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 Bacteriophage multiplication Lytic cycle Summary References Introduction Viral Multiplication
- 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 1. Attachment 2. Penetration 3. Biosynthesis - Synthesis of Phage Nucleic Acids and Proteins 4. Maturation - The Assembly of Phage Particles 5. Release of Phage Particles
- 7. 7 Phage adsorption and DNA injection Assembly of bacteriophage
- 8. 8
- 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. 10 Entry of enveloped animal virus 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 1. W.B. Hugo and A.D. Russel: Pharmaceutical Microbiology, Blackwell Scientific publications, Oxford London. 2. Prescott and Dunn., Industrial Microbiology, 4th edition, CBS Publishers & Distributors, Delhi. 3. Pelczar, Chan Kreig , Microbiology, Tata McGraw Hill edn. 4. Malcolm Harris, Balliere Tindall and Cox: Pharmaceutical Microbiology. 5. Rose: Industrial Microbiology. 6. Probisher , Hinsdill et al: Fundamentals of Microbiology, 9th ed. Japan 7. Cooper and Gunn’s: Tutorial Pharmacy, CBS Publisher and Distribution. 8. Peppler : Microbial Technology. 9. I.P., B.P., U.S.P.- latest editions. 10. Ananthnarayan : Text Book of Microbiology, Orient-Longman, Chennai 11. Edward: Fundamentals of Microbiology. 12. N.K.Jain: Pharmaceutical Microbiology, Vallabh Prakashan, Delhi REFERENCES
- 19. 19