78 Questions
What is the percentage of patients with meningitis who have a positive latex test for cryptococcal capsular antigen?
90%
Which of the following yeast species is associated with meningitis and has a positive capsule?
C.neoformans
What is the treatment for localized pulmonary disease caused by Cryptococcus neoformans?
Fluconazole
Which of the following yeast species produces arthroconidia?
Geotrichum
What is the purpose of partnering RF testing with the latex test for cryptococcal capsular antigen?
To rule out false-positive results due to rheumatoid factor
Which of the following is a characteristic of C.albicans?
Forms chlamydospores
What is the primary treatment for meningitis or other severe infection caused by Cryptococcus neoformans?
Amphotericin B with flucytosine
Which of the following is a characteristic of T.beigelii?
Has a positive capsule and produces blastoconidia
What is the primary goal of cell seeding in a 6-well plate?
To ensure cells reach a confluency of 90-100%
What is the purpose of virus dilution in cell culture?
To create 10x serial dilutions of the virus
What is the characteristic of the nucleic acid in DNA viruses?
It is always double-stranded
What is the shape of the capsid of the majority of DNA viruses?
Icosahedral
Which of the following DNA viruses is enveloped and has double-stranded DNA?
Hepadnavirus
What is the size range of viruses in nanometers?
10-300 nm
What is the characteristic of Parvovirus?
It is a naked single-stranded DNA virus
What is the tropism of Parvovirus B19?
It infects only erythroid progenitor cells
What is the primary advantage of in vivo viral cultivation?
Identificaiton and diagnosis of pathogenic viruses in clinical specimens
What is the purpose of using 0.7% soft agar in bacteriophage culture media?
To create clear zones of lysed bacterial cells
What is a characteristic of low-passage cell lines?
They remain virus-sensitive through 20-50 passages
What is the advantage of using continuous cell lines?
They can be passed and remain sensitive to virus infection indefinitely
What is the purpose of using trypsin in enzymatic method for cell extraction?
To inhibit cells from sticking together
What is the primary purpose of primary cell lines?
Identification and diagnosis of pathogenic viruses in clinical specimens
What is the significance of 100% confluence in cell culture?
It results in apoptosis
What is the purpose of using Dulbecco's Modified Eagle Medium (DMEM) in cell culture?
To nourish cells with bovine serum
What is the primary purpose of adding antimicrobials to viral transport media?
To inhibit contaminants such as bacteria and fungi
What is the term for the structures that are not supposed to be inside tissues or host cells?
Inclusions
What is the type of microscopy that allows visualization of the external structure of the virus?
Scanning Electron Microscope
What is the term for the giant cell made up of different cells infected by viruses?
Syncytium
What is the purpose of collecting convalescent serum in viral serology?
To evaluate immune status
What is the term for the microscopic method that detects and visualizes viral proteins expressed in cells via Ag-Ab reactions?
Immunofluorescence Assay
What is the primary purpose of enzyme immunoassay (ELISA)?
To measure the quantity of antigen or antibody
What is the term for the process of collecting and transporting specimens for viral culture?
Specimen transport
What is the purpose of rinsing the microtiter plate well after immobilizing the antibody?
To remove unbound antibodies
What is the function of the enzyme-linked antibody in ELISA?
To catalyze a color-changing reaction
In indirect ELISA, what is the purpose of the enzyme-linked secondary antibody?
To react with the constant region of other antibodies
What is the outcome when the antigen is present in the sample in ELISA?
A color change occurs, indicating the presence of the antigen
What is the difference between ELISA and indirect ELISA?
ELISA detects the presence of antigens, while indirect ELISA detects the presence of antibodies
What is the purpose of the colorless substrate in ELISA?
To catalyze a color-changing reaction
What binds to the immobilized antigen in indirect ELISA?
The antibodies in the serum
What is immobilized on the surface of the microtiter plate well in indirect ELISA?
The antigen
What is the primary mechanism by which the hepatitis C virus causes cell necrosis?
Immune mediated cytolysis
Which of the following groups is at an increased risk of hepatitis C infection?
People who have been infected with HIV
What is the sequence of tests used to diagnose hepatitis C?
EIA → RIBA → PCR
What is the mode of transmission of hepatitis C from an infected mother to her child?
Through birth
What is the occupation of individuals who are at an increased risk of hepatitis C infection due to constant exposure to needles?
Medtechs
What is the characteristic of hepatitis C virus that makes it a non-cytopathic virus?
It enters the liver cell and undergoes replication
What is the mode of transmission of hepatitis C that is not mentioned in the text?
Through contaminated food and water
What is the characteristic of Hepatitis D virus that makes it a satellite virus?
It borrows structures from HBsAg
What is the primary requirement for the production and transmission of HDV?
HBV to provide HBsAg
What is the typical duration of the incubation period of Hepatitis D?
3-7 weeks
What is the characteristic of the genetic material of Hepatitis D virus?
Negative-sense RNA
What is the typical outcome of Hepatitis D infection in people with chronic HBV?
Severe chronic symptoms
What is the characteristic of the delta antigen produced in the early stages of Hepatitis D infection?
Small delta antigen
What is the typical mode of transmission of Hepatitis D virus?
Horizontal transmission through contact with infected blood
What is the shape of the Hepatitis B viral capsid?
Icosahedral
Which of the following is NOT a form of the Hepatitis B virus?
Triangular
What is the name of the antigen that appears first in the serum during Hepatitis B infection?
Hepatitis B surface antigen (HBsAg)
Who are at increased risk of Hepatitis B infection?
Infants born from mothers with Hepatitis B and MSM
What is the term for the antibody that means the virus is actively multiplying in the liver?
Total hepatitis B core antibody (anti-HBc)
How can Hepatitis B core antigen (HBcAg) be detected?
Through a liver biopsy
What is the size range of the Hepatitis B virus?
22-200 nanometers
What is the primary site of rubulavirus replication after silent entry into the respiratory tract?
Local lymph nodes
What is the most common complication of mumps in adults?
Orchitis
What is the characteristic of the incubation period of rubulavirus?
It is variable, ranging from 2-4 weeks
What is the primary route of transmission of rubulavirus?
Inhaled respiratory droplets
What is the characteristic of the virus in the bloodstream during mumps?
It has a particular affinity for the salivary glands
What is the characteristic of salivary gland swelling in mumps?
It is non-suppurative
What is the period during which the virus is shed in the saliva after the onset of salivary gland swelling?
3-9 days
What is the characteristic of rubulavirus infection of the testicles?
It causes orchitis
What is the characteristic of rubulavirus infection of the ovaries?
It causes oophoritis
What is the characteristic of the generalized spread of rubulavirus in the body?
It affects salivary glands and other body sites
What is the mode of transmission of Enterovirus?
Via ingestion of contaminated food and water
What is the genomic structure of Poliovirus?
Positive-sense ssRNA genome
What is the function of VP4 protein in Poliovirus?
Internal protein
What is the characteristic of the protein capsid of Poliovirus?
Icosahedral symmetry
What is the primary site of Poliovirus replication?
Local lymphoid tissue
What is the outcome of Poliovirus infection in the CNS?
Destruction of motor neurons
What is the primary reason for the paralysis caused by Poliovirus?
Destruction of motor neurons
This quiz covers the structure and classification of the Hepatitis B virus, including its capsid forms, surface and core antigens, and clinical manifestations. It also discusses people with increased risk of Hepatitis B.
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