POXVIRIDAE

• STRUCTURE: ds-DNA, linear, enveloped. Complex symmetry, i.e. no regular symmetry.

  • Lateral Bodies are on each side of the dumb-bell shaped capsid.

• REPLICATION: Poxvirus has its own transcriptase, thus replication occurs exclusively in the cytoplasm.

  • Replication is carried out in small granules in cytoplasm. This is the same place from which the poxvirus gets its envelope.

• VARIOLA MAJOR and MINOR: Causative agent of smallpox.

  • History: VACCINE

    • 1798, Jenner used cowpox virus to innoculate against smallpox.

    • Smallpox vaccination was stopped in 1972.

• VACCINIA VIRUS: Attenuated vaccine strain, used in research.

• COWPOX VIRUS: Produces self-limited localized infection in humans.

• MONKEYPOX VIRUS: Not widespread or contagious like human smallpox.

• MOLLUSCUM CONTAGIOSUM VIRUS: Wart-like slightly elevated lesions.

  • Histologically you see large cytoplasmic inclusions called Molluscum Bodies.

• Psuedopox: Animal poxvirus transmitted from cows. Lesions are nodular and on fingers, and can ulcerate.

Category: Microbiology Notes