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    VIRUSES

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    Are Viruses Living orAre Viruses Living or

    NonNon--living?living? Viruses are both and neither

    They have some properties of lifebut not others For example, viruses can be killed,

    even crystallized like table salt

    However, they cant maintain aconstant internal state(homeostasis).

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    What a Virus Isnt

    Not a bacterium...

    Not independent... Cannot survive in absence of a living cell

    within which to replicate...

    Antibiotics generally dont work on them...

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    Whatare Viruses?Whatare Viruses?

    A virus is a non-

    cellular particle madeup of genetic materialand protein that can

    invade living cells.

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    What Viruses Are...

    Infectious agents composed mainly of nucleic acid

    with a protein coat (capsid)

    Visible with electron microscope (10-200 nM)

    Carry on normal cell-like function (unless free, then

    infectious)

    In infectious form: no growth; no respiration??? Can enter living plant, animal or bacterial cell

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    Discovery of VirusesDiscovery of VirusesBeijerinck (1897)coined the Latin namevirus meaning poison

    He studied filteredplant juices & foundthey caused healthyplants to become sick

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    Tobacco Mosaic VirusTobacco Mosaic Virus

    Wendell Stanley(1935) crystallized

    sap from sicktobacco plants

    He discovered

    viruses were made ofnucleic acid andprotein

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    SmallpoxSmallpox

    Edward Jenner (1796)developed a smallpoxvaccine using milder

    cowpox virusesDeadly viruses aresaid to be virulent

    Smallpox has beeneradicated in theworld today

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    Viewing VirusesViewing Viruses

    Viruses areViruses are smallersmallerthan the smallest cellthan the smallest cell

    Measured inMeasured in

    nanometersnanometersViruses couldnt beViruses couldnt beseen until theseen until the electronelectronmicroscopemicroscope waswasinvented in theinvented in the 2020thth

    centurycentury

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    Electron Microscopy

    Mitra, K. & Frank, J., 2006. Ribosome dynamics: insights from atomic structure modeling into cryo-electron

    microscopy maps.Annual review of biophysics and biomolecular structure, 35, 299-317.

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    X-ray Crysta

    llography of Viruses

    Symmetry of protein shells makes them uniquely

    well-suited to crystallographic methods

    Viruses are the largest assemblies of biological

    macromolecules whose structures have been

    determined at high resolution

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    ViralViralStructureStructure

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    Virus Appearence? 1. Capsid

    2. Core and genetic material (DNA/RNA)

    Capsid: outer shell of the virus which encloses genetic material

    (link: chemical structure of capsid helps determine immune

    response to virus)

    capsid is made of many identical individual proteins

    protein core under capsid protecting genetic material

    sometimes an additional covering (lipid bilayer w/embedded

    proteins) on outside known as an envelope ( like a baseball)

    various forms: rods, filaments, spheres, cubes, crystals

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    CharacteristicsCharacteristics

    Non living structures

    Noncellular

    Contain a protein coat called thecapsid

    Have a nucleic acid core containing

    DNA or RNA Capable of reproducing only when

    inside a HOST cell

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    CharacteristicsCharacteristics

    Some viruses areenclosed in anprotective envelope

    Some viruses may havespikes to help attach tothe host cell

    Most viruses infectonly SPECIFIC hostcells

    CAPSID

    ENVELOPE

    DNA

    SPIKES

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    CharacteristicsCharacteristics

    Viral capsids(coats) are madeof individualprotein subunits

    Individual

    subunits arecalled capsomeres CAPSOMERES

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    Capsid

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    capsomere: unit/molecule associated with capsid structure

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    CharacteristicsCharacteristics

    Outside of host cells,viruses are inactive

    Lack ribosomes and

    enzymes needed formetabolism

    Use the raw materials

    and enzymes of the hostcell to be able toreproduce

    EBOLAVIRUS

    HIVVIRUS

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    Size of VirusesSize of Viruses

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    Viral ShapesViral Shapes

    Viruses come in a variety ofshapes

    Some may be helical shape likethe Ebola virus

    Some may be polyhedral

    shapes like the influenza virusOthers have more complex

    shapes like bacteriophages

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    T

    ypical

    Virus Shapes

    RODS SPHERES

    CUBES

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    The Structure of Viruses

