M1: Virus Viroids Prions & Fungi Flashcards
0
Q
A complete infectious particle combing these structural elements. Can be envisioned as a delivery system that surrounds a nucleic acid payload.
A
Virion
1
Q
Infectious particles. Acellular. Not considered living organisms. DNA or RNA, never both. They are obligate intracellular parasites.
A
Viruses
2
Q
Infectious agents that are minimally constructed of two components. ______ either RNA or DNA but not both.
A
Viruses. Genome
3
Q
Two components of Viruses
A
Genome & Capsid
4
Q
A protein containing structure designed to protect the genome
A
Capsid
5
Q
Viruses in coconut
A
Kadang kadang
6
Q
Obligate intracellular parasites of plants. Acellular. Naked RNA. No human diseases known.
A
Viroids
7
Q
Infectious protein composed entirely of protein which cause transmissible spongiform encephalopathies. Highly resistant to inactivation. Do not elicit an inflammatory response or an antibody response.
A
Prions
8
Q
Prions: pathogenic
A
Beta pleated sheet
9
Q
Prions: non pathogenic
A
Alpha helix
10
Q
Prions are infectious proteins: cellular form of the protein ______ is encoded by the host’s chromosomal DNA.
A
PrP
11
Q
Prions are infectious proteins: is susceptible to protease and soluble in detergent
A
PrPc
12
Q
Same AA, different protein
A
Conformers
13
Q
Prions are infectious proteins: abnormal _________ modify folding of normal prion like proteins found in the body (code by human genes) and has high beta sheath content.
A
Isoform PrPsc
14
Q
Present with cereberal problems
A
Kuru (kuria/guria)
15
Q
Presenting symptoms are like dementia
A
Creutzfeldt Jakob Disease
16
Q
Appearance of the vacuolated neurons as well as their loss of function and the lack of an immune response or inflammation
A
Spongiform encephalopathies
17
Q
Human prion diseases
A
CJD, Kuru, vCJD, GSS syndrome, FFI & Sporadic Fatal Insomnia
18
Q
Also known as mad cow disease
A
Bovine spongiform encephalopathy
19
Q
Impervious to standard viral disinfection procedures. Very long incubation periods. As long as 30 years.
A
Animal prion disease
20
Q
Animal prion diseases
A
Scrapie, Transmissible milk encephalopathy, BSE & chronic wasting disease
21
Q
From sheep and goats
A
Scrapie
22
Q
From mule, deer & elk
A
Chronic wasting disease
23
Q
Transmission of prions through cut in skin, transplantation of contaminated tissues, use of contaminated medical devices and ingestion of infected tissue.
A
Infected tissue
24
Susceptible population in prion's disease
Women & Children of Foretribe in New Guinea, Neurosurgeon, transplant and patients
25
Progressive neurodegenerative disease. Loss of muscle control, shivering, myoclonic jerks, loss of coordination, rapidly progressive dementia and death.
Prions
26
Treatment for Prions
No available
27
Type of nucleic acid found in the virus particle is perhaps the most fundamental and straightforward of viral properties
Viral genome
28
Most common forms of viral genomes found in nature
ssRNA & dsDNA
29
DNA viruses
Hepadna, Herpes, Adeno, Pox, Parvo, Polyoma & Papilloma "HHAPPPPy"
30
RNA viruses
Coronavirus, Calicivirus, Hepevirus, Picornavirus, Flavivirus, Retrovirus & Togavirus "CCHeaP FaRT"
31
Range in size from 20-300nm. All have protein coat (capsid). Composed of repeating capsomeres. In some, covered with lipoprotein envelope.
Viral structure
32
Nucleic acid + capsid
Nucleocapsid
33
Shape Viral symmetry
Spherical (Icosahedral) or Helical
34
Are enveloped
Helical viruses
35
Can be enveloped or naked
Icosohedral viruses
36
Attachment to host cell receptors
Surface proteins
37
Interaction between nucleocapsid and envelope
Matrix protein
38
Evasion of host defenses
Antigenic (serotypic) variants
39
Lipid containing membrane surrounding the nucleocapsid.
