1. DR. MOHAMMED ARIF. ASSOCIATE PROFESSOR. CONSULTANT VIROLOGIST. HEAD OF THE VIROLOGY UNIT. Medical virology, Laboratory session-1

2. Electron micrographs of medically important viruses  DNA - viruses : 1- Herpesviridae. 2- Adenoviridae. 3-Hepadnaviridae. 4- Poxviridae.

3. 1- Family - Herpesviridae.  Enveloped, lose envelope.  Icosahedral nucleocapsid.  The viral genome is ds-DNA.  Eight human herpes viruses.  Examples of diseases:  HSV-1 : Gingivostomatitis, keratoconjunctivitis, meningoencephalitis, herpetic whitlow.  HSV-2 : Genital herpes, neonatal herpes.  varicella –zoster virus ( VZV ) : varicella, zoster.

4. Family – Herpesviridae.  Cytomegalovirus (CMV) : Infectious mononucleosis like syndrome, congenital infection, severe diseases in the immunocompromized.  Epstein Barr virus (EBV ) : infectious mononucleosis, Nasopharyngeal carcinoma, Burkitts lymphoma.

5. EM of herpes virus.

6. EM of herpes virus

7. 2- Family- Adenoviridae  Unenveloped.  Icosahdral nucleocapsid ( spherical particle).  The viral genome is ds-DNA.  Examples of diseases : Pharyngoconjunctival fever, keratoconjunctivitis, pneumonia, gastroenteritis, hemorrhagic cystitis.

8. EM of adenoviruses

9. EM of adenoviruses.

10. 3- Family : Hepadnaviridae ( hepatitis B virus ).  Three forms of particles.  The complete hepatitis B virus (HBV ) particle is enveloped with ds-DNA genome ( the large particles)  The free hepatitis B surface antigen particles (HBsAg), 22-nm in diameter.  The filament form of HBsAg particles.  Diseases : hepatitis B.

11. EM of Hepatitis B virus (HBV ).

12. 4- Family : Poxviridae ( pox viruses ).  Brick shaped.  The viral genome is ds-DNA.  Complex structure.  Diseases : smallpox ( variola).

13. EM of poxvirus.

14. RNA viruses.  1- Family : orthomyxoviridae ( Influenza viruses ).  2- Family : Rhabdoviridae ( Rabies virus ).  3- Family : Reoviridae ( Rotaviruses).  4- Family : Caliciviridae ( Caliciviruses).  5- Family : Filoviridae ( Marburg virus & Ebola virus).  6- Arenaviridae ( Lassa virus ).

15. 1- Family – Orthomyxoviridae ( influenza viruses ).  Pleomorphic.  Enveloped.  Covered with two glycoprotein spikes:  Hemagglutinin and neuraminidase.  The viral genome consists of 8- segments of ss-RNA.  Diseases : Influenza ( flue ), pneumonia.

16. EM of influenza viruses.

18. 2- Family : Rhabdoviridae ( Rabies Virus ).  Bullet shaped.  Enveloped.  The viral genome is ss-RNA, negative strand.  Diseases : Rabies, acute encephalitis.

19. EM of Rabies virus.

20. 3- Family : Reoviridae ( Rotaviruses).  Unenveloped.  The virus particle has a wheel structure (double capsid).  Spherical particles.  The viral genome consists of 11- segments of ds-RNA  Diseases : The major cause of infantile diarrhea.

21. EM of Rotaviruses.

22. 4- Family : Caliciviridae ( caliciviruses ).  Unenvelpoed.  Spherical particles with cup- shaped depressions.  The viral genome is SS-RNA with positive polarity.  Diseases : Diarrhea.

23. EM of caliciviruses.

25. 5- Family : Filoviridae. ( Marburg virus & Ebola virus).  The virus is filament in shape.  Unenveloped.  the viral genome is ss-RNA with negative polarity.  Diseases : Hemorrhagic fever.

26. EM of Marburg virus & Ebola virus.

27. Family : Arenaviridae Sandy appearance. Enveloped. ss-RNA, 2-segments with negative polarity. Lassa virus. Diseases : Lassa hemorrhagic fever.

28. Family Arenaviridae ( Lassa virus ).

29. family : Arenaviridae ( Lassa virus ).

30. Egg inoculation routes.  1- Chorio allantoic membrane ( CAM ).  2- Allantoic membrane.  3- Yolk sac.  4- Amniotic cavity.

31. Chorioallantoic membrane ( CAM ).

32. 2-Allantoic cavity

33. 3-Amniotic cavity

34. 4-Yolk sac