是一类非细胞型微生物演示课件

1、1,病毒（virus,是一类非细胞型微生物 主要特点 体积非常微小，需在电子显微镜观察 结构简单，无细胞结构，只含一种类型核酸（DNA或RNA） 严格的细胞内寄生，只能在活细胞中增殖 对抗生素不敏感，但对干扰素敏感,2,3,形态,大小: （纳米，nm） The largest : （300X100 nm, 痘病毒） The smallest: 10 nm 形态：球形或杆状，也有复合状,4,5,6,7,8,HIV,9,Bacteriophage T4,10,结构,基本结构 核心 Viral core 衣壳 Capsid 辅助结构 包膜 Envelope 其他 病毒体 Virion 核衣壳 Nuc

2、leocapsid,11,核心,成分：DNA 或 RNA,病毒复制 功能 决定病毒的各种特性 具有感染性 编码病毒结构蛋白和功能蛋白,病毒核酸的特性：具有感染性 将提纯的病毒核酸（如肠道病毒RNA）如加至活细胞可以启动病毒复制从而感染细胞。从感染细胞中可以获得子代完整病毒颗粒,12,病毒衣壳,成分：蛋白质 由壳粒组成。壳粒是衣壳的形态学亚单位，多肽分子是衣壳的化学亚单位 功能 保护病毒核酸 参与感染过程 具有抗原性,13,按壳粒排列方式的对称型,螺旋对称型（helical symmetry） 20面体立体对称型（icosahedral symmetry） 复合对称型（complex symme

3、try,14,病毒包膜,是包绕在病毒核衣壳外面的双层膜 主要成分是蛋白质、多糖及脂类，常以糖蛋白或脂蛋白形式存在 蛋白质是由病毒基因编码，多糖、脂类来自宿主细胞膜、核膜或空泡膜,15,包膜特性与功能,有包膜的病毒以“出芽” 方式释放 有包膜病毒对脂溶剂（如乙醚、氯仿）敏感，能灭活病毒，乙醚常用于鉴定病毒有无包膜 功能 维护病毒体结构的完整性 具有与宿主细胞膜亲和及融合的性能 具有病毒抗原的特异性,16,病毒复制,复制周期 吸附、穿入、脱壳、生物合成、装配与释放 病毒本身没有独立的蛋白合成酶系统，必须借助宿主细胞的蛋白合成体系合成病毒蛋白 病毒复制周期时间因病毒而异 腺病毒25h 小RNA病毒6

4、-8h 流感病毒15-30h,17,dsDNA病毒复制示意图,18,ssRNA病毒复制示意图,19,ssRNA逆转录病毒复制示意图,20,吸附,通过病毒体表面的配体蛋白与易感细胞表面特异性受体相结合 吸附过程可在几分钟到几十分钟内完成,21,穿入,吞饮：无包膜病毒被宿主细胞吞噬，进入胞内 融合：有包膜病毒的包膜与宿主细胞膜直接融合，病毒核衣壳进入细胞 直接穿入,22,脱壳,在细胞溶酶体酶的作用下，脱去衣壳蛋白释放病毒核酸,23,生物合成,早期蛋白合成阶段 转录、翻译而产生病毒生物合成中必需的酶类及某些抑制或阻断细胞核酸和蛋白质合成的非结构蛋白 晚期蛋白合成阶段 复制病毒核酸，转录、翻译而产生病

5、毒的结构蛋白 隐蔽期 生物合成阶段用电镜方法在细胞查不到完整病毒，用血清学方法也测不到病毒抗原 各病毒隐蔽期长短不一,24,装配,无包膜病毒 先形成空心衣壳，核酸从衣壳裂隙进入形成核衣壳 有包膜病毒 核衣壳与细胞的膜系统（浆膜或核膜）结合形成包膜 包膜的蛋白质（包括糖蛋白）是由病毒基因组编码，故具有病毒的特异性和抗原性 装配的部位 除痘病毒外，DNA病毒均在细胞核内装配 RNA病毒与痘病毒则在细胞浆内装配,25,释放,无包膜病毒 均以破胞方式释放 有包膜的病毒 以出芽方式释放到细胞外 通常细胞不死亡，仍能继续分裂增殖,26,病毒增殖异常,顿挫感染 缺陷病毒 干扰现象,形成包涵体 某些病毒在宿主

