Download Individual Virology

Individual
Virology
Chapter Respiratory viruses
[Requirement]
Master all of the contents about Influenza viruses
Understand the clinical illnesses caused by other respiratory viruses.
[Class hour: 1 hour ]
[Outline]
sectionⅠCharacteristic properties of common respiratory viruses
Shape and strecture
viruses
Influenza
virus
Diameter
(nm)
Nucleic
acid
80-120
ssRNA
Envo
lope
+
Parainflue-nz
a virus
100-250
ssRNA
+
Measles
virus
120-250
ssRNA
+
H,N
No.of
serotypes
diseases
3
Influenza, Common
cold,
Bronchitis
4
Common cold
Croup
Pneumonia
1
Measles, SSPE
1
Mumps,
Menungutis,
Orchitis
1
Bronchiolitis,
Pneumonia
Postnatal
and
congenital rubella
variable
H(+)
N(-)
Mumps
virus
110-360
ssRNA
+
Respirato-ry
syncytial
virus
90-130
ssRNA
+
Rubella
virus
50-70
ssRNA
+
1
Rhinovirus
15-30
ssRNA
_
>110
Common cold
Coronavirus
80-100
ssRNA
+
>3
Common cold
3
Upper resp. tract
infection,
diarrhea
33
Acute resp. disease,
Pneumonia,
Conjunctivitis
Reovirus
Adenovirus
60-90
dsRNA
70-90
dsRNA
_
_
_
sectionⅡ Influenza virus
Ⅰ.Biological properties
1.Morphology and structure: spherical, filamentous, 80-120nm, helical symmetry
1)core:
(1) -ssRNA, segmented( 8 pieces ), easily recombined to form new mutant
(2) NP: surround and bind the RNA, type-specific, stable.
(3) Polymerase: RNA-dependent RNA polymerase.
2)Middle layer structure: stable, keep shape and intact.
3)Envelope: lipid bilayer, spikes:
(1) Hemagglutinin ( HA ): trimer, 2units: HA1and HA2
* agglutiate human and some animal RBC
* be related to the adsorption of viruses
* antigenicity: show great variability
Abs to the HA are protective, neutralize viral infectivity.
(2) Neuraminidase ( NA ): tetramer
* be related to the release of viruses: hydrolyze the terminal neuraminic acid
of glycoprotein on surface of cell.
* antigenicity: variable
2.Type and variation
Based on antigenicity of NP: Influenza A, B, C.
Based on HA, NA: subtype
* Antigenic drift: minor antigenic changes.
* Antigenic shift: major antigenic changes.
3.Cultivation
Culture in amniotic or allantoic cavity of chicken embryo.
Grow poorly in cell culture.
4.Resistance
Inactivated 56℃ 30min. sensitive to lipo-solvents.
Ⅱ.Pathogenesis and immunity
Ⅲ.Microbiological detection
Ⅳ.Control
Vaccine: inactivated, attenuated-live.
Chapter
Enteroviruses
[Requirement]
Master the common properties of enteroviruses.
Master the pathogenesis of poliovirus.
Master the clinical illnesses caused by Coxackie virus, ECHO virus and New
enteroviruses.
Master the biological properties and pathogenesis of rotaviruses.
[Class hour: 1 hour ]
[Outline]
Enterovirus belong to picornaviruses, they are all found in the intestines and excreted
in the feces.
