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FTIB > microbiology > Flashcards

microbiology Flashcards

1
Q

what proportion of the world’s biodiversity are bacteria

A

2/3

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2
Q

give 2 examples of industries that use microbes

A

pharmaceuticals - antibiotics

food and drink industry

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3
Q

what are the 2 most successful medical interventions for treating/preventing microbial infections

A

antibiotics

vaccines

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4
Q

what is an ecosystem

A

organisms and chemical/environmental factors that impact and create it

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5
Q

what is a habitat

A

part of the ecosystem most suited to a certain form of life - the place where an organism lives

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6
Q

what is a niche

A

small, specific area of habitat - the role of an organism in its environment
rapid change can induce feast or famine state

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7
Q

what is species abundance

A

the number of organisms in an environment

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8
Q

what is species richness

A

the diversity of species within an environment

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9
Q

what are the 4 different life strategies

A

photoautotroph
photoheterotroph
chemoautotroph
chemoheterotroph

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10
Q

what does chemo mean in terms of energy consumption

A

get energy by chemical oxidation of organic compounds

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11
Q

what does photo mean in terms of energy consumption

A

get energy from light

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12
Q

what does autotroph mean in terms of carbon consumption

A

get carbon from CO2

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13
Q

what does heterotroph mean in terms of carbon consumption

A

get carbon from preformed organic compounds

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14
Q

give an example of a photoautotroph

A

plants, algae

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15
Q

give an example of a photoheterotroph

A

purple/green non sulphur bacteria

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16
Q

give ab example of a chemoautotroph

A

extremophiles in hydrothermal vent

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17
Q

give an example of a chemoheterotroph

A

humans and animals

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18
Q

what proportion of the surface of the earth does the marine environment cover

A

2/3

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19
Q

list some physical parameters of our oceans

A 
salinity 
temperature 
pressure 
nutrients 
pH
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20
Q

describe the neritic zone

A

mid temperature and low pressure
nutrient rich with diverse marine life
contains photosynthetic organisms

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21
Q

describe the oceanic zone

A

pressure increases with depth
more chemotrophs due to lack of light
large diversity of life

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22
Q

what is the salinity of the great salt lake

A

27%

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23
Q

explain the pink/blue sea

A

different colours caused by construction of a railroad which blocked of rivers and nutrient flow
this nutrient difference caused different microbes to inhabit different sides of the railroad resulting in the colour change

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24
Q

what is the only form of life found in the dead sea and especially which kinds

A

microscopic

especially photoheterotrophs and halophiles

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25
Q

why can we float on the surface of the dead sea

A

because the salt increases the density

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26
Q

what are the 4 different levels of slat tolerance

A

non-halophile - no salt tolerance - <0.3%
halotolerant - high tolerance for saline 0.3-3%
halophile - rely on salt for growth >3%
extreme halophile - e.g. great salt lake 30%

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27
Q

give 2 examples of halophilic fungi

A

hortaea werneckii

wallemia ichthyophaga

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28
Q

give an example of 2 halophilic archaea and how they can be used in human products

A

haloferax mediterranei
halobacterium
they can be used as health supplements and in some cooking sauces

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29
Q

how do organisms maintain their water-salt balance internally

A

they regulate the movement of water and ions across the membrane

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30
Q

what is the response if we have an organisms with high internal solute conc

A

we will get an influx of water to maintain osmotic balance between the cell and the environment

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31
Q

what is the response of a cell being placed in a solute rich environment

A

water is expelled from the cell and the cell will become dehydrated

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32
Q

how do halophiles stop flow of water from low internal salinity to high external salinity

A

they produce compatible solutes which increases the internal salinity preventing the outflow of water
this results in maintenance of the water salt balance in halophiles

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33
Q

are compatible solutes toxic to cellular processes

A

no

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34
Q

what did the sorcerer II global ocean sampling expedition find

A
  • samples taken at 200 mile intervals and assessed using molecular methods
  • SAR11 bacteria discovered - most abundant organism on the planet - newly discovered - very few had been cultured in the lab previously
  • a number of new proteins and known proteins were identified
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35
Q

the most abundant families of bacteria are novel and ……..……..