Viral envelope
40
Acquired as the virus exits from the cell in a process called
Budding
41
All enveloped viruses acquire their enveloped viruses from plasma membrane except
Herpesvirus
42
Herpesvirus are from
Nuclear membrane
43
Are less stable and more easily inactivated
Enveloped viruses
44
Naked Viruses
Calici, Picorna, Reo, Parvo, Adeno, Papilloma & Polyoma "CPR PAPP"
45
All DNA viruses have double stranded DNA except
Parvovirus
46
All DNA viruses have linear DNA except
Papilloma, Polyoma & Hepadna
47
All DNA viruses are icosahedral except
Poxvirus
48
All DNA viruses replicate in the nucleus except
Poxvirus
49
All RNA viruses have single stranded RNA except
Reovirus & Rotavirus
50
All RNA viruses replicate in the cytoplasm except
Influenza & Retrovirus
51
All viruses are haploid except
Retroviruses
52
Contain either DNA or RNA but not both. Genomes can either be single or double stranded. Genomes can either be positively or negative polarity. Some RNA viruses have a segmented genome.
Viral genome
53
Segmented Genome
Bunyaviruses, Orthomyxoviruses(Influenza), Arenaviruses & Reoviruses "BOAR"
54
Must transcribe negative strand to positive.
Negative stranded RNA viruses
55
Brings its own RNA dependent RNA Polymerase
Virion
56
Negative stranded RNA viruses
Arenaviruses, Bunyaviruses, Paramyxoviruses, Orthomyxoviruses, Filoviruses & Rhabdoviruses "Always Bring Polymerase Or Fail Replication"
57
Distinguished from all other RNA viruses by the presence of an unusual enzyme, ____________ which converts a single stranded RNA viral genome into double stranded viral DNA.
Retroviridae. Reverse transcriptase.
58
Can produce antigenic, drug resistant or attenuated variants.
Mutations
59
Causes epidemics. Influenza viruses.
Genomic reassortment
60
One virus produces a protein that can be used by another virus. Example is hepatitis D & B.
Complementation
61
Two different viruses infect the same cell
Phenotypic mixing
62
Slow and progressive change in the antigenic composition of MO. Altered immunological responses and susceptibility.
Mutation Antigenic Drift
63
Sudden change in the molecular structure of MO. New strains. Little or no acquired immunity to these novel strains. New epidemics or pandemics.
Antigenic shift
64
Following initial attachment, the ability of a virus to infect other cells disappears.
Eclipse period
65
For a period of time, then reaches a plateau after which no additional increase in virus yield occurs.
Exponential growth
66
Visual or functional change in infected cells
Cytopathic effect
67
Oncogenic viruses induce transformation and unrestrained growth
Malignant transformation
68
Infected cells appear normal, but are producing large numbers of progeny virions
Commensal symbiosis
69
Bind cytokines and block their ability to interact with receptors on their intended targets
Cytokine decoys
70
Reduces the expression of antigen presenting cells and inactivate complement
Virokines
71
Of surface proteins
Antigenic variants
72
Produces virus for long periods of time. Can serve as a source of infection for others.
Carrier state
73
Not producing virus at the present but can be reactivated at a subsequent time
Latent infections
74
Low incubation period often measured in years
Slow virus infections
75
Finding antibody in one who previously had none
Seroconversion
76
Can be used to diagnosed current infection
Presence of IgM
77
Cannot be used to diagnose current infection. Antibody may be due to an infection in the past.
Presence of IgG
78
Gold standard in viral diagnosis
Presence of viral DNA or RNA
79
Eukaryotic ( true nucleus, 80s ribosomes, mitochondria) Complex carbohydrate cell walls: chitin, glucan & mannan.