1. Classification:
Type
viruses
Clinical illness
Polioviruses
1-3
Coxsackievirus
A 1-24
B 1-6
Echoviruseses
1-34
New enteroviruses
Rotaviruses
68
69
70
71
72
A- C
V- G
Paralysis
Aseptic meningitis
Myocarditis
Paralysis
Myocarditis
Paralysis
Pneumonia; bronchiolitis
Acute haemorrhagic conjumctivitis
Myocarditis; Paralysis
Hepatitis A
Diarrhea (humans; animals)
Diarrhea (animals)
2. Common properties of enteroviruses:
(1) +ssRNA, infectivity
(2) 22-30nm, icosahedral, spherical, the capsid consists of four major peptides
(VP1,VP2,VP3,VP4), non-enveloped
(3) assembly in cytoplasm
(4) parasite in entero, transmitted by digestive tract
(5) they can give rise to viraemia
(6) resistance: resistant to lipo-solvents, pH3-5, resist 56℃ 30min
(7) variety of clinical sign: CNS, diarrhea, myocardial damage, rash, etc
(8) they are common in children than adults
(9) in temperate climates they cause infections usually in the summer and autumn
sectionⅠ Poliovirus
Ⅰ.Biological properties:
1.27-30nm, spherical, non-nevoloped
2.+ssRNA, 7500bp, 3′terminal: polyA, 5 terminal: Vpg
3.4 structural proteins: Vp1-4
4.culture in primates cells, CPE
5.3 serotypes, non-cross reaction
Ⅱ.Pathogenesis and Immunity
1.source of infection: patients, viruses-carrier
2.mode of transmission: fecal-oral route
virus---month---multiply in oropharynx or intestinal lymphanode---first
viremia---multiply in other lymph-tissues---second viremia---CNS( moter
neurons in the anterior horn of spinal cord) ---paralytic poliomyelitis
Immunity: secrete IgA, neutralization Ab: IgG, IgM
Ⅲ.Microbiological detection
1.Isolation of virus: from throat swabs, feces.
2.Detects Abs: neutralization test.
Ⅳ.Control
1.Inactivated vaccine: Salk vaccine
2.Attenuated-live Sabin vaccine
3.γ-globulin
SectonⅡ Coxackie virus, ECHO virus and New enteroviruses
Ⅰ.Coxackie virus
Coxackie virus group
Type
A
1-24
B
1-6
Clinical illness
Aseptic meningitis
Febrile illness
Herpangina
Hand, foot and mouth disease
Neonatal disease
Bornholm disease
Myocarditis, hepatitis
Meningitis
Ⅱ. ECHO virus
Main syndromes: Aseptic meningitis
Paralysis
Rash
Respiratory disease
Other features: Pericarditis and myocarditis
Neonatal infection
Ⅲ. New enteroviruses (shown aboved)
SectonⅢ Rotaviruses
Ⅰ.Biological properties
1.65-75nm, icosahedral, double-shelld capsids (inner capsid, wheel-like)
2.dsDNA: 11segments,
3.Culture: difficult
4.Type: basic on outer capsid, 7 groups(A-G), most of the human rotavirus are of
group A
Ⅱ.Pathogenesis
Transmission: fecal-oral route
6 months-2 years children
Ⅲ.Diagnosis
1.Electron Microscope
2.E:ISA
3.RT-PCR
Ⅳ.Control
1.pay attention to hygiene
2.expectant treatment
3.vaccines are in research
Chapter 36 Herpesviruses
[Requirement]
Master the common properties of herpesviruses.
Master the classification and associated diseases of herpesviruses.
[Class hour: 0.25 hours ]
[Outline]
Ⅰ.Classification
Classification and associated diseases of herpesviruses
Viruses
Clinical illness
Herpes simplex virus 1 ( HSV-1 )
Gingivostomatitis
Labial herpes
Keratoconjunctivitis
Herpesencephalitis
Herpes simplex virus 2 ( HSV-2 )
Genital herpes
Neonatal herpes
Cervical carcinoma
Varicella-zostervirus ( VZV )
Varicella
Zoster
Epstein-Barr virus (EBV )
Infectious mononucleosis
Burkitt′s lymphoma
Nasopharyngeal carcinoma
Cytomegalovirus (CMV )
Cytomegalic inclusion body disease
Mononucleosis
Congenial deformity
Human herpesvirus 6 ( HHV 6 )
Roseola
Ⅱ.Common properties
1.Linear dsDNA.
2.Icosahedral, spherical, 162 capsomers.
3.Enveloped 150-200nm, necleocapsid 100nm.
4.Most can grow in HDC, CPE.
5.Various infectious expression:
apparent infection
latent infection
integrating infection
congenital infection
Chapter Arboviruses
[Requirement]
Master the common properties of arboviruses.
[Class hour: 0.25 hours ]
[Outline]
Ⅰ.Common properties
1.Spherical, 20-50nm, a few: 70-130nm.
2.+ssRNA, icosahedral, enveloped, hemagglutinin.
3.Sensitive to heat, lipo-solvents, acid.
4.Intra-cytoplasmic multiplication, newborn mice are susceptible.
5.Reproduce in arthropods, arthropods are vector and reservoir host.
6.Epidemics with marked geographical and seasonal distribution.
