Oz - Pages 1 through 14 Flashcards
(114 cards)
1
Q
a. Spirochete; non-staining by normal stains
b. Causes syphilis
A
Treponema pallidum
2
Q
Transmitted by direct contact with infectious lesion (chancre)
A
syphilis; caused by Treponema pallidum
Spirochete
3
Q
- onset of symptoms 10-90 days (avg 21)
(a) Chancre – painless, small round, firm
(b) Lasts 3-6 weeks; “heals” w/o treatment
A
Primary Syphilis
Microbe = Treponema pallidum
Spirochete
4
Q
phase of syphilus - rash over wide area occurs 1-6 mos later if not treated
A
Secondary syphilis
Microbe = Treponema pallidum
Spirochete
5
Q
multi-organ – if not treated
A
Tertiary syphilis
Microbe = Treponema pallidum
Spirochete
6
Q
Treponema pallidum is identified by?
A
. Identify by antigen-detection methods [RPR] or dark field microscopic exam of lesion fluid (depends on the stage of disease)
7
Q
Treponema pallidum is identified by?
A
. Identify by antigen-detection methods [RPR] or dark field microscopic exam of lesion fluid (depends on the stage of disease)
8
Q
a. Spirochete; non-staining by normal stains
b. Causes Lyme Disease
A
Borrelia burgdorferi
Spirochete
9
Q
Tick-borne (esp. deer tick) – bite; prolonged association (24+ hr)
A
Borrelia burgdorferi
Spirochete
10
Q
Clinical: Early stages asymptomatic and difficult to differentiate
(1) Skin lesion - red macule/papule > 5 cm (erythema migrans)
(2) Neurologic and cardiac involvement – encephalitis, facial palsy, etc
A
Borrelia burgdorferi
Spirochete
11
Q
Diagnosis of Borrelia burgdoferi
is it mainly clinical or do we use specific tests?
A
Diagnosis: MAINLY clinical findings; immunological tests for antigen after several weeks (IFA, ELISA)
12
Q
Spirochete; non-staining by normal stains
b. Causes Leptospirosis
A
Leptospira interrogans
13
Q
Transmission: skin contact with urine of infected animals (e.g. rats, swine, badgers,
rodents, deer, fox); especially via contaminated water (or moist soil)
A
Leptospira interrogans
Spirochete; non-staining by normal stains
14
Q
Transmission of Leptospira interrogans?
A
Transmission: skin contact with urine of infected animals (e.g. rats, swine, badgers,
rodents, deer, fox); especially via contaminated water (or moist soil)
15
Q
Clinical: Fever, headache, myalgia, chills, conjunctival involvement –> renal and liver
failure
A
Leptospira
Spirochete; non-staining by normal stains interrogans
16
Q
Lab Dx of Leptospira interrogans
A
Diagnosis: immunological tests (rising Ab titer), IFA, ELISA
17
Q
skin contact with urine of infected animals
(e.g. rats, swine, badgers,
rodents, deer, fox); especially via contaminated water (or moist soil) Area of world not mentioned
A
Leptospira interrogans
Spirochete; non-staining by normal stains
18
Q
Biological Threat agents?
A
Burkholderia pseudomallei
Burkholderia mallei (is very closely related to B. pseudomallei)
Encephalitis BTA’s including the following:
Eastern/ Western/Venezuelan encephalitis viruses
BTA Hemorrhagic Fever Viruses Including the following:
Rift Valley Fever (Zoonotic in humans) *
Congo-Crimean Hemorrhagic Fever (CCHF)
Ebola Hemorrhagic Fever virus *
Marburg hemorrhagic Fever virus *
19
Q
Biological threat agent AND Hemorrhagic Fever Viruses Including the following:
A
Rift Valley Fever (Zoonotic in humans) *
Congo-Crimean Hemorrhagic Fever (CCHF)
Ebola Hemorrhagic Fever virus *
Marburg hemorrhagic Fever virus *
20
Q
Encephalitis Viruses AND Biological threat agent:
A
Eastern/ Western/Venezuelan encephalitis viruses
21
Q
Causes Melioidosis
A
Burkholderia pseudomallei – Biological threat agent
22
Q
(1) Causes Melioidosis (mel-ee’-oy-doe’-sis) - especially persons with pre-existing
major illness
A
Burkholderia psuedomallei (Bio threat agent)
23
Q
Endemic in Southeast Asia, N. Australia, and South Pacific (~165,000 cases per
year; 89,000 deaths) – Reservoir in various animals
Transmitted by direct contact with contaminated soil and surface water
A
Burkholderia psuedomallei (Bio threat agent)
24
Q
What does Burkholderia pseudomallei cause?