A

unculturable

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36
Q

give examples of technology development that is allowing us to investigate deep ocean

A

submarines that are able to withstand high blood pressure

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37
Q

what are hydrothermal vents and why are they sometimes called black smokers

A

they are vents on the ocean floor that are found near volcanically active areas
black smokers - water rises and deposits iron sulphide

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38
Q

using submarines what have we discovered about hydrothermal vents

A

that even thought they are very hostile environments there is a high level of macroscopic life meaning that microbial life must also exist

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39
Q

at what depth are black smokers usually found

A

2000m

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40
Q

how many meters results in a gain of an atm

A

10m = 1atm

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41
Q

what is the deepest place on the earth

A

the mariana trench - 11000m = 1100atm

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42
Q

what are the 3 different levels of pressure tolerance

A
  • piezotolerant - can grow at atmospheric pressure and can tolerate increased pressure
  • piezophile - optimal growth is above atmospheric pressure
  • extreme piezophile - requirement for high pressure for growth and survival - unable to survive at sea level
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43
Q

name 3 structural features that high pressure tolerant organisms require

A 
compartmentalisation (integrity) 
interactive structure (functional)
a level of fluidity
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44
Q

compare the membranes of extreme piezophile and piezotolerant organisms

A

EXTREME PIEZOPHILE
- membrane is as fluid as possible
- increase in the number of unsaturated lipids
- allows membrane to move around at high pressure
PIEZOTOLERANT
- membrane is as solid as possible
- increased number of saturated lipids

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45
Q

can humans withstand high pressure

A

no

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46
Q

what conditions are mines and caves associated with

A

high salt levels
mineral rich
extreme temperature
no light

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47
Q

how do organisms play a role in the formation of caves and mines

A
  • acidification of water results in the sculpture of caves
  • changing the composition of rock and precipitate out chemicals
  • iron/sulphur oxidising minerals contain microbes that produce sulphuric acid. this removes sulphur from the minerals making the surrounding water very acidic - negative pH values
  • acidophiles can turn water red when they remove sulphur from minerals
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48
Q

what alterations are made to membranes to tolerate pH and give an example

A

membranes contain glycerol ethers which are more tolerant to low pH - lactobacillus acidophiles

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49
Q

what happens to the spotted lake in Canada over summer

A

water in the lake evaporates over summer revealing large mineral spots

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50
Q

describe the growth of microbes at their minimum temperature

A

slow growth
enzymatic reactions reduced
membrane gelling

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51
Q

describe the growth of microbes at their optimal temperature

A

rapid growth

enzymes performing at their highest

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52
Q

describe the growth of microbes at their maximum temperature

A 
loss of membrane stability 
protein denaturation 
cell death 
collapse of cytoplasmic membrane 
thermal lysis
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53
Q

what are the 4 different levels of temperature tolerance in microbes

A

psychrophile - optimum growth <15 C
thermophile - heat tolerant
hyperthermophile - extreme heat tolerance
mesophile - optimum growth at body temperature

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54
Q

give an example or use of a psychrophile

A

listeria monocytogenes

Chlamydomonas nivails

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55
Q

give an example or use of a thermophile

A

their spores are used as a biological indicator measuring sterilisation

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56
Q

give an example or use of a hyperthermophile

A

thermus aquaticus - PCR

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57
Q

give an example or use of a mesophile

A

E.coli and other human pathogens

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58
Q

compares membranes of psychrophiles and hyperthermophiles

A 
PSYCHROPHILES 
- low temperature, membrane becomes too solid 
- need to keep interactive and fluid 
- increase unsaturated fatty acids 
HYPERTHERMOPHILES 
- high temperature, membrane becomes too liquid 
- to maintain integrity solidify fats 
- increase saturated fatty acids
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59
Q

what are the cryoprotectant heat shock proteins used for

A

they prevent proteins unfolding and denaturing

they maintain correct structure and activity of proteins

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60
Q

is there overlap between extremophiles

A

yes i.e. can be heat and salt tolerant

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61
Q

what does each earth strata in soil represent

A

a different microenvironment

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62
Q

stratification of soil = stratification of ………….

