th lecture mumps

					Cultivation of Viruses
                      By


      Dr. Emad AbdElhameed Morad

  Lecturer of Medical Microbiology and Immunology
 Viruses are obligate intracellular organisms.
 So, they must be cultivated on living cells.
 So, viruses could be cultivated on either:

                          Cell culture

 Embryonated eggs

                       Laboratory animals
                     Cell culture
 Cell culture monolayer is the most commonly used system for
  isolation of viruses.
 Cell culture has three types:
   1) Primary cell line:
          Prepared for example from monkey kidney.
          These cells can divide for 4-6 passages then die.
   2) Human diploid cell line:
          Prepared from human embryo fibroblasts.
          These cells can divide for 50 passages then die.
   3) Continuous cell line:
          Prepared from tumor cells.
          Example, HeLa cell line derived from carcinoma of the cervix.
          These cells can divide indefinitely.
 Detection of viral growth in tissue culture


Cytopathic effect
Plaque formation
Inclusion bodies
Hemadsorption
Interference
  Cytopathic effect (CPE)
 They are changes which occur in the cells of the cell
  culture.
 Examples:
1. Cell death.
2. Rounding and grape like cluster formation.
3. Syncytium formation (multinucleated giant cell
   formation).
4. Cell transformation (the cells become malignant
   cells).
    Plaque formation
 Plaques are virally infected areas in the cell
 culture.
 Each plaque is produced by a single virus.
 These plaques are seen by the naked eye as
 unstained areas when using vital stains as
 neutral red.
   Inclusion bodies
 They are sites of assembly of the virus
 components inside the infected cells.
 May be intranuclear or intracytoplasmic.
 Could be seen by the light microscope.
   Hemadsorption
 When red blood cells are added to the
 infected cells, they will appear as rosettes.
 This is useful in case of influenza and mumps
 viruses.
        Interference
 Some viruses do not produce CPE on cell
 culture.
 However, the growth of these viruses on cell
 culture is detected by interference with the
 formation of CPE by other viruses.
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posted:1/13/2011
language:English
pages:10