How does Cellular Heparan Sulfate Function in Viral Pathogenicity?

Heparan sulfate （HS） is ubiquitously expressed on the surfaces and in the extracellular matrix of virtually all cell types, making it an ideal receptor for viral infection. Compared with wild‐type viruses, cell culture‐adapted laboratory strains exhibit more efficient binding to cellular HS receptors. HS‐binding viruses are typically cleared faster from the circulation and cause lower viremia than their non‐HS‐binding counterparts, suggesting that the HS‐binding phenotype is a tissue culture adaptation that lowers virus fitness in vivo. However, when inoculated intracranially, efficient cell attachment through HS binding can contribute to viral neurovirulence. The primary aim of this review is to discuss the roles of HS binding in viral pathogenicity, including peripheral virulence and neurovirulence. Understanding how heparan sulfate functions during virus infection in vivo may prove critical for elucidating the molecular mechanism of viral pathogenesis, and may contribute to the development of therapeutics targeting HS.

Viral pathogens and plant parasitic nematode

This special focus is dedicated to three parts：i）One of the most ubiquitous viral pathogens of stone fruit tree,Plum pox virus（PPV）;ii）a re-emerging pathogen,Wheat streak mosaic virus（WSMV）of cereal crops in Central Europe;and iii）a less studied plant parasitic,cyst-forming nematode in cereal crops Heterodera avenae.

Roles of HIV-1 auxiliary proteins in viral pathogenesis and host-pathogen interactions

Active host-pathogen interactions take place during infection of human immunodeficiency virus type 1 (HIV-1). Outcomes of these interactions determine the efficiency of viral infection and subsequent disease progression. HIV- infected cells respond to viral invasion with various defensive strategies such as innate, cellular and humoral immune antiviral mechanisms. On the other hand, the virus has also developed various offensive tactics to suppress these host cellular responses. Among many of the viral offensive strategies, HIV-1 viral auxiliary proteins (Tat, Rev, Nef, Vif, Vpr and Vpu) play important roles in the host-pathogen interaction and thus have significant impacts on the outcome of HIV infection. One of the best examples is the interaction of Vif with a host cytidine deaminase APOBEC3G. Although specific roles of other auxiliary proteins are not as well described as Vif-APOBEC3G interaction, it is the goal of this brief review to summarize some of the preliminary findings with the hope to stimulate further discussion and investiga- tion in this exhilarating area of research.

Reverse genetics: Unlocking the secrets of negative sense RNA viral pathogens

Negative-sense RNA viruses comprise several zoonotic pathogens that mutate rapidly and frequently emerge in people including Influenza, Ebola, Rabies, Hendra and Nipah viruses. Acute respiratory distress syndrome, encephalitis and vasculitis are common disease outcomes in people as a result of pathogenic viral infection, and are also associated with high case fatality rates. Viral spread from exposure sites to systemic tissues and organs is mediated by virulence factors, including viral attachment glycoproteins and accessory proteins, and their contribution to infection and disease have been delineated by reverse genetics; a molecular approach that enables researchers to experimentally produce recombinant and reassortant viruses from cloned cD NA. Through reverse genetics we have developed a deeper understanding of virulence factors key to disease causation thereby enabling development of targeted antiviral therapies and well-defined live attenuated vaccines. Despite the value of reverse genetics for virulence factor discovery, classical reverse genetic approaches may not provide sufficient resolution for characterization of heterogeneous viral populations, because current techniques recover clonal virus, representing a consensus sequence. In this review the contribution of reverse genetics to virulence factor characterization is outlined, while the limitation of the technique is discussed withreference to new technologies that may be utilized to improve reverse genetic approaches.