A

bacteria

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63
Q

what is a winogradsky column used for

A

it is an enclosed system allowing the study of microbial communities

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64
Q

describe aerobes and give an example

A

growth in oxygen

e.g. Neisseria spp - meningitis, gonorrhoea

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65
Q

describe anaerobes and give an example

A

death in oxygen

e.g. actinomyees spp - soil

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66
Q

describe facultative anaerobes and give an example

A

can survive with or without oxygen

e.g. E.Coli

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67
Q

describe aerotolerant organisms and give an example

A

can grow in oxygen but metabolise anaerobically

e.g. rhizobium spp

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68
Q

describe microaerophiles and give an example

A

prefer reduced oxygen
can’t respire anaerobically
e.g. lactobacillus spp, campylobacter spp

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69
Q

what does spp mean

A

2 or more species of the genus

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70
Q

what is a rhizosphere

A

area of soil around plants containing a diverse population of microbes that utilise plant secretions e.g. proteins and sugars

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71
Q

what is microbial presence in soil essential for

A

proper root formation

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72
Q

how do the microbes in the rhizosphere act

A

microbes consume minerals and feed them back into the plant, promoting growth

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73
Q

how are microbes associated with the atmosphere

A

microbes have been associated with clouds, impacting out weather systems

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74
Q

how does precipitation occur and how is this useful for microbes

A

precipitation occurs through ice particles forming in clouds
- ice forms around nucleation particles (bacteria)
- particles are taken up into the atmosphere
this allows for widespread dispersal of microbes

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75
Q

……..…………. allows ice formation at higher temperatures

A

p.syringae

76
Q

how does p.syringae allow ice formation at higher temperatures

A

the bacteria produce ice nucleation active proteins which increase freezing temperature
this punctures plant cells, allowing bacteria to penetrate
p.syringae is presented in snowfall, proving their role in precipitation - bacteria use this as their mode of transport

77
Q

what is Vibrio fischeri

A

a gram negative bacteria that produces fluorescent light

78
Q

describe the mutualistic relationships between V fischeri and the Hawaiian bobtail squid

A

the moon above the ocean casts a shadow from the squid and the v fischeri colonise the squid and release light to counteract this. this helps the squid hunt and helps it evade predators
the squid provides a selective environment exclusively for v fischeri and the v fischeri provide the bioluminescence advantage to the squid

79
Q

what is the hawaiian bobtail squid

A

a nocturnal squid that uses moonlight hunting and employs v fischeri in a symbiotic relationship to aid its hunting

80
Q

describe vibrio colonisation

A
  1. peptidoglycan signals epithelial cells to secrete mucous trapping bacteria
  2. v fischeri accumulate deep into the crypts of the squid after travelling down the light organ
  3. squid produces antibiotic against gram +ve bacteria which causes v fischeri to outcompete other microbes
  4. v fischeri activate the chitinolytic enzyme in the squid which digests chitin the environment
  5. chitinobiose attracts VF and more VF move over the pores and colonise
  6. VF becomes non motile and induces host epithelial cell swelling and release light
81
Q

describe the light organ of the squid and how it is used

A
  • light is emitted from the light organ in the squid mantle. the light organ has epithelial cells which form a ciliated surface on it structure beating water into the light organ
  • water is passed through the ciliated cells and over the pores before travelling down the light organ and
82
Q

describe newborn squid VF colonisation

A
  1. sterile - crypts are sterile in the first 30 mins
  2. permissive - initial mixed bacterial population in the crypt and mucous is shed by epithelial cells to attract the bacteria
  3. restrictive - antibiotic production to inhibit certain bacteria and VF is immune to this
  4. specific - specific VF colonisation due to chitinobiose secretion and an antibiotic compound against bacteria
    VF are colonised within 2 hrs of birth
83
Q

