Lecture 11 Flashcards
What are examples of DNA viruses?
Adenovirus and parvovirus.
How many serotypes does adenovirus have?
Adenovirus has 52 serotypes.
What are some characteristics of adenovirus?
Adenovirus is stable to low pH, bile, and proteases.
Adenovirus is 70-90 nm in size.
Adenovirus has an icosahedral shaped DNA.
Adenovirus can hemagglutinate red blood cells.
What is the oncogenic property of adenovirus?
Adenovirus has the ability to transform cells in culture and cause cancer in animals but not humans.
What is the therapeutic potential of adenovirus?
Adenovirus can be used as a vector to carry and express foreign genes for therapeutic purposes, e.g., gene therapy.
What is the life cycle of adenovirus?
Adenovirus attaches to host cells by two-stage interactions, the initial stage the penton fibre attached with the host cell receptor. CD46 is the most common receptor for adenovirus. Attachment of the penton base occurs with the host cell’s αV integrin protein during the secondary interaction.
Internalization occurs via endocytosis, and the virus enters the host cell cytoplasm in a vesicle.
The viral DNA replicates in the nucleus, followed by bioassembly and release.
How is adenovirus isolated in the lab?
Graham cells (HEK 293) are used to isolate adenovirus for types 40 & 41 (Enteric).
What populations are at risk of acute respiratory illness caused by adenovirus?
Military recruits, boarding schools, etc.
What disease does adenovirus cause in the eyes?
Keratoconjunctivitis.
In what population can adenovirus cause invasive disease?
BMT and HSCT patients.
How does coronavirus transmit?
By respiratory droplets.
What is the structure of coronavirus?
Coronavirus is a spherical enveloped virus.
What is the mechanism of coronavirus replication?
Coronavirus releases its RNA into the cells, which form proteins in the cytoplasm.
How is coronavirus diagnosed in the lab?
Lab diagnosis of coronavirus involves RT-PCR and antigen detection for mass screening.
What is the difference in infectiousness between SARS and COVID-19?
For SARS, there was 11 days between onset of illness and maximum infectivity, so the disease could be identified and quarantined before the patient became infectious, but COVID-19 patients are infectious 2 days before symptoms show.
Why is SARS-CoV-2 more infectious than SARS?
SARS-CoV-2 binds up to 20 times tighter than SARS to ACE2.
Why is SARS-CoV-2 threatening to the elderly?
SARS-CoV-2 is vasculotropic and causes endothelialitis, resulting in microvascular thrombosis.
What are the severe symptoms of COVID-19?
Vascular leakage, pulmonary edema, clotting, and inflammation.
What genetic mutation made SARS-CoV-2 more transmissible?
A D614G AA substitution in the spike glycoprotein.
What are some characteristics of parvovirus?
Parvovirus is a small (18 - 26 nm) icosahedral virus that is non-enveloped and single-stranded DNA.
Erythrovirus-B19 is the main parvovirus.
What is the most common age group affected by erythrovirus?
Erythrovirus is most common among 4-10 year olds.
What is the duration of long-term epidemic cycles of erythrovirus?
The long-term epidemic cycles of erythrovirus are usually 4/5 years.
How many phases does a parvovirus infection have?
A parvovirus infection has two phases.
When does the first phase of parvovirus infection occur and what happens?
The first phase of parvovirus infection occurs 6-14 days post-infection and involves intense viraemia and nasal shedding