    Tobacco

    Mosaic

    Virus

    HIV

    Bacteriophage

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    Helical VirusesHelical Viruses

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    Polyhedral VirusesPolyhedral Viruses

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    More Virus Shapes

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    Complex VirusesComplex Viruses

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    Taxonomy ofTaxonomy of

    VirusesViruses

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    ira Taxonomyira TaxonomyExamplesExamples

    Herpesviridae

    Herpesvirus

    Human herpes virus 1, HHV 2, HHV 3

    Retroviridae

    Lentivirus Human Immunodeficiency Virus 1, HIV 2

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    Herpes VirusHerpes Virus

    SIMPLEXI and II

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    AdenovirusAdenovirus

    COMMONCOLD

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    Influenza VirusInfluenza Virus

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    PapillomavirusPapillomavirus Warts!Warts!

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    RNA or DNA Virus

    Do or do NOT have an envelope

    Capsid shape

    HOST they infect

    Used for VirusUsed for Virus

    IdentificationIdentification

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    Bacteriophages

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    PhagesPhages

    Viruses that attackbacteria are calledbacteriophage or just

    phageT-phages are aspecific class of

    bacteriophages withicosahedral heads,double-stranded DNA,and tails

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    TT--phagesphages

    The most commonly studiedT-phages are T4 and T7They infect E. coli , an

    intestinal bacteriaSix small spikes at the baseof a contractile tail are usedto attach to the host cellInject viral DNA into cell

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    EscherichiaColi

    Bacterium

    T - EVENPHAGESATTACKTHISBACTERIUM

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    E. Coli and the

    Bacteriophage

    What it looks like in real

    life

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    T-Even Bacteriophages

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    Diagram of TDiagram of T--44BacteriophageBacteriophage

    Head with 20triangular

    surfacesCapsidcontains DNA

    Head & tailfibers madeof protein

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    Composition ofT-Even

    Bacteriophage

    Capsid: brains of virus,

    tightly-wound protein

    protecting nucleic acids Body: attached to

    capsid head, rod-like

    structure w/retractible

    sheath, hollow core

    Tail: at end of core is a

    spiked plate carrying 6

    slender tail fibers,

    anchor virus to its host

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    R

    et

    rovirusesR

    et

    roviruses

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    Characteristics of RetrovirusesCharacteristics of Retroviruses

    Contain RNA, not DNA

    Family Retroviridae

    Contain enzyme called ReverseTranscriptase

    When a retrovirus infects a cell,

    it injects its RNA and reversetranscriptase enzyme into thecytoplasm of that cell

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    Change DNA

    into RNA.

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    ENZYME

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    RetrovirusesRetroviruses

    The enzyme reversetranscriptase (orRTase), which causessynthesis of acomplementary DNAmolecule (cDNA) using

    virus RNA as atemplate

    RTase

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    RetrovirusesRetroviruses

    HIV, the AIDSvirus, is a retrovirus

    Feline LeukemiaVirus is also aretrovirus

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    Viroids & PrionsViroids & Prions

    dd

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    ViroidsViroids

    Small, circular RNAmolecules without aprotein coat

    Infect plantsPotato famine inIreland

    Resemble intronscut out ofeukaryotic

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    PrionsPrionsPrions are infectiousproteins They are normal bodyproteins that getconverted into an alternateconfiguration by contactwith other prion proteins They have no DNA orRNA

    The main protein involvedin human and mammalianprion diseases is calledPrP

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    Prion DiseasesPrion Diseases

    Prions formPrions form insolubleinsolubledeposits in the braindeposits in the brainCauses neurons toCauses neurons torapidly degeneration.rapidly degeneration.

    Mad cow diseaseMad cow disease (bovine(bovinespongiform encephalitis:spongiform encephalitis:BSE) is an exampleBSE) is an examplePeople in New GuineaPeople in New Guinea

    used to suffer fromused to suffer fromkurukuru, which they got, which they gotfrom eating the brainsfrom eating the brainsof their enemiesof their enemies

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    Viral ReplicationViral Replication

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    How do viruses work?