Human cord blood-derived viral pathogens as the potential threats to the hematopoietic stem cell transplantation safety:A mini review

Umbilical cord blood(UCB) is a valuable source of hematopoietic stem cells(HSCs) and potential alternative for bone marrow transplantation for patients who lack human leukocyte antigen(HLA)-matched donors. The main practical advantages of UCB over other HSC sources are the immediate availability, lower incidence of graft-versus-host disease, minimal risk to the donor, and lower requirement for HLA compatibility. However, the use of UCB is limited by delayed engraftment and poor immune reconstitution, leading to a high rate of infection-related mortality. Therefore, severe infectious complications, especially due to viral pathogens remain the leading cause of morbidity and mortality during the post-UCB transplantation(UCBT) period. In this context, careful screening and excluding the viral-contaminated UCB units might be an effective policy to reduce the rate of UCBT-related infection and mortality. Taken together,complete prevention of the transmission of donor-derived viral pathogens in stem cell transplantation is not possible. However, having the knowledge of the transmission route and prevalence of viruses will improve the safety of transplantation. To the best of our knowledge, there are few studies that focused on the risk of virus transmission through the UCB transplant compared to other HSC sources. This review summarizes the general aspects concerning the prevalence, characteristics, and risk factors of viral infections with a focus on the impact of viral pathogens on cord blood transplantation safety.

Pitfalls of restriction enzyme analysis in identifying, characterizing,typing, and naming viral pathogens in the era of whole genome data, as illustrated by HAdV type 55

Restriction endonuclease analysis(REA),or restriction fragment length polymorphism(RFLP),was useful for identifying and determining the relatedness and putative identities of microbial strains(Tang et al.,1997)and for characterizing and discriminating large numbers of samples inexpensively in the past。

河北省廊坊市牛主要病毒性腹泻病原感染状况检测及牛冠状病毒演化分析

牛病毒性腹泻病原严重危害畜牧业生产,BVDV、BoAstV、BCoV、MRV、BKoV、BoNeV、BNoV、BRV、BToV被认为是引起牛群腹泻的病原,不仅如此,BVDV、BCoV和BToV除了能引起消化道症状外还能引起呼吸道症状,BVDV不仅能引起消化道和呼吸道症状,还会导致母牛生殖功能异常,这些疾病对畜牧业造成巨大的经济损失。为了解牛主要病毒性腹泻病原流行情况,本次试验通过PCR检测方法对我国河北地区323份腹泻牛粪样品进行常见9种病毒性牛腹泻病原进行检测。结果显示,BVDV阳性检出率1.85%(6/323)、BCoV阳性检出率14.24%(46/323)、BRV阳性检出率57.89%(187/323)、BoAstV阳性检出率0.31%(1/323)、BoNeV阳性检出率10.84%(35/323)、BNoV阳性检出率4.33%(14/323)、MRV阳性检出率2.48%(8/323)、BToV阳性检出率4.64%(15/323)、BKoV阳性检出率11.76%(38/323)。混合感染共有76份,占比23.53%(76/323)。HBLF2302株的全基因序列、S、HE、N、M和E基因进行同源性和遗传进化分析发现,HBLF2302与BCoV/NMG1/2022基因同源性最高,为GIIb亚型。基于氨基酸序列比对和HBLF2302的S蛋白三级结构预测发现,在S蛋白中157号位突变为157T,854号位点突变为854I。318V为独特突变,改变了与侧链残基的作用力,与631C形成氢键连接。并发现中国株区别于其它地区的GⅡb亚型,位于ORF1a区域有三个独特位点。本研究丰富了牛腹泻病原的流行病学数据,为牛腹泻病的防控奠定基础。

不同基因型牛病毒性腹泻病毒对BALB/c小鼠致病性研究

牛病毒性腹泻病毒(BVDV)是危害养牛业的重要病原。2021年本实验室从患有肺炎的牛肺中分离出1株BVDV(毒株编号为JS2201),经鉴定为1b亚型。为了评价该分离株的毒力与致病性,分别建立了分离株与参考株BVDV-1型Oregon C24V株、BVDV-2型C1602株BVDV感染BALB/c小鼠模型,通过检测攻毒后小鼠临床症状、体重变化、病毒血症情况、血液中白细胞与淋巴细胞的变化、组织器官的病理组织学变化及病毒载量,比较了分离株JS2201与1型和2型参考株的致病性差异。结果显示:BVDV分离株JS2201与参考株均能够成功感染BALB/c小鼠,攻毒BALB/c小鼠均形成病毒血症,导致血液中白细胞数量、淋巴细胞数量以及淋巴细胞百分比短暂下降;BVDV分离株JS2201株攻毒组小鼠肝脏、肾脏、肺脏、脾脏中BVDV载量要高于C24V、C1602株攻毒组;攻毒组小鼠均表现为间质性肺炎病变,JS2201株攻毒组与1型参考株C24V株攻毒组小鼠肺脏病理组织学变化相似,BVDV-2型参考株C1602株攻毒组小鼠肺脏病变更为严重。综上,本研究成功建立了不同亚型BVDV急性感染BALB/c小鼠的模型,且比较分析了分离株与参考株之间的致病性差异,为BVDV疫苗的研制以及致病机制的研究奠定了基础。