what happens when the VF threshold is reached in squid

A
  1. pores close and prevent microbe entry
  2. the process is controlled by LPS which acts as a signal to stop VF attraction by squid
  3. squid growth ceases, appendages regress, mucous production stops
  4. apoptosis of area around epithelial cells is induced to stop water beating across pores
  5. the squid gets a fresh influx and efflux of microbes every day
84
Q

what is LPS

A

lipopolysaccharide which is found on the cells surface of bacteria

85
Q

describe the diel cycles of the squid and VF

A

DAY
- squid buries in sand
- remaining bacteria replicate throughout the day to reach peak
NIGHT
- light organ full of VF and bioluminescence enables hunting
- going into day, bacteria are removed seeding the environment with VF for the next squid generation

86
Q

describe quorum sensing in bioluminescence - the Lux operon

A
  1. Lux L synthesises AHL which binds to Lux R which produces a TF
  2. the TF activates bioluminescence genes
  3. increased activation of Lux L results from Lux R activating its gene
  4. we get amplification
87
Q

what is quorum sensing

A

when bacteria sense their population size and coordinate their behaviour

88
Q

give 3 examples where we see quorum sensing

A

biofilm formation
virulence
antibiotics

89
Q

why doesn’t bioluminescence occur at low VF densities

A

because it is an energy expensive process and an small colony size would have a very small effect so it is not worth the cost

90
Q

what does quorum sensing rely on to sense the population size

A

autoinducers

91
Q

what do AIs do when the threshold has been reached

A

they activate cellular processes to respond
when density increases AI feed back into the cell and bind to transcription activators which results in transcription of genes for the desired response

92
Q

what is the response of AHL at low densities

A

AHL diffuses out of the cell at low conc

no light is produced

93
Q

what is the response of AHL at high cell density

A

AHL binds to Lux R
increased activation of Lux L
increased expression of Lux genes
light produced

94
Q

give examples of other quorum sensing operons

A

agr operon controls virulence in S aureus

P. aeruginosa has 2 quorum sensing sytems - las and rhl

95
Q

what is a biofilm

A

microbes adherent to each other or a surface, contained within an extracellular matrix

96
Q

the majority of microbes prefer to be in a ………… state

A

sessile

97
Q

what are the steps in biofilm formation

A
  1. cells colonise surface and easily detach
  2. quorum sensing promotes rapid growth
  3. extracellular matrix production
  4. mature biofilm formation
  5. quorum sensing detects growth slowing and aids biofilm dispersal
  6. nutrients inside the biofilm deplete when it gets large
98
Q

what is biofouling

A

fouling of underwater structures with micro/microorganisms

99
Q

what can biofouling lead to (disadvantages)

A

complete loss of functionality

detrimental economic impact due to increased energy and fuel costs and reduced speed

100
Q

……… ………… are essential for biofouling

A

microbial biofilms

101
Q

what are the steps in biofouling

A
  1. conditioning film
  2. multispecies microbial biofilm
  3. chemical signals attract secondary colonisers - unicellular algae
  4. invertebrate larvae and sponge colonisation
  5. algae and invertebrates grow a large community
102
Q

give examples of how biofilms can form in medicine

A 
prosthetic hip 
breast implant
dentures 
urinary catheter 
voice prosthetics
103
Q

what is the problem with biofilms in medicine

A

they are difficult to treat and they make devices difficult to remove

104
Q

why are drugs becoming more inactive for

A

due to antimicrobial resistance

105
Q

what stage of a biofilm is more dangerous, when it is intact or when it starts to disperse

A

dispersal - the cells are more pathogenic and highly virulent

106
Q

give an example of a space biofilm

A

biofilm in Russian space shuttle caused corrosion and blocked water purification systems

107
Q

how do biofilms change with changes in gravity

A

normal gravity - flat biofilm

microgravity - column and canopy shaped biofilms

108
Q

why does classical microbiology restrict growth

A

because it does not cater for organisms found in all environments
the lab conditions are far form reality

