1. VIRUSES CHAPTER 18
Part 1

2. T-4 Virus - infects E. coli
Characteristics
non-living particles
invade living cells
pathogenic - named after the disease they cause or organ they infect
smallest of all organisms
T-4 Virus - infects E. coli

4. VIRUS - an obligate intracellular parasite
INFECTIOUS MONONUCLEOSIS

5. Wendell Stanley (1904 - 1971) first isolated TMV in 1935.
Origin of Viruses
Wendell Stanley ( ) first isolated TMV in 1935.
Viruses may have originated from host cells
first seen by an electron microscope
Tobacco mosaic virus - first virus discovered

6. 1886 - “Living Fluid Infectant” - the virus passed through filters that held bacteria.

7. Viral Structure Inner core - contains viral DNA or RNA (never both)
Capsid - outer coat of protein
Envelope - outer layer on larger viruses

8. Various Shapes of Viruses

9. Viral Replication Lytic Cycle
1. Attachment
2. Injection
3. Replication
4. Assembly
5. Lysis

10. LYSOGENIC CYCLE 1. Attachment 2. Injection
Viral DNA integration (provirus)
4. Cell division
5. Replication
6. Assembly
7. Lysis

11. L Y S O G E N I C L Y T I C

12. VIRUSES CHAPTER 18
Part 2

13. Edward Jenner - discovered a vaccine for smallpox

14. Smallpox Variola (Major & Minor)
First virus to be studied in detail
Edward Jenner
First vaccine - cowpox virus (vaccinia virus)

15. Child with smallpox

16. (Ali Maow of Merka, Somalia, contracted smallpox in 1977 at the age of 23. His was the last known case of smallpox in the world.)
Last case of smallpox

17. Icosahedral Virus (many sides)
Wart virus
Polio - Naked, small, icosahedral virus

18. Enveloped Virus
INFLUENZA VIRUS

19. Children with measles (uncommon today)

20. BACTERIOPHAGE
E-Coli Bacteria

21. Attachment of a phage to the cell wall of E-Coli

22. Temperate vs. Virulent Viruses

23. HERPES ZOSTER (“Shingles”)

24. HERPES VIRUS
HERPES

25. Herpes I and II Complex
Herpes I – Oral, mouth, sores and lips “cold sores, fever blisters.”
Herpes II – Genital.
Both can be spread even if sores are not present. Dormant to attacks (or outbreaks) can be brought on by: general illness, fatigue, physical or emotional stress, menstruation, trauma to area – sexual activity, immunosuppression due to chemotherapy, steroids, medications.
Symptoms, diagnosed, treated, pain, cure.

26. Retroviruses RNA viruses
Reverse transcriptase makes DNA from its RNA
Includes HIV, polio & some cancers
HIV

27. Retrovirus Cycle

28. HIV / AIDS

30. Louis Pasteur - discovered a vaccine for rabies

31. PATHWAY OF
RABIES
VIRUS

32. Animal Rabies in U. S. 1999

33. Bozeman biology virus