Virology Flashcards
Viruses differ from living cells in that
They are acellular
Have EITHER DNA or RNA
Unable to reproduce independent of cells
For viral replication, a virus must
Invade a host cell and cause it to reproduce viral enzymes and components
Viral components are later assembled to form a
Complete virus
Bacteriophage are…..to a bacteria
Specific
Morphology of a virus
Nuclei acid core (DNA or RNA)
Surrounded by capsid composed of capsomeres
Viral symmetries
Icosahedral and helical
Lytic
Virulent
Lysogenic
Temperate or avirulent
Cultivated via
Living host cells
virulent bacteriophage may be used in …. for detection. Of and identification of ….
Phage typing
Pathogenic bacteria
Bacteria are characterized by their
Resistance or susceptibility to a particular virus
The multiplication of a virulent bacteriophage is called the …. because the host is usually lyse in the final stage
Lytic cycle
Steps of the lytic cycle
Adsorption/attachment Penetration Biosynthesis Maturation Lysis
Adsorption/attachment
Attachment of particular virus to the cell wall of a specific bacteria. Attachment to specific receptor site
Penetration
Injection of nucleic acid of virus into the host. May be chemical (lysozyme) or mechanical
Biosynthesis
Nonessential host metabolism is shut down and host genome is degraded.
Host uses viral DNA to produce early proteins (enzymes that degrade the host genome and replicate viral DNA. The host then produces late proteins to synthesize viral components and to assemble those components during maturation.
Viral DNA and capsids assembled into complete viruses
Maturation
Eclipse
Period of time when no complete viruses are present
Lysis
Phage lysozyme lyses bacterial cell wall and the replicated viruses are released. The number of viruses released per host cell is called burst size
Picornaviridae
Genus: Enteroviruses - polio viruses
Disease: Polio
Genus: Rhinoviruses
Disease: common cold
Calciviridae
Genus: Norovirus
Disease: Acute gastroenteritis
Togaviridae
Genus: Rubivirus
Disease: Rubella
Orthomyxoviridae
Genus: influenza virus
Flavivirdae
Genus: Zika, Dengue, Hep C , Yellow Fever
Paramyxoviridae
Mumps virus
Rubeola virus
Reoviridae
Rotavirus - vomiting and diarrhea in children
Rhabdoviridae
Rabies
Retroviridae
HIV1 and HIV2 (aids)
HTLV-1 and HTLV-2 (T cell leukemia)
Coronaviridae
Coronavirus - upper respiratory infections, bronchitis
Filoviridae
Ebola virus
DNA viruses
(Poxy, herpes, adeno, papova, hepadna)
Poxviridae
Orthopoxvirus-
Smallpox, cowpox
Herpesviridae
herpes 1 - cold sore
Herpes simplex virus 2 - genital herpes
Varicella zoster - chickenpox
Epstein-Barr - mononucleosis, lymphoma,
Papovaviridae
Papillomavirus -warts, genital warts
Hepadnaviridae
Hepatitis B
Hepatitis A
Infectious hepatitis benign jaundice)
Transmitted: fecal -oral
Symptoms: flu like, abdominal pain, chills, dark urine, light stools
Treatment: gamma globulins as prophylaxis, vaccine
Hepatitis B
Serum hepatitis
Causes: sever liver damage, cancer and death. Can be co infection with Hep D
Transmission: contact with body fluids, contaminated instruments, breast milk
Vaccine
Hepatitis C
Causes liver cirrhosis
Transmitted via body fluids or instruments
No vaccine or guarenteed cure
Hepatitis E
None-A / None-B, no serological tests approved
Feal/oral transmission
Similar to other symptoms but can be fatal for pregnant women
No FDA approved vaccine
