plaque morphology, in vitro, in mammalian cells were found to be indistinguishable between the parental and recombinant viruses. Although the e GFP-CA16 showed smaller plaque size as compared to recombinant CA16, both were found to exhibit similar growth trends and EC50 of NITD008. In summary, this stable infectious c DNA clone should provide a valuable experimental system to study CA16 infection and host response. The e GFP-CA16 is expected to provide a powerful tool to monitor e GFP expression in infected cells and to evaluate the antiviral activity of potential antiviral agents in the treatment of CA16 infections.展开更多
Background Coxsackievirus A16(CVA16)is one of the major etiological agents of hand,foot and mouth discase(HFMD).This study aimed to investigate the molecular epidemiology and evolutionary characteristics of CVA16.Meth...Background Coxsackievirus A16(CVA16)is one of the major etiological agents of hand,foot and mouth discase(HFMD).This study aimed to investigate the molecular epidemiology and evolutionary characteristics of CVA16.Methods Throat swabs were collected from children with HFMD and suspected HFMD during 2010-2019.Enteroviruses(EVs)were detected and typed by real-ime reverse transcription-polymerase chain reaction(RT-PCR)and RT-PCR.The genotype,evolutionary rate,the most recent common ancestor,population dynamics and selection pressure of CVA16 were analyzed based on viral protein gene(VPI)by bioinformatics software.Results A total of 4709 throat swabs were screened.EVs were detected in 3180 samples and 814 were CVA16 positive.More than 81%of CVA 16-positive children were under 5 years old.The prevalence of CVA 16 showed obvious periodic fluctuations with a high level during 2010--2012 followed by an apparent decline during 2013--2017.However,the activities of CVA16 increased gradually during 2018-2019.All the Beijing CVA16 strains belonged to sub-genotype BI,and B Ib was the dominant strain.One B Ic strain was detected in Bejing for the first time in 2016.The estimated mean evolutionary rate of VPI gene was 4.49x 103 substitution/site/year.Methionine gradually fixed at site-23 of VP1 since 2012.Two sites were detected under episodic positive selection,one of which(site-223)located in neutralizing linear epitope PEP71.Conclusions The dominant strains of CVA 16 belonged to clade B lb and evolved in a fast evolutionary rate during 2010-2019 in Beiing.To provide more favorable data for HFMD prevention and control,it is necessary to keep attention on molecular epidemiological and evolutionary characteristics of CVA16.展开更多
Coxsackievirus A16 belongs to the family Picornaviridae,and is a major agent of hand-foot-and-mouth disease that infects mostly children,and to date no vaccines or antivi-ral therapies are available.2A protease of ent...Coxsackievirus A16 belongs to the family Picornaviridae,and is a major agent of hand-foot-and-mouth disease that infects mostly children,and to date no vaccines or antivi-ral therapies are available.2A protease of enterovirus is a nonstructural protein and possesses both self-cleavage activity and the ability to cleave the eukaryotic translation initiation factor 4G.Here we present the crystal structure of coxsackievirus A162A protease,which interestingly forms hexamers in crystal as well as in solution.This structure shows an open conformation,with its active site accessible,ready for substrate binding and cleav-age activity.In conjunction with a previously reported“closed”state structure of human rhinovirus 2,we were able to develop a detailed hypothesis for the conforma-tional conversion triggered by two“switcher”residues Glu88 