109
Q

classical microbiology is time consuming what other techniques are we using now

A

using DNA for identification

microarray

110
Q

what are the steps in DNA identification of a microbe

A
  1. extract DNA and digest it
  2. clone into plasmid vectors before sequencing
  3. analysis to ID
111
Q

what are the different types of omics

A

genomics
proteomics
transcriptomics
metabolomics

112
Q

what are the steps in microarray analysis

A
  1. insert ss DNA into each square of the grid –> target gene
  2. extract mRNA and synthesise cDNA
  3. combine samples and add to microarray
  4. measure fluorescence
113
Q

what is a microbiome

A

a large and mixed population of microbes coexisting together under many circumstances

114
Q

what is the aim of the human microbiome project

A

to characterise the human microbiota to further out understanding of how the microbiome impacts human health and disease

115
Q

give an example of how different areas of the body have different microbial environments

A

all areas of the mouth have similar microbiota but this is very different to the microbiota of the nose even though these structures are in close proximity - perhaps to do with temperature differences

116
Q

gut bacteria is a big area of study - what areas have been looked into

A

research into IBS

obesity is associated with increased firmicutes and 90% less Bacteroidetes than a lean person

117
Q

how can the microbiome be influenced

A 
it changes with age 
changes depending on birth type 
changes depending on if breast fed
changes depending on exposure to antibiotics 
changes depending on nourishment
118
Q

what is symbiosis

A

close and usually obligatory association of 2 organisms of different species living together

119
Q

what is mutualism

A

symbiosis where both organisms benefit

120
Q

what is commensalism

A

symbiosis where one organism benefits and the other is neither hindered or benefited q

121
Q

what is parasitism

A

symbiosis where the parasite benefits at the expense of causing detriment to the host

122
Q

are microbes found in isolation or pure culture

A

very rarely

123
Q

what is a commensal

A

lives in or on the host without injuring or benefitting the host

124
Q

give examples of gut microbes that are commensals

A
  • remodel VitB12 from diet to allow absorption
  • involved production of thiamine, riboflavin and VitK
  • metabolism of bile salts to allow reabsorption and recirculation
125
Q

what is a pathogen

A

an organism that causes damage and disease to the host

126
Q

what are Robert kochs postulates

A

1 - pathogen must be absent in all healthy individuals and present in all diseased
2 - pathogen must be isolated form diseased and grown on pure culture
3 - pathogen must cause same disease in inoculated host
4 - pathogen must be re-isolated from inoculated host

127
Q

what are primary pathogens

A

organisms that always cause disease in a healthy individual

128
Q

what is pathogenicity

A

the ability to cause disease

129
Q

what is virulence

A

the degree or magnitude of capacity to cause disease

130
Q

what are virulence factors

A

a product made by an organism that contributes to overall virulence

131
Q

describe tetanus

A
  • tetanus toxin is released by C tetani following growth of the organism in anaerobic environments of a deep punctured wound
  • on release the toxin binds to peripheral neuronal axons and undergoes retrograde transport to the inhibitory interneuron where it prevents the release of inhibitory neurotransmitters such as glycine and GABA
  • the neuron continues to be activated resulting in muscle contraction in both agonist and antagonist musculature - results in tetanic spasm
132
Q

what does the tetanus vaccine do

A

it prevents disease by inhibiting binding of the toxin to the nerve endings
the vaccine is made from chemically detoxified tetanus toxin

133
Q

what is an opportunistic pathogen

A

the capacity of these organisms to cause disease is dependent on the opportunity present e.g. geography, antibiotic, stress, age, genetics, nutrition

134
Q

what is Neisseria meningitidis

A
  • organisms found in the community at the back of the throat and generally do not cause disease
  • sometimes colonisation with a new strain which we have no immunity to can result in disease and this frequently occurs in new uni students
  • this causes meningitis
135
Q

what is the vaccine for meningitis

A

protection mechanism is mediated by immunity to the capsule

136
Q

what does staph aureus cause

A
  • it is a skin organism that the majority of people are colonised with
  • on the skin alone it is not dangerous but if it enters the blood it can cause significant disease
  • access to the blood (bacteraemia) may be after surgery or via catheters
137
Q

what is zoonosis

A

when a disease is transmitted from animals to man

138
Q

give 3 examples of zoonosis

A
  • campylobacter jejuni - most common cause of gastroenteritis in man and comes from poultry
  • enterohaemorrhagic E.coli - can cause haemolytic uremic syndrome in man, especially children and is transmitted from cattle
  • rabdoviridiae causes rabies in man and is transmitted from bats
139
Q

susceptibility to infection is ………………., what are some of the factors that it is dependent on