A
Causes acute pulmonary infection; acute localized infection (ulcer/nodule/abscess), septicemia, multiple organ involvement
25
How long until symptoms appear with Burkholderia pseudomallei?
(a) Symptoms often appear 2-4 weeks after exposure
| b) May be subclinical and/or delayed (years
26
How long until symptoms appear with Burkholderia pseudomallei?
(a) Symptoms often appear 2-4 weeks after exposure
| b) May be subclinical and/or delayed (years
27
Causes Glanders
Burkholderia mallei
28
- disease of horses (equine) (highly communicable); rarely
| humans; Causes nasal mucus discharge, lung lesions
Glanders from Burkholderia mallei
29
Where is Burkholderia mallei prevalent?
Endemic to parts of Africa, Asia, Middle East, and S. America (eradicated from
N. America and Europe)
30
Can Burkholderia mallei transmit from animals to humans?
Transmitted from animals to humans (rare) via contact with blood and body
fluids into skin abrasions or mucosal surfaces (not environmental sources)
* Affects lungs and airways; causes septicemia, cutaneous lesions, liver, spleen, fever
* Fatality rate 95% in untreated; 50% in treated
31
(1) Soil and water source – very hardy; challenging hospital control
(2) Infrequent pathogen - Causes pneumonia in immunocompromised or cystic fibrosis patients
Burkholderia cepacia
32
pneumonia in cystic fibrosis patients think....
Burkholderia cepacia
33
If Burkholderia mallei is transmitted from an animal to a human... what are the clinical symptoms and the fatality rate?
Transmitted from animals to humans (rare) via contact with blood and body
fluids into skin abrasions or mucosal surfaces (not environmental sources)
* Affects lungs and airways; causes septicemia, cutaneous lesions, liver, spleen, fever
* Fatality rate 95% in untreated; 50% in treated
34
are Bulkhoderia Abx resistant?
YES... Most are resistant to multiple ABX
35
Four anaerobes?
Peptostreptococcus
Fusobacterium
Faecalibacterium
Bifidobacterium
36
a. Gram-positive cocci, usually chains
b. Anaerobic
c. Normal microbiota of vagina, GI, skin
d. Cause generalized necrotizing soft tissue infections, including Pelvic Inflammatory Disease; bone and joint, and other infections
Peptostreptococcus
37
Peptostreptococcus found where?
| Causes?
c. Normal microbiota of vagina, GI, skin
d. Cause generalized necrotizing soft tissue infections, including Pelvic Inflammatory Disease; bone and joint, and other infections
38
a. Gram-negative bacilli
b. Anaerobic
c. Periodontal infections, skin ulcers
Fusobacterium
39
Fusobacterium
gram stain?
aerobic or anaerobic?
causes?
a. Gram-negative bacilli
b. Anaerobic
c. Periodontal infections, skin ulcers
40
a. Gram-positive bacillus, non sporeforming
b. Anaerobic
c. An abundant normal gut microbiota; may boost immune system
d. Lower levels in gut may be associated with clinical disorders
Faecalibacterium
41
Lower levels in gut may be associated with clinical disorders
Faecalibacterium
42
Faecalibacterium
Gram stain?
aerobic or anaerobic?
found where?
a. Gram-positive bacillus, non sporeforming
b. Anaerobic
c. An abundant normal gut microbiota; may boost immune system
d. Lower levels in gut may be associated with clinical disorders
43
Where is faecalibacterium found?
a lot or very few found?
boosts what?
