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Biosciences > Microbial Growth and Antibiotics, Microbial Disease > Flashcards

Microbial Growth and Antibiotics, Microbial Disease Flashcards

1
Q

Cocci

A

Spherical shaped bacteria

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2
Q

Staphylococci

A

Multiple spherical cocci
Causes boils and food poisoning
Skin infections
MRSA

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3
Q

Diplococci

A

Pairs of cocci
Meningitis
Gonorrhoea

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4
Q

Strepococci

A

Chains of cocci
Causes sore throats
Used in yogurt making

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5
Q

Desiccation

A

State of extreme dryness

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6
Q

Light sensitive pigment found in bacteria

A

Bacteriochlorophyll

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7
Q

How do bacteria obtain their energy?

A

Sunlight

Oxidation of chemical compounds

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8
Q

Photoautotrophs

A

Phototrophs which carry out photosynthesis using an inorganic source of carbon (e.g. carbon dioxide)

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9
Q

Photoheterotrophs

A

Phototrophs which carry out photosynthesis using an organic source of carbon

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10
Q

Chemoautotrophs

A

Chemotrophs which obtain their energy by oxidising inorganic compounds

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11
Q

Chemoheterotrophs

A

Chemotrophs which obtain their energy by oxidising organic compounds

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12
Q

Mesosome

A

Infoldings of the cell surface membrane and possess enzymes used in respiration
Plays a part in cell division aiding the separation of DNA into new cells

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13
Q

Bacterial cell wall

A

Rigid structure that maintains shape of cell

Made of my rein and is a mucopeptude

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14
Q

Gram stain

A

Allows distinction of bacteria by gram positive/negative
Gram positive bacteria retain the stain due to the cell wall containing at least 40% murein. Gram negative don’t retain the stain as they have as little as >
>5%

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15
Q

Halophile

A

Extremophile that can grow in areas of high salt concentrations or in salt crystals.
Habitats include salt marshes and salt lakes

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16
Q

Adaptations of halophiles

A

1) High salt conc. in cytoplasm to prevent water loss
2) Optimal protein folding to tolerate conditions
3) Cell wall made of glycoproteins and stabilised by Na+ to maintain cell structure
4) Na+ pumped out for K+ to exploit energy transfer differences
5) Bacteriorhodopsin and other pigments give red/orange colour of salt flats

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17
Q

Psychophile

A

Extremophile that’s optimal growth temperature is below 15 degrees in places like the artic

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18
Q

Why are low temperatures bad for cells

A

Freezes water which prevents metabolic processes

And forms ice crystals which pierce the cell membrane

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19
Q

Adaptations of psychrophiles

A
  • Cold adapted enzymes
  • Very fluid cell membranes due to increased unsaturated fatty acids
  • Antifreeze proteins bind to ice crystals preventing them from piercing cell membranes
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20
Q

Thermophile

A

Extremophile with optimum growth temperatures of above 45 degrees
(Hyperthermophiles live in 80+)

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21
Q

Problems for cells with high temperatures

A

Denature protein and increase membrane fluidity

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22
Q

Adaptations of thermophiles

A
  • more Saturated fatty acids in membrane lipids to reduce fluidity
  • more chemical bonds (e.g. Disulfide) to maintain protein shape.
  • Fewer branching polypeptides on the surface of proteins.
  • Chaperones to help refold denatured enzymes/proteins
  • DNA is stabilised using DNA binding proteins and reverse DNA gyrase
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23
Q

Reverse DNA gyrase

A

Introduces positive supercoils into DNA

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24
Q

Alkalinophiles

A

Grow at pH values over 9
Soda lakes
High carbonate soils

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25
Q

Acidophiles

A

Grow in pH values below 5
Sulphuric pools
Geysers
Mine drainage polluted areas

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26
Q

Adaptations of alkalinophiles

A
  • membrane lipids and cell walls that resist dissolution by alkali
  • maintain intracellular pH around 9 so their proteins are adapted to this
  • have low H+ concentrations which is important for ATP synthase to provide energy, so H+ is actively pumped in
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27
Q

Adaptations of acidophiles

A
  • Acid resistant cell walls and membranes

- Excess H+ is actively pumped out

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28
Q

What are aseptic techniques?