氯化-N-十二烷基吡啶-1-乙酰胺杀灭或抑制病原体的活性研究

季铵盐类表面活性剂是一类低毒、高效的广谱消毒剂,能杀灭多种细菌和病毒,在养殖业和医学等领域的消毒中应用前景广阔。研究旨在明确自主合成的季铵盐类表面活性剂氯化-N-十二烷基吡啶-1-乙酰胺(C12cmpC)对禽源致病菌和牛病毒性腹泻病毒(BVDV)的抗菌抗病毒活性。通过MIC、MBC和时间杀菌试验,明确C12cmpC的体外杀灭、抑制革兰阴性和阳性细菌的效果。通过细胞形态观察、细胞活性检测和BVDV m RNA的qRT-PCR检测,初步明确C12cmpC的抗病毒活性。结果表明,C12cmpC对鹅大肠杆菌(QS195313)的MIC为250 mg·L^(-1),MBC为500 mg·L^(-1)。C12cmpC对大肠杆菌和金黄色葡萄球菌标准株的MIC为31.25 mg·L^(-1),MBC为62.5 mg·L^(-1)。此外,C12cmpC对MDBK细胞的最大安全浓度为5 mg·L^(-1)。其与BVDV作用1、5、30、60 min后,MDBK细胞中病毒m RNA水平均显著降低。研究表明新型季铵盐类表面活性剂氯化-N-十二烷基吡啶-1-乙酰胺具有较好的抗菌抗病毒活性,研究为新型消毒剂的开发提供了理论依据。

病毒类基因工程疫苗研究进展

疫苗接种被认为是控制病原体和预防人类以及动物疾病最有效的方法之一.近年来由于病毒性疾病来势汹汹,传统疫苗如灭活或减毒活疫苗的局限性及潜在问题日益突显,而基因工程技术的进步使得疫苗设计和研发得以改进,由此衍生的病毒类基因工程疫苗作为下一代疫苗越来越受到研究者的高度关注.通过病毒类基因工程疫苗的类型,重点介绍不同疫苗的开发原理、特点及用途,探讨其应用前景和发展趋势,旨在为新发病毒类疾病疫苗的研发提供参考.

不同症状类型苜蓿病毒病AMV病原检测及其寄主范围测定

为明确采自田间不同症状类型苜蓿病毒病病样中苜蓿花叶病毒(alfalfa mosaic virus,AMV)的带毒情况、症状表现与叶绿素含量的相关性及AMV的寄主范围,本试验通过田间调查采样、症状归类、丙酮乙醇混合液法和双抗体夹心酶联免疫吸附测定(DAS-ELISA)法对不同病样的叶绿素和AMV含量进行测定和检测,并对提纯至不同症状类型病样中AMV对9科32种植物的致病性进行测定。结果表明田间苜蓿病毒病病样有轻花叶、重花叶、叶片边缘褪绿黄化型和叶片畸形皱缩花叶矮化型4种症状类型,均带有AMV,且叶绿素含量、AMV含量与症状表现之间具有正相关性,症状表现最严重的叶片畸形皱缩花叶矮化型病样的叶绿素a、b、总叶绿素含量均比对照低58.00%以上,类胡萝卜素含量比对照高134.06%,AMV含量最高,为252.96 pg·mL^(-1);寄主范围测定表明AMV可侵染7科27种植物,对西葫芦致病性最强,症状表现为局部枯斑,30 d时AMV浓度为316.19 pg·mL^(-1)。

Evaluation of the Pathogenicity of a Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus Variant in Piglets

