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Micro > Exam 2 > Flashcards

Exam 2 Flashcards

1
Q

What is mycology?

A

study of fungi

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2
Q

what groups of organisms are classified as fungi

A

molds
mushrooms
yeast

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3
Q

true or false fungi are classified as prokaryotes

A

false
- classified as eukaryotes

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4
Q

which is larger, bacteria or fungi? how big

A
  • fungi –> 4 mcm
  • bacteria –> 1 mcm
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5
Q

which organism (fungi or bacteria) has mitochondria and ER present in their cytoplasm?

A

Fungi

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6
Q

which organism has sterol absent in their cell membrane

A

bacteria (except mycoplasma)

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7
Q

what is fungi cell wall content

A

chitin

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8
Q

what is bacteria cell wall content

A

peptidoglycan

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9
Q

what is the function of spores in both organisms

A
  • in fungi they are used for reproduction
  • in bacteria they are used for survival not reproduction
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10
Q

which organisms perform thermal dimorphism

A

fungi (change structure with heat)

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11
Q

what is the cell wall of fungi composed of

A

polysaccharides (including chitin)
- marked differently from those found in bacteria

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12
Q

true or false fungi grow best above 25 degrees celsius

A

false
- thats why not many are pathogenic to humans with 37 degrees body temp

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13
Q

what type of parasites are fungi (obligate or opportunist)

A

opportunist

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14
Q

why are fungi able to synthesize useful products

A

large ability to break down a wide range of organic material

providing them with a huge metabolic capability to synthesize products

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15
Q

what products are fungi able to synthesize

A

Steroids
Organic Acids
Foodstuffs
Antibiotics
Vitamins
Enzymes

SO FAVE

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16
Q

what does opportunistic mean

A

bacteria can live on their own but are likely to infect hosts with weakened immunity

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17
Q

what does obligate mean

A

organisms that cannot live without a host

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18
Q

what does facultative mean

A

can survive in environments with or without oxygen

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19
Q

fungi are mostly saprophytes, what does this mean?

A

feeding on decaying organic material

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20
Q

why does fungi growth need to be controlled

A

they’re responsible for spoilage of food and medicines

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21
Q

why are fungi so bad if they rarely infect humans?

A

because when they do they are usually persistent and difficult to treat

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22
Q

what are the four common form of fungi

A
  1. yeats
  2. yeasts like fungi
  3. dimorphic fungi
  4. filamentous fungi
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23
Q

what are the three ways in which fungi asexually reproduce

A
  1. growth and spread of hyphal filaments
  2. asexual reproduction of spores
  3. simple cell division (budding yeasts)
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24
Q

what are sexual spores of fungi usually resistent to

A

chemicals
drying
heating
freezing

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25
Q

what is an example of yeasts

A
  • Saccharomyces cerevisiae (baker’s yeast, brewer’s yeast)
  • cryptococcus neoformans ( causes lung infection)
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26
Q

how do yeasts reproduce

A

by budding and binary fission

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27
Q

what is budding

A

offspring emerges as a bud on side of parents cell and pinches off

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28
Q

how many offspring can a parent cell (yeast) reproduce

A

24

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29
Q

how do yeast like fungi reproduce

A

budding but become elongated to form pseudohyphae (elongated filaments)

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30
Q

how many forms do dimorphic forms exist as

A

2

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31
Q

how do dimorphic fungi grow

A

as yeasts or filaments
- yeasts at 37 degrees
- filaments below 22 degrees

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32
Q

what is the most important dimorphic fungi

A

histoplasma capsulatum
- causes disease that manifests from a mild chest infection to a fatal spread through the body
- starling bird shit

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33
Q

true or false bread mold requires light

A

false

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34
Q

how do filamentous fungi grow

A

as long, slender, branching filaments called hyphae

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35
Q

what is the structure of hyphae

A
  • divided by branches with walls dividing each hyphae into separate walls
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36
Q

what is mycelium

A

a compact tuft that hyphae form as they typically grow together above a surface

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37
Q

how do we quantify filamentous fungi

A

measuring mass

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38
Q

what 3 things make up the cell wall of fungi
what do they do for cell
what happens if any part is broken