    Viruses make use of the host cells chemical energy,

    protein and nucleic acid synthesizing ability to replicate

    themselves...

    each virus attacks a specific type of cell cold viruses attack cells of the lung

    the AIDS virus attacks T4 cells of the

    immune system

    fish viruses are just as specific

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    Bottom Line...

    All viruses only exist to make more viruses

    Most are harmful

    Replication = host cell death.

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    VirusalMechanism

    Viruses contain single- or double- stranded DNA

    or RNA

    Often, the virus alters the intracellularenvironment enough to damage or kill the cell

    (oops!!)

    If enough cells are destroyed, disease results!

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    Role ofRNA/DNARole ofRNA/DNA Supplies the codes for building the protein coat

    (capsid) and for producing enzymes needed toreplicate more viruses

    Information given so newly-built viruses can lyse cells(e.g., bacteriophage)

    Result: cell destroyed.

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    Viral AttackViral Attack

    Viruses are very specific as towhich species they attack

    HOST specific Humans rarely share viral diseases

    with other animals

    Eukaryotic viruses usually haveprotective envelopes made fromthe host cell membrane

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    5Steps of Lytic Cycle5Steps of Lytic Cycle

    1. Attachment to the cell 2. Penetration (injection) of viral DNA or

    RNA

    3. Replication (Biosynthesis) of new viralproteins and nucleic acids 4. Assembly (Maturation) of the new

    viruses

    5. Release of the new viruses into theenvironment (cell lyses) : DNA incorporated(10 minutes) hundreds of virions appear causingthe cell to rupture, releasing hundreds of small

    viral replicates

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    Bacteriophage ReplicationBacteriophage Replication

    Bacteriophageinject theirnucleic acidThey lyse (breakopen) the

    bacterial cellwhen replicationis finished

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    Bacteriophage Attack

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    Attachment Phage attaches by tail fibers tohost cell

    Penetration Phage lysozyme opens cell wall,

    tail sheath contracts toforce tail core and DNA intocell

    Biosynthesis Production of phage DNA

    and proteins Maturation Assembly of phage particles

    Release Phage lysozyme breaks cell wall

    Lytic Cycle ReviewLytic Cycle Review

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    Common steps in the assembly of alldsDNA viruses

    Unique portal ring at one Vertex

    Scaffolding proteins

    Procapsid assembled empty of DNA

    DNA pumped into procapsid through portal ring

    DNA moves back through portal to enter cell

    Pathway

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    Attachment:Phage attachesto host cell.

    Penetration:Phage pnetrates hostcell and injects itsDNA.

    Merozoites releasedinto bloodsteam fromliver may infect newred blood cells

    1

    2

    3

    Bacterialcell wall

    Bacterialchromosome

    Capsid DNA

    Capsid

    Sheath

    Tail fiber

    Base plate

    Pin

    Cell wall

    Tail

    Plasma membrane

    Sheath contracted

    Tail core

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    4 Maturation:Viral components areassembled into virions.

    Tail

    5 Release:Host cell lyses andnew virions arereleased.

    DNA

    Capsid

    Tail fibers

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    OneOne--step GrowthCurvestep GrowthCurve

    V l LV l L

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    Viral LatencyViral Latency

    Some viruses have the ability tobecome dormant inside the cellCalled latent viruses

    They may remain inactive for longperiods of time (years)Later, they activate to produce new

    viruses in response to some externalsignalHIV and Herpes viruses are

    examples

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    Lysogenic CycleLysogenic Cycle

    Phage DNA injected into host cellViral DNA joins host DNA forming aprophageWhen an activation signal occurs,the phage DNA starts replicating

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    Lysogenic CycleLysogenic Cycle

    Viral DNA (part of prophage) may stayinactive in host cell for long periods oftime

    Replicated during each binary fission

    Over time, many cells form containingthe prophages

    Viral LatencyViral Latency

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    Viral LatencyViral LatencyOnce a prophage cell is activated, host cell enters the

    lytic cellNew viruses form a & the cell lyses (bursts)Virus said to be virulent (deadly)

