Virology – Microbiology Flashcard
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Unlock answersWhat are the three different classifications of viruses in regard to Nucleic acid content |
1.DNA(ss,ds) 2.RNA(ss,ds,neg strand,pos strand) 3.Retroviruses |
| What are the three types of capsids? |
| polyhedral,helical,and complex |
| What are the five steps of viral reproduction? |
Attachment,Entry,Viral replication, Assembly,and Release |
| What are the three ways a virus can enter a cell? |
1.Direct penetration(shoots genome in) 2.Membrane fusion(envelope fuses) 3.Phagocytosis |
| explain dsDNA viral replication |
| goes to nucleus,some integrate with cells genome,transcribe RNA using viral DNA,translation takes place and proteins go back to nucleus,the VDNA replicates and joins the proteins for assembly |
| Explain +ssRNA viral replication |
Goes directly to ribosomes functioning as mrna, produces proteins, uses vrna polymerase to change from + to - to produce more +ssrna |
| What three enzymes do retro viruses come with? |
Reverse transcriptase(transcribe DNA from RNA) Integrase(puts vgenome into cells genome) Protease(cleaves RT and integrase) |
| Explain how a retrovirus reproduces |
| RT attaches to the rna and transribes dna,then replicates it,INT puts the DNA into cells genome,the cell transcribes the dna and makes rna,through translation proteins,and the enzymes are produced , this joins some rna left over from transcription and is assembled then protease cleaves RT from INT activating virus |
| Explain -ssrna viral replication |
| comes with vrna polymerase that turns it into +ssrna then goes to ribosomes as mrna |
| explain dsrna viral replication |
The positive strand acts as mrna, the neg strand acts as a template |
| explain ssdna viral replication |
Dna goes to genome,transcribed into vrna, goes to ribosomes produces proteins,back to nucleus for assembly |
| Where are DNA Retro and RNA viruses assembled |
DNA viruses are assembled in the nucleus Retro and RNA viruses are assembled in the cytoplasm |
What are the three ways viruses are released from a cell? |
Budding(viruses with envelope) Exocytosis Lysis |
| How can some virus cause cancer? |
| some viruses integrate their own promoter turning gene on, some viruses damage the repressor gene,some viruses carry their own oncogenes |
| Poxivirdae main human pathogen |
Small pox a)variola major b)variola minor |
| How is smallpox spread? |
requires close contact,spread by inhalation of virus, in droplets and dried crust |
| smallpox disease |
| infects organs then moves to skin |
| smallpox epidemiology |
| first human disease to be eradicated,1967 WHO went on campain, declared eradicated in 1980, |
| what are the six types of Herpesviridae |
1.herpes simplex 1 and 2 2.Varicella zoster (chickenpox) 3.Epstein bar(mono) 4.Cytomegalovirus 5.HHV8(roseola) 6.HHV8(Koposi sarcoma) |
| What are the three stages of a HHV-1 and 2 infection? |
1.initial infection-enters through cuts and abrasions,lesions may appear,infected cells fuse with noninfected forming a syncytium 2.Latency stage-goes to nerve cells,carried to sacral ganglia in genital herpes and trigeminal ganglia in oral herpes 3.comes out of latency-any kind of stress causes |
| What are the five types of herpes simplex |
1.Oral herpes simplex (usually hsv1) 2.Genital Herpes simplex(can be either) 3.Ocular Herpes simplex(Hsv1 from gang cause blindness) 4.Whitelow Herpes simplex(get from touching sores) 5.Neonatal herpes simplex(usually infected during birth very serious) |
| Hsv epidemiology |
| Transmitted through body contact,70% of all transmission is from asymptomatic host,can be controlled with nucleotide analogs |
| HHV-3 Varicella-Zoster transmission |
Respitory droplets,fluid in the lesions |
What happens if hhv-3 Varicella-zoster comes out of latency? |
| it becomes shingles herpes-Zoster |
| Epstein-Barr virus disease |
Burkitts lymphoma Mononucleosis |
| Epstein-Barr pathology |
| gets into blood,invades B cells,B cells become large with multiple nuclei,the T-cells kill the infected b-cells |
| What does Epstein-Barr virus cause in the immunocompromised? |
| Oral hairy leukoplakia |
| Epstein-Barr virus epidemiology |
| children are usually asymptomatic,teens have more symptoms,young males usually with malaria can get burkitts lymphoma which is a cancer in the cheek |
What three diseases have Epstein-Barr been associated with? |
a.Nasopharyngeal cancer b.Chronic fatigue syndrome c.Hodgkins lymphoma |
| Cytomegalovirus transmission |
| By repeated exchange of bodily secretions usually sex |
| Cytomegalovirus symtoms |
most are asymptomatic,babies and immunosuppresed are symtomatic |