Since May 2006,a highly pathogenic porcine reproductive and respiratory syndrome virus （HP-PRRSV） variant characterized by 30 amino acids deletion within its NSP2-coding region emerged and caused extensive economic losses to China＇s pig industry.To investigate the in vivo pathogenicity and immune responses of the newly emerging PRRSV,3 groups of 60-d-old conventional piglets were inoculated intranasally with a representative strain of the HP-PRRSV variant HuN4 with 3 different infection doses （3×103-3×105 TCID50）.The results revealed that the virus variant caused severe disease in piglets and the significant clinical characteristics consisted of persistently high fever （41.0-41.9oC） and high morbidity and mortality （60-100%）,the marked clinical signs of PRRS and severe histopathogenic damages in multiple organs.It induced rapid and intense humoral immune responses and seroconversion was detected in most infected pigs at 7 d post-infection （DPI）.The virus vigorously replicated in vivo and the highest virus average titer was 9.7 log copies mL-1 serum at 7 DPI.Elevated levels of IFN-g and IL-10 cytokine production in serum in this study were also observed.Taken together,our results demonstrated that the HP-PRRSV variant HuN4 strain is highly pathogenic for piglets and suitable to be a reference strain of highly virulent PRRSV for evaluating the efficacy of the new vaccines.

猪圆环病毒3型的分离及致病性分析

猪圆环病毒3型(porcine circovirus type 3,PCV3)是2016年由美国首次报道引起母猪繁殖障碍的一种新型猪圆环病毒,该病毒的致病性尚不完全清楚。为研究PCV3对断奶仔猪的致病性,本研究用PK-15细胞自临床病料分离到1株PCV3毒株,命名为PCV3/CH/HB/XY/2018,全基因组测序分析表明,该毒株属于PCV3a-IM基因亚型。分别用PCV3阳性病料初始匀浆液和第8代细胞培养物采用滴鼻和肌肉注射2种方式感染28日龄断奶仔猪,每组试验猪5头,并设置空白对照组。通过观察和分析试验猪的临床表现、体温、增重、病毒血症、各组织的病毒载量和病理变化等方面评价仔猪感染试验结果。结果显示:PCV3阳性病料初始匀浆液和细胞培养物在感染断奶仔猪后均会引起仔猪出现体温上升、消瘦、皮炎和生长缓慢等现象;病毒血症时间超过14 d,但21 d消失,病毒的组织分布结果表明,PCV3主要感染扁桃体、淋巴结等免疫器官,在脾、肺和扁桃体等组织中的病毒载量最高;感染猪可出现间质性肺炎、淋巴小结增生和嗜酸性粒细胞增多等病理变化。本研究表明PCV3/CH/HB/XY/2018毒株对断奶仔猪有致病性,为PCV3的致病机制研究奠定了基础。

乌鲁木齐米东区社区获得性病毒性肺炎患儿的病原体检测与流行病学情况分析

目的探讨与分析乌鲁木齐米东区社区获得性病毒性肺炎患儿的病原体检出与流行病学情况,希望为预防社区获得性病毒性肺炎的发生提供参考。方法选择2023年3月—2023年5月在乌鲁木齐米东区人民医院诊治的90例社区获得性病毒性肺炎患儿作为本次课题研究的对象,采集所有患儿的鼻咽拭子,采用多病原核酸检测技术检测病原体状况。结果在90例患儿中,检出流感病毒A型阳性6例、流感病毒B型22例、副流感病毒1型2例、副流感病毒2型1例、鼻病毒25例、呼吸道合胞病毒15例、腺病毒10例、人类偏肺病毒3例、博卡病毒6例。检出混合感染9例,占比10.0%,其中2种病毒混合感染7例,3种病毒混合感染2例。不同性别人群的多病原核酸检测分布情况对比,差异无统计学意义(P>0.05);<1岁人群的鼻病毒、流感病毒B型检出率显著高于其他年龄段人群(P<0.05);冬季人群的流感病毒B型检出率显著高于其他季节,其他病毒在不同季节与年龄人群的分布情况对比,差异无统计学意义(P>0.05)。结论乌鲁木齐米东区社区获得性病毒性肺炎患儿的病原体以鼻病毒、流感病毒B型、呼吸道合胞病毒、腺病毒为主,可表现为混合感染,年龄、季节与鼻病毒、流感病毒B型感染的发生密切相关。