6、细胞内增殖，其细胞质或细胞核内会出现一种光学显微镜下可见的斑块结构，称包涵体。它是病毒在细胞内增殖的场所,27,顿挫感染,原因 宿主细胞不能提供病毒复制所需的酶、能量或成份 病毒虽被复制，但不能装配释放,28,缺陷病毒,因病毒基因组不完整或有点突变而不能进行正常复制的病毒，当与辅助病毒共同培养，如能为其提供缺乏的物质，则缺陷病毒也能培殖 腺病毒相关病毒（缺陷病毒）与腺病毒（辅助病毒） 丁型肝炎病毒（缺陷病毒）与乙型肝炎病毒（辅助病毒,29,干扰现象,两种病毒感染同一细胞时，一种病毒会干扰另一病毒复制 原因 与干扰素（IFN）产生有关 病毒改变了宿 主细胞代谢途径 意义 联合使用疫苗,30,理化

7、因素对病毒的影响,灭活 病毒受理化因素作用后，失去感染性 灭活病毒仍保留某些特性，如抗原性、红细胞吸附、细胞融合等,31,物理因素,温度 病毒耐冷不耐热。-70C长期保存。冻融可杀死病毒 60C 30 min或100C数秒即可杀死病毒，但HBV需100C 10 min方可杀死 有包膜病毒比无包膜病毒对热更敏感 pH 多数在pH 59范围稳定 肠道病毒耐酸（pH 35） 射线 X线、射线可将病毒核酸致死性断裂，从而杀死病毒,32,化学因素,脂溶剂：乙醚、氯仿、去氧胆酸盐 有包膜病毒敏感。无包膜病毒无作用（如肠道病毒） 消毒剂：过氧乙酸、甲醛、戊二醛、卤素 杀死大多数病毒，但病毒对消毒剂抵抗力比细

8、菌强，尤其是无包膜病毒 常用甲醛来制备灭活疫苗 其他 抗生素：对病毒无作用 中草药：有一定作用,33,病毒的变异现象 感染性变异（毒力变异） 条件致死株：减毒活疫苗（脊灰） 抗原性变异 耐药性变异 机制 基因突变基因重组,34,病毒与其他微生物的比较,35,小结,病毒的概念 病毒的结构与化学组成 病毒的复制 理化因素对病毒的影响,14. Techniques used to Study Viruses,Living hosts. Man. Pasteur used rabbits to study and develop rabies vaccines. Walter Reed develop

9、ed a mouse model of yellow fever. Transgenic animals, particularly mice invaluable,Embryonated eggs used to propagate viruses in the early decades of this century. Effective for the isolation primary cell cultures which can be maintained for a short period in culture); or immortalized cell lines, wh

10、ich grow in culture indefinitely. Viruses can be grown in them,16. Quantifying viruses,The plaque assay - dilutions of the virus are used to infect a cultured cell monolayer, covered with agar to restrict virus diffusion virus. Results in localized cell killing and little fleas have lesser fleas and

11、 so ad infinitum,Viruses consist of proteins, nucleic acids and sometimes lipids. However there are other infectious agents studied by virologists. Viroids small (200-400nt), circular RNAs, possessing no capsid or envelope. Associated with certain plant diseases. They are infectious obligate intrace

12、llular parasites. Virusoids are satellite, viroid-like RNAs, larger than viroids (approximately 1000nt). Depend on the presence of virus replication for multiplication (hence satellite), they are packaged into virus capsids as passengers. Present in animals and plants. Associated with disease,3. Pri

