Introduction to Viruses Flashcards Preview

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Flashcards in Introduction to Viruses Deck (17):
1

First virus?

Tobacco mosaic virus

2

Basic properties of viruses

Small (filterable), consist of protein, nucleic acid (sometimes lipid and carbohydrates), obligate parasites that utilize host cell machinery for their reproduction.

3

Are all viruses enveloped?

No, HIV is. Adenovirus is not.

4

Group I viral genomes

DNA, double stranded. Papovavirus, adenovirus, herpes virus, etc.

5

Group II viral genomes

Single stranded DNA (polarity + or -), parvovirus

6

Group III viral genomes

Double stranded RNA

7

Group IV viral genomes

Single stranded RNA (polarity +)

8

Group V viral genomes

Single stranded RNA (polarity -)

9

Group VI viral genomes

Single stranded RNA, replicated via DNA (reverse transcriptase), polarity +

10

Are viruses observed directly?

No, look for signs of virus like cytopathic effect, inclusion body formation, or hemadsorption

11

How to viruses work?

Free particles in tissue or environment inject their genetic material into a host cell, viral genome is replicated and transcribed. Viral mRNAs are translated and proteins are processed. Particles assemble inside host, then burst or bud to exterior.

12

Routes of viral infection

Oral/fecal, respiratory, transcutaneous, sexual, contact with infectious bodily fluid.

13

Persistent viruses

Can stay in the host without being cleared.

14

Most effective way to combat viral infection?

Vaccines

15

Inactivated vaccines

Killed viruses, elicit antibody responses. No chance of infecting the vaccinee. May not provide lifelong immunity.

16

Subunit vaccines

Part of a virus is used as the immunogen. Elicit antibody responses. No chance of infecting the vaccinee. May not provide lifelong immunity.

17

Life, attenuated vaccines

Viruses that replicate in the body. B and T cell responses. Induce longer lasting immunity. Elicit helper T cell responses. Potential for revertants.