Fungi
80
Major membrane sterol
Ergosterol
81
Inhibit ergosterol synthesis
Imidazole antifungals
82
Bind more tightly to ergosterol than cholesterol
Polyene antifungals
83
Fungi require organic carbon
Heterotrophic nutrition
84
Living on dead organic material (DOM)
Saprophytic/Saprobic
85
Fungus living on another organism
Parasitic
86
Thermal dimorphism. Two basic forms of Fungi.
Molds & Yeasts
87
Single cells & budding
Yeast
88
Hyphae & Mycelia. Mitosis.
Molds
89
Septate hyphae
Transverse walls
90
Nonseptate hyphae
Multinucleated
91
Two types of host response
Granulomatous & Pyogenic responses
92
Some can be detected by using this for delayed hypersensitivity reaction
Skin tests
93
Predisposes to disseminated disease
Reduce cell-mediated immunity
94
Fungal Toxins & Allergies: liver necrosis due to amanitin & phylloidin
Amanita mushrooms
95
Fungal Toxins & Allergies: ingestion of contaminated peanuts and grains causes liver cancer due to aflatoxin
Aspergillus flavus
96
Fungal Toxins & Allergies: inhalation of the spores causes allergic bronchopulmonary aspergillosis (IgE mediated)
Aspergillus fumigatus
97
Dissolves human cells allowing visualization
Microscopy of KOH preparation
98
Low pH inhibits the growth of bacteria
Saboraud's agar
99
For early infection. Tests for fungal antigens or antibodies to fungal antigens.
DNA probes
100
Infect only superficial keratinized structures. Transmission is thru direct contact (dogs & cats)
Dermatophytoses
101
Three Important dermatophytes
Microsporum canis, Epidermophyton floccosum & Trichophyton tonsurans "MET"
102
Athletes foot
Tinea pedis
103
Jock itch
Tinea cruris
104
Superficial skin infection of cosmetic importance. Hypopigmented areas. Spaghetti and meatballs appearance on 10% KOH.
Malasezzia furfur (Tinea Versicolor)
105
Dimorphic fungus that lives on vegetation. Occurs most often in gardeners, especially those who prune roses. Transmission is thorn prick.
Sporothrix schenckii (Sporotrichosis)
106
Arthrospores form spherules filled with endospores. Granulomata in bones & CNS. Dissemination in those who have defective CMI.
Coccidioides Immitis
107
Inhaled microconidia develop into budding yeast inside macrophages. Spreads to liver and spleen. Dissemination in those who have defective CMI.
Histoplasma Capsulatum
108
Chronic PNA. Ulcerated granulomas. Lytic bone lesions. Prostatitis.
Blastomyces Dermatidis
109
Chronic PNA. Painful ulcers on mouth & nose.
Paracoccidioides Brasiliensis
110
Oral trush, vulvovaginitis, intertrigo, skin infections & onychomycosis
Candida Albicans Immunocompetent
111
Esophagitis, subcutaneous nodules & right sided endocarditis
Candida Albicans Immunocompromised
112
Curd like discharge
Vulvovaginitis
113
Skin infections
Satellite lesions
114
Asymptomatic lung infection. Meningitis. Encephalitis.
Cryptococcus neoformans
115
Infections. Aspergilloma (fungus ball) in lung cavities.
Aspergillus fumigatus
116
Asthmatic symptoms with expectoration of brownish bronchial plugs
Allergic Bronchopulmonary Aspergillosis (ABPA)
117
Saprophytic molds with nonseptate hyphae with walls and branches at right angles. Rhino-orbital cerebral infection with eschar formation. Patients with diabetic ketoacidosis, burns or leukemia.
Rhizopus oryzae & Mucos spp. (mucormycosis)
118
Are heterotryphic, non photosynthetic organisms. Can cause disease in the immunocompetent more so in the immunodeficient individual.
Fungi
119
Is directed at inhibiting structures unique to fungi minimize the risk of adverse effects on human cells
Antifungal therapy