13、ons,Prions. “pree ons” believed to consist of a single type of protein with no nucleic acid component. The prion protein there can be many reasons for non-permissiveness e.g. no receptor. restringent or restrictive, cell is transiently permissive and a few virus are produced. Virus production stops

14、but the genome remains in the cell, examples include Epstein Barr Virus and herpes simplex virus. This kind of infection may still have serious consequences e.g cell transformation and cancer,History of Virology,Viruses are probably as old as life on earth. Ancients were aware of viral diseases,Perh

15、aps the first written record of a virus infection consists of a heiroglyph from Memphis, drawn in approximately 1400BC, which depicts a temple priest called Siptah showing typical clinical signs of paralytic poliomyelitis,Smallpox, endemic in China by 1000BC. Recognizing that survivors of smallpox o

16、utbreaks were protected from subsequent infection, the practice of variolation developed. Involved inhalation of dried crusts from smallpox lesions, or in later modifications, inoculation of the pus from a lesion into a scratch on the forearm. Practice survived until this century,On May 14, 1796, Ed

17、ward Jenner used cowpox-infected material obtained from the hand of Sarah Nemes, a milkmaid from Berkley in Gloucestershire to vaccinate 8 year old James Phipps. On July 1, 1796, Jenner challenged the boy by deliberately inoculating him with material from a real case of smallpox ! He did not become

18、infected,In 1892, Dmitri Iwanowski, a Russian botanist, showed that extracts from diseased tobacco plants could transmit disease to other plants after passage through ceramic filters fine enough to retain the smallest known bacteria. Generally recognised as the beginning of Virology In 1898, Martinu

19、s Beijerinick confirmed & extended Iwanowskis results on tobacco mosaic virus & was the first to develop the modern idea of the virus, which he referred to as contagium vivum fluidum (soluble living germ,Compiled from Virus Taxonomy, the Sixth Report of the International Committee on Taxonomy of Vir

20、uses (ICTV) 1995. N.B: you can search this document using the Find command of the browser (Edit Menu) 63U-11 virus, Bunyaviridae75V-2374 virus, Bunyaviridae75V-2621 virus, Bunyaviridae78V-2441 virus, Bunyaviridae Abadina virus, ReoviridaeAbelson murine leukemia virus, RetroviridaeAbras virus, Bunyav

21、iridaeAbraxas grossulariata cypovirus 8, ReoviridaeAbraxas grossulariata NPV, BaculoviridaeAbsettarov virus, FlaviviridaeAbu Hammad virus, BunyaviridaeAbu Mina virus, BunyaviridaeAbutilon mosaic virus, GeminiviridaeAcado virus, ReoviridaeAcalypha yellow mosaic virus, GeminiviridaeAcantholyda erythro

22、cephala NPV, BaculoviridaeAcara virus, BunyaviridaeAcciptrid herpesvirus 1, HerpesviridaeAchaea janata NPV, BaculoviridaeAcherontia atropas virus, TetraviridaeAcheta domestica densovirus, ParvoviridaeAcholeplasma phage Oc1r, InoviridaeAcholeplasma phage 10tur, InoviridaeAcholeplasma phage L2, Plasma

23、viridaeAcholeplasma phage L51, InoviridaeAcholeplasma phage M1, PlasmaviridaeAcholeplasma phage MV-L1, InovindaeAcholeplasma phage MVG51, InoviridaeAcholeplasma phage 01, PlasmaviridaeAcholeplasma phage vl, PlasmaviridaeAcholeplasma phage v2, PlasmaviridaeAcholeplasma phage v4, PlasmaviridaeAcholepl

24、asma phage v5, PlasmaviridaeAcholeplasma phage v7, PlasmaviridaeAchroia grisella NPV, BaculoviridaeAcidalia carticcaria NPV, BaculoviridaeAcleris gloverana NPV, BaculoviridaeAcleris variana NPV, BaculoviridaeAcrobasis zelleri entomopoxvirus, PoxviridaeAcronicta aceris NPV, BaculoviridaeActebia fenni