An abundant normal gut microbiota; may boost immune system
44
a. Gram-positive bacilli, often branched, non-sporeforming
b. Anaerobic
c. An abundant normal microbiota of gut, vagina, mouth
d. An important component of probiotics
Bifidobacterium
45
Bifidobacterium
Gram stain?
aerobic or anaerobe?
found where?
important why?
a. Gram-positive bacilli, often branched, non-sporeforming
b. Anaerobic
c. An abundant normal microbiota of gut, vagina, mouth
d. An important component of probiotics
46
List all of the Bacteria of significance in this lecture (8 of them)
```
Treponema pallidum
Borrelia burgdorferi
Leptospira interrogans
Burkholderia spp
Peptostreptococcus
Fusobacterium
Faecalibacterium spp
Bifidobacterium
```
47
The true influenza is a what problem as you contract it?
It is a respiratory problem... not an intestinal problem initially.... after it becomes systemic you can see other issues like the possible nausea and vomiting which is MAINLY in children and probably due to the fever
48
Influenza virus AKA
Myxovirus
49
(1) Cough, runny nose -> generalized aches and muscle pain, fever (possible nausea and vomiting in children probably due to fever)
(2) Incubation 1-2 days; symptoms 5-7 days (cough 7-14 days)
(3) Viral Pneumonia (about 10% of admissions) – high mortality
(4) Secondary Bacterial Pneumonia sometimes follows viral URT infections
Influenza virus (Myxovirus)
50
How is influenza transmitted?
Transmitted by droplets and contact (especially hands) and by inhalation of droplets
51
common cold is only what?
how does this differ from the flu?
upper respiratory
6 hours of upper respiratory, then high fever with aches and pains with nausea and vomiting
52
Epidemiology of influenza virus (myxovirus)?
Epidemiology
(1) Outbreaks, Epidemic, or Pandemic
(2) Illness: Tens of millions each year; 3 to 5 million seriously ill
(3) Mortality: Few hundred thousand; >40K in US
53
Epidemiology of influenza virus (Myxovirus)
(1) local or widespread?
(2) Illness: annual rate?
(3) Mortality?
Epidemiology of influenza virus (Myxovirus)
(1) Outbreaks, Epidemic, or Pandemic
(2) Illness: Tens of millions each year; 3 to 5 million seriously ill
(3) Mortality: Few hundred thousand; >40K in US
54
what is the viral structure of influenza?
(1) Core with 8 strands of RNA
(2) Envelope
- ----(a) Lipid bilayer from previous host cell (animal specific or adapted to other types of cells)
- ----(b) Hemagglutinin and Neuraminidase – used for attachment and virulence
(3) Matrix protein (capsid)
55
Viral structure of influenza has what three things?
(1) Core with 8 strands of RNA
(2) Envelope
(3) Matrix protein (capsid)
(refer to image on PDF)
56
This microbe uses Hemagglutinin and Neuraminidase – used for attachment and virulence...
Influenza virus (Myxovirus)
57
Two microbes listed in this PDF that have hemagglutinin as virulence factor?
Influenza virus
Burkholderia psuedomallei
58
The antigenic types of Influenza are based on what?
Types based on surface antigens
| Hemagglutinin (H) and Neuraminidase (N)
59
(a) Animal strain based on original “source” of viral envelope
(b) Infectivity of animal virus to humans is due to adaptation to enter human cell
membranes
Influenza: Antigenic Types (A, B, C)
(1) Types based on surface antigens
Hemagglutinin (H) and Neuraminidase (N)
so animal strain based on viral envelope and infectivity to humans is an adaption to be able to enter our cells
60
(a) Common human subtypes: H3N2, H1N1 (human strain)
(b) Numerous swine subtypes, some adapted to humans, e.g. 2009 H1N1 (highly transmissible)
(c) Numerous avian subtypes, some adapted to humans; e.g. emerging subtype H5N1, H7N9 (considered dangerous)
Type A
influenza virus
61
Type A Influenza Virus
(a) Common human subtypes: ?