and Tyr89 located within the bll2-cII loop.Substrate recognition assays revealed that amino acid residues P1′,P2 and P4 are essential for substrate specificity,which was verifi ed by our substrate binding model.In addition,we compared the in vitro cleavage effi ciency of 2A pro-teases from coxsackievirus A16 and enterovirus 71 upon the same substrates by fl uorescence resonance energy transfer(FRET),and observed higher protease activity of enterovirus 71 compared to that of coxsackievirus A16.In conclusion,our study shows an open conformation of coxsackievirus A162A protease and the underlying mechanisms for conformational conversion and substrate specifi city.These new insights should facilitate the future rational design of effi cient 2A protease inhibitors.展开更多
Dear Editor,Coxsackievirus A16(CA16)is one of the major viral pathogens associated with hand,foot,and mouth disease.CA16 belongs to the Enterovirus genus of the Picornaviridae family and possesses a single-stranded po...Dear Editor,Coxsackievirus A16(CA16)is one of the major viral pathogens associated with hand,foot,and mouth disease.CA16 belongs to the Enterovirus genus of the Picornaviridae family and possesses a single-stranded positivesense RNA genome(Mao et al.,2014).Reverse genetics is an important tool for CA16 research.Previously,a reverse genetics T7 polymerase-based system was de-展开更多
Dear Editor,Coxsackievirus A16(CV A16)and enterovirus 71(EV71)are currently the two primary causative agents of handfoot-and-mouth disease(HFMD)(Solomon et al.,2010;Mao et al.,2014),threatening health of children worl...Dear Editor,Coxsackievirus A16(CV A16)and enterovirus 71(EV71)are currently the two primary causative agents of handfoot-and-mouth disease(HFMD)(Solomon et al.,2010;Mao et al.,2014),threatening health of children worldwide.They both belong to the Enterovirus genus of展开更多
手足口病（hand，foot and mouth disease，HFMD）是婴幼儿常见传染病，主要表现为发热，手、足和口腔部的疱疹，由非脊髓灰质炎肠道病毒属的柯萨奇病毒（Coxsackievirus）A（CoxA）和B组，埃可病毒（ECHO viruses）4、6、7型等感染引起...手足口病（hand，foot and mouth disease，HFMD）是婴幼儿常见传染病，主要表现为发热，手、足和口腔部的疱疹，由非脊髓灰质炎肠道病毒属的柯萨奇病毒（Coxsackievirus）A（CoxA）和B组，埃可病毒（ECHO viruses）4、6、7型等感染引起，CoxA16和人肠道病毒71型（enterovirus 71，EV71）感染尤其常见。1958年，加拿大首次分离出CoxA16[1]，1969年，加利福尼亚首次报道了EV71[2]，至1972年美国纽约、孟加拉国、澳大利亚陆续出现中枢神经系统感染流行时才真正分离出EV71病毒[1]。早期发现的手足口病病原体主要为CoxA16，20世纪70年代后，EV71与CoxA16感染交替出现，成为手足口病的主要病原体[3]。二者均在世界范围内引起多次暴发。CoxA16：美国（1968年）[4]、日本（1970年）[5]、澳大利亚（1991年）[6]、台湾（2006至2008年）[7]、西班牙（2009年）[8]；EV71：马来西亚（2000至2003年）[9]、新加坡（2000年）[10]、泰国（2008至2009）[11]、韩国（2008至2009年）[12]、中国阜阳（2008年）[13]。显然，手足口病已成为一种世界性疾病，已引起了全世界人民的重视。本文拟从病原学、临床表现、病毒基因型和核苷酸序列与临床表现的关系以及发病机制方面，对手足口病的两种主要病原体，即EV71和CoxA16的区别和联系进行综述。展开更多
目的探究活动性肺结核患者血清核苷酸结合寡聚化结构域蛋白2(nucleotide-binding oligomerization domain 2,NOD2)、自噬相关蛋白16样蛋白1(autophagy related protein 16 like protein 1,ATG16L1)水平与病情、预后的关系。方法选择2020...目的探究活动性肺结核患者血清核苷酸结合寡聚化结构域蛋白2(nucleotide-binding oligomerization domain 2,NOD2)、自噬相关蛋白16样蛋白1(autophagy related protein 16 like protein 1,ATG16L1)水平与病情、预后的关系。方法选择2020年1月—2022年1月在陕西省结核病防治院治疗的110例活动性肺结核患者作为活动性肺结核组,同一时间在本院进行健康体检的60名健康人作为健康对照组。ELISA法检测血清NOD2、ATG16L1水平。将活动性肺结核组分为轻度组、中度组和重度组,通过标准化治疗后根据疗效分为预后良好组和预后不良组,分析NOD2、ATG16L1水平与病情及预后的关系。分析活动性肺结核患者血清NOD2与ATG16L1水平的相关性。用ROC曲线评估NOD2、ATG16L1对活动性肺结核患者预后的评估价值,Cox回归分析活动性肺结核患者预后的影响因素。结果活动性肺结核组血清NOD2、ATG16L1水平明显高于健康对照组(P<0.05),且随着病情的加重,NOD2、ATG16L1水平呈上升趋势(P<0.05)。活动性肺结核患者血清NOD2与ATG16L1水平呈正相关(r=0.360)。与预后良好组比较,预后不良组血清NOD2、ATG16L1水平明显升高(P<0.05)。ROC曲线显示,NOD2、ATG16L1水平预测活动性肺结核患者预后的曲线下面积分别为0.878(95%CI:0.814~0.941)和0.815(95%CI:0.731~0.900)。患者病情、血清NOD2、ATG16L1水平均是活动性肺结核患者预后不良的危险因素(P<0.05)。结论活动性肺结核患者血清NOD2、ATG16L1水平高表达,与病情发展密切相关,可在一定程度上预测患者的预后。展开更多