25、ca NPV, BaculoviridaeActias selene Cypovirus 4, ReoviridaeActias selene NPV, BaculoviridaeActinomycetes phage 108/016, MyoviridaeActinomycetes phage 119, SiphoviridaeActinomycetes phage A1-Dat, SiphoviridaeActinomycetes phage Bir, SiphoviridaeActinomycetes phage f115-A, SiphoviridaeActinomycetes pha

26、ge f150A, SiphoviridaeActinomycetes phage f31C, Siphoviridae,Actinomycetes phage M1, SiphoviridaeActinomycetes phage MSP8, SiphoviridaeActinomycetes phage P-a-1, SiphoviridaeActinomycetes phage R1, SiphoviridaeActinomycetes phage R2, SiphoviridaeActinomycetes phage SK1, MyoviridaeActinomycetes phage

27、 SV2, SiphoviridaeActinomycetes phage VP5, SiphoviridaeAdelaide River virus, RhabdoviridaeAdeno-associated virus 1, ParvoviridaeAdeno-associated virus 2, ParvoviridaeAdeno-associated virus 3, ParvoviridaeAdeno-associated virus 4, ParvoviridaeAdeno-associated virus 5, ParvoviridaeAdisura atkinsoni NP

28、V, BaculoviridaeAdoxophyes orana NPV, BaculoviridaeAedes aegypti densovirus, ParvoviridaeAedes aegypti entomopoxvirus, PoxviridaeAedes aegypti NPV, BaculoviridaeAedes albopictus densovirus, ParvoviridaeAedes annandalei NPV, BaculoviridaeAedes atropalpus NPV, BaculoviridaeAedes epactius NPV, Baculovi

29、ridaeAedes nigromaculis NPV, BaculoviridaeAedes pseudoscutellaris densovirus, ParvoviridaeAedes scutellaris NPV, BaculoviridaeAedes sollicitans NPV, BaculoviridaeAedes taeniorhynchus NPV, BaculoviridaeAedes tormentor NPV, BaculoviridaeAedes triseriatus NPV, BaculoviridaeAedia leucomelas NPV, Baculov

30、iridaeAeromonas phage 29, MyoviridaeAeromonas phage 37, MyoviridaeAeromonas phage 43, MyoviridaeAeromonas phage 44RR2.8t, MyoviridaeAeromonas phage 51, MyoviridaeAeromonas phage 59.1, MyoviridaeAeromonas phage 65, MyoviridaeAeromonas phage Aeh1, MyoviridaeAeromonas phage Aeh2, MyoviridaeAfrican cass

31、ava mosaic virus, GeminiviridaeAfrican green monkey cytomegalovirus, HerpesviridaeAfrican green monkey HHV-like virus, HerpesviridaeAfrican green monkey polyomavirus, PapovaviridaeAfrican horse sickness viruses 1 to 10, ReoviridaeAfrican swine fever virus, African swine fever-like virusesAG83-1746 v

32、irus, BunyaviridaeAG83-497 virus, BunyaviridaeAgaricus bisporus virus 1, UnassignedAgaricus bisporus virus 4, Partitiviridae,Agraulis vanillae virus, TetraviridaeAgrobacterium phage PIIBNV6, MyoviridaeAgrobacterium phage PS8, SiphoviridaeAgrobacterium phage PT11, SiphoviridaeAgrobacteriurn phage Y,

33、SiphoviridaeAgrochola helvolva cypovirus 6, ReoviridaeAgrochola lychnidis cypovirus 6, ReoviridaeAgropyron mosaic virus, PotyviridaeAgrotis exclarnationis NPV, BaculoviridaeAgrotis ipsilon NPV, BaculoviridaeAgrotis segeturn cypovirus 9, ReoviridaeAgrotis segeturn NPV, BaculoviridaeAguacate virus, Bu

