6/30/15
1
Some Virus Resources on the Web:
ViralZone: http://viralzone.expasy.org/
International Committee on the Taxonomy of Viruses:
http://www.ictvdb.org/
Viral origins: http://www.mcb.uct.ac.za/tutorial/virorig.html
6 & 9.6 - Viruses (for more details on human pathogens see Ch 24 & 25)
A virion
Relative size
Surprise! giant Mimivirus 500 nm (or 0.5 um)
6/30/15
2
Virus ID
*Signs & Symptoms
DNA eg: PCR
*Serology
TEM
Light & Fluorescent Microscopy
Cytopathic effects: make hosts cells strange
Classification: Type of Nucleic Acid (see also T6.2):
DNA or RNA? If RNA, which kind?
Retroviridae only
From: Clinical Microbiology Made Ridiculously Simple
6/30/15
3
Classification: What capsid morphology?
polyhedral
eg: Adenovirus
Classification: What capsid morphology?
helical
eg: tobacco mosaic virus
complex eg: T4 bacteriophage
Classification: envelope?
6/30/15
4
Phage plaques on bacterial lawn
Phage culturing (have to grow with host bacteria)
Phage added
close-up (TEM)
No phage
Viral Reproduction
eg: lytic Bacteriophage (like T4)
Viral Reproduction
eg: lysogenic Bacteriophage (such as lambda)
becomes a prophage/ provirus for a time
6/30/15
5
Animal virus differences:
Entry
fusion
endocytosis
Other animal virus differences
envelope sometimes
carry along?
euk. cell compartments
effects
