Medical virology , Laboratory session-1

1. Medical virology , Laboratory session-1 Dr. Mohammed Arif. Associate professor. Consultant virologist. Head of the virology unit.

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.

17. 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 .

24. 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