34、nyaviridaeAhlum water-borne virus, TombusviridaeAino virus, BunyaviridaeAkabane virus, BunyaviridaeAKR (endogenous) murine leukemia virus, RetroviridaeAlabama argillacea NPV, BaculoviridaeAlajuela virus, BunyaviridaeAlcaligenes phage 8764, SiphoviridaeAlcaligenes phage A5/A6, SiphoviridaeAlcaligenes

35、 phage A6, MyoviridaeAlcelaphine herpesvirus 1, HerpesviridaeAlcelaphine herpesvirus 2, HerpesviridaeAlenquer virus, BunyaviridaeAletia oxygala NPV, BaculoviridaeAleutian disease virus, ParvoviridaeAleutian mink disease virus, ParvoviridaeAfalfa cryptic virus 1, PartitiviridaeAlfalfa cryptic virus 2

36、, PartitiviridaeAlfalfa latent virus, CarlavirusAlfalfa mosaic virus, BromoviridaeAlfuy virus, FlaviviridaeAllerton virus, HerpesviridaeAlligatorweed stunting virus, ClosterovirusAllitrich herpesvirus 1, HerpesviridaeAllomyces arbuscula virus, UnassignedAlmeirim virus, ReoviridaeAlmpiwar virus, Rhab

37、doviridaeAlphaea phasma NPV, BaculoviridaeAlsophila pometaria NPV, BaculoviridaeAlstroemeria mosaic virus, PotyviridaeAlstroemeria streak virus, PotyviridaeAlstroemeria virus, CarlavirusAltamira virus, ReoviridaeAlteromonas phage PM2, CorticoviridaeAmapari virus, ArenaviridaeAmaranthus leaf mottle v

38、irus, PotyviridaeAmathes c-nigrum NPV, BaculoviridaeAmazon lily mosaic virus, Potyviridae,Aglais urticae cypovirus 2, ReoviridaeAglais urticae cypovirus 6, ReoviridaeAglais urticae NPV, BaculoviridaeAgraulis vanillae cypovirus 2, ReoviridaeAgraulis vanillae densovirus, ParvoviridaeAgraulis vanillae

39、NPV, BaculoviridaeAndraca bipunctata GV, BaculoviridaeAneilema virus, PotyviridaeAngel fish reovirus, ReoviridaeAnhanga virus, BunyaviridaeAnhembi virus, BunyaviridaeAnisota senatoria NPV, BaculoviridaeAnomala cuprea entomopoxvirus, PoxviridaeAnomis flava NPV, BaculoviridaeAnomis sabulifera NPV, Bac

40、uloviridaeAnomogyna elimata NPV, BaculoviridaeAnopheles A virus, BunyaviridaeAnopheles 8 virus, BunyaviridaeAnopheles crucians NPV, BaculoviridaeAntequera virus, BunyaviridaeAnthela varia NPV, BaculoviridaeAnthelia hyperborea NPV, BaculoviridaeAntheraea eucalypti virus, TetraviridaeAntheraea mylitta

41、 cypovirus 4, ReoviridaeAntheraea paphia NPV, BaculoviridaeAntheraea pemyi cypovirus 4, ReoviridaeAntheraea pemyi NPV, BaculoviridaeAntheraea polyphemus NPV, BaculoviridaeAntheraea yamamai NPV, BaculoviridaeAnthonomus glandis PV, BaculoviridaeAnthoxan, thum latent blanching virus, HordeivirusAnthoxa

42、nthum mosaic virus, PotyviridaeAnthrenus museorum NPV, BaculoviridaeAnthriscus virus, CarlavirusAnthriscus yellows virus, SequiviridaeAnticarisia gemmatalis MNPV, BaculoviridaeAntitype xanthomista cypovirus 6, ReoviridaeAotine herpesvirus 1, HerpesviridaeAotine herpesvirus 2, HerpesviridaeAotine herpesvirus 3, HerpesviridaeApamea anceps GV, BaculoviridaeApamea anceps NPV, BaculoviridaeApamea sordens GV, BaculoviridaeApanteles fumi