多重核酸检测系统同时检测22种呼吸道病原体的应用效果研究

目的采用多重核酸检测系统同时检测22种呼吸道病原体,了解韶关市儿童急性呼吸道感染(ARI)常见病毒病原体的构成情况及流行特征。方法选择粤北人民医院作为监测点,按要求及时采集呼吸道患者标本886份送至韶关市疾病预防控制中心微生物检验室,采用多重核酸检测系统定性检测22种呼吸道病原体,包括新型冠状病毒、冠状病毒HKU1、冠状病毒NL63、冠状病毒229E、冠状病毒OC43、人类偏肺病毒、人鼻病毒/肠道病毒、甲型流感病毒、甲型流感病毒H1、甲型流感病毒H1-2009、甲型流感病毒H3、乙型流感病毒、副流感病毒1型、副流感病毒2型、副流感病毒3型、副流感病毒4型、呼吸道合胞病毒、副百日咳杆菌、百日咳杆菌、肺炎衣原体、肺炎支原体。同时采用传统的荧光定量逆转录-聚合酶链反应(RT-PCR)对上述样品进行同样项目的检测,对比检测结果准确性。结果886份标本中检出阳性425份,核酸检出率为47.97%(425/886),FluA检出率最高,为15.46%,其他病毒的检出率从高到低依次为鼻病毒(HRV)9.48%、人副流感病毒(HPIV)6.55%、乙型流感病毒(FluB)5.87%、RSV 4.29%、腺病毒(ADV)2.82%、MPV 2.03%、HCoV 1.02%、HBoV 0.45%。FluA、HRV、HPIV、FluB、RSV和MPV的分布有一定季节特征,而ADV、HCoV和HBoV季节特征均不明显。FluA、HPIV、RSV在1~<3岁组检出率均较高;HRV、MPV、HCoV在1~<3岁组检出率均较高;FluB在≥6岁组检出率较高。荧光定量PCR检测结果与上述检测结果一致。结论韶关市儿童急性呼吸道感染(ARI)的病毒病原种类较多,位于前3位依次是FluA、HRV和HPIV。部分病原感染有季节流行特征,与年龄也存在一定相关性。

家蚕BmNPV压力选择品系的细菌病发生及其病原分离鉴定

【目的】调查鉴定核型多角体病毒(BmNPV)压力选择家蚕相关品系细菌病发病原因,为蚕作生产上家蚕抗Bm NPV品种细菌病防治提供理论依据。【方法】相同批次和饲养条件下,对BmNPV压力选择自建品系P50Nn(n表示代)和抗Bm NPV品种4个母种品系苏N、菊N、明N、虎N的正常保种组发生家蚕细菌病情况进行初步调查,分离培养病蚕肠道细菌,开展16S rDNA分子鉴定、革兰氏染色和扫描电镜等形态学鉴定,以及糖发酵、吲哚试验等20项生化鉴定。【结果】细菌病导致家蚕BmNPV压力选择品系添食BmNPV第3代次的P50N3结茧率为47.63%,抗BmNPV育种母种品系添食BmNPV多代次的菊N结茧率最低为34.72%,而未添食过BmNPV的对照品系P50结茧率为96.15%,P50N3和菊N结茧率与P50呈极显著差异(P<0.01)。病蚕肠道细菌经过多次分离纯化,显微镜观察球状细菌较多;分子鉴定后获得肠球菌属(Enterococcus)、葡萄球菌属(Staphylococcus)、柠檬酸杆菌属(Citrobacter)、沙雷氏菌属(Serratia)、克雷伯氏菌属(Klebsiella)、假单胞菌属(Pseudomonas)和肠杆菌属(Enterobacter)等7类细菌属,其中葡萄球菌属占比(30.00%)最高,其次为肠球菌属和沙雷氏菌属,均为16.67%。选择分子鉴定一致性最高的8株不同细菌,进一步进行形态学鉴定和生化鉴定,与分子鉴定结果一致。【结论】家蚕BmNPV压力选择品系的细菌病发生主要由葡萄球菌、肠球菌和多种肠杆菌科细菌引起,在BmNPV压力选择早期家蚕细菌病发生更严重。