A
  1. glucosamine polymer chain
  2. glucans
  3. proteins
  • these things maintain rigidity of cell wall. if they’re broken down the cell becomes leaky and cannot replicate
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39
Q

what types of fungi are rhizopus stolonifer and mucor heiemalis

A

both members of zygomycetes (lower fungi)

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40
Q

how do rhizopus stolonifer and mucor heiemalis reproduce

A

by means of sporangiospores

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41
Q

how are rhizopus stolonifer and mucor heiemalis commercially used

A

they both produce a large number of organic acids and are used in the production of steroids

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42
Q

what organic acids do rhizopus stolonifer and mucor heiemalis produce

A

fumaric, lactic, citric

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43
Q

what is claviceps purpurea a contaminent of

A

cereal rye

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44
Q

how are claviceps purpurea commercially important

A

important source of pharmaceutical products

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45
Q

how do ergot alkaloids contribute to biological activity

A
  • control hemmorhage
  • induction of childbirth
  • treatment of migraine and headaches
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46
Q

why is aspergillus niger commercially important

A

spoilage organism
-hay
-nuts
-grain

produces acid
-citric acid
-gluconic acid

fermented products
-sake sauce
-soy sauce

produce enzymes
-proteases
-amylases
-diastase

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47
Q

what does contamination lead to

A

production of myotoxins which cause liver damage

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48
Q

what do aspergillus cause

A

disease called aspergillosis –> lung and ear disease

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49
Q

how are pencillium chrysogenum commercially important

A

best role for its role in production of penecillin
–> natural product penecillin G
- frequent contaminent of food and is seen as green or blue mold
- used in production of fumeric, citric, gluconic, oxalic acids

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50
Q

What are candida albicans?

A

yeasts like fungi

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51
Q

candida albicans are usually kept in check with other microflora but in what conditions can it overgrow?

A

antibiotic therapy
long-term steroids
diabetes
immunosuppressive therapy
diet
alcoholism
vitamin deficiency

ALDI DAV

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52
Q

what is thrush

A

yeast infection of the mouth or vagina

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53
Q

what is caused by filamentous fungi

A

cause diseases of the skin hair and nails
- affect keratinized area

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54
Q

what are these diseases of the skin referred to as

A

tinea & dermatomycoses and ringworm

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55
Q

where does the name ringworm come from

A

tinea corposis- circular lesions on the skin which resemble worm under the skin

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56
Q

what is tinea-pedis

A

althletes foot

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57
Q

what is one of the most common infectious diseases

A

althletes foot

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58
Q

how does althletes foot occur

A
  1. a single spore initiates infection
  2. spore germinates and pentetrates stratum corneum
  3. fungus produces branching septae hyphae
  4. branching septae hyphae forms athrospores by fragmentation of hyphae
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59
Q

what does the athletes foot infection begin as

A

cracking or scaling between toes

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60
Q

what is an example of the class of antifungals referred to as polyene macrolides

A

amphotericin
- broad spectrum

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61
Q

what is polyene macrolides mode of action

A

bind to membrane ergosterols

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62
Q

what class of anti-fungals inhibits DNA biosynthesis by being incoorporated into fungal RNA –> inhibition of protein synthesis

A

flourinated pyrimidines

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63
Q

what is an antifungal that inhibits cell division by interfering with microtubule formation in the nucleus

A

antifungal antibiotics
-ex. griseofulvin

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64
Q

inhibit ergosterol synthesis by inhibition of cytochrome P-450

A
  • clotrimazole
  • ketoconazole

Imidazoles

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65
Q

What class of antifungals block fungal cell wall synthesis

A

echinocandins ex: caspofungin

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66
Q

Are protozoa single-celled or multicellular?

A

single celled

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67
Q

Are protozoa prokaryotic or eukaryotic?