A

Procedures used to prevent the introduction of extraneous organisms into a culture or sterile apparatus

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29
Q

Sources of contamination

A

Non-sterile apparatus
An individual (skin/breath)
Work surfaces
The air

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30
Q

Aseptic techniques used to avoid contamination

A

Use of sterile apparatus (syringe/pipette)
Avoid contact of sterile apparatus with work surfaces/skin
Flame top of test tubes/bottles/inoculating loop
Minimal exposure to air

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31
Q

Binary fission

A

Asexual reproduction of bacteria

1) cell elongation, DNA replicates and attaches to mesosome
2) septum begins synthesis, dividing the cell
3) septum divides genetic material and forms 2 daughter cells
4) daughter cells separate and cycle repeats

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32
Q

Staphylococci

A

Clusters of cocci

Causes boils and food poisoning

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33
Q

Diplococci

A

Pairs of cocci

Causes pneumonia, meningitis, gonorrhoea

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34
Q

Streptococci

A

Chains of cocci

Causes sore throat, used in yogurt making

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35
Q

Bacilli

A

Rod shaped
Singular - causes typhoid fever
Chains of rods - free living, nitrogen fixing bacteria

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36
Q

Spirillia

A

Rigid spiral structure
Found in stagnant water
Causes syphillis

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37
Q

Vibrio

A

Curved, rod shape

Causes cholera

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38
Q

Capsule

A

Consists of polysaccharide and polypeptide
Protects against phagocytosis and antibodies
Prevents dehydration

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39
Q

Prokaryote cell wall

A

Rigid structure that maintains the shape of bacteria cell

Made of murein and is a mucopeptide

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40
Q

Prokaryote cell membrane

A

Similar fluid mosaic structure to eukaryotes

Is selectively permeable and controls what enters and leaves the cell

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41
Q

Prokaryote mesosome

A

Infoldings of the cell surface membrane and possess enzymes involved in respiration
Plays a part in cell division aiding the separation of DNA into new cells

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42
Q

Circular DNA

A

No defined nucleus

Unassociated with histones

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43
Q

Prokaryote flagellum

A

Allows mobility
Simpler than eukaryotes
Made of contractile protein flagellin

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44
Q

Lag phase

A
  • Little/no cell division occurs, but cells may increase in size
  • Cells are synthesising rna, proteins and enzymes
  • Some enzymes may be produced to utilise particular nutrients in the culture
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45
Q

Log/exponential phase

A
  • Cells divide at maximum rate
  • nutrient levels, temperature and pH are all optimal for growth
  • no limiting factor
  • primary metabolites required for growth secreted here
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46
Q

Stationary phase

A
  • population stays consistent due to equal numbers of produced cells and dying cells
  • level of nutrients decreases
  • pH/temp becomes unfavourable
  • toxin/waste increase
  • secondary metabolites are secreted
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47
Q

Death phase

A

Unfavourable conditions cause death rate to be greater than growth rate
Autolysis may occur

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48
Q

Obligate aerobes

A

Can only grow with oxygen present

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49
Q

Obligate anaerobes

A

Can only divide in anaerobic conditions

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50
Q

Facultative aerobes

A

respire aerobically when oxygen level is higher and anaerobically when low

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51
Q

Aerotolerant anaerobes

A

Grow well in anaerobic conditions but can tolerate aerobic conditions

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52
Q

Filamentous fungi

A

Consist of fine, branched threads known as hyphae that form a mass known as mycelium

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53
Q

Fungal cell wall

A

Made of chitin

Strong and rigid allowing enzyme secretion and absorbing of soluble products

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54
Q

Coenocytic hyphae

A

Filamentous fungi consisting of a multinucleotide cytoplasm with no cross walls (aseptate)

