是一類非細胞型微生物演示課件

1、1,病毒（virus,是一類非細胞型微生物 主要特點 體積非常微小，需在電子顯微鏡觀察 結(jié)構(gòu)簡單，無細胞結(jié)構(gòu)，只含一種類型核酸（DNA或RNA） 嚴格的細胞內(nèi)寄生，只能在活細胞中增殖 對抗生素不敏感，但對干擾素敏感,2,3,形態(tài),大小: （納米，nm） The largest : （300X100 nm, 痘病毒） The smallest: 10 nm 形態(tài)：球形或桿狀，也有復合狀,4,5,6,7,8,HIV,9,Bacteriophage T4,10,結(jié)構(gòu),基本結(jié)構(gòu) 核心 Viral core 衣殼 Capsid 輔助結(jié)構(gòu) 包膜 Envelope 其他 病毒體 Virion 核衣殼 Nuc

2、leocapsid,11,核心,成分：DNA 或 RNA,病毒復制 功能 決定病毒的各種特性 具有感染性 編碼病毒結(jié)構(gòu)蛋白和功能蛋白,病毒核酸的特性：具有感染性 將提純的病毒核酸（如腸道病毒RNA）如加至活細胞可以啟動病毒復制從而感染細胞。從感染細胞中可以獲得子代完整病毒顆粒,12,病毒衣殼,成分：蛋白質(zhì) 由殼粒組成。殼粒是衣殼的形態(tài)學亞單位，多肽分子是衣殼的化學亞單位 功能 保護病毒核酸 參與感染過程 具有抗原性,13,按殼粒排列方式的對稱型,螺旋對稱型（helical symmetry） 20面體立體對稱型（icosahedral symmetry） 復合對稱型（complex symme

3、try,14,病毒包膜,是包繞在病毒核衣殼外面的雙層膜 主要成分是蛋白質(zhì)、多糖及脂類，常以糖蛋白或脂蛋白形式存在 蛋白質(zhì)是由病毒基因編碼，多糖、脂類來自宿主細胞膜、核膜或空泡膜,15,包膜特性與功能,有包膜的病毒以“出芽” 方式釋放 有包膜病毒對脂溶劑（如乙醚、氯仿）敏感，能滅活病毒，乙醚常用于鑒定病毒有無包膜 功能 維護病毒體結(jié)構(gòu)的完整性 具有與宿主細胞膜親和及融合的性能 具有病毒抗原的特異性,16,病毒復制,復制周期 吸附、穿入、脫殼、生物合成、裝配與釋放 病毒本身沒有獨立的蛋白合成酶系統(tǒng)，必須借助宿主細胞的蛋白合成體系合成病毒蛋白 病毒復制周期時間因病毒而異 腺病毒25h 小RNA病毒6

4、-8h 流感病毒15-30h,17,dsDNA病毒復制示意圖,18,ssRNA病毒復制示意圖,19,ssRNA逆轉(zhuǎn)錄病毒復制示意圖,20,吸附,通過病毒體表面的配體蛋白與易感細胞表面特異性受體相結(jié)合 吸附過程可在幾分鐘到幾十分鐘內(nèi)完成,21,穿入,吞飲：無包膜病毒被宿主細胞吞噬，進入胞內(nèi) 融合：有包膜病毒的包膜與宿主細胞膜直接融合，病毒核衣殼進入細胞 直接穿入,22,脫殼,在細胞溶酶體酶的作用下，脫去衣殼蛋白釋放病毒核酸,23,生物合成,早期蛋白合成階段 轉(zhuǎn)錄、翻譯而產(chǎn)生病毒生物合成中必需的酶類及某些抑制或阻斷細胞核酸和蛋白質(zhì)合成的非結(jié)構(gòu)蛋白 晚期蛋白合成階段 復制病毒核酸，轉(zhuǎn)錄、翻譯而產(chǎn)生病

5、毒的結(jié)構(gòu)蛋白 隱蔽期 生物合成階段用電鏡方法在細胞查不到完整病毒，用血清學方法也測不到病毒抗原 各病毒隱蔽期長短不一,24,裝配,無包膜病毒 先形成空心衣殼，核酸從衣殼裂隙進入形成核衣殼 有包膜病毒 核衣殼與細胞的膜系統(tǒng)（漿膜或核膜）結(jié)合形成包膜 包膜的蛋白質(zhì)（包括糖蛋白）是由病毒基因組編碼，故具有病毒的特異性和抗原性 裝配的部位 除痘病毒外，DNA病毒均在細胞核內(nèi)裝配 RNA病毒與痘病毒則在細胞漿內(nèi)裝配,25,釋放,無包膜病毒 均以破胞方式釋放 有包膜的病毒 以出芽方式釋放到細胞外 通常細胞不死亡，仍能繼續(xù)分裂增殖,26,病毒增殖異常,頓挫感染 缺陷病毒 干擾現(xiàn)象,形成包涵體 某些病毒在宿主

6、細胞內(nèi)增殖，其細胞質(zhì)或細胞核內(nèi)會出現(xiàn)一種光學顯微鏡下可見的斑塊結(jié)構(gòu)，稱包涵體。它是病毒在細胞內(nèi)增殖的場所,27,頓挫感染,原因 宿主細胞不能提供病毒復制所需的酶、能量或成份 病毒雖被復制，但不能裝配釋放,28,缺陷病毒,因病毒基因組不完整或有點突變而不能進行正常復制的病毒，當與輔助病毒共同培養(yǎng)，如能為其提供缺乏的物質(zhì)，則缺陷病毒也能培殖 腺病毒相關(guān)病毒（缺陷病毒）與腺病毒（輔助病毒） 丁型肝炎病毒（缺陷病毒）與乙型肝炎病毒（輔助病毒,29,干擾現(xiàn)象,兩種病毒感染同一細胞時，一種病毒會干擾另一病毒復制 原因 與干擾素（IFN）產(chǎn)生有關(guān) 病毒改變了宿 主細胞代謝途徑 意義 聯(lián)合使用疫苗,30,理化

7、因素對病毒的影響,滅活 病毒受理化因素作用后，失去感染性 滅活病毒仍保留某些特性，如抗原性、紅細胞吸附、細胞融合等,31,物理因素,溫度 病毒耐冷不耐熱。-70C長期保存。凍融可殺死病毒 60C 30 min或100C數(shù)秒即可殺死病毒，但HBV需100C 10 min方可殺死 有包膜病毒比無包膜病毒對熱更敏感 pH 多數(shù)在pH 59范圍穩(wěn)定 腸道病毒耐酸（pH 35） 射線 X線、射線可將病毒核酸致死性斷裂，從而殺死病毒,32,化學因素,脂溶劑：乙醚、氯仿、去氧膽酸鹽 有包膜病毒敏感。無包膜病毒無作用（如腸道病毒） 消毒劑：過氧乙酸、甲醛、戊二醛、鹵素 殺死大多數(shù)病毒，但病毒對消毒劑抵抗力比細

8、菌強，尤其是無包膜病毒 常用甲醛來制備滅活疫苗 其他 抗生素：對病毒無作用 中草藥：有一定作用,33,病毒的變異現(xiàn)象 感染性變異（毒力變異） 條件致死株：減毒活疫苗（脊灰） 抗原性變異 耐藥性變異 機制 基因突變基因重組,34,病毒與其他微生物的比較,35,小結(jié),病毒的概念 病毒的結(jié)構(gòu)與化學組成 病毒的復制 理化因素對病毒的影響,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