A complete overview of Replication in viruses

A complete overview of Replication in viruses

1. UNIT III 3.1 Virus replication Presented by: Mohammad Abuzar( M. Pharm ) Assistant Professor School of Pharmacy AIKTC, New Panvel .

2. CONTENTS 2

3. 3 INTRODUCTION

4. 4 Viral multiplication   For a virus to multiply, it must invade a host cell and take over the host's metabolic machinery. A single virion can give rise to several or even thousands of similar viruses in a single host cell. This process can drastically change the host cell and usually causes its death. In a few viral infections, cells survive and continue to produce viruses indefinitely. A viral one-step growth curve - No new infective virions are found in a culture until after biosynthesis and maturation have taken place

5. 5 Multiplication of Bacteriophages   Bacteriophages can multiply by two alternative mechanisms: The lytic cycle - ends with the lysis and death of the host cell The lysogenic cycle - the host cell remains alive in the lysogenic cycle Bacteriophage infecting E. coli

6. 6 Lytic cycle of bacteriophage   Attachment Penetration Biosynthesis - Synthesis of Phage Nucleic Acids and Proteins Maturation - The Assembly of Phage Particles Release of Phage Particles

7. Phage adsorption and DNA injection 7 Assembly of bacteriophage

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9. 9 Replication of animal virus   1. Adsorption of Virions Through a random collision of the virion with a plasma membrane receptor site protein, frequently a glycoprotein 2. Penetration Entry of naked animal virus

10. Entry of enveloped animal virus 10 Entry of enveloped virus by endocytosis

11. 11 3. Uncoating The removal of the capsid and release of viral nucleic acid 4. Replication and transcription of DNA 5. Synthesis and Assembly of Virus Capsids 6. Virion Release Naked virions appear to be released most often by host cell lysis. Enveloped virus - budding

12. 12 Release of viruses by Budding

13. 13 Replication of Animal Virus

14. 14 Multiplication of Animal cells

15. 15 Multiplication of DNA containing Virus

16. 16 Biosynthesis of RNA Virus

17. 17 Summary Virus can multiple by lytic or lysogenic cycle Steps in lytic cycle – attachment, penetration, biosynthesis, assembly and release Lysogeny involves the formation of a prophage DNA virus replicates in nucleus RNA virus replicates in cytoplasm

18. 18 W.B. Hugo and A.D. Russel: Pharmaceutical Microbiology, Blackwell Scientific publications, Oxford London. Prescott and Dunn., Industrial Microbiology, 4th edition, CBS Publishers & Distributors, Delhi. Pelczar , Chan Kreig , Microbiology, Tata McGraw Hill edn . Malcolm Harris, Balliere Tindall and Cox: Pharmaceutical Microbiology. Rose: Industrial Microbiology. Probisher , Hinsdill et al: Fundamentals of Microbiology, 9th ed. Japan Cooper and Gunn’s: Tutorial Pharmacy, CBS Publisher and Distribution. Peppler : Microbial Technology. I.P., B.P., U.S.P.- latest editions. Ananthnarayan : Text Book of Microbiology, Orient-Longman, Chennai Edward: Fundamentals of Microbiology. 12. N.K.Jain : Pharmaceutical Microbiology, Vallabh Prakashan , Delhi REFERENCES

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