VirusesLeonardus, S.Si.

Learning Outcomes

Should be able to:1 Identify the characteristics of the virus 2 Explain how the replication of virus3 Explain the role of beneficial and harmful

viruses 4 Explain the modes of transmission and

prevention of diseases due to viruses

Introduction

Disesased tobacco plant

Grinded leaves

Diseasead leaf extract

Sprayed

Healthy tobacco

Become disesased

tobacco plant

IntroductionA. Mayer (1883)

Dmitri Ivanovsky (1892)

Disesased tobacco leaves are

grinded

Diseasead tobacco leaf extract Is filtered

Diseasead tobacco leaf

filtrate

Become disesased tobacco plant

Healthy tobacco

Sprayed

Filtrat

Introduction

Adolf Mayer, Germany (1883)  research about the mosaic disease of tobacco, cause dwarfism, spotted leaves conclusion: disease was caused by a very small bacterium (can’t be seen even with microscope)

Dmitry Iwanowsky, Russian (1892) suspected the mosaic disease was caused by another organism smaller than bacterium (still in doubt) conclusion: error with the filtration, bacterium was cause of the disease

Introduction

Martinus W. Beijerinck, Holland, 6 years later filtering is done by Iwanowsky is right, the conclusion: the causative agent of viral diseases escape filter (filterable virus) VIRUS light microscope can not be observed

The development of the science of viruses (virology) virus is a life form non cellular / can not breed without infecting organism another surviving

Ivanovsky and Beijerinck = discoverer of the virus

Introduction

IntroductionTobacco Mosaic Virus (TMV)

Characteristic: Size Size: 25-300 nm

(1nm = 10-9m) Smallest

viruses: poliovirus

Greatest Virus: Pox Virus

Viewed: electron microscope (1930)

Characteristic: Size

Characteristic: Size

Characteristic: Shape

Sphere: influenza virus & Human Immunodeficiency Virus

Oval: Rabies virusRod: Tobacco Mosaic VirusPolyhedral: Adenovirus T-shaped: Bacteriophage

Characteristic: Shape

Characteristic: Shape

Characteristic: Shape

Characteristic: Shape

Characteristic: Shape

Characteristic: Size & Shape

Non-cellular/acellular Virion crystallized (harmful) Obligat intracellular parasite Nucleic acid (genetic material): DNA or RNA

(ss/ds & circular/linear) Capsid (protein envelope): protein coat

covering the genetic material, composed of a large number of protein subunits capsomeres

The capsid/capsomeres giving the virus its shape helical of capsomer-rod/polyhedral/complex

Nucleic acid and capsid form a structure called Nucleocapsid

Characteristic: structure & function

DNA and RNA structure

Characteristic: structure & function

DNA and RNA structure

Characteristic: structure & function

Characteristic: structure & function

Characteristic: structure & function

1. Virus with envelope composed of lipids, proteins and carbohydrates lipoprotein, glycolipid, glycoproteins (helps virus to infect the cells) form spike e.g. influenza virus, herpesvirus

2. Naked virus, without envelope, e.g. TMV, adenovirus

Characteristic: structure & function

Virus with envelope: influenza virus

Characteristic: structure & function

BioFlix: Influenza virus mechanismBioFlix: Influenza virus mechanism

Reproduction = ReplicationOnly occur inside a living cell (host cell)

Bacteriophage reproduces through 2 cycles: lytic and lysogenic

Reproduction

Reproduction

5STEPS

Reproduction: BacteriophageReproduction: Bacteriophage

Reproduction: BacteriophageReproduction: Bacteriophage

Reproduction: Animal Virus

Reproduction: Animal Virus

Viruses show characteristics of life if it is on another organism cell (host cell)

Virus host cell in the form of bacterial, eukaryotic microorganisms (protozoa and fungi), plant cells, and animal cells/human cells

Viruses that attack plant cells can enter the cell through an intermediary other plants by insects

Viruses that attack animal cells or human cells can enter the cells of animals or other human cells through the food, beverage (water), blood, wounds, bites, air

Habitat

ICTV ≠ Linnaeus 4 taxon level = Order, Famili, Genus, Spesies

Order -virales Famili -viridae Genus -virus Spesies English end with -virus

Example of the classification based on ICTV: Order : Mononegavirales Famili : Filoviridae Genus : Filovirus Spesies : Ebola virus Zaire

