13 - Viruses (for more details on pathogens see Ch 24 & 25)

13 - Viruses(for more details on pathogens see Ch 24 & 25)

Some Virus Resources on the Web:

http://www.virology.net/garryfavweb.html

International Committee on the Taxonomy of Viruses http://www.ictvdb.org/

Viral origins: http://www.mcb.uct.ac.za/tutorial/virorig.html

A virion

capsomere

Relative size

Signs & Symptoms

DNA eg: PCR

Serology

TEM

Light & Fluorescent Microscopy

Nucleic Acid: DNA or RNA?

If RNA, which kind?

Retroviridae only

From: Clinical Microbiology Made Ridiculously Simple

Capsid morphology

helical polyhedral

capsomere

Capsid morphology

complex, eg: T4 bacteriophage

Enveloped viruses

Phage plaques on bacterial lawn

(regular spacing is due to type of test & careful placement of samples)

Phage culture

Lytic Bacteriophage (like T4)

Lysogenic Bacteriophage (such as lambda)

Animal viruses:

entry

Other differences

envelope?

carry

euk. Compartments

effects

From: Clinical Microbiology Made Ridiculously Simple

Parvoviridae

adenovirus

Erythrovirus B19

Fifth disease = erythema infectiosum = slapped-cheek disease

(also: Parvovirus)

Mastadenovirus

Papillomaviridae

plantar

genital

Polyomaviridae

Polyomavirus

JC = JCPyV -> causes

progressive multifocal leukoencephalopathy (PML)

Human Papilloma Virus (HPV)

(formerly together in Papovaviridae)

Orthopoxvirus variola virus (VARV) vaccinia virus (VACV) cowpox virus (CPXV) camelpox virus (CMLV

Poxviridae

envelope

E. Jenner

HHV1 = HSV1

HHV2 = HSV2

Simplexvirus

Herpesviridae

Varicellavirus = HHV3 = VZV

chickenpox

shingles

Lymphocryptovirus (HHV4) = Epstein-Barr virus

Normal retina

Cytomegalovirus (HHV5 = CMV)

“mono”

with CMV

Roseolavirus = HHV6 & 7?

roseola

Orthohepadnavirus

Hepatitis B

Hepadnaviridae

*ASTRO

Astroviridae: Astrovirus

Caliciviridae

Norwalk virus = Norovirus

Picornaviridae

Enterovirus

Human poliovirus -> polio

“iron lungs” when respiratory muscles paralyzed

Rhinovirus

Hepatovirus

Alphavirus:

Western equine encephalitis (WEE)

EEE

Venezuelan EE (VEE)

Rubivirus

rubella = German measles

Togaviridae

Flaviviridae

Flavivirus spp.

Yellow Fever

Dengue (Bone-break) Fever

Japanese, St. Louis, Russian & West Nile encephalitis

Hepacivirus

Hepatitis C

SARS coronavirus-> Sudden Acute Respiratory Syndrome April 2003

Coronaviridae

Human coronavirus (HcoV)

G: Lyssavirus

-> rabies

Rhabdoviridae

Filoviridae

Marburg virus (MARV)

Reston Ebola virus (REBOV)Zaire Ebola virus (ZEBOV)

Morbillivirus -> measles = rubeola

Rubulavirus -> mumps

Pneumovirus Human respiratory synctial virus (HRSV)

Paramyxoviridae

Paroxyovirus

neuramidase

hemagglutinin

Orthomyxoviridae: Influenzavirus

BunyavirusHantavirus

Hantaan virus (HTNV) -> Korean hemorrhagic fever = hemorrhagic fever with renal syndrome (HFRS)

Sin Nombre virus (SNV; originally Muerto Canyon virus) -> hantavirus pulmonary syndrome (HPS)

Bunyaviridae

Arenaviridae Arenavirus

Lassa virus

Lentivirus eg: HIV

Deltaretrovirus eg: HTLV-1, -2

Retroviridae

Reoviridae Rotavirus

Rotavirus A or B Coltivirus

Colorado tick fever virus Orbivirus

Viroids

Potato spindle tuber

Prions

cause transmissable spongiform encephalopathies

normal (PrP) protein prion

Examples ofanimal prion diseases: scrapie, BSE (mad cow), chronic wastinghuman prion diseases: Creutzfeldt-Jakob, kuru, (n)vCJD

(each black spot is ~15 usual virus particles, so Mimivirus is about the size of 2-3 of those black spots together)

Relative sizes

Fungal

Small bacterium ~400 micrometers/ microns in dia.

Always surprises:

giant viruses (2003)

then: Sputnik viruses of Mimivirus (2008), stay tuned