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55
Q

Mechanisms of antibiotic action

A

1) inhibiting cell wall synthesis
2) cell membrane disruption
3) inhibiting mRNA translation
4) inhibiting nucleic acid synthesis

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56
Q

Exotoxins

A

Proteins secreted by bacteria which cause many symptoms of disease

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57
Q

Endotoxins

A

Lipopolysaccharides present in bacterial walls which can be released during break down of the bacterium after death

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58
Q

How do pathogens cause disease

A

Damaging host tissues

Production of toxins

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59
Q

Factors affecting pathogenicity of bacteria

A
  • cell wall/capsule features affecting attachment + entry
  • types of toxins
  • infectivity
  • invasiveness
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60
Q

What on bacterial cell walls allows attachment?

A

Ligands and glycocalyx

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61
Q

Ligand

A

Attachment protein made of polysaccharide

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62
Q

Glycocalyx

A

Attachment protein made of glycoproteins

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63
Q

Infectivity

A

Number of bacteria needed to cause infection

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64
Q

Very Infectious bacteria example

A

Typhoid fever

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65
Q

Not very infectious bacterium

A

Salmonella food poisoning

Many are required

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66
Q

Invasiveness

A

Ability of the bacteria to spread

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67
Q

How does a bacteria typically invade the host

A

Blood and nymph systems

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68
Q

Very invasive bacteria

A

Bubonic plague and anthrax

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69
Q

Characteristics of an invasive bacteria

A

Able to avoid phagocytosis and other body defences.

Able to get through tough fibres, connective tissues and intercellular cement.

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70
Q

Methods of disease transmission

A
  • airborne
  • food-borne
  • water-borne
  • contact
  • sexual intercourse
  • vector-borne
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71
Q

How is malaria transmitted

A

Vector-borne

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72
Q

Diseases transmitted by sexual intercourse

A

HIV

Gonorrhoea

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73
Q

How is athletes foot transmitted

A

Contact

74
Q

Water-borne disease examples

A

E. coli
Typhoid
Cholera

75
Q

Food-borne disease examples

A

Salmonella food poisoning

Typhoid

76
Q

Airborne disease examples

A

Influenza
Measles
Whooping cough

77
Q

Cholera

A

Water-borne disease caused by vibrio cholerae

78
Q

Contamination examples leading to transmission of vibrio cholerae

A

Transmitted by ingestion of improperly purified water, sewage contaminated water and contaminated food

79
Q

Vibrio-cholerae structure

A

Comma shaped
Flagellum
Plasmid
Capsule

80
Q

Oral rehydration solution

A

Treatment of diarrhoea which restores the water and ions lost.
Contains H2O, Cl-, Na+ and C6H12O6

81
Q

Cholera symptoms

A

Diarrhoea
Dehydration
Stomach cramps, vomiting, fever

82
Q

Bacteria that causes boils and food poisoning

A

Staphylococci

83
Q

Bacteria causes pneumonia

A

Diplococci

84
Q

Bacteria which causes sore throats and used in yogurt making

A

Streptococci

85
Q

Bacteria causes typhoid fever

A

Bacilli

86
Q

Free living nitrogen fixing bacterium

A

Chains of bacilli

87
Q

Bacteria causes anthrax

A

Bacilli

88
Q

Bacteria that is a common symbiont of gut

A

E. Coli bacilli

89
Q

Saprotroph of fresh water and causes syphillis

A

Spirilla

90
Q

Bacteria causes cholera

A

Vibrio

91
Q

How is diarrhoea treated?

A

Using oral rehydration solution

92
Q

What does ORS contain?