文摘A sensitive reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for human enterovirus 71 (EV71) and Coxsackievirus A16 (CVA16) infection was further evaluated. The one step reaction was performed in a single tube at 65?C for 45 min for EV71 and 35 min for CVA16. The detection limits of RT-LAMP assays for both EV71 and CVA16 were 0.1 of a 50% tissue culture infective dose (TCID50) per reaction, based on 10—Fold dilutions of a titrated EV71 or CVA16 strain. The specific assay showed there were no cross-reactions with Coxsackievirus A (CVA) viruses (CVA 2, 4, 5, 7, 9, 10, 14, and 25), Coxsackievirus B (CVB) viruses (CVB 1, 2, 3, 4, and 5) or ECHO viruses (ECHO 3, 6, 11, and 19). In parallel with commercial quantitative real-time polymerase chain reaction (qRT-PCR) diagnostic kits for EV71 and CVA16, the RT-LAMP assay was evaluated with 515 clinical specimens, the results showed the RT-LAMP assay and the qRT-PCR assay were in complete agreement for 513/515 (99.6%) of the specimens. Two samples with discrepant results from two methods were further verified by nested reverse transcription polymerase chain reaction (nRT-PCR) assay and sequencing to be true positives for CVA16. In conclusion, RT-LAMP assay is demonstrated to be a sensitive and specific assay and have a great potential for the rapid and visual screening of EV71 and CVA16 in China, especially in those resource-limited hospitals and rural clinics of provincial and municipal regions.
文摘目的:对比分析15~24个月及2~5岁CA16感染的普通型与危重症手足口病(hand,foot and mouth disease,HFMD)患者外周血中CD8^+T细胞的表达情况,寻找发现与CA16致病有关的免疫病理因素。方法:收集2014年5-8月间昆明市儿童医院感染科确诊的儿童HFMD病例外周血标本共72例,其中普通型32例,危重症40例,采用流式细胞术对患者外周血CD8^+T淋巴细胞亚群进行检测分析。结果:15~24个月普通型HFMD患者外周血CD8^+T淋巴细胞百分比略高于正常健康儿童参考值,而危重症患者CD8^+T细胞略低于正常参考值。此外,与正常参考值相比,2~5岁普通型及危重症患者外周血中CD8^+T淋巴细胞百分比均减低,其中危重症患者略低于普通型患者。结论:CA16感染后,不同年龄、不同病情的HFMD患者外周血中CD8^+T细胞的表达变化不太明显,说明CA16感染后,患者体内的CD8^+T细胞基本能够发挥正常的抗病毒免疫效应。而在危重症时,两个年龄段患者CD8^+T细胞百分比略低或减低,说明CA16的持续性感染可能对机体CD8^+T细胞的表达产生了影响,使其杀伤病毒效应减低,这可能是CA16感染诱导神经系统并发症发生的免疫病理因素之一。
基金supported by Shandong Provincial Preventive Medicine Association Project(LYH 2017‐26).
文摘In 2008,China launched a national surveillance system for hand‐foot‐and‐mouth disease(HFMD).Several million cases of HFMD are reported every year,coxsackievirus A16(CVA16)was the leading cause of HFMD epidemic in Yantai city,China in recent years,but the information of epidemiology and molecular characterization of CVA16 in Yantai is limited.The aim of this study is to investigate the epidemiological characteristics and pathogenic spectrum of HFMD,and most importantly,the molecular characterization of CVA16 in Yantai from 2018 to 2021.A total of 2,000 clinical samples were collected in Yantai city from 2018 to 2021 and the enterovirus typing was performed using real‐time reverse transcriptase–polymerase chain reaction(qRT‐PCR).VP1 coding regions of 41 CVA16 isolates were amplified and Sanger sequenced,and phylogenetic analysis was performed.During the study period,HFMD became prevalent from May to August each year.It peaked in June and declined in September.The incidence was highest in children aged 1 to 5 years,while more common in males than females.1,617 out of 2,000 clinical collection of samples were tested positive for enterovirus.Among them,614 were identified as CVA16,45 were enterovirus A71(EV A17),and 958 were other enterovirus serotypes.All 41 CVA16 strains belonged to the Bla and B1b genotypes.Homology analysis showed that 41 CVA16 isolates shared 83.2%–100%nucleotide and 93.7%–100%amino acid similarity among themselves.The results of this study update molecular epidemiology of CVA16 and provide a reference for HFMD prevention and control.