A

Eukaryotic

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68
Q

T/F: most protozoa are parasites that can only reproduce inside an animal host

A

true

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69
Q

Is it hard to cultivate ameba in the laboratory?

A

no, it is cultivated easily

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70
Q

why are some protozoa difficult to grow in the lab?

A

they have both human and insect stages in their life cycle –> require complex media supplemented with RBC

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71
Q

what is an example of a protozoa that is difficult to grow in the lab

A

Plasmodium (AKA malaria)

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72
Q

where are protozoal infection the most common?

A

tropical countries

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73
Q

why are protozoal infection more common in tropical countries?

A

tropical temps promote the reproduction of both protozoa themself and their insect vectors

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74
Q

what is the protozoa responsible for Trichomoniasis

A

Trichomonas vaginalis

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75
Q

what is the protozoa responsible for malaria?

A

Plasmodium falciparum (responsible for 75%)

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76
Q

what is the protozoa responsible for amoebic dysentery?

A

Entamoeba histolyticum

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77
Q

what is the protozoa responsible for Trypanosomiasis?

A

-Trypanosoma brucei (African Sleeping Sickness)
-Trypanosoma cruzi (Chagas Disease - American Sleeping Sickness)

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78
Q

what is the most common protozoal pathogen in industrialized countries?

A

trichomoniasis

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79
Q

How is trichomoniasis transmitted?

A

sexual contact

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80
Q

does trichomoniasis infect men or women more?

A

affect both genders at the same frequency

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81
Q

what do “azole” drugs typically treat and how?

A

fungi infections by targeting ergosterol synthesis

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82
Q

what are the two “azole” drugs that are used to treat protozoal infections?

A

metronidazole and tinidazole

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83
Q

What is malaria caused by?

A

Plasmodium protozoa

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84
Q

what are the four main species of malaria?

A

-P. falciparum
-P. vivax
-P. ovale
-P. malariae

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85
Q

what parasite related to malaria infects monkeys but could also infect humans?

A

P. knowlesi

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86
Q

what is the insect vector for malaria?

A

female anopheles mosquito

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87
Q

T/F: the life cycle of malaria consists of a sexual and asexual cycle

A

true

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88
Q

where does the sexual cycle of malaria occur?

A

the female mosquito

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89
Q

where does the asexual cycle of malaria occur?

A

humans

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90
Q

What are sporozoites?

A

motile form of parasite

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91
Q

where are sporozoites in the malaria life cycle?

A

they are introduced into the host following the insect bite and then develop in the liver

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92
Q

what are schizonts?

A

Cyst-like structures formed by Plasmodium that contains thousands of merozoites

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93
Q

what occurs to schizonts?

A

they burst and release merozoites

94
Q

What are merozoites?

A

daughter parasites of sporozoites

95
Q

What are trophozoites?

A

the active, motile feeding stage of a sporozoan parasite

96
Q

What is an erythrocytic cycle?

A

malaria parasite found in the blood

97
Q

what is an exoerythrocytic cycle?

A

malaria parasite found in the liver

98
Q

what are the characteristics of P. falciparum?

A

-48 hr erythrocytic cycle in humans
-produces malignant tertian malaria
-“malignant”: the most severe form of malaria
-“tertian”: fever believed to return every 3 days

99
Q

What are the characteristics of P. vivax?

A

-benign tertian malaria
-rarely fatal
-exoerythrocytic forms may persist for many years and cause relapses

100
Q

what are the characteristics of P. ovale?

A

-48 hr erythrocytic cycle
-exoerythrocytic stage
-rare

101
Q

what are the characteristics of P. malariae?

A

-quartan malaria
-72 hr erythrocytic cycle
-no exoerythrocytic cycle

102
Q

Patients with what disease are protected from malaria?

A

Sickle Cell Anemia

103
Q

how does sickle cell anemia protect against malaria?

A

-excess production of CO restricts availability of hemoglobin
-APC

104
Q

Which of the following protozoal infections cause sleeping sickness?
A. Yellow Fever
B. Malaria
C. Trypanosomiasis
D. Athlete’s Foot

A

C. Trypanosomiasis

105
Q

what medications are used to treat trichomoniasis?

