Prof Dr. Drh Pratiwi Ts,MS Pengenalan Virus Prof Dr. Drh Pratiwi Ts,MS virus -prof PTS -micro 2014 11/12/2018

Virus Merupakan parasites obligate intracellular berukuran kecil, terdiri atas RNA atau DNA genome yang mengeliliongi sebagai perlindungan, sehingga virus dilindungi oleh protein (virus-coded protein coat) Virus terlihat semacam mobile genetic elements, sebagian besar kemungkinan merupakan asal dari sel dan berbentuk khusus menrupakan long co-evolution antara virus dan host virus -prof PTS -micro 2014 11/12/2018

Introduction to Virology A virus is an obligate intracellular parasite containing genetic material surrounded by protein Virus particles can only be observed by an electron microscope virus -prof PTS -micro 2014 11/12/2018

Introduction to Virology The classification of viruses is based on the type of nucleic acid contained within RNA viruses---also known as a retrovirus DNA viruses virus -prof PTS -micro 2014 11/12/2018

Mengenal virus Recognizing the shape, size, and structure of different viruses is critical to the study of disease Viruses have an inner core of nucleic acid surrounded by protein coat known as an envelope Most viruses range in sizes from 20 – 250 nanometers virus -prof PTS -micro 2014 11/12/2018

Replikasi virus Untuk memperbanyak diri virus sanagat tergantung kepada host sel khusus yang memberikan supply bahan metabolik kompleks dan mesin biosintetik pada sel eukaryotic atau prokaryotic cells. Virus tidak dapat membentuk energi Karena merupakan obligate intracellular parasites, selama replikasi tergantng dari supply bahan biokimia dari eukaryotic atau prokaryotic cells Complete virus particle disebut virion. virus -prof PTS -micro 2014 11/12/2018

Why are some viruses harmful? Virus invades cell When your cells make viruses instead of operating normally, YOU get sick Virus forces cell to make copies of virus Eventually so many copies are made, the cell explodes, releasing all of the new viruses 11/12/2018 Introduction – Structure – Replication – Virology – Medicine - Review virus -prof PTS -micro 2014

Let’s look at the Defining Properties of Viruses Viruses are parasites that invade cells Viruses have either DNA (Deoxyribose Nucleic Acid) or RNA (Ribonucleic Acid) Viruses direct the synthesis of new virus within a host cell. Newly made viruses infect other cells. virus -prof PTS -micro 2014 11/12/2018

Tahap Replikasi virus Replication Viruses replicate within a host cell while utilizing the host cell’s nucleic acids. Viral life cycle consists of six stages within the host cell Attachment Penetration Uncoating Multiplication Assembly Release virus -prof PTS -micro 2014 11/12/2018

2 Tipe Virus 1. Nucleic Acid 2. Capsid ( di selubungi Protein) DNA atau RNA ( harus salah satu) 2. Capsid ( di selubungi Protein) Some Viruses: A. Envelope B. Enzymes virus -prof PTS -micro 2014 11/12/2018

The Size and Morphology of Selected Viruses virus -prof PTS -micro 2014 11/12/2018

Structure of viruses A – naked, not containing an envelope aroud capsid B – enveloped, containing an envelope around the capsid virus -prof PTS -micro 2014 11/12/2018

Morfologi virus virus -prof PTS -micro 2014 11/12/2018

Viral Structure Capsid (Coat Protein) Envelope protects viral genome from host endonucleases capsomeres Binding Sites Envelope derived from the host cell virus -prof PTS -micro 2014 11/12/2018

The General Structure of Viruses virus -prof PTS -micro 2014 11/12/2018 Figure 6.1

virus -prof PTS -micro 2014 11/12/2018

Introduction – Structure – Replication – Virology – Medicine - Review The concept of a virus as an organism challenges the way we define life: * Viruses do not breathe. * Viruses do not metabolize. * Viruses do not grow. * However, they do reproduce. 11/12/2018 Introduction – Structure – Replication – Virology – Medicine - Review virus -prof PTS -micro 2014

Classification by Biological, Chemical, and Physical Properties RNA-Containing Viruses Picornaviridae Paramyxoviruses Caliciviridae Orthomyxoviruses Togaviruses Bunyaviridae Arenaviridae Flaviviridae Coronaviridae Reoviridae Rhabdoviridae Birnaviridae Filoviridae Retroviridae virus -prof PTS -micro 2014 11/12/2018

Classification by Biological, Chemical, and Physical Properties DNA-Containing Viruses Hepadnaviridae Parvoviridae Papovaviridae Adenoviridae Herpesviridae Poxviridae Iridovoridae virus -prof PTS -micro 2014 11/12/2018

Contoh virus penyebab penyakit Viral Diseases-Examples Influenza Rabies HIV Hepatitis virus -prof PTS -micro 2014 11/12/2018

Ukuran virus Smallest infectious agents Most are so small, they can only be seen with an electron microscope Animal viruses Proviruses- around 20 nm in diameter Mimiviruses- up to 450 nm in length Viewing viruses Special stains and an electron microscope Negative staining outlines the shape Positive staining shows internal details Shadowcasting technique virus -prof PTS -micro 2014 11/12/2018

Penanaman virus The cultivation of viruses is complex and includes three common methods Chicken egg culture Cell culture Animal inoculation virus -prof PTS -micro 2014 11/12/2018

Cultivation of Viruses A. Chick Embryos: Virus growth in an embryonated chick egg may result in the death of the embryo (eg, encephalitis virus), the production of pocks or plaques on the chorioallantoic membrane (eg, herpes, smallpox, vaccinia), the development of hemagglutinins in the embryonic fluids or tissues (eg, influenza), or the development of infective virus (eg, polio virus type 2). virus -prof PTS -micro 2014 11/12/2018

How Viruses Multiply - Viruses Hidden viruses “hide” for a while inside host cells before becoming active. virus -prof PTS -micro 2014 11/12/2018

How Viruses Multiply - Viruses Active viruses enter cells and immediately begin to multiply, leading to the quick death of the invaded cells. virus -prof PTS -micro 2014 11/12/2018

Replikasi virus virus -prof PTS -micro 2014 11/12/2018

virus -prof PTS -micro 2014 11/12/2018 Figure 6.13

Kultur virus virus -prof PTS -micro 2014 11/12/2018

Viruses Can Help Cells, Too Since viruses can transport DNA and RNA into cells, scientists are exploring Gene Therapy In Gene Therapy, viral genetic material is replaced with new DNA In time, this could be used to cure genetic diseases. Currently we have no cure for these types of illnesses virus -prof PTS -micro 2014 11/12/201811/12/2018

Sampai jumpa virus -prof PTS -micro 2014 11/12/2018