(b) subtypes? high transmissible ex?
(c) Numerous ___ subtypes, some adapted to humans; e.g. emerging subtype _____ ?
(a) Common human subtypes: H3N2, H1N1 (human strain)
(b) Numerous swine subtypes, some adapted to humans, e.g. 2009 H1N1 (highly transmissible)
(c) Numerous avian subtypes, some adapted to humans; e.g. emerging subtype H5N1, H7N9 (considered dangerous)
62
which types of Influenza virus are antigenically stable?
Types B and C
63
What are the virulence factors of Influenza?
(1) High rate of gene recombination and mutation
(2) Surface antigen changes (gene recombination as well as gene mutation)
(3) Hemagglutinin and Neuraminidase are factors both of attachment and cause some symptoms
(4) Virulence Factors
----(a) Animal-specific envelope (e.g. human strains infect humans; avian strains infects avians; swine strains)
----(b) Surface antigen changes (e.g. Avian Influenza (H5N1)
----(c) Adaptation of virus envelope to enter and replicate in human cell
64
Do antivirals work for Influenza?
Antiviral medications available – start treatment within 48 hours to be effective
65
Vaccine for Influenza?
(1) Made with the most common 3 antigens
(2) Required annually to match antigenic strains moving toward USA (World Health Org., CDC, and DoD labs track location and movement of strains around the world)
66
Lab Dx of Influenza?
Laboratory diagnosis -- immunodiagnostic tests, PCR, and cell culture
67
a. RNA viruses
| b. Primary causes of the common cold
Rhinovirus, Respiratory Syncytial Virus (RSV), and Corona virus
68
the overall most prevalent agent (over 160 antigen types) of RNA viruses
Rhinovirus
69
(a) Second most common agent of colds
(b) Multiple antigenic types (about 30 types)
(c) New Highly Virulent Variants in Recent Years
Corona virus
70
Corona virus:
| New Highly Virulent Variants in Recent Years.... including which two?
SARS (Severe Acute Respiratory Syndrome) (several thousand cases, about 30% mortality)
• MERS-CoV (Middle East Respiratory Syndrome – Corona Virus) – severe acute respiratory illness (fever, cough, shortness of breath), several hundred persons ill and about 30% mortality since 2012 (mostly Jordan, Saudia Arabia); camels are likely source
71
aka Human Orthopneumovirus, - the primary agent in infants and young children
Respiratory Syncytial Virus (RSV)
72
(a) Hundreds (thousands ?) of antigenic types exist; Antigenic groups A and B
(b) Can cause severe infections
(c) Immunoglobulins are not necessarily protective against future infections
(d) Development of vaccine is very challenging
Respiratory Syncytial Virus (RSV)
73
How is the common cold spread (RNA viruses)?
Transmitted by droplets and contact (especially hands and eyes) and by inhalation of droplets
74
a. Enveloped RNA virus - member of Paramyxovirus family; 4 antigenic types
b. Causes croup, bronchitis, cold-like symptoms; especially in children
c. Laboratory diagnosis -- immunodiagnostic tests, PCR, cell culture
Parainfluenza virus
75
Parainfluenza virus
causes what? in which population?
virulence factors?
a. Enveloped RNA virus - member of Paramyxovirus family; 4 antigenic types
b. Causes croup, bronchitis, cold-like symptoms; especially in children
76
a. Enveloped RNA virus - member of Paramyxovirus family, subfamily Pneumovirus (discovered 2001)
b. Causes upper and lower respiratory tract illness (very prevalent)
Human Metapneumovirus (hMPV)
77
Causes upper and lower respiratory tract illness (very prevalent)
(1) Common cold, bronchiolitis, pneumonia, croup
(2) Outbreaks primarily in late winter – early spring
(3) Incubation 3-5 days; shedding for few weeks
(4) Affects all ages; more frequent and more severe in young children
(5) Similar signs/symptoms to RSV (same taxonomic family)
Human Metapneumovirus (hMPV)
78
Human Metapneumovirus (hMPV)
causes what?
when?
incubation for... shedding for?
ages?
similar signs and symptoms to?