A

metronidazole or tinidazole

106
Q

what medications are used to treat giardiasis?

A

metronidazole or tinidazole

107
Q

what medications are used to treat Amoebic dysentery?

A

metronidazole or tinidazole

108
Q

what medication is used to treat trypanosomiasis?

A

pentamidine

109
Q

drugs used to treat the acute attack of malaria act on…?

A

the parasites in the blood –> can cure malaria with no exoerythrocytic stage

110
Q

drugs used for prophylaxis of malaria act on…?

A

merozoites emerging from liver cells

111
Q

drugs used for the radical cure of malaria act on…?

A

parasites in the liver

112
Q

drugs that act on mosquito gametes help prevent what?

A

prevent transmission by the mosquito

113
Q

what drug is used to treat P. falciparum, mixed organisms, or unknown malaria

A

quinine

114
Q

what drug is used to treat P malariae, P. vivax or P. ovale

A

chloroquine

115
Q

why has the use of drugs for treatment of malaria changed?

A

developed resistance to chloroquine and other successful early drug combinations

116
Q

T/F: monotherapy has been largely abandoned in favor or artemisinin-based combination therapy for the treatment of malaria?

A

true

117
Q

What are the four reasons antimalarial drugs are used?

A

-treat acute attack
-radical cure
-chemoprophylaxis
-prevent transmission

118
Q

what are the characteristics of quinine?

A

-derived from cinchona bark
-blood schizonticidal drug effective against the erythrocytic forms of all four species
-no effect on exoerythrocytic forms or gametocytes

119
Q

what are the characteristics of artemisinin?

A

-derived from herb qinghao
-often only drugs that can effectively treat resistant P. falciparum

120
Q

what is considered to be the second leading cause of death from parasitic disease worldwide?

A

amoebiasis (Entamoeba histolytica)

121
Q

what drugs are used to treat amoebiasis (Entamoeba histolytica)?

A

metronidazole or tinidazole followed by diloxanide for acute invasive intestinal amoebiasis

122
Q

what do the drugs used to treat trypanosomiasis depend on?

A

the disease stage

123
Q

what drug is used to treat trypanosomiasis in the first stage?

A

pentamidine and suramin

124
Q

what drug is used to treat trypanosomiasis in the second stage?

A

-melasoprol
-eflonithine
-nifurtimox

125
Q

T/F: Viruses have cellular structure

A

False, they only have genomic structure (RNA/DNA)

126
Q

Who/what are susceptible to virus infection?

A

all cellular organisms

127
Q

where do viruses grow/reproduce?

A

inside host cells

128
Q

what is a free-living virus particle called? (outside the host)

A

virion

129
Q

what is in the nucleocapsid of a virus?

A

-coat (capsid)
-nucleic acid core (DNA or RNA)

130
Q

what does the coat (capsid) of a virus do?

A

encloses the nucleic acid

131
Q

T/F: some virus have a lipoprotein envelope and some viruses do not

A

true

132
Q

what are viruses that have a lipid envelope susceptible to?

A

-drying
-solvents and disinfectants

133
Q

T/F: viruses that do not have a lipoprotein envelope are not easily treated with chemicals or heat

A

true

134
Q

what is the common structure of a virus?

A

not a true sphere but an icosahedron (comprising 20 triangular sides)

135
Q

what is an example of a virus with a tail?

A

bacteriophage

136
Q

what is an example of a virus that has a structure of long curved or coiled filaments?

A

Ebola

137
Q

what is an example of a virus that has a filamentous structure?

A

tobacco mosaic (helical capsid)

138
Q

what is an example of a virus that has a structure that resembles a brain?

A

smallpox

139
Q

what are examples of DNA viruses?

A

-herpesviruses (chickenpox, shingles)
-adenoviruses (common cold)

140
Q

what are examples of RNA viruses?