文摘Background Enterovirus 71 （EV71） and coxsackievirus A16 （Cox A16） are major causative agents for hand, foot and mouth disease （HFMD）. Studies indicate that the frequent HFMD outbreaks result in a few hundreds children＇s death in China in recent years. The vaccine and other research for HFMD need to be developed urgently. The aims of our study were： to explore dynamic development of mother-source neutralizing antibodies against EV71 and Cox A16 in infants from Jiangsu Province, China, and to provide the fundamental data for further establishing of corresponding immunization course. Methods Peripheral blood samples were collected from 133 of parturient women once immediately before delivery and their infants at two and seven months of age. Method of micro-dose cytopathogenic effect was used to measure neutralizing antibodies against EV71 and Cox A16, respectively. Results Seropositive rates of anti-EV71 and anti-Cox A16 in prenatal women were 79.7% （106/133） and 92.5% （123/133）, respectively; geometric mean titers （GMTs） were 29.0 and 61.9; 75.9% （101/133） prenatal women were both positive in anti-EV71 and anti-Cox A16; seropositive rates of anti-EV71 and anti-Cox A16 were 25.6% （34/133） and 38.3% （51/133） in infants at two months of age; GMTs were 12.3 and 18.0, respectively. GMTs of anti-EV71 were significantly higher for infants at seven months （82.6） compared with that at two months （P 〈0.05）, showing infants had inapparently infected by EV71 during two to seven months. Although only one offspring （0.75%） at seven months was found having anti-Cox A16 transfered from maternal, this observation suggested no maternal antibody may remain in infants at seven months. Conclusions The prevalence of EV71 and Cox A16 were relatively high in Jiangsu Province. Bivalent vaccine against both EV71 and Cox A16 should be developed, and the ideal time point for prime immunization for infants is around 2-5 months of age.
基金supported by the Science and Technology Plan Projects of Wuhan (grant No. 2013060501010157)
文摘Coxsackievirus A16(CA16) is one of the major causes of hand, foot, and mouth disease(HFMD) worldwide, which is a common illness that affects children. The frequent occurrence of HFMD outbreaks has become a serious public health problem in Asia. Therefore, it is important to understand the pathogenesis and replication of CA16. In this study, a stable infectious c DNA clone of an epidemic strain of Coxsackievirus A16(CA16) was assembled, and subsequently a reporter virus(e GFP-CA16) was constructed by inserting the e GFP gene between the 5'-UTR and the N-terminus of VP4, with the addition of a 2A protease cleavage site(ITTLG) at its C-terminus. This was transfected into Vero cells to generate infectious recombinant viruses. The growth characteristics and plaque morphology, in vitro, in mammalian cells were found to be indistinguishable between the parental and recombinant viruses. Although the e GFP-CA16 showed smaller plaque size as compared to recombinant CA16, both were found to exhibit similar growth trends and EC50 of NITD008. In summary, this stable infectious c DNA clone should provide a valuable experimental system to study CA16 infection and host response. The e GFP-CA16 is expected to provide a powerful tool to monitor e GFP expression in infected cells and to evaluate the antiviral activity of potential antiviral agents in the treatment of CA16 infections.
基金supported by the Key Technologies R&D Program of the National Ministry of Science(2018ZX10713001-003)the Special Fund of the Pediatric Medical Coordinated Development Center of Beijing Hospitals Authority(XTCX201822)the National Natural Science Foundation of China(81350019).
文摘Background Coxsackievirus A16(CVA16)is one of the major etiological agents of hand,foot and mouth discase(HFMD).This study aimed to investigate the molecular epidemiology and evolutionary characteristics of CVA16.Methods Throat swabs were collected from children with HFMD and suspected HFMD during 2010-2019.Enteroviruses(EVs)were detected and typed by real-ime reverse transcription-polymerase chain reaction(RT-PCR)and RT-PCR.The genotype,evolutionary rate,the most recent common ancestor,population dynamics and selection pressure of CVA16 were analyzed based on viral protein gene(VPI)by bioinformatics software.Results A total of 4709 throat swabs were screened.EVs were detected in 3180 samples and 814 were CVA16 positive.More than 81%of CVA 16-positive children were under 5 years old.The prevalence of CVA 16 showed obvious periodic fluctuations with a high level during 2010--2012 followed by an apparent decline during 2013--2017.However,the activities of CVA16 increased gradually during 2018-2019.All the Beijing CVA16 strains belonged to sub-genotype BI,and B Ib was the dominant strain.One B Ic strain was detected in Bejing for the first time in 2016.The estimated mean evolutionary rate of VPI gene was 4.49x 103 substitution/site/year.Methionine gradually fixed at site-23 of VP1 since 2012.Two sites were detected under episodic positive selection,one of which(site-223)located in neutralizing linear epitope PEP71.Conclusions The dominant strains of CVA 16 belonged to clade B lb and evolved in a fast evolutionary rate during 2010-2019 in Beiing.To provide more favorable data for HFMD prevention and control,it is necessary to keep attention on molecular epidemiological and evolutionary characteristics of CVA16.