A

multifactorial

factors: susceptibility, agent, exposure, dose, virulence

140
Q

most mutations are lethal but what happens if one is advantageous

A

the resulting organism proliferates rapidly and becomes dominant, outgrowing its competitors

141
Q

why is microbial evolution so rapid

A

it is rapid because unlike humans, their growth is rapid

142
Q

what can mutations in microbes cause

A

altered sensitivity to drugs
altered receptor recognition (of tissue)
altering recognition by the host (immunity)

143
Q

name two examples of virulence associated traits

A

toxins and adhesins

144
Q

how are new trait acquired in a bacterial population

A

by horizontal gene transfer and rapid growth ensures spread within a population

145
Q

what are the 3 types of horizontal gene transfer

A

natural transformation - uptake of naked DNA
conjugation - genetic exchange between bacteria
transduction - exchange due to phage predation

146
Q

what are the stages of bacterial growth

A

lag
log
stationary
death

147
Q

what are the steps of transformation

A
  1. ss DNA released when bacteria lyse and die
  2. uptake of DNA and incorporation into the genome of other bacteria through homologous recombination into chromosomes
    (competency factor increase uptake and are produced in response to quorum sensing)
    it is thought that it evolved as a mechanism of bacterial repair
148
Q

what are conjugative plasmids

A

plasmids that encode the genes that are required for the transfer pilus - self replicating pieces of DNA

149
Q

what are the steps in conjugation (bacterial sex) - E.coli

A
  1. DNA exchange occurs when an F +ve strain carrying the plasmid meets an F -ve strain with no plasmid
  2. the F pilus makes contact with the cell pulling them closer together
  3. a relaxosome forms through which ss DNA passes and the double helix is regenerated by DNA pol
150
Q

what is the relaxosome made of

A

several proteins that are able to recognise a specific site on the conjugation plasmid

151
Q

what do some of the other genes on the conjugative plasmid encode for

A

virulence factors

152
Q

what are HFr strains

A

strains in which plasmids integrate into chromosomes at high frequency

153
Q

what are the steps that lead to transduction

A

it is dependent on infection by phages which are capable of both the lytic and lysogenic cycle

  • lytic - virus uses host to replicate DNA an dproteins an produce new particles and burst out of the cell killing it
  • lysogenic - viral DNA integrated to bacterial chromosome where it is replicated - reversion to lytic cycle if bacteria are under threat
154
Q

what are the 2 types of transduction

A

generalised and specialised

155
Q

what is generalised transduction

A

bacterial chromosome part wrongly packaged into phage head

DNA then injected into the new cell which may integrate into the chromosome

156
Q

what is specialised transduction

A

sometimes phages take DNA that lies adjacent to bacterial DNA resulting in chimeric phage with a mix of viral and bacterial genes

157
Q

what are some scars of DNA transfer

A

change in codons

remnants of phage proteins etc

158
Q

what are pathogenicity islands

A

when large pieces of DNA are integrated - frequently encode structures with virulence traits

159
Q

does transferred DNA always persist

A

no - maybe because of:

  • restriction enzyme of CRISPR recognises DNA
  • endonuclease activity
160
Q

what happens if transferred DNA does persist

A

it may multiple within the chromosome and produce a toxin

161
Q

elements can excise - what is clean excision

A

when excised element is identical to the inserted element

162
Q

elements can excise - what is inefficient excision

A

excised DNA contains genes from the host chromosome

163
Q

how was penicillin discovered

A

by accident - alexander flemming was a messy scientist
he found some bacteria that had grown overnight and saw that something (penicillin) was being produced by mould and was killing the bacteria