(1) Common cold, bronchiolitis, pneumonia, croup
(2) Outbreaks primarily in late winter – early spring
(3) Incubation 3-5 days; shedding for few weeks
(4) Affects all ages; more frequent and more severe in young children
(5) Similar signs/symptoms to RSV (same taxonomic family)
79
a. DNA Virus, non-enveloped (>50 types); members of the family Adenoviridae
b. Etiologic agent of 5% to 10% of all viral infections (50% of infections before age 5)
Adenovirus
80
(1) "Acute Respiratory Disease" in military recruits (80%) -- types 4, 7
(2) Conjunctivitis -- types 2,3,5,7,8,19,21,37
(3) Atypical pneumonia -- type 37
(4) Cold-like disease -- types 1, 2, 5, 6
(5) Gastrointestinal disease (15%) -- types 40, 41
(6) Also: Croup/Bronchitis, Sore Throat, Cystitis
Adenovirus
81
Causes pneumonia... ALL of them
Hint: 8 total
Burkholderia cepacia (cystic fibrosis patients)
Influenza virus (Myxovirus) (viral pneumonia and often secondary bacterial penumonia following)
Human Metapneumovirus (hMPV)
Adenovirus (atypical pneumonia)
Human Immunodeficiency Virus (HIV) (Pneumocystis carinii (protozoan))
Measles virus (secondary comp)
Histoplasma capsulatum (penumonia /hepatitis / meningitis)
Pneumocystis jirovecii pneumonia (Causes pneumonia in immunocompromised persons, e.g. cancer, chemotherapy, HIV/AIDS – low frequency)
82
adenovirus vaccine for?
Vaccine available against types 4 and 7
83
Adenovirus
a. DNA Virus, non-enveloped (>50 types); members of the family Adenoviridae
Name all of things it can cause... 6 bullet points, but 10 total
Etiologic agent of 5% to 10% of all viral infections (50% of infections before age 5)
(1) "Acute Respiratory Disease" in military recruits (80%) -- types 4, 7
(2) Conjunctivitis -- types 2,3,5,7,8,19,21,37
(3) Atypical pneumonia -- type 37
(4) Cold-like disease -- types 1, 2, 5, 6
(5) Gastrointestinal disease (15%) -- types 40, 41
(6) Also: Croup/Bronchitis, Sore Throat, Cystitis
84
Big thing about adenovirus conjunctivitus?
No pirulent exudate...
85
General characteristics of Herpes viruses
(1) DNA virus, enveloped, large size
| (2) Cause latent and sometimes recurring diseases
86
causes fever blisters, cold sores, gingivostomatitis, keratoconjunctivitis (e.g. neonate, contact lens wearer), genital lesions, meningitis (neonate)
Herpes simplex (types 1 2) --
87
(1) Primary lesion generally more severe
than subsequent lesions
(2) Viruses hide (go latent) in nerve ganglia serving region of the primary lesion
(3) Lesions recur periodically -- usually in response to some type of stress stimulus (excess UV light at beach, onset of menstrual period, emotional stress of death or illness of loved one)
(4) Virus held in check primarily by cell-mediated immunity although antibodies exist.
(5) No adequate vaccine is available.
(6) Treat with medication to relieve symptoms, but not to cure/eradicate virus
Herpes simplex
88
causes chicken pox and shingles (latent/recurring)
Herpes zoster (HZV)
89
(a) Acquired via respiratory tract
(b) Causes vessicle-type skin lesions - moderately large, relatively few, mostly on trunk of body
(c) Viruses may hide in nerve ganglia
(d) Viruses held in check by CMI
Chicken pox
90
how are the chicken pox acquired?