基金the National Basic Research Program(973 Program)(Nos.2014CB542800 and 2011CB915501)the National Natural Science Foundation of China(Grant No.31170702).
文摘Coxsackievirus A16 belongs to the family Picornaviridae,and is a major agent of hand-foot-and-mouth disease that infects mostly children,and to date no vaccines or antivi-ral therapies are available.2A protease of enterovirus is a nonstructural protein and possesses both self-cleavage activity and the ability to cleave the eukaryotic translation initiation factor 4G.Here we present the crystal structure of coxsackievirus A162A protease,which interestingly forms hexamers in crystal as well as in solution.This structure shows an open conformation,with its active site accessible,ready for substrate binding and cleav-age activity.In conjunction with a previously reported“closed”state structure of human rhinovirus 2,we were able to develop a detailed hypothesis for the conforma-tional conversion triggered by two“switcher”residues Glu88 and Tyr89 located within the bll2-cII loop.Substrate recognition assays revealed that amino acid residues P1′,P2 and P4 are essential for substrate specificity,which was verifi ed by our substrate binding model.In addition,we compared the in vitro cleavage effi ciency of 2A pro-teases from coxsackievirus A16 and enterovirus 71 upon the same substrates by fl uorescence resonance energy transfer(FRET),and observed higher protease activity of enterovirus 71 compared to that of coxsackievirus A16.In conclusion,our study shows an open conformation of coxsackievirus A162A protease and the underlying mechanisms for conformational conversion and substrate specifi city.These new insights should facilitate the future rational design of effi cient 2A protease inhibitors.
基金supported by grants from the Science and Technology Commission of Shanghai Municipality (13ZR1462900)the Shanghai Institutes for Biological Science (SIBS),Chinese Academy of Science (CAS) (2013KIP317)+1 种基金the support of the SA-SIBS scholarship programYouth Innovation Promotion Association of CAS (2016249)
文摘Dear Editor,Coxsackievirus A16(CA16)is one of the major viral pathogens associated with hand,foot,and mouth disease.CA16 belongs to the Enterovirus genus of the Picornaviridae family and possesses a single-stranded positivesense RNA genome(Mao et al.,2014).Reverse genetics is an important tool for CA16 research.Previously,a reverse genetics T7 polymerase-based system was de-
文摘Dear Editor,Coxsackievirus A16(CV A16)and enterovirus 71(EV71)are currently the two primary causative agents of handfoot-and-mouth disease(HFMD)(Solomon et al.,2010;Mao et al.,2014),threatening health of children worldwide.They both belong to the Enterovirus genus of
文摘目的探究活动性肺结核患者血清核苷酸结合寡聚化结构域蛋白2(nucleotide-binding oligomerization domain 2,NOD2)、自噬相关蛋白16样蛋白1(autophagy related protein 16 like protein 1,ATG16L1)水平与病情、预后的关系。方法选择2020年1月—2022年1月在陕西省结核病防治院治疗的110例活动性肺结核患者作为活动性肺结核组,同一时间在本院进行健康体检的60名健康人作为健康对照组。ELISA法检测血清NOD2、ATG16L1水平。将活动性肺结核组分为轻度组、中度组和重度组,通过标准化治疗后根据疗效分为预后良好组和预后不良组,分析NOD2、ATG16L1水平与病情及预后的关系。分析活动性肺结核患者血清NOD2与ATG16L1水平的相关性。用ROC曲线评估NOD2、ATG16L1对活动性肺结核患者预后的评估价值,Cox回归分析活动性肺结核患者预后的影响因素。结果活动性肺结核组血清NOD2、ATG16L1水平明显高于健康对照组(P<0.05),且随着病情的加重,NOD2、ATG16L1水平呈上升趋势(P<0.05)。活动性肺结核患者血清NOD2与ATG16L1水平呈正相关(r=0.360)。与预后良好组比较,预后不良组血清NOD2、ATG16L1水平明显升高(P<0.05)。ROC曲线显示,NOD2、ATG16L1水平预测活动性肺结核患者预后的曲线下面积分别为0.878(95%CI:0.814~0.941)和0.815(95%CI:0.731~0.900)。患者病情、血清NOD2、ATG16L1水平均是活动性肺结核患者预后不良的危险因素(P<0.05)。结论活动性肺结核患者血清NOD2、ATG16L1水平高表达,与病情发展密切相关,可在一定程度上预测患者的预后。