A

-influenza
-coronavirus
-retroviruses (AIDS, T-cell, leukemia)

141
Q

what is an example of a hepadna virus?

A

Hepatitis B virus

142
Q

what are the characteristics of adenovirus?

A

-“common cold”
-non-envelope
-DNA virus (linear ds DNA)

143
Q

what are the characteristic of Influenza?

A

-enveloped virus
-segmented viral genome
-hemagglutinin and neuraminidase

144
Q

What is hemagglutinin?

A

-protein on influenza that mediates entry of virus into cell
-highly immunogenic

145
Q

what is hemagglutinin’s immunogenic ability?

A

-capable of stimulating the immune system
-how immunity to influenza through is developed vaccines

146
Q

What is neuraminidase?

A

breaks sialic acid (component of host cell memb.) for the virions incorporation

147
Q

when does infection of influenza begin?

A

attachment of the viral hemagglutinin to neuraminic (sialic) acid residues on host cells

148
Q

what occurs in the infection of influenza after the virus enters the cell?

A

-the nucleocapsid separates from the envelope and migrates to the nucleus
-activation of viral RNA

149
Q

what type of illness is influenza?

A

respiratory

150
Q

what is the M1 located on the influenza virus?

A

holds RNA in place

151
Q

what is the M2 located on the influenza virus?

A

proton channel (entry of H+ ions)

152
Q

what are the symptoms of influenza?

A

-headache
-fever
-cough
-sore throat
-aching muscles/joints

153
Q

what are the three main types of influenza?

A

A,B,C

154
Q

what is the most severe form of influenza?

A

influenza A

155
Q

what are the structural characteristics of corona viruses?

A

-large single stranded RNA genome
-fatty outer envelope
-spikes on outer surface

156
Q

what is corona viruses named corona viruses?

A

-crown or “corona” of club-shaped spikes on their surface

157
Q

how are coronaviruses transmitted?

A

-coughing
-sneezing
-person-to-person contact
-touching objects containing viral particles

158
Q

T/F: coronaviruses are rapidly inactivated by 70% ethanol or 90% isopropanol, soaps, detergents, and UV lights

A

true

159
Q

What are the steps of conrona virus infecting a host cell?

A
  1. binding and viral entry
  2. release of viral genome
  3. replication of viral genomic RNA
  4. transcription of viral RNA
  5. translation of viral proteins
  6. assembly of viral particles
  7. formation of mature virion
160
Q

what does HIV stand for?

A

human immunodeficiency virus

161
Q

what are the characteristics of Retrovirus (HIV)?

A

-contains two identical copies of the RNA genome
-enveloped
-transcriptase

162
Q

how does retrovirus weaken a person’s immune system?

A

destroys important cells that fight disease and infection

163
Q

what are the three enzymatic activities of reverse transcriptase

A
  1. reverse transcriptase activity
  2. ribonuclease activity
  3. DNA polymerase
164
Q

what is the reverse transcriptase activity of reverse transcriptase?

A

to synthesize DNA from an RNA template

165
Q

what is the ribonuclease activity of reverse transcriptase?

A

to degrade the RNA strand of RNA:DNA hybrid

166
Q

what is the DNA polymerase activity of reverse transcriptase?

A

to make double-stranded DNA from single-stranded DNA

167
Q

T/F: viruses have their own metabolic machinery

A

false

they do not have their own metabolic machinery and will hijack their host’s metabolic process to replicate

168
Q

how do viruses replicate?

A
  1. polypeptide binding site on virus interact with receptors on host cell
  2. the receptor-virus complex enters the cell through receptor-mediated endocytosis
    3.viral nucleic acids use the host machinery to synthesize acids and proteins (this step varies in RNA and DNA viruses)
169
Q

what are the steps of replication for RNA viruses?

A

-enzymes within the virion synthesize mRNA from its viral RNA template
-translated by host cell into various enzymes (structural enzymes and RNA polymerase)

170
Q

what are the steps of replication for DNA viruses?