A

H2O
Cl-
Na+
C2H12O6

93
Q

What does the influenza virus contain

A

RNA

RNA polymerase

94
Q

What is the significance of the influenza virus and its strains

A

There are 3 strains A, B and C due to the virus having such a high rate of mutation.
A causes serious epidemics

95
Q

Which epithelial cells does the influenza virus typically infect

A

Nose, throat and sometimes bronchi

96
Q

Transmission of influenza virus

A

Airborne so enters via respiratory passages in air droplets when coughing/sneezing
Poor ventilation and overcrowding increase infectivity

97
Q

Incubation period

A

Time between infection and development of symptoms

98
Q

Influenza incubation period

A

2 days

99
Q

Symptoms of influenza

A

Sore throat, head ache, back ache, joint pain, fever up to 40 degrees, sweating, shivering, dry cough.
Symptoms can last up to 7 days

100
Q

What are typical complication of influenza and why?

A

Development of bronchitis and pneumonia due to damage to epithelial lining of trachea and bronchi making secondary invasion by bacterial pathogens more likely.

101
Q

Reverse transcriptase in viruses

A

Produces DNA in the host cell using RNA as a template

102
Q

HIV

A

Human immunodeficiency virus
A retrovirus containing RNA and reverse transcriptase.
Enzyme and nucleic acid are surrounded by a nucleocapsid and then a lipid envelope.
This contains glycoproteins on the surface.
HIV attacks helper T cells

103
Q

Nucleocapisd

A

Structure on a virus made from an inner protein coat and then an outer protein capsid

104
Q

What is the first phase of symptoms of HIV?

A

Body produces HIV antibodies
Short flu like illness
Skin rash
Swollen glands

105
Q

Antibody/HIV positive phase

A

Period between infection and onset of clinical signs

May last a a few weeks or years

106
Q

AIDS related complex (ARC)

A
  • Opportunistic bacterial, viral and fungal infections

- Loss of weight and a reduction in the number of T lymphocytes

107
Q

Phase 4 of symptoms of HIV

A

Opportunistic infections of body organs
Development of secondary cancers
Development of HIV wasting syndrome and dramatic weight loss
Typically death from pneumonia

108
Q

Antiretroviral therapy (ART)

A

Used method of treatment for HIV infection
Reduces levels of HIV in the blood
Allows immune system to repair itself
Prevents any resulting illnesses

109
Q

Antiretroviral (ARV) HIV drugs

A
  • Prevent multiplication of the virus

- Classified based on how they interfere with the HIV life cycle

110
Q

Classes of HIV life cycle ARV interferes with

A
  • Reverse transcriptase inhibitors
  • Protease inhibitors
  • Fusion and entry inhibitors
  • Integrase inhibitors
111
Q

Combination therapy

A

Taking two or more ARV drugs at a time

112
Q

Highly active antiretroviral therapy

A

Taking 3 or more anti-HIV drugs

113
Q

Dependant factors on drug choices for HIV infection

A 
Availability
Price of drugs
Number of pills
Side effects of the drugs
Pre-existing medical conditions
114
Q

How does HIV bind to T lymphocytes

A

Via CD4 receptors

And CCR5 receptors

115
Q

Preventing HIV infection

A 
Reduced promiscuity
Safe sex
Blood screening
Provision of clean needles for drug users Possible elective Caesarean section
Bottle feeding over breast feeding
116
Q

Post exposure prophylaxis (PEP)

A

Taken by an individual if they believe they’ve been infected.
Within 72 hours following high exposure.
Month long treatment with serious side effects and non guaranteed effectivity.
Involves same drugs given to HIV+ patients

117
Q

Pre-exposure prophylaxis (PEP)

A

Course of HIV drugs intended for HIV negative individuals at risk of infection.
Drugs taken prior to sex to reduce risk of contracting HIV.
No major side effects.

118
Q

Transmission of HIV

A

Blood, semen or vaginal secretions.

  • Sexual transmission
  • Blood products/transmission of infected blood
  • Sharing needles
  • Mother to baby
119
Q

How does HIV attach to CD4 helper T cells

A

Glycoproteins (gp120) on their surface binding specifically to receptor sites on the membrane of the helper T cells.