    INACTIVESTAGEACTIVE

    STAGE

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    Virulent VirusesVirulent Viruses

    HOST

    CELL

    LYSES &

    DIES

    The Lysogenic CycleThe Lysogenic Cycle

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    The Lysogenic CycleThe Lysogenic Cycle

    L t n in E k tL t n in E k t

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    Latency in EukaryotesLatency in EukaryotesSome eukaryotic virusesremain dormant for manyyears in the nervoussystem tissues Chickenpox (caused bythe virus Varicellazoster) is a childhoodinfectionIt can reappear later inlife as shingles, a painfulitching rash limited tosmall areas of the body

    SHINGLES

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    Latency in EukaryotesLatency in Eukaryotes

    Herpes viruses alsobecome latent in thenervous system

    A herpes infection lastsfor a persons lifetime

    Genital herpes (HerpesSimplex 2)

    Cold sores or feverblisters (HerpesSimplex1)

    SKINTOSKINCONTACT

    PASSEDATBIRTHTO

    BABY

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    The Virus Invasion

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    Whats Infected by a Virus?

    All living things have some susceptibility to a

    particular virus

    Virus is specific for the organism Within a species, there may be a 100 or more

    different viruses which can affect that species

    alone

    Specific: for example, a virus that only affects

    one organism (humans and smallpox)

    Influenza can infect humans and two animals

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    DifferentTypes of Viruses

    Major classifications: animal, plant, bacterial

    Sub-classified by arrangement and type of nucleic

    acid

    Animal virus group: double-stranded DNA, single-stranded DNA, double-stranded RNA, single-

    stranded RNA, retrovirus

    Influenza: SS-RNA

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    Do Viruses ever Change?

    Mutations do occur.

    If the mutation is harmful, the new virus particlemight no longer be functional (infectious)

    However, because a given virus can generate many,many copies, a small number of non-functionalviruses is not important

    Mutation is not necessarily damaging to the virus --

    it can lead to a functional but new strain of virus

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    VirulenceVirulence

    VIRUS DESTROYING HOST CELL

    Lytic and Lysogenic CyclesLytic and Lysogenic Cycles

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    Lytic and Lysogenic CyclesLytic and Lysogenic Cycles

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    Defense Against Viruses

    First Line: skin and mucous membrane, whichalso lines the gastrointestinal and respiratorypassageways

    skin is tough and stomach acidity acts as adisinfectant

    Second Line: after the virus enters the blood andother tissues, white blood cells and related cells

    (phagocytes) consume them accumulation of phagocytes in area of infection is

    known as puss

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    Defense Against Viruses

    Antibodies are the best defense against viruses

    unfortunately, they are specific in their action

    chickenpox antibody will only attack a chickenpox virus a particular virus stimulates the production of a particular

    antibody

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    Defense Against Viral Infection

    Animals are protected in several ways:

    1)intracellular: if a particular virus attacks cells, our

    bodies produce interferons

    interferons (alpha, beta or gamma) are proteins which

    interact with adjacent cells and cause them to become more

    resistant to infection by the virus

    if the resistance is not quite good enough, we become sick

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    Defense Against Viral Infection

    2)immune system (extracellular): kills the virusoutside the cell

    also kills the infected cells

    virus cannot spread

    eventually the virus is completely removed and weget better

    exception: HIV because it infects cells of theimmune system, itself

    chemicals/drugs: acyclovir, AZT, HIV proteaseinhibitor, several fish vaccines available.

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    Major Fish Viruses

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    Major Viral Infections in Fish

    Infectious pancreatic necrosis (IPN)

    Viral hemorrhagic septicemia (VHS)

    Infectious hematopoetic necrosis (IHN)

    Channel catfish virus disease (CCVD)

    (1) I f i P i N i

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    (1)Infectious Pancreatic Necrosis

    (IPN)

    What?: viral infection of salmonids (trout and char)

    Time: Acute

    Result: high mortality (fry and fingerlings)

    Rare in larger fish (good thing!)