Acquired via respiratory tract
91
what holds chicken pox in check?
cell mediated immunity
92
(a) HZV re-emerges from hiding in nerve ganglia
(b) Cause numerous, small, closely- spaced vessicles in area served by the infected nerve ganglion (e.g. across shoulder, under arm from breast to shoulder blade, across thigh)
(c) Virus outbreak subsides after few-to several weeks, but may recur periodically
(d) Virus held in check by cell-mediated immunity
Shingles
93
Are there vaccines for chickpox and shingles?
Vaccines available! (chickenpox and shingles)
94
where do all herpes hide?
nerve ganglia
95
(1) Transmitted by oral secretions (saliva)
(2) Infects B-cell
(3) Causes infectious mononucleosis in adolescents and adults
- ----(a) Fever, sore throat, enlarged lymph nodes, fatigue, swelling of liver or spleen
Epstein-Barr virus (EBV)
96
Epstein-Barr virus (EBV)
eliminated by?
reactivated by?
associated with?
(4) Virus may be eliminated by Cell Mediated Immunity or go into latency
(5) Latent viruses may reactivated (switch to lytic cycle) upon B-cell stimulation, e.g. by an unrelated infection
(6) May be associated with chronic diseases (unknown, uncertain)
97
These three cause mononucleosis or mono like symptoms:
Epstein-Barr virus (EBV) - (infectious mononucleosis)
Cytomegalovirus (CMV) - (occasionally causes MONO with microcephaly, jaundice, multiple organ involvement... in immunosuppressed patients causes FEBRILE mononucleosis)
Human Immunodeficiency Virus (HIV) - (Mononucleosis-like" or "flu-like" illness. Fever, night sweats, malaise, rash, and muscle and joint pain. Lymphadenopathy may develop.)
98
Causes congenital cytomegalic inclusion disease in children
Cytomegalovirus (CMV)
99
(a) Baby is infected from vaginal microbiota during birthing
(b) Occasionally causes CMV mononucleosis with microcephaly, jaundice, multiple organ involvement
(c) Impairment of central nervous system is associated with development of mental/physical retardation. Rarely causes obvious illness.
congenital cytomegalic inclusion
caused by Cytomegalovirus (CMV)
100
Causes congenital cytomegalic inclusion disease in children
Latent virus infection in immunosuppressed / immunocompromised organ transplant, malignancy, AIDS
- --(a) Febrile mononucleosis
- --(b) Multiple organ involvement (pneumonitis, hepatitis, GI ulcerations, encephalopathy)
- --(c) Severity of disease related to competency of cell-mediated immunity
Cytomegalovirus (CMV)
101
Multiple organ involvement (pneumonitis, hepatitis, GI ulcerations, encephalopathy)
Febrile mononucleosis
Severity of disease related to competency of cell-mediated immunity
Cytomegalovirus (CMV)
102
Cytomegalovirus (CMV) causes what?
Causes congenital cytomegalic inclusion disease in children
Febrile mononucleosis in immunosuppressed patients w/ Multiple organ involvement (pneumonitis, hepatitis, GI ulcerations, encephalopathy)
103
a. RNA virus; 8 species (A-H)
b. The most common cause of severe epidemic diarrhea in infants and young children (Rotavirus A accounts for 90% of infections) -- Vaccine (2006)
c. Fecal to oral transmission
d. Vaccine
Rotavirus
104
The most common cause of severe epidemic diarrhea in infants and young children (Rotavirus A accounts for 90% of infections) -- Vaccine (2006)
Rotavirus
105
the major worldwide cause of epidemic and sporatic viral gastroenteritis - causes ~90 % of epidemic nonbacterial gastroenteritis (schools, families, camps, etc.) (21 million cases in USA; 200K deaths worldwide annually).