164
Q

what are the 5 types of antibiotics

A
  • inhibition of bacterial cell wall synthesis or destruction of synthesis enzymes
  • inhibition of protein synthesis by bacteria - binding to ribosome
  • disruption of microbial cell membranes
  • inhibition of reproduction by interfering with nucleic acid synthesis
  • inhibition of cell metabolism and growth
165
Q

what are the common uses of antibiotics clinically

A
  • treatment of infection
  • post surgery recovery - breaking skin allows bacteria in
  • chemotherapy - immune system suppressed
  • chronic diseases
166
Q

what is streptomycin effective against

A

M tuberculosis

167
Q

what is the second leading cause of death worldwide

A

infectious diseases

168
Q

drug resistance in which diseases is predicted to have the largest impact

A

E.coli
malaria
TB

169
Q

what are some causes of resistance

A
  • over prescribing antibiotics
  • not finishing treatment course
  • overuse of antibiotics in livestock
  • poor infection control in hospitals
  • lack of hygiene and poor sanitation
  • lack of new antibiotics being developed
170
Q

what is intrinsic resistance

A

the innate ability of bacteria to resist activity of a particular antibiotic due to structural and functional characteristics

171
Q

what is acquired resistance

A

microbe obtains resistance to antibiotic which it was previously susceptible to sue to mutation or acquisition of foreign resistance genes

172
Q

why are gram -ve bacteria more resistant to antibiotics

A

because the antibiotics can’t cross the membrane very easily

173
Q

what is triclosan effective against

A

gram -+ve and some gram -ve but does not inhibit pseudomonas because they carry a gene that makes a protein that is insensitive to the antibiotic

174
Q

what are some ways that microbes acquire resistance

A
  • minimising antibiotic entry
  • mutating the target of the antibiotic - changing chemical groups - can change affinity or block site
  • inactivate the antibiotic by hydrolysis
    resistance is inevitable
175
Q

why is less money being spent on antimicrobial resistance compared to other areas of health

A

because pharma companies are profit making organisations and are trying to make as much money as possible for share holders
antibiotics are cheap and effective so don’t make so much money as drugs for chronic long term conditions

176
Q

how does resistance happen

A
  1. bacteria susceptible to antibiotic but bacterial genomes are subject to mutation
  2. they acquire additional genes via horizontal transfer
  3. natural selection occurs and resistant population is favoured
177
Q

what 2 factors mean resistance can occur very quickly

A

horizontal gene transfer

short generation time

178
Q

mutations that increase resistance often come at a cost of what

A

reduced growth which is subsequently regained by additional compensatory mutations

179
Q

……..….. ………. plays a role in resistance development

A

spatial location

180
Q

how do B lactam become resistant

A

they have sites for enzymatic degradation of penicillin and caohaloporins

181
Q

what are potential solutions to AMR

A
  • reduce demand
  • increase the number of effective antimicrobial drugs
  • a global coalition for action on AMR
  • global public awareness
  • improved hygiene
  • reduced unnecessary use of antimicrobials in agriculture
  • promote new diagnostics to reduce misdiagnosis
  • promote vaccines and other alternatives
  • improve working rewards of people working on infectious diseases
  • improve global surveillance of AMR
182
Q

what are new diagnostic techniques for infectious disease

A

molecular diagnostic techniques - e.g. sequencing

183
Q

what are alternatives too antibiotics

A 
protein based 
bacteriophage use 
photoexcited quantum dots for killing multidrug resistant bacteria 
alligators 
bdellovibrio
184
Q

how are American alligators alternatives for antibiotics

A

their wounds heal rapidly and without infection

they produce cationic antimicrobial peptides with antimicrobial properties

185
Q

how are bdellovibrio alternatives for antibiotics

A

they are gram -ve bacteria and members parasitize other bacteria by entering their periplasmic space and feeding on biopolymers
they prey on other bacteria so could be used as antibiotics

FTIB (6 decks)

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