A

-viral DNA is transcribed into mRNA in the nucleus of the host cell (uses RNA polymerase of the host cell)
-translation of mRNA in virus-specific proteins
-coat proteins assemble around viral DNA
-virions released by budding or host cell lysis

171
Q

smallpox can infect who

A

humans only

172
Q

HIV can infect who

A

humans and other primates

173
Q

vertical transmission

A

from pregnant mother to baby via breastmilk

174
Q

horizontal

A

from one individual to another of the same species not in a parent-child relationship

175
Q

what virus transmits through transplacental

A

cytomegalovirus

176
Q

which virus has transmission at time of birth

A

hep B, HIV, HPV

177
Q

Which virus transmits through breast feeding

A

human T-cell lymphotrophic virus

178
Q

how do viruses transmit through droplet nuclei

A

particles expelled into air during sneezing coughing or talking
ex: flu, COVID, respiratory system

179
Q

how do viruses transmit through the fecal-oral route

A

primary infection for viruses is gastro-intestinal tract or associated organs. don’t eat shit ???
ex: hep A and polio

180
Q

what are examples of sexually transmitted disease

A

HIV/AIDS

181
Q

What viruses do insect vectors transmit

A

dengue fever virus, west nile

182
Q

how is flu transmitted

A

aerosol droplets, chickens

183
Q

how is SARS transmitted

A

aerosol droplets, civet cat

184
Q

how is encephalitis transmitted

A

bite of various mosquitos, wild birds

185
Q

what is direct contact

A

direct contact with infected patients or contaminated objects in which virus is introduced to skin
ex: warts, and in some cases, blood stream, pox viruses

186
Q

direct introduction

A

into the bloodstream
ex: used needles, Hep B, rabies following animal bites

187
Q

how do viruses usually reproduce once inside human cell vs. a latent virus

A

usually reproduces and causes the cell to die via lysis and releases new virus particles

BUT

some viruses enter a latent (dormant) state in a small fraction of infected cells and DON’T cause immediate damage but give rise to a persistent infection

188
Q

What is an example of a latent virus that can reactivate with suitable stimuli causing it to reproduce and kill the cell “normally”

A

varicella zoster = chicken pox–> shingles

189
Q

true or false: herpes is a latent virus

A

true
- cold sores appear following the reactivation of stimulus of exposure to UV

190
Q

which viruses can cause viral cancers

A

HPV –> cervical cancer
Hep B and C –> liver cancer

191
Q

what is the first defense against a virus

A

barrier function of intact skin

192
Q

true or false broken skin and mucous membranes are less likely to become vulnerable to attack

A

false
- if you said true are you okay?

193
Q

what happens when virus gets inside you

A

initiation of innate and subsequently adaptive immune system

194
Q

what two ways can a virus attack the host defense

A

subversion of the immune response
evasion of immune detection and attack by killer cells

195
Q

What does subversion of the immune response mean

A

viruses inhibit IL-1 or TNF alpa that coordinate the innate and adaptive responses

ex: pox virus expresses proteins that mimic cytokine receptors. These pseudoreceptors bind cytokines and prevent them from reaching their natural receptors and thus moderating immune response

196
Q

What does evasion of human detection and attack by killer cells mean

A

how once viruses are inside the host cell they can escape immune detection and avoid attacks by cytotoxic t-cells and NK cells

197
Q

How are viruses able to avoid these immune responses

A
  1. interference w/ surface proteins on infected cells making the lymphocytes and NK cells unable to recognize and attack
  2. interference w/ apoptotic pathway
  3. adopting baby turkey ploy –> produce MHC markers that body thinks is its own and leaves alone
198
Q

what does “-vir” mean

A

antiviral agents

199
Q

what type of antiviral is abacavir and zidovudine

A

nucleoside reverse transcriptase inhibitors

200
Q

What type of antivirals are nevirapine

A

non-nucleoside reverse transcriptase inhibitors

201
Q

What type of antivirals are atanzanavir

A

protease inhibitors

202
Q

What type of antivirals are acyclovir

A

Viral DNA Polymerase inhibitors

203
Q

which drug is a neurominidase inhibitor

A

oseltamivir (flu)