120
Q

How does HIV DNA enter the host nucleus

A

Viral RNA and reverse transcriptase are released and enter the T lymphocyte.
In the helper T cell, viral DNA is formed by the enzyme reverse transcriptase using the viral RNA as a template.
Viral DNA enters the nucleus and attached to host DNA and then replicates with it.
Can remain latent for up to 10 years in the nucleus depending on activation of infected T lymphocyte.

121
Q

Following entry to the nucleus, how does HIV lead to infection of other cells in the host?

A

Viral DNA controls synthesis of viral proteins and RNA within the cell.
HIV particles are assembled and the cell is destroyed as viruses are released. The infect other T lymphocytes causing their concentration in the blood to decrease.

122
Q

Common opportunistic diseases resulting from AIDS

A

Kaposis sarcoma and pneumonia

123
Q

How does HIV lead to opportunistic infections and ultimately death.

A

Virus attacks T lymphocytes which stimulate antibody production by B lymphocytes in the immune response to combat infection. As the immune response breaks down, the individual suffers opportunistic disease and then death.

124
Q

Bioassay

A

Enables the effectiveness of a compound (antibiotic or disinfectant) to be determined by its effect on the growth of a microorganism.

125
Q

What can bioassays be used to screen?

A

Microorganisms to determine if they produce an effective antibiotic.
By measuring their ability to inhibit bacterial growth on a bacterial lawn

126
Q

Antibiotic

A

Compound usually produced by a microorganisms which inhibits it kills bacteria

127
Q

Mechanisms of antibiotic action

A

1) inhibiting cell wall synthesis
2) cell membrane disruption
3) inhibiting mRNA translation
4) inhibiting Nucleic acid synthesis
5) antimetabolite activity

128
Q

Inhibiting cell wall synthesis

A

Mechanism of antibiotic action
E.g. Penicillins and ampicillin
Inhibit enzymes involved in synthesis of peptide cross links in the cell wall, causing it to weaken. Results in osmotic lysis.

129
Q

Osmotic lysis

A

When water constantly enters a cell due the wall becoming weaker resulting in a pressure increase which causes the cell to burst

130
Q

Cell membrane disruption

A

Mechanism of antibiotic action
E.g. polymyxin B
Alteration of the cell membrane structure making it more permeable and leading to cell death by osmotic lysis

131
Q

Examples of antibiotics mechanisms that are bacteriocidal

A

Inhibition of cell wall synthesis
Cell membrane disruption
Antimetabolite activity

132
Q

Examples of antibiotic mechanisms that are bacteriostatic

A

Inhibition of mRNA translation

Inhibition of nucleic acid synthesis

133
Q

Why are antibiotics ineffective against viruses

A

They possess none of the structures or processes that antibiotics typically act against

134
Q

Inhibiting mRNA translation

A

Mechanism of antibiotic action
E.g. streptomycin and tetracyclines
Inhibit protein synthesis by binding across bacterial ribosomes but don’t affect eukaryotic cells

135
Q

Inhibiting nucleic acid synthesis

A

Mechanism of antibiotic action
E.g.ciprofloxacin
Inhibits dna replication

136
Q

Antimetabolite activity

A

Mechanism of antibiotic action
E.g. Sulfonamides
Inhibition of enzyme reaction
Interference with metabolic pathways

137
Q

Broad spectrum antibiotics

A

Effective against a wide range of bacteria

May be used to treat undetermined bacterial infections

138
Q

Tetracyclines

A

Bacteriostatic Antibiotic
Mechanism works by inhibiting mRNA translation
Broad spectrum antibiotic

139
Q

Narrow spectrum antibiotic

A

Effective against a small specific group of bacteria

140
Q

Streptomycin

A

Bacteriostatic antibiotic
Mechanism works via inhibition of mRNA translation
Narrow spectrum antibiotic used to test streptococcus bacteria

141
Q

Antibiotic resistance to penicillin

A

Bacteria possessing a genetic mutation enabling production of penicillinase which breaks down the antibiotic.