    History: Isolated in Pacific NW in 1960s, wiped out brook

    trout in Oregon in 1971-73

    Size: Only 65 nM in diam., smallest of fish viruses

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    IPN: generalnotes

    Single capsid shell, icosohedral symmetry, no envelope

    Contains two segments of DS-RNA

    Fairly stable and resistant to chemicals (acid, ether, etc.),

    variable resistance to freezing

    Remains infectious for 3 months in water (uh oh!)

    Targets pancreas and hematopoietic tissues of kidney and spleen

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    IPN: epizootiology (disease process)

    Who?: All salmonids, brook trout most susceptible,

    marine fish (flounder?)

    Reservoirs (where)?: carriers, once a carrier always a

    carrier, virus particles shed in feces/urine Transmission (how?): horizontal, by waters via

    carriers or infected fry; vertical from adults to

    progeny; experimentally by feeding infected material,

    IP injection

    Pathogenesis: entry via gills, digestive tract

    Environmental factors: mortality reduced at lower

    temps (why?); however, carriers not reduced

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    IPN: pathology (what do we see?)

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    IPN: detection, diagnosis and control

    Isolation: whole fry, kidney, spleen, pyloric cecae, sexfluids are all good sources, .i.e. check these!!!

    Presumptive tests: epizootiological evidence and/or typical

    PCR in infected cells

    Definitive tests: serology

    (fluorescent antibody test (FAT))

    Control: avoid virus in water, virus-free

    stock, destruction of infected stock,

    vaccine exists now!

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    Other species known to be

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    Other species known to be

    susceptible

    amago salmon (Oncorhynchus rhodurus)Arctic char (Salvelinus alpinus)Atlantic menhadden (Brevoortia tyrannus)carangids (Carangidae)chinook salmon (Oncorhynchus tshawytscha)chum salmon (Oncorhynchus keta)cichlids (Cichlidae)coho salmon (Oncorhynchus kisutch)common scallop (Pecten maximus)

    cutthroat trout (Salmo c

    larki)cyprinids (Cyprinidae)

    Danube salmon (Salmo hucho)drums/croakers (Sciaenidae)eels (Anguilla spp)grayling (Thymallus thymallus)

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    More

    halibut (Hippoglossus stenolepis) herrings/sardines (Clupidae)Jap. amberjack (Seriola quinqueradiata) lake trout (Salvelinus namaycush)lampreys (Petromyzontyidae) left-eye flounders (Bothidae)loach (Misgurnus anguillicaudatus) loaches (Cobitidae)masou salmon (Oncorhynchus masou) Pacific salmon (Oncorhynchus spp)perches (Percidae) pikes (Esocidae)silversides (Atherinidae) sockeye salmon (Oncorhynchus nerka)soles (Soleidae) Southwest European nase (C. toxostoma)

    striped snakehead (Channa striatus) suckers (Cotostomidae)

    summer flounder (Paralichthys dentatus) turbot (Psetta maxima)white seabass (Moronidae) whitefish (Coregonidae)carp (Cyprinus carpio) goldfish (Carassius auratus)redfin perch (Perca fluviatilis) southern flounder (P. lethostigma)yellowfin bream (Acanthopagrus australis)

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    Asymptomatic carriers...

    coalfish (Pollachius virens)common carp (Cyprinus carpio)discus fish (Symphysodon discus)goldfish (Carrasius auratus)heron (Ardea cinerea)loach (Cobitidae)minnow (Phoxinus phoxinus)noble crayfish (Astacus astacus)pike (Esoxlucius)

    river lamprey (Lampetra fluviata

    lis)shore crab (Carcinus maenas)

    Spanish barbel (Barbus graellsi)white suckers (Catostomas commersoni)

    Infectious pancreatic necrosis in Atlantic salmon.

    Note swollen stomach and 'pop eye'

    Source: Australian Animal Health Laboratory

    ...what now???

