Viruses Flashcards
What infectious agents are dependent on host cells?
Prions and viruses
What infectious agents are independent of host cells?
Which are prokaryotes? Unicellular/multicellular eukaryotes?
Prokaryotes: Bacteria, mycobacteria
Eukaryotes:
Unicellular - Fungi, protozoa
Multicellular - parasites
Are fungi unicellular or multicellular? Protozoa?
Both are unicellular
Which infectious organisms primarily incite a lymphocytic inflammatory reaction?
Viruses, protozoans
Which infectious organisms primarily incite a granulomatous inflammatory rxn?
Mycobacteria, fungi
What infectious organisms primarily incite a granulocytic/pyogenic inflammatory rxn?
Bacteria
What infectious organisms primarily incite an eosinophilic inflammatory reaction?
Multicellular parasites
What two things can shift the equilibrium of the symbiosis of our microbiome?
- host immunodeficiency
2. changes in composition of microbiome (pathogens or antibiotics)
Property of infectious agent that reflects disease producing potential
Virulence
movement of organisms from one usually isolated ecosystem to a new ecosystem
Emerging infections
What are the routes bugs take to infect the host?
Inhalation, ingestion, injection (blood stream), sexual transmission, direct contact w/ skin
What are the routes bugs take to infect the blood stream?
Insect vectors, injection (drug abuse or iatrogenic), sepsis
What would infection/inflammation of gallbladder be called? Bladder?
Gallbladder - cholecystitis
Bladder - cystitis
What is general infection/inflammation of GI tract called?
Gastroenteritis
What is a localized infection called?
Abscess/Granuloma
No nucleic acid, protein only, subverts host protein
Prion
Contains DNA or RNA, lmtd # of structural and enzymatic proteins, uses host machinery for replication
Virus
What are the structural proteins of a virus for?
Viral capsule, Usually for cell targeting and stabilization of nucleic acid
What is the viral trophism (what cells do viruses prefer to infect)?
Host cells that are targeted depend on presence of viral receptors – subversion of normal cell receptors
T or F. Viruses have organelles.
False
What is the size range for viruses?
20 - 300 nm
What types of enzymes do viruses generally have (2 broad types?
Polymerases, proteases
What ability allows RNA viruses to evade host humoral responses and vaccines?
Rapid antigen drift
What is an inclusion? Where does it occur?
Area of viral replication inside of the cell - can occur in the nucleus or the cytoplasm
What are the 3 ways viruses produce disease?
- Direct cytopathic effects
- Anti-viral immune rxns - CTLs kill infected cells
- Transformation of host cell to neoplasm
What direct cytopathic effects can viruses have?
apoptosis, shut off host protein synthesis
How do viruses transform host cell into neoplasm?
Stimulate cell growth and division, Inactivate tumor suppressors and mitotic check points, Insertional mutagenesis
What viruses cause respiratory infections
influenza, rhinovirus
What viruses cause gastrointestinal infections?
Norovirus, rotavirus, EBV (mononucleosis, B-cell lymphoma), hepatitis A
What viruses infect blood stream?
Arbovirus (West Nile), HIV
What viruses are sexually transmitted?
Herpes simplex, papillomavirus (genital warts, squamous carcinoma), HIV
Where in the cell do most RNA viruses replicate?
Cytoplasm
_____ strand is translated in RNA viruses.
Positive
direct translation but to produce more RNA complementary RNA must serve as template for RNA production by viral polymerase
Single strand positive
cRNA must be produced for translation but the negative strand can serve as template for polymerase
Single strand negative
What type of virus has reverse transcriptase which produces DNA which may be inserted in to host genome?
Retroviruses
What RNA viruses cause exanthemas (viral rashes + systemic symptoms)?
Measles (Rubeola), mumps
What RNA viruses cause gastroenteritis?
Norwalk, rotavirus
What RNA viruses cause viral hemorrhagic fevers?
Ebola, yellow fever, Marburg
Rabies: DNA or RNA virus?
RNA
HIV: DNA or RNA virus?
RNA
Where in the cell do most DNA viruses replicate?
Nucleus
T or F. DNA viruses have more antigenic drift than RNA viruses.
False
DNA or RNA virus? Adenovirus
DNA
DNA or RNA virus? Smallpox
DNA
DNA or RNA virus? Herpes simplex (HSV)
DNA
DNA or RNA virus? Herpes zoster (HZV)
DNA
DNA or RNA virus? EBV
DNA
DNA or RNA virus? HPV
DNA
What diseases can herpes zoster (HZV) cause?
chickenpox, Shingles
