Download MIB 311 - Fountain University, Osogbo

MIB 311 Virology
Lecturer: Muse Oke
Email –
[email protected]
Course outline
•  Definition of viruses
•  Importance of viruses
•  General characteristics of plant, animal
and bacterial viruses
•  Classification of viruses
•  viral replication strategies
•  Full description of select viruses
including symbiotic characteristics
Objectives of the course
•  provide students with a good
understanding of viruses and their
- structures
- classification systems
- replication strategies
- non-living status
Week I: what are viruses?
What are viruses?
•  Acellular infectious agents
•  infect all living things
•  Intracellular parasites
Bacteriophages/
bacterioviruses
Archaeoviruses
Eukaryoviruses
Week 2: why study viruses?
Why study viruses
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Most abundant biological entities on the planet - 1031
Excellent molecular biology tools
Infections
Cancers
Treating bacterial infections?
protein expression
Some of our genome is from viruses
Most prolific genetic inventors
Transfer genes between species – enhance biodiversity
Production of vaccines
Train the immune system
Week 3: components and
structures of viruses
Capsid Symmetry
Helical
Icosahedral
Complex
Structures of Viruses
T-even Coliphage
Archaeoviruses
Ebola
HIV
Week 4: classification of viruses
Baltimore Classification System
Group I: dsDNA e.g most prokaryotic viruses
II: ssDNA e.g bacteriophage ΦX174
III: dsRNA e.g rotavirus
IV: + strand RNA e.g polio virus; tobacco mosaic
virus
•  V: - strand RNA e.g. Influenza, Ebola
•  VI: ssRNA e.g HIV
•  VII: ds gapped-DNA e.g hepatitis B virus
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Week 5: ‘Life cycle’ of viruses
Temperate phage Bacteriophage Lambda
Lysogenic
Lytic
Bacteriophage lambda
Week 6: Smallpox virus
Eradication of the smallpox virus is
one of the greatest achievements
of science and the human race
Smallpox
•  First human disease to be eradicated (1979)
•  80% of infected children died
•  responsible for an estimated 300–500 million
deaths during the 20th century.
•  The history of vaccination is the history of
smallpox.
Week 7: And finally…a few
unusual viruses
Like giant viruses Giant viruses
•  Giant because
1. they are much larger (850 – 1500 nm)
than all previously characterized viruses
(10 – 100 nm)
•  blurred the distinction between viruses
and cells
•  May need to redefine ‘life’
Further reading
•  Willey, J. M., Sherwood, L., Woolverton,
C. J., & Prescott, L. M. (2008). Prescott,
Harley, and Klein's microbiology. New
York: McGraw-Hill Higher Education.
Critical thinking questions
•  Why are viruses considered non-living?
•  What is so unusual about giant viruses?