142
Q

How can a bacteria obtain the genes for drug resistance

A

Spontaneous mutation

Transfer of genes for resistance from other bacteria

143
Q

Vertical gene transmission

A

Resistance arisen due to random mutation which are passed on to future generations of bacteria.
Repeated exposure to antibiotics can lead to more bacteria surviving, causing their number in the population to increase.
Increase in allele frequency

144
Q

Horizontal gene transmission

A

Occurs by conjugation
Does not involve gene transmission to the next generation, instead increases the number of antibiotic-resistant bacteria in a population.
Can occur between different bacterial species

145
Q

Conjugation

A

Process of gene transmission
Occurs when one bacterium transfers a copy of its plasmid (or multiple) to another bacterial cell.
- Donor cell produces pilus connecting cells.
- Donor cell replicates plasmid and passes copy.
- Recipient cell receives plasmid which may contain gene for antibiotic resistance.

146
Q

Transmission of dna via transduction

A

Bacteriophage (vector) infects a bacterium and it’s DNA and the host DNA split.
New bacteriophages are assembled w/ bacteriophage DNA or bacterial DNA.
When a bacteriophage containing bacterial DNA infects a new cell, the DNA can be integrated into the new cells DNA.

147
Q

Transmission of dna via transformation

A
  • DNA from a lysed bacterial cell (or environment) is bound to DNA binding protein in host cell wall.
  • One foreign strand enters the host cell as the other strand breaks down.
  • Single DNA strand is bound to the DNA of the host cell.
  • Host cell is transformed.
148
Q

Virus

A

Obligate intracellular parasite which reproduces inside a living host cell.
They cause disease by the combined effects of damage to host cells via replication and toxins produced during replication.

149
Q

MRSA

A
  • Methicillin-resistant staphylococcus aureus
  • Name given to any of this strain resistant to one or more antibiotics
  • difficult to treat
  • prevalent in hospitals
150
Q

Why is MRSA prevalent in hospitals?

A
  • Many antibiotics are being used which enables development of multiple-resistance
  • Close proximity of patients ideal for infection transmission
  • Weak and sick individuals more vulnerable to infection by MRSA
151
Q

C. Difficile

A
  • Most important cause of hospital acquired diarrhoea
  • Anaerobic bacteria present in gut in 3% healthy adults and 66% infants
  • Causes problems in patients given incorrect antibiotic as it disturbs balance of bacteria
152
Q

Capsomere

A

Protein subunits which make up the outer protein coat/capsid of a virus.

153
Q

Ebola virus

A

Aggressive pathogen that causes a highly lethal haemorrhagic fever syndrome.

154
Q

Why is the Ebola virus difficult to control?

A

It’s natural host is unknown.
Has rapid progression.
Can survive for several days outside of body.

155
Q

General structure of Ebola virus

A

Member of the Filovirus family.

Contains RNA, RNA polymerase, glycoproteins.

156
Q

Which strain of the Ebola virus has the highest death rate?

A

Zaire strain

157
Q

Transmission of Ebola virus

A

In blood, body fluids or organs of infected.
•giving care to infected
•handling unsterilised needles or medical equipment
• unprotected sex with an infected person

158
Q

Viral replication of Ebola

A
  • Glycoproteins bind to receptors on cell membrane
  • Virus enters by endocytosis
  • Protein coat removed on entry, RNA + RNA polymerase are released
  • RNA is replicated, transcribed and translated to produce viral RNA and proteins
  • New viruses are assembled which bud out the cell
159
Q

Cells targeted by Ebola virus

A
  • Liver cells
  • Immune system cells
  • Endothelial cells (line inside of blood vessels)
160
Q

Initial symptoms of ebola

A

Fever, headache, joint and muscle pain, sore throat, intense muscle weakness, 2 to 21 days after infection.

161
Q

Later symptoms of ebola

A

Diarrhoea, vomiting, rash, stomach pair, impaired kidney and liver function.
Patient bleeds internally, may bleed from ears, eyes, nose or mouth.