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    (2) ViralHemorrhagic Septicemia (VHS)

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    (2)ViralHemorrhagic Septicemia (VHS)

    What?: Viral disease of European salmonids

    When?: Recognized in Denmark in 1949, isolated

    from Pacific Coast in 1989 Size: rhabdovirus, bullet-shaped (one rounded

    end), 185 x 65 nM, lipoprotein envelope

    non-segmented SS-RNA

    Constitution: sensitive to ether and chloroform,heat, acid, resistant to freeze-drying

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    ViralHemorrhagic Septicemia (VHS)

    Pathogenesis: infection results in viremia, disrupts many

    organ systems, 200-300g fish most affected

    Environmental factors: low temp (< 8oC, 46oF)

    External pathology: lethargy, hanging downward in water

    (dropsy), swimming in circles, exopthalmia, dark

    discoloration, hemorrhages in roof of mouth, pale gillsw/focal hemorrhages

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    ViralHemorrhagic Septicemia (VHS)

    Internal pathology: gut devoid of food, liver pale,

    hemorrhages in connective tissue, kidney gray and swollen

    (chronic), red and thin (acute)

    Histopathology: necrosis of liver, kidney nephrons,

    spleen, pancreas, melanin in kidneys and spleen (OUCH!)

    Isolation/tests: isolated from kidney/spleen,epizootiological evidence, definitive test is serum

    neutralization, or FAT.

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    ViralHemorrhagic Septicemia (VHS)

    External hemorrhages

    Liver red in acute stage

    Viral haemorrhagic septicaemia in rainbow trout

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    Viral haemorrhagic septicaemia in rainbow trout.

    Note swollen stomach and pop eye

    Viral haemorrhagic septicaemia in rainbow trout.

    Note pale color of stomach region, pinpoint

    haemorrhages in fatty tissue, and pale gills

    Source:THstein

    Type Prevalent host type and location

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    Type Prevalent host type and location

    I-aFarmed rainbow trout and a few other freshwater fish in continental

    Europe[10]

    I-bMarine fish of the Baltic Sea, Skagerrak, Kattegat,North Sea,

    Japan[1]

    I-c Farmed rainbow trout Denmark

    I-d Farmed rainbow trout inNorway, Finland, Gulf of Bothnia

    I-e Rainbow trout in Georgia, farmed and wild turbot in the Black Sea[11]

    II Marine fish of the Baltic Sea

    III

    Marine fish of the British Isles and northern France, farmed turbot in

    the UK and Ireland, and Greenland halibut (Reinhardtius

    hippoglossoides) in Greenland[12]

    IV-aMarine fish of the Northwest Pacific (North America), North

    American north Atlantic coast,[13] Japan, and Korea[1][14]

    IV-b Freshwater fish in North American Great Lakes region[14]

    Virus presence spread through much of the Great Lakes from 2003-2007.

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    ViralHemorrhagic Septicemia

    Prevention: clean broodstock and water = clean fish, avoid

    infected broodstock, test and slaughter

    Can spread very quickly from farm to farm: avoid close

    proximity to other farms

    Vaccines are under development.

    One EPA-approved disinfectant: Virkon AQUATIC

    (made by Dupont). Bleach kills the VHS virus.

    (3 ) Infectious Hematopoietic Necrosis

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    (3)Infectious Hematopoietic Necrosis

    (IHN)

    Who: sockeye, chinook, rainbows; cohos resistant

    When?: 1950s in Oregon hatcheries. 100 million

    mortalities between 1970-1980, if infected, 70%

    mortality likely, esp. in young fish (fry: 90-95%

    mort. possible)

    What?: bullet shaped rhabdovirus, non- segmented

    SS-RNA, sensitive to heat and pH, glycoprotein is

    spiked on surface of virus

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    Infectious Hematopoietic Necrosis (IHN)

    Reservoirs: survivors life-long carriers, adults shed virusat spawning

    Transmission: horizontal, primary mode is vertical viaovarian fluid (virus hitches ride on sperm into egg);

    however, feces, urine, and external mucus possible. Also,

    feeding and inoculation have worked experimentally

    Pathogenesis: gills suspected; incubation period dependson temp, route, dose, age; extensive hemorrhaging,necrosis of many tissues; death usually due to kidneyfailure

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    Infectious Hematopoietic Necrosis (IHN)

    Environmental factors: temp. very important,

    slows below 10C, holding in tanks/handling

    increase severity (doesnt occur naturally >15 C)

    External pathology: lethargy, whirling, dropsy,exopthalmia, anemia, hemorrhaging of

    musculature/fins, scoliosis

    Internal pathology: liver, kidney, spleen pale;

    stomach/intestines filled with milky fluid;petechial hemorrhaging

    Histopathology: extensive necrosis of

    hematopoetic tissue of kidney/spleen

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    Infectious Hematopoietic Necrosis (IHN)

    Definitive diagnosis: serum neutralization, FAT, ELISA

    Prevention: avoidance, quarantine, clean water with UV,ozone, virus-free stock; test, slaughter, disinfect; disinfect

    eggs; vaccines under development; elevated water temp

    No vaccines as of June 2007.