| How does cytomegalovirus hurt babies? |
| crosses placenta and gets into stem cells of embryo,causing birth defects such as retardation,hearing and visual damage,and death |
HHV-6 what does it cause and what disease has it been associated with |
Roseola and it has been associated with multiple sclerosis |
| HHV-8 who and what |
prevalent in aids patients, causes Kaposis sarcoma |
| what are the three types of warts? |
a.seed warts-fingers and toes b.planter warts-soles of the feets c.genital warts |
How many types of hpv are there? how many are spread by sex? |
approximately 100 30 are spread by sex |
How many of the sexually transmitted hpv can give you cancer? |
10 of the 30 can cause cancer but all 30 will give you an abnormal pap |
| how many of the sexually transmitted hpv will give you warts? how many of these can give you cancer? |
5 will give you warts, 3 of these can give you cancer meaning that there are 7 cancer causing strains that are onlly detected with a pap |
| Hepadnavirdae pathology |
| hep b, infects liver causes jaundice can cause liver cancer from asymptomatic to chronic infections lasting 20-40 years |
| Hepadnaviridea treatment and prevention |
treat with interferon,prevent with a vaccine,resistant to normal cleaners need 10% bleach to kill |
| Adenoviridae, disease, prevention |
common cold,conjunctivitis attenuated vaccine,only used in military because of associations with cancer |
| HTLV Human T-cell lymphotrophic viruses disease? |
| Causes chronic leukemia, virus carrys own oncogene, spread by sex,needles,blood transfusions,and breastmilk |
| What are the two types of HIV |
HIV 1-reproduces faster,found in europe and US HIV 2-replicates more slowly found in west africa |
| What type of cells does HIV infect? |
a.T-helper cells b.Macrophages c.Microglial d.smooth muscle e.Dendritic cells |
| What are the three stages of developing aids |
A.initial infection-release viruses all over 6months B.clinical latency-body produces abs,viral levals plummet,tc-cells kill Th cells,patient unaware 5-10 years C.Development of aids-body cannot keep making Th cells,Th count falls below 200/ul,immune system becomes impaired |
What is the most important source of transmission for hiv |
infected cells(wbc)-approximately 5000 infected cells per ml of blood, can be 10000 per ejaculate,can ce in wbc of vagina
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| List the ways people catch hiv from high to low |
1.anal sex 2.Vaginal for women 3.vaginal for uncircumsized men 4.vaginal for circumsized men |
| how do you diagnose HIV? AIDS? |
diagnose HIV with an elisa or a pcr diagnose AIDs if TH drops below 200 per ul of blood |
| Family orthomyxoviridae disease? |
| the flu two strains A and B |
What is unusual about the structure of orthomyxoviridae? |
| contains 8 -ssrna, also has envelope |
| what are the two major antigens on orthomyxoviridae? what do they do? |
1.HA-attach to pulmonary cells and cause phag 2.NA-hydrolisis your mucus |
| What is the difference between antigenic drift and antigenic shift? |
antigenic drift is slow minor changes in which the HA and NA mutate giving new strains,happens every few years antigenic shift is a cell with two strains at once and will trade pieces of rna creating an entirely new strain with different HA and NA happens every 10 years |
| Family paramyxoviridae disease? |
1.Measles (Kopliks spots) 2.parainfluenza(croup) 3.Mumps (swollen glands) |
| Family Rhabdoviridae treatment |
| five shots of antirabies serum to stomache |
| Family picornaviridae disease? |
common cold polio hepatitis A |
| Rhinovirus causes what? |
| common cold over 100 types |
| how is rhinovirus spread? |
| spread by aerosol,fomites,skin to skin,person to person most common,only takes 1 virus,spread whether symptomatic or not,often spread by getting into eyes |
| how do you get Enteroviruses-poliomyelitis? |
| oral fecal route,from lakes and pools, goes from intestines to brain, |
| what are the four types of polio? |
1.asymptomatic 2.minor polio(flu like) 3.nonparalytic(muscle spasms and back pain) 4.paralytic (affects motor cortex,causes paralysis) |
| Hepatovirus disease? |
| Hepatitis A found in fecal matter,can survive bleach, does not cause cancer |
| Togaviridae disease |
| Rubiviris-rubella or german measles,causes a rash,in adults causes arthritis,in pregnant women causes birth defects |
| what does coronaviridae cause |
| second leding cause of common cold |
| what does Hepatits C do to you? |
| develope chronic liver disease,developes into cancer |
| you can onlly get Hepatitis D if you have |
| hep b |
| what type of hepatitis is very rare in this country? |
| hep E |
| the end |