204
Q

whuch drug is an M2 ion blocker

A

ratelgravir

205
Q

What do reverse transcriptase inhibitors do

A

Act against reverse transcriptase - an enzyme HIV uses early in the replication cycle to make DNA copies of RNA genome (typified by zidovudine)

206
Q

what is zidovudine

A

the first drug to be introduced for the treatment of HIV
- diminishes HIV-associated dementia

207
Q

what is the down side of using this medication too long

A

because the virus is a constantly moving target, and resistance develops with long-term use, especially in the later stages of the disease

208
Q

what are non-nucleoside reverse transcriptase inhibitors

A

chemically diverse compounds that bind to the reverse transcriptase enzyme near the catalytic site and inactivate it

209
Q

what drugs are available that are considered NNRTI

A

efavirenz and nevirapine (related compounds are etravirine and rilpivirine)

210
Q

What are protease inhibitors

A

bind to the site where cleavage occurs and their use, in combination w reverse transcriptase inhibitors, has transformed the therapy of aids
- block new HIV from becoming mature HIV

211
Q

What are fusion inhibitors?

A

agents that inhibit fusion of HIV with host cells
ex: enfurvitide

212
Q

What do DNA polymerase do

A

inhibits viral DNA polymerase and gets incoorporated into DNA to terminate the nucleotide chain

213
Q

how many times more potent is acyclovir against the herpes virus enzyme than the host enzyme

A

30x

214
Q

What are integrase inhibitors

A

agents that block the virally encoded integrase enzyme that splices the viral DNA into the host genome forming the provirus

215
Q

what is an example of integrase inhibitor and when is it used

A

Ex; ratelgravir
- used in the treatment of HIV as part of combination therapy

216
Q

how is varicella zoster (chix pox and shingles) used in immunocompetent people

A

orally

217
Q

how is varicella zoster (chix pox and shingles) used in immunocompromised people

A

IV

218
Q

what does prophylactically mean

A

prevention

219
Q

When are prophylactic antibiotics given?

A

in patients who are to be treated with immunosuppressant drugs or radiotherapy and who are at risk of herpes which may lead to reactivation of latent virus

220
Q

what are neuraminidase inhibitors (flu)

A

prevents release of intact virions from the host cell

221
Q

What is neuraminidase?

A

It is an enzyme that catalyses a cleavage reaction which allows the new viral particles to escape from the host cell and spread infection.

222
Q

how does one become infected w these

A

infection of these RNA viruses begin w attachment of viral hemagluttin to neuraminic acid residues on host cells
- viral particle enters by endocytosis
- endosome is acidified following the influx of h+ through the M2 (viral protein) ion channel
- dissambly of virus occurs and RNA enters the host nuclei so replication of virus can occur

223
Q

what are neuraminidase inhibitors like zanamivir and oseltamivir active against

A

influenza A and B

224
Q

which “old” drug effectively blocks the M2 ion channel, inhibiting dissambly of the virus

A

amantadine

225
Q

true or false amantadine is effective against influenza A and B

A

false, only A

226
Q

What are immunoglobulins?

A

antibodies directed against the virus envelope and can neutralize certain viruses and prevent their attachment to host cells

227
Q

what are interferons

A

they bind to specific ganglioside receptors on host cell
- they induce the production of enzymes that inhibit the translation of viral mRNA –> halt replication

228
Q

what are immunomodulators

A

drugs that act by moderating the immune response to viruses or use an immune mechanism to target a virus

229
Q

what is inosine pranobex

A

interferes w viral nucleic acid synthesis –> used to treat herpes infection of mucosal tissues or skin

230
Q

what is tribavirin

A

a synthetic nucleoside that alters virus nucleotide pools or interfere with the synthesis of viral mRNA

231
Q

How much histoplasma capsulatum is subclinical and how is it tested?

A

95% - tests by skin

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