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    (4)ChannelCatfish Virus Disease (CCVD)

    Contagious herpes virus affecting only channel catfish less

    than four months old

    Occurs in SE United States, California, Honduras

    Acute hemorrhagia, high mortality, discovered in 1968

    Agent: enveloped capsid, icosohedral nucleocapsid with162 capsomeres

    Physio/chemical properties: easy to kill, sensitive to

    freeze-thaw, acid, ether, etc.

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    ChannelCatfish Virus Disease (CCVD)

    Environmental factors: optimal temperature 28-30C,

    common during warmer months, cooler water = big

    difference

    epizootiology: horizontal, vertical suspected

    external pathology: spiral swimming; float with head at

    surface; hemorrhagic fins, abdomen; ascites; pale or

    hemorrhagic gills; exophthalmia

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    ChannelCatfish Virus Disease (CCVD)

    Internal pathology: hemorrhages of liver, kidney,

    spleen, gut, musculature; congestion of

    mesenteries and adipose

    Histopathology: necrosis of kidney, other organs;macrophages in sinusoids of liver, etc.;

    degeneration of brain

    Presumptive diagnosis: clinical signs,

    epizootiological evidence

    Definitive diagnosis: SN or FAT.

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    ChannelCatfish Virus Disease (CCVD)

    Prevention: avoid potential carriers (survivors) or infected

    fry, keep temperature below 27oC (will still produce

    carriers), attenuated vaccine shows some promise

    Therapy: none available...

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    ChannelCatfish Virus Disease

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    ChannelCatfish Virus Disease

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    However, you can always take precautions!

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    UY - 2011

    Treatment for ViralTreatment for ViralDise

    ase

    Dise

    ase

    VaccinesVaccines

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    UY - 2011

    VaccinesVaccines

    An attenuated virus is a weakened, lessvigorous virus

    Attenuate" refers to procedures that

    weaken an agent of disease (heating) A vaccine against a viral disease can bemade from an attenuated, less virulentstrain of the virus

    Attenuated virus is capable of stimulatingan immune response and creating immunity,but not causing illness

    Perbandingan beberapa tipe vaksin ikan

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    UY - 2011

    IHNV, VHSV,

    HIRRV, IHV-

    1

    Terbatas pada protein

    immunogensTanpa resiko infeksi;Mudah

    dikembangkan & produksi;

    Vaksin Stabil; Menginduksi

    respon imun cellular &

    humoral

    DNA vaccineDNA vaccineGenerasiGenerasi

    IIIIII

    IHNV, VHSV,

    SVCV

    Sulit dalam purifikasi

    (biaya produksi tinggi)

    Tidak mengaktifkan imun

    respon seluler

    Tidak mahal,

    Memungkinkan

    produksi skala besar

    RecombinantRecombinant

    proteinprotein

    vaccinevaccine

    GenerasiGenerasi

    IIII

    IPNV, IHNV,

    VHSV, CCVMahal, Potensi resiko

    terinfeksi

    Imunitas jangka

    panjang,M

    enginduksirespon imun cellular

    dan humoral

    LiveLive

    attenuatedattenuatedvaccinevaccine

    VHSV, RSIV,

    GCHV, ISAV,

    IPNV, IHNV,

    SVCV, CCV

    Mahal,Kasus perkasus

    tdk ada efeknya,

    Imunitas jangka pendek

    -> perlu injeksi booster

    Resiko infeksi (-)

    InactivatedInactivated

    vaccinevaccine

    GGenerasienerasi II

    JenisVirusKekuranganKelebihanJenisVaksin

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