龙江医家邹德琛治疗小儿病毒性心肌炎经验

小儿病毒性心肌炎因其初期表现易被误诊误治,错过最佳治疗时间,致使贻误病情。龙江医派著名医家邹德琛教授认为,小儿病毒性心肌炎辨治可基于东垣脾胃之论及叶桂温病之说,从小儿脏腑发育不充,脾胃本弱及小儿常因外受温热病邪而患本病两方面进行辨证论治。邹德琛用药高妙,善于运用经方及药对,用药简而轻灵,且结合辨证对经方进行加减化裁。通过总结邹德琛治疗小儿病毒性心肌炎的辨治思路及用药规律,配以验案,欲为中医临证治疗小儿病毒性心肌炎提供参考。

血凝素蛋白145位潜在糖基化位点对H9N2禽流感病毒生物学特性的影响

从某肉鸡场分离的A/Chicken/Jiangxi/106/2012(H9N2)(JX106)毒株,其HA蛋白在145位氨基酸由S突变为N,使得在该处增加了一个潜在的糖基化位点NGT。本研究以JX106为研究对象,通过反向遗传操作获得重组病毒rgJX106-HA145N和rgJX106-HA145S。利用不同方法探究了HA蛋白145位糖基化位点对病毒的毒力、复制、受体亲和力和致病性等方面的影响。研究发现,rgJX106-HA145N和rgJX106-HA145S在A549细胞上的复制、对鸡胚的感染力无明显差异,而HA蛋白145位无糖基化位点的rgJX106-HA145S与α2,6-唾液酸受体的亲和力更强,在小鼠肺脏中复制更快、致病力更强且能产生更高的交叉HI效价,这一结果提示流感病毒血凝素的糖基化对病毒诱导的体液免疫具有重要影响。

内蒙古籽用西葫芦种子病毒鉴定及消毒效果评价

【目的】对内蒙古籽用西葫芦种子病毒进行鉴定,明确其种子携带病毒的情况;对带毒种子进行不同消毒处理,筛选出有效的消毒方法,为内蒙古地区籽用西葫芦病毒病的防治提供依据。【方法】采集具有典型病毒病症状的金粒1号、金丰娇子、瑞丰9号、金丰光板、希望9号、晶莹118籽用西葫芦种子,对其进行反转录PCR检测及病毒序列分析对比,采用温汤、干热、磷酸三钠、盐酸、药剂等对带毒种子进行消毒处理,并采用实时荧光定量PCR技术检测带毒量,测定消毒种子的发芽率和发芽势。【结果】采用反转录PCR扩增,在6个品种籽用西葫芦种子中检测到黄瓜花叶病毒(cucumber mosaic virus,CMV)、小西葫芦黄化花叶病毒(zucchini yellow mosaic virus,ZYMV)、西瓜花叶病毒(watermelon mosaic virus,WMV)。通过5种处理方法对籽用西葫芦种子进行消毒,结果表明,温汤、干热、磷酸三钠、盐酸和药剂处理均能不同程度地降低籽用西葫芦种子带毒量,其中磷酸三钠处理对CMV的消毒率为99.68%,药剂处理对ZYMV的消毒率为99.74%,温汤处理对WMV的消毒率为99.89%,且不影响种子的发芽率和发芽势。【结论】内蒙古籽用西葫芦种子病毒病病原为CMV、ZYMV、WMV,且存在复合侵染。磷酸三钠处理对籽用西葫芦种子病毒病消除效果最佳。

基于“伏邪-免疫”动态解构乙肝“伏”与“发”及临床证治

乙型病毒性肝炎(简称乙肝)“伏”与“发”的动态过程符合中医伏邪的发病特点,亦反映免疫状态的变化。“冬伤于寒”(外感)和“冬不藏精”(内因)共同导致病“伏”,此时免疫不应答,疾病暂未发作。正邪相争,即免疫应答活跃,乙肝急性发作,此为疾病转折点和治疗关键。正气极虚时,正虚劳复,伏邪亦可暴发,危及生命。乙肝后期,正邪相争不及,疾病慢性化,免疫炎症反复损伤,久则进展至肝硬化、肝癌等,此过程符合伏邪成巢、久病入络的机制。因此,在治疗上,急性期从少阳(或兼阳明)论治;慢性期从肝脾或肝肾同治,结合补法和托法以透邪外出;后期形质改变,则从痰瘀论治,形气同调,以通络消癥。并列举临床典型案例,以期为乙肝临床证治提供参考与借鉴。