- --(1) 18-48 hours incubation, causes vomiting, diarrhea, cramps, and low-grade fever
- --(2) Illness lasts 12-60 hours and often remits spontaneously
Norwalk virus (Norovirus)
106
describe Norwalk virus (Norovirus) morphology
RNA virus, non-enveloped -- Norwalk virus is the only species of the genus Norovirus, and “Norwalk virus” is the preferred nomenclature
107
Severe epidemic diarrhea in infants and Children
Rotavirus
108
Sapovirus and Astrovirus cause what? in which age group?
less frequent, causes of gastroenteritis in children and adults than Norovirus.
Children under 2 yo are predominant.
109
How are the Norwalk virus (Norovirus) [and Sapovirus and Astrovirus] spread?
Transmitted by food, water, vomitus – very difficult to prevent spread
110
Causes Acquired Immune Deficiency (AIDS)
(1) Decreased immunity
(2) Increased opportunistic infections
(3) Total cases: ~50+ million; Deaths: ~20+ million (since 1970)
(4) Hot spots of infection: Southern Africa, Southern and Southeastern Asia
Human Immunodeficiency Virus (HIV)
111
General characteristics (Retrovirus group)
(1) Medium sized, enveloped RNA virus
(2) Structure and composition
(a) Envelope
• Glycoprotein-41 (GP-41)
• Glycoprotein-120 (GP-120)
• Antigenically variable
(b) Capsid: Protein-24 (P-24)
(c) Core
• Two strands of RNA
• Reverse transcriptase -- an enzyme which produces a DNA copy of the genomic RNA (this is an extremely unusual approach)
Human Immunodeficiency Virus (HIV)
112
Two antigenic types: HIV-1 present worldwide and HIV-2 primarily found in Western Africa. (Antigenic variations within each type.)
Human Immunodeficiency Virus (HIV)
113
General characteristics Human Immunodeficiency Virus (HIV)
(Retrovirus group)
(1) ____ sized, _____ RNA virus
(2) Structure and composition
(a) Envelope
• Glycoprotein-____
• Glycoprotein-____
• Antigenically variable
(b) Capsid:_______
(c) Core
• Two strands of RNA
• Reverse transcriptase -- an enzyme which produces a DNA copy of the genomic RNA (this is an extremely unusual approach)
General characteristics (Retrovirus group)
(1) Medium sized, enveloped RNA virus
(2) Structure and composition
(a) Envelope
• Glycoprotein-41 (GP-41)
• Glycoprotein-120 (GP-120)
• Antigenically variable
(b) Capsid: Protein-24 (P-24)
(c) Core
• Two strands of RNA
• Reverse transcriptase -- an enzyme which produces a DNA copy of the genomic RNA (this is an extremely unusual approach)
114
Interactions Between HIV & Cells
(1) _____ attaches to the CD4 marker on the cell membrane [can infect cells that do not have CD4 markers if they co-infect with another Retrovirus]. GP-41 attaches to a different protein, ______.
(2) The ____ strands enter the host cell
(3) * Reverse transcriptase uses the RNA strands as a template to produce new viral DNA
(4) * The new viral DNA is incorporated into the host cell’s DNA -- remains latent for prolonged period of time
* Unusual characteristic
(5) Alters the ability of ?
(6) New virions released from infected cells by ?
Interactions Between HIV & Cells
(1) GP-120 attaches to the CD4 marker on the cell membrane [can infect cells that do not have CD4 markers if they co-infect with another Retrovirus]. GP-41 attaches to a different protein, CXCR4.
(2) The RNA strands enter the host cell
(3) * Reverse transcriptase uses the RNA strands as a template to produce new viral DNA
(4) * The new viral DNA is incorporated into the host cell’s DNA -- remains latent for prolonged period of time
* Unusual characteristic
(5) Alters the ability of CD4 cell to produce cytokines
(6) New virions released from infected cells by budding - ultimately kills CD4 cell
