prions infectious proteins inherited and transmissible by ingestion, transplant, and surgical...
TRANSCRIPT
Prions• Infectious proteins
• Inherited and transmissible by ingestion, transplant, and surgical
instruments
• Spongiform encephalopathies: Sheep scrapie, Creutzfeldt-Jakob
disease, Gerstmann-Sträussler-Scheinker syndrome, fatal familial
insomnia, mad cow disease
• PrPC: Normal cellular prion protein, on cell surface
• PrPSc: Scrapie protein; accumulates in brain cells forming plaques
• Plant viruses: Enter through wounds or via insects.
• Viroids: Infectious RNA; e.g., potato spindle tuber disease.
Figure 13.23
• Single-stranded DNA, nonenveloped viruses– Parvoviridae
• Human parvovirus• Fifth disease• Anemia in
immunocompromised patients
Table 13.2 (1 of 20)
Virus Families
Single-Stranded RNA, + Strand, Nonenveloped
• Enterovirus– Enteroviruses include
poliovirus and coxsackievirus.
• Rhinovirus• Hepatitis A virus
Table 13.2 (7 of 20)
Double-Stranded DNA, Nonenveloped Viruses
• Mastadenovirus– Respiratory infections
in humans– Tumors in animals
Table 13.2 (2 of 20)
Double-Stranded DNA, Nonenveloped Viruses
• Papillomavirus (human wart virus)
• Polyomavirus– Cause tumors; some
cause cancer
Table 13.2 (3 of 20)
Double-Stranded DNA, Enveloped Viruses
• Orthopoxvirus (vaccinia and smallpox viruses)
• Molluscipoxvirus– Smallpox– Molluscum
contagiosum– Cowpox
Table 13.2 (4 of 20)
Double-Stranded DNA, Enveloped Viruses
• Simplexvirus (HHV1 and HHV 2)• Varicellavirus (HHV 3)• Lymphocryptovirus (HHV 4)• Cytomegalovirus (HHV 5)• Roseolovirus (HHV 6)• HHV 7• Kaposi's sarcoma (HHV 8)
– Some herpesviruses can remain latent in host cells.
Table 13.2 (5 of 20)
Double-Stranded DNA, Enveloped Viruses
• Hepadnavirus (Hepatitis B virus)– Use reverse
transcriptase to produce DNA from mRNA.
Table 13.2 (6 of 20)
Single-Stranded RNA, + Strand, Nonenveloped
• Hepatitis E virus• Norovirus causes
gastroenteritis.
Table 13.2 (8 of 20)
Single-Stranded RNA, + Strand, Enveloped
• Alphavirus– Alphaviruses are
transmitted by arthropods; include EEE, WEE.
• Rubivirus (rubella virus)
Table 13.2 (9 of 20)
Single-Stranded RNA, + Strand, Enveloped
• Arboviruses can replicate in arthropods; include yellow fever, dengue, SLE, and West Nile viruses
• Hepatitis C virus
Table 13.2 (10 of 20)
Single-Stranded RNA, + Strand, Enveloped
• Coronavirus– Upper respiratory
infections– SARS
Table 13.2 (11 of 20)
Single-Stranded RNA, – Strand, One RNA Strand
• Vesiculovirus • Lyssavirus (rabies
virus)• Cause numerous
animal diseases
Table 13.2 (12 of 20)
Single-Stranded RNA, – Strand, One RNA Strand
• Filovirus– Enveloped, helical
viruses– Ebola and Marburg
viruses
Table 13.2 (13 of 20)
Single-Stranded RNA, – Strand, One RNA Strand
• Paramyxovirus• Morbillivirus• Paramyxovirus
– Parainfluenza– Mumps– Newcastle disease
Table 13.2 (14 of 20)
Single-Stranded RNA, – Strand, One RNA Strand
• Hepatitis D virus– Depends on
coinfection with Hepadnavirus
Table 13.2 (15 of 20)
Single-Stranded RNA, – Strand, Multiple RNA Strands
• Influenzavirus (Influenza viruses A and B)
• Influenza C virus– Envelope spikes can
agglutinate RBCs.
Table 13.2 (16 of 20)
Single-Stranded RNA, – Strand, Multiple RNA Strands
• Bunyavirus (CE virus)• Hantavirus
Table 13.2 (17 of 20)
Single-Stranded RNA, – Strand, Multiple RNA Strands
• Arenavirus– Helical capsids contain
RNA-containing granules
– Lymphocytic choriomeningitis
– VEE and Lassa Fever
Table 13.2 (18 of 20)
Single-Stranded RNA, Two RNA Strands, Produce DNA
• Lentivirus (HIV)• Oncogenic viruses
– Use reverse transcriptase to produce DNA from viral genome.
– Includes all RNA tumor viruses
Table 13.2 (19 of 20)