Ⅱ.Diseases caused by arboviruses
1.Encephalitis: e.g. B encephalitis.
2.Systemic infection: e.g. denge fever.
3.Hemorrhagic fever: e.g. epidemic hemorrhagic fever.
4.Hepatitis associated infection: e.g. yellow fever.
Chapter 36 Herpesviruses
[Requirement]
Master the common properties of herpesviruses.
Master the classification and associated diseases of herpesviruses.
[Class hour: 0.25 hours ]
[Outline]
Ⅰ.Classification
Classification and associated diseases of herpesviruses
Viruses
Clinical illness
Herpes simplex virus 1 ( HSV-1 )
Gingivostomatitis
Labial herpes
Keratoconjunctivitis
Herpesencephalitis
Herpes simplex virus 2 ( HSV-2 )
Genital herpes
Neonatal herpes
Cervical carcinoma
Varicella-zostervirus ( VZV )
Varicella
Zoster
Epstein-Barr virus (EBV )
Infectious mononucleosis
Burkitt′s lymphoma
Nasopharyngeal carcinoma
Cytomegalovirus (CMV )
Cytomegalic inclusion body disease
Mononucleosis
Congenial deformity
Human herpesvirus 6 ( HHV 6 )
Roseola
Ⅱ.Common properties
1.Linear dsDNA.
2.Icosahedral, spherical, 162 capsomers.
3.Enveloped 150-200nm, necleocapsid 100nm.
4.Most can grow in HDC, CPE.
5.Various infectious expression:
apparent infection
latent infection
integrating infection
congenital infection
Chapter Retroviruses
[Requirement]
Master the structure, pathogenesis, of HIV.
Understand the genes, replication, diagnosis and control of HIV.
[Class hour: 1.5 hours ]
[Outline]
Retroviridae include 3 dubfamilies:
1. Oncovirinae: HTLV-1, HTLV-2
2. Spumavirivae:
3. Lentivirinae: HIV
*Human immunodeficiency virus ( HIV )
Pathogen of AIDS ( Acquired Immune Deficiency Syndrome ).
Ⅰ.Biological properties
1.Spherical, 100nm, enveloped, spikes.
2.Structure:
Core: 2 copies of +ssRNA ( dimmer ); reverse transcriptase; P7.
Capsid protein: P24.
Matrix protein: P17.
Envelope: gp41
gp120: *binding site for CD4 receptor of T cells.
*be able to stimulate the production of neutralizing antibodies.
*easy variation.
3.Genes:
Structural genes: gag: coding for capsid proteins ( p17, p24, p7 )
pol: coding for protease, reverse transcriptase etc.
env: coding for gp120, gp41.
Regulatory genes: tat: regulating the synthesis of viral proteins ( + ).
rev: regulating the synthesis of viral proteins ( + ).
nef: regulating the synthesis of viral proteins ( - ).
LTR: contain promotor and enhancer sequences.
4.Resistance
56℃inactivated.
5.Replication
RNA---cDNA---RNA:DNA---dsDNA---integrated host DNA---stay latent or
enter a productive cucle
Ⅱ.Pathogenesis & immunity
1.Infectious source: patients, infectious people.
2.Transmission pathway:
1)By blood or blood products;
2)Sexual transmission;
3)Vertical transmission: from mother to child.
3.Pathogenesis:
* gp120 of HIV select CD4 receptor of T4 cells---viruses multiply in T4
cells---cell-mediated immunodeficiency---opportunistic infections and tumors occur.
* Destruction of T4 cells is achieved by:
① Viral replication
② Syncytium formation via membrane gp120 binding to cell CD4
antigen
③ Cytotoxic T cell lysis of infected cells
④ Cytotoxic T cell lysis of T4 cells carrying gp120 released from
infected cells
⑤ Natural killer cells
⑥ Antibody-dependent cell cytotoxicity.
4.Clinical features
Exposure---Seroconversion---Asymptomatic---PGL or ARC---AIDS
Ⅲ.Diagnosis
1.Isolation of the virus in culture
2.The detection of viral components or detection of proviral DNA or RNA
3.The presence of antibody to HIV antigens in the serum.
Ⅳ.Control
1.Vaccines:
Several vaccines ( gene-engineering enveloped Ag vaccine, polypeptides
vaccine, recombing vaccine ) are under trial.
2.Drugs:
AZT, ddI, ddC, 3TC etc.