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MLT-RNA Viruses I
Virology
Question | Answer |
---|---|
In Baltimore Classification system, there are how many groups of vuruses? | 7 |
What is the characteristic of group I viruses, and example? | dsDNA viruses, Herpesvirus |
What is the characteristic of group II viruses, and example? | ssDNA(+) viruses, Parvovirus |
What is the characteristic of group III viruses, and example? | dsRNA viruses, Rotavirus |
What is the characteristic of group IV viruses, example? | ssRNA(+) viruses, Coronavirus |
What is the characteristic of group V viruses, example? | ssRNA(-) viruses, Orthomyxoviruses |
What is the characteristic of group VI viruses, example? | ssRNA(+)-RT with DNA intermediate in life-cycle, Retroviruses |
What is the characteristic of group VII viruses, example? | dsDNA-RT viruses DNA with RNA intermediate in life-cycle, Hepadnaviruses(HBV) |
What are the example spp of Orthomyxoviruses? | Influenza A, Influenza B, Influenza C |
What are the examples of surface proteinthat could be found on Influenza viruses? | 1.Haemagglutinin 2.Neuraminidase 3.Haemagglutinin esterase 4. M1 protein 5.M2 Ion channel |
Influenza viral transcription involves cap snatching, what it is? | Viral PB2 cleaves 5’ methylguanosine cap & 10-13 nucleotides from the host mRNA |
What is the function of the 10-13 nucleotides host mRNA from cap snatching? | Act as primer for transcription by viral transcriptase, PB1. |
How many segments of Influenza virus? | 8 |
Which segment is responsible for making Haemagglutinin? | 4 |
Which segment is responsible for making Neuraminidase? | 6 |
What are the proteins will be produced by mRNA segment 7? | M1 and M2 |
What are the proteins will be produced by mRNA segment 8? | NS1 and NS2 |
What is antigenic shift? | 1. two or more different strains of a virus 2. combine to form a new subtype 3. a mixture of the surface antigens |
No animal hosts have been identified for __________? | Influenza B |
As there is no host for Influenza B, there is no ___________ and ___________? | 1.genome reassortment 2.antigenic shift |
virus remains infectious on non-porous surfaces for up to ________? | 48 hours |
What is the preferred specimen for Influenza detection? | Nasopharyngeal aspirates or nasopharyngeal swab |
To do a viral culture, tissue culture on _________, __________ or _________? | MDCK (Mardin-Darby canine kidney), Vero or MRC-5 cells |
What is cytopathic effect? | 1.Structural change of the host cell, due to the viral infection 2.The infecting virus causes lysis of the host cell 3. when the cell dies without lysis due to an inability to reproduce |
If the cytopathic effect is no obvious, how to confirm viral growth? | direct immunofluorescent (IF) antibody for antigen detection |
What is the TAT for viral culture? | 3-10 days |
What is the sensitivity and TAT for direct immunofluorescent (IF) ? | 1.70-90% 2.1-4hr |
What is the sensitivity and TAT for Rapid Antigen test (Immunochromatogenic assay)? | 1.59-93% 2.<30mins |
For the real-time PCR detection of Influenza A, what are the two rounds of PCR? | 1.Type specific PCR to confirm Influenza A infection 2.Sub-type specific PCR |
What is the target gene for Type specific PCR? | MP (Matrix protein) gene |
What are the targets for Sub-type PCR? | 1.Only done when MP gene is positive 2. primer pairs for H1, H3, H5 and H7 |
What is the host receptors that Human Influenza viruses will bind to ? | α2,6-linked sialic acid |
What are the 4 classes of antiviral drugs have been developed? | 1.Adamantanes 2.Neuraminidase inhibitors 3.Membrane fusion inhibitors 4.RNA-dependent RNA polymerase inhibitors |
What are the two oral antiviral drug? | 1.Amantadine 2.Oseltamivir (Tamiflu) |
What is the most effective way to prevent and control influenza infection? | Vaccination |
What is the group no. of Coronavirus under Baltimore classification system? | Group 4, ssRNA(+) |
What is the genome size of Coronavirus? | 26-32kbp |
What are the example of Coronavirus? | SARS, MERS |
CoVs are separated into 4 genera based on phylogeny, what are they? | 1.Apha-CoV 2.Beta-Cov 3.Gamma-Cov 4.Delta-CoV |
What are the 2 genera Coronavirus that are human pathogens? | Alpha-CoV and Beta-CoV |
What will be used for RNA virus culture? | Vero E6 cells |
What is the target region for the detection of SARS-CoV using RT-PCR? | N (nucleocapsidprotein) gene region at the 3′ end of the SARS-CoV genome |
What is the drug used to treat RNA viral infection? | Ribavirin |