162
Q

Diagnosis of ebola

A

Blood or body fluid samples can be tested, a diagnosis can be made.
Those suspected of infection are isolated.
If +ve, transferred to a hospital high-level isolation unit.
If negative, other diseases are tested for.

163
Q

Treatment of Ebola

A

No vaccine or licensed drug available.
Treatment of symptoms:
- Provision of intravenous fluids (IV) and balancing electrolytes (body salts)
- Maintenance of oxygenstatus and blood pressure
- Treatment of other infections if they occur

164
Q

Possible treatments of ebola

A
  • Vaccines
  • siRNA to prevent translation by binding to viral RNA
  • Antibodies which bind to glycoproteins
165
Q

Bacteriophage

A

Viruses that infect prokaryotic cells

166
Q

Lytic cycle of bacteriophage

A

Pathway following infection of host cell which results in lysis of cell.

167
Q

Lysogeny

A

Viral DNA is incorporated into the DNA of the prokaryote host and remains dormant as most virus genes are not expressed. However, the viral genome is replicated every time the host cell divides. Virus referred to as provirus. Host cell considered lysogenic.

168
Q

Malaria

A

Caused by infection with the protozoan Plasmodium. Transmitted by a female Anopheles mosquito.

169
Q

Life cycle of Plasmodium in mosquito

A
  • Mosquito picks up Plasmodium from infected humans when feeding (provide eggs w/ protein).
  • It reproduces in gut of mosquito, making thousands, which move to salivary glands.
  • Mosquito feeds again on uninfected person, Plasmodium passes into blood, w/ anticoagulant in saliva.
170
Q

Symptoms of Malaria

A
  • Fever, headache, nausea, sweating, vomiting, diarrhoea, general aches and pains.
  • Complications such as severe anaemia
  • With some species, parasite can accumulate in blood vessels of the kidney causing kidney failure, or accumulate in the brain causing seizures, brain damage and coma.
171
Q

Prevention methods of malaria

A
  • Avoid being bitten, insect repellent + mosquito nets
  • Insecticides (spraying breeding sites and bed nets).
  • Antimalarial drugs prior to and after travel
172
Q

Examples of antimalarial drugs

A

Atovaquone + proguanil mefloquine (Larium)

Doxycycline.

173
Q

Treatment of malaria

A
  • Chloroquine + proguanil, although rarely used due
    to ineffectiveness against the main malaria parasite.
  • Injection of high doses of drugs used to prevent parasite.
174
Q

Why is eradication of malaria difficult?

A
  • Increase in drug resistant Plasmodium, increase in insecticide resistant mosquitoes.
  • Difficult to produce vaccine due to plasmodium occupying liver + red blood cells.
  • Larvae of mosquitos live in stagnant water, so draining removes breeding sites.
175
Q

Possibility of vaccine against malaria?

A

Recent trials with vaccines against malaria at various points in its life cycle where it is vulnerable to attack are successful.

176
Q

Virus

A

Intracellular parasite which reproduce inside living host cells, using their metabolic processes.
Cause damage by toxins and damage to tissues.

177
Q

Protozoan plasmodium

A

Type of parasite which causes malaria in humans. Travels in female Anopheles mosquitos, being picked up when mosquito feeds to provide eggs w/ protein.

178
Q

Life cycle of plasmodium upon entry into human host

A
  • Once in blood stream, they travel to the liver, enter cells and multiply.
  • They leave the liver, enter red blood cells and multiply again.
  • Plasmodium causes cell to burst, releasing more for further infection. Coincides with associated symptoms of malaria.
179
Q

Anticoagulant

A

Substance that helps prevent blood clots. Used by mosquitos so they can more easily take up blood.

180
Q

Individuals most at risk of malaria

A
  • Pregnant women with depressed immune systems

- Children with weaker immune systems

181
Q

Dominant allele

A

Always expressed in the phenotype

Biosciences (24 decks)

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