Classification

Based on the genetic material:1. DNA virus2. RNA virus

Based on the infected host cell:1. Bacteria virus (E. coli): Bacteriophage-DNA-T42. Eukaryotic microbe virus (protozoo & fungi):

RNA-Mycovirus3. Plant virus mostly RNA-Tobacco mosaic virus

(TMV)4. Animal virus: DNA or RNA-Influenza virus

Classification

Plant viruses:1. Tobacco mosaic virus (TMV) mosaic disease,

tobacco, dwarfism, stunted growth, leaf spots, can attack other plants, eg tomatoes

2. Tungrovirus rice, dwarfism, leafhoppers, (VUTW)

3. Citrus leprosis virus (CiLV) orange, orange mites

Role: harmful

Animal viruses:1. Newcastle Disease Virus (NCDV): tetelo, chicken,

diarrhea, coughing, death2. Foot and Mouth Disease Virus (FMDV): cattle,

blistering & slime around foot & mouth3. Avian Influenza Virus: avian, respiratory system,

influenza virus A (H5N1), spread to other animal4. Rabies virus rabies, dog, monkey, cat, human,

central nervous system, hydrophobia, anxiety, agressiveness, loss of muscular control, lead to death

Role: harmful

Virus : Influenza Virus Disease : influenza/flu Infect : upper part of

respiratory system Symptoms : sneezing,

fatigue Types :

A: human, pig, birds B: human, seal, ferret C: human, dog, pig

Transmission: air-borne

Role: harmful

Virus : HIV Disease : AIDS Infect : T cell, immune

system Symptoms : disease

complication Transmission: sexual

intercourse (oral nor anal), blood transfusion, syringe sharing

Role: harmful

Virus : Hepatitis virus Disease : Hepatitis B Infect : liver cell Symptoms : fatigue, flu-like symptoms, dark urine,

pale-colored stool, abdominal pain, loss of appetite, unexplained weight loss, yellow skin and eyes

Transmission: Water-borne, food & beverage (contaminated), unwashed

fruit, uncooked/raw vegetables, ice cube Drugs addicted, sexual intercourse, blood transfusion,

having many sexual partners, bloody as cut, nosebleed, menstruation, personal equipment (contact by patients: toothbrushes, razors or manicure tools)

Role: harmful

Virus : Ebolavirus Disease : Ebola Infect : Immune system Symptoms : vomiting,

diarrheic, malaise, headache, muscle aches, abdominal pain, bleeding internal organs, fever, rash, inflammation of the liver, kidney damage, and decreased platelet count

Transmission: direct contact with body fluids or skin

Role: harmful

Virus : Measles virus Disease : measles Infect : skin cell Symptoms : fever, cough,

blistering skin Transmission : air-borne,

skin to skin contact

Role: harmful

Virus : Polio virus Disease : polio Infect : central nervous system Symptoms : paralyze limbs Transmission: air-borne,

contaminated foods and beverages

Role: harmful

Virus : Mumps virus Disease : mumps (gondong) Infect : parotic gland (saliva

gland) Symptoms : swollen behind the

ears Transmission: air-borne, saliva,

contaminated foods and beverages.

Role: harmful

Virus : Herpes simplex virus Disease : herpes Infect : mucosa epithelial cells (skin, mouth,

genital) Symptoms : blisters Transmission: air-borne, skin and skin contact

Role: harmful

Virus : Human papilloma virus Disease : papilloma Infect : skin cell Symptoms : warts (skin, genital) can growth to

cancer Transmission: skin contact, utilize tools together,

sexual intercourse

Role: harmful

1. Produce vaccine (substance that contains weakened pathogens or its antigenic part)

2. Mutagen: agent causing mutation3. Vector agent4. Reduce pathogenic bacteria

Roles: Beneficial

Avoid sharing syringe, avoiding free sex, avoidance of breastfeeding mothers to children

Vaccination: gives passive immunity OPV (Oral Polio Vaccine) Rabies vaccine Hepatitis B vaccine Influenza vaccine MMR (Measles Mumps Rubella) vaccine

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