LIFE CYCLES OF VIRUSES

VIRUSES CAN EXHIBIT TWO TYPES OF LIFE CYCLES. 1. THE LYTIC CYCLE 2. THE LYSOGENIC CYCLE SOME VIRUSES EXHIBIT ONLY THE LYTIC CYLE. SOME VIRUSES CAN EXHIBIT BOTH LYTIC AND LYSOGENIC CYCLES.

The Lysogenic Cycle

VARIETY OF ANIMAL VIRAL INFECTIONS - LYTIC OR LYSOGENIC VIRUSES?

TRANSDUCTION

HOW ANIMAL VIRUSES ENTER ANIMAL CELLS

HOW ARE ANIMAL VIRUSES CULTURED IN THE LABORATORY CLASSIFICATION OF MEDIA LIVING MEDIA AND NON-LIVING MEDIA

CELL CULTURE

HOW ARE CELL CULTURES GROWN?

CYTOPATHIC EFFECT - CPE SOME VIRUSES, WHEN THEY INFECT A CELL, CHANGE THE MORPHOLOGY OF THE CELL IN VERY SPECIFIC WAYS.

ANTIVIRAL AGENTS GENERALIZATIONS AMANTADINE TAMIFLU (RELENZA) A VARIETY OF NUCLEOSIDE ANALOGS –ACYCLOVIR, AZT, 3TC, DDI, DDC PROTEASE INHIBITORS INTERFERONS

AMANTADINE

AVARIETY OF NUCLEOSIDE ANALOGS

PROTEASE INHIBITORS AND INTERFERONS

HEPATITIS VIRUSES HAV – 50% HBV – 30% HCV – 20% MODE OF TRANSMISSION CHRONICITY - CHRONIC OR ACUTE INFECTION TREATMENT/VACCINE

UNCONVENTIONAL INFECTIVE AGENTS VIROIDS SMALL CIRCULAR MOLECULES OF SINGLE STRANDED RNA COMPOSED OF 359 NUCLEOTIDES BEST STUDIED VIROID CAUSES DISEASE IN POTATOES 10X SMALLER THAN SMALLEST KNOWN VIRUS

PRIONS INFECTIOUS SELF REPLICATING PROTEINS COMPOSED OF ABOUT 250 AMINO ACIDS 100X SMALLER THAN THE SMALLEST KNOWN VIRUS CAUSATIVE AGENT OF MAD COW DISEASE (BOVINE SPONGIFORM ENCEPHALOPATHY) AND TWO HUMAN DISEASES –CREUTZFELDT - JAKOB DISEASE (CJD) –KURU