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Microbio > Exam 1 > Flashcards

Exam 1 Flashcards

1
Q

a bacterial, viral, or fungal agent of disease

A

pathogen

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2
Q

a method to amplify DNA in vitro using many cycles of DNA denaturation, primer annealing, and DNA polymerization using a heat-stable polymerase

A

polymerase chain reaction (PCR)

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3
Q

a living organism that requires a microscope to be seen

A

microbe

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4
Q

the sum of all genomes of all members of a community of organisms

A

metagenome

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5
Q

a noncellular particle containing a genome that can only replicate inside of a cell

A

virus

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6
Q

cells lacking a nucleus; includes bacteria and archaea

A

prokaryotes

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7
Q

cells with a nucleus

A

eukaryotes

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8
Q

the three domains

A

bacteria, archaea, eukarya

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9
Q

the total genetic information contained in an organism’s chromosomal DNA

sequence of all the nucleotides in a haploid set of chromosomes

A

genome

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10
Q

what does the genes in a microbe’s genome and the sequence of DNA tell us about

A

how that microbe grows and associates with other species

microbial capabilities are defined by genome sequences

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11
Q

organisms exist in both _________ and ___________ forms

A

macroscopic and microscopic

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12
Q

major categories of microbes include

A

bacteria
archaea
microbial eukaryotes
viruses

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13
Q

microbes may grow in

A

communities, such as a biofilm

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14
Q

includes all the microbes that live on or in us
may be commensalism or mutualism (mostly)
mostly harmless microbes but can cause problems sometimes

A

the human microbiome

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15
Q

what parts of the body would not be included in the human microbiome

A

blood, cerebrospinal fluid, internal organs

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16
Q

true or false: the composition of the human microbiome is unique to each individual

A

true

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17
Q

what are the 3 domains

A

bacteria, archaea, eukarya

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18
Q

humans harbor diverse species from a limited number of __________: Actinobacteria, Bacteriodetes, Firmicutes, Fusobacteria, and Proteobacteria

A

phyla

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19
Q

what do microbiome differences arise from

A

genetics, age, lifestyle, environment, etc

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20
Q

proportions of microbes in the microbiome are heavily influenced by

A

anatomical site

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21
Q

your microbiome begins developing at birth and reaches a ________ state by age 3

A

stable

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22
Q

what are some factors that can fluctuate your microbiome

A

puberty, weight changes, diet, pregnancy, stress, cohabitation, new pets, job changes, children, medications, sports, travel, menopause

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23
Q

an imbalance in the microbial community that is associated with diseases

A

dysbiosis

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24
Q

animals that are used to direct physiological impact of the microbiome, allowing us to prove causation

A

gnotobiotic animals

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25
Q

all microbes are known, includes germ-free

A

gnotobiotic

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26
Q

an increase in Firmicutes would result in

A

obesity

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27
Q

a decrease in bacteroidetes is associated with

A

obesity

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28
Q

a decrease in verrucomicrobia is associated with

A

obesity

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29
Q

an increase in actinobacteria is associated with

A

obesity

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30
Q

a decrease in F. prausnitzii results in

A

obesity

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31
Q

disadvantages of using a germ-free animal

A
  • more susceptible to pathogens
  • poorly developed immune system
  • lack key nutrients
  • lower cardiac output, thin intestinal walls, and altered behavior
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32
Q

failure of immunoregulation is due to inadequate exposures to the microorganisms that drive development of the immune system

A

old friends hypothesis

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33
Q

the process by which pathogens produce disease

A

pathogenesis

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34
Q

a microbe that causes disease

A

pathogen

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35
Q

causes disease in a healthy host; can breach host defense mechanisms

A

primary pathogens

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36
Q

causes disease only in immunocompromised hosts or in specific circumstances

A

opportunistic pathogens

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37
Q

started the notion of handwashing

A

Ignaz Simmelweis

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38
Q

theory that states that microbes can cause disease

A

germ theory

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39
Q

koch’s postulates establish a __________ relationship between a microbe and a specific disease

A

causative

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40
Q

koch’s postulates (4)

A
  1. the microbe is found in all cases of the disease but is absent from healthy individuals
  2. the microbe is isolated from the diseased host and grown in pure culture
  3. when the microbe is introdued into a healthy, susceptible hsot, the same disease occurs
  4. the same strain of microbe is obtained from the newly diseased host
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41
Q

a complex bidirectional network of communication between the Central Nervous System, the intestine, and the intestinal microbiota

A

microbiome-gut-brain axis

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42
Q

which cranial nerve is an important part of the microbiome-gut-brain axis

A

the vagus nerve

neurochemicals made by the brain initiate efferent vagus nerve impulses that travel from the brain to the gut, whereas gut bacteria make neurotransmitter-like chemicals that acan fire afferent signals back along the axis to the brain

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43
Q

the serial passage of a pathogenic organism from an infected individual to an uninfected individual, thus transmitting disease

A

chain of infection (transmission of disease)

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44
Q

a culture containing only a single strain or species of microorganism

A

pure culture

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45
Q

a visible cluster of microbes on a plate, all derived from a single founding microbe; usually consists of a clone, except for infrequent mutations

A

colony

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46
Q

exposure of an individual to a weakened version of a microbe or microbial antigen to provoke immunity and prevent development of disease upon reexposure

A

vaccination

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47
Q

a body’s resistance to a specific disease

A

immunity

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48
Q

an organism’s cellular defense against pathogens

A

immune system

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49
Q

the stimulation of an immune response by deliberate innoculation with a weakened pathogen, in hopes of providing immunity to disease caused by the weakened pathogen

A

immunization

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50
Q

a chemical that kills microbes

A

antiseptic agent

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51
Q

free of microbes

A

aseptic

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52
Q

a molecule that can “kill” or inhibit the growth of selected microorganisms

A

antibiotic

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53
Q

provide a set of criteria to establish a causative link between an infectious agent and a disease

A

Koch’s postulates

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54
Q

established the practice of vaccination, or inoculation with cowpox to prevent smallpox

A

Edward Jenner

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55
Q

developed the first vaccines that were based on attenuated strains

A

Louis Pasteur

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56
Q

showed that antiseptics could prevent the transmission of pathogens from doctor to patient

A

Ignaz Semmelweis and Joseph Lister

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57
Q

discovered that the Penicillum mold generates a substance that kills bacteria

A

Alexander Fleming

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58
Q

purified the substance penicillin, the first commercial antibiotic to save human lives

A

Howard Florey and Ernst Chain

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59
Q

discovered viruses as filterable agents of infection that aren’t cells

A

Dmitri Ivanovsky and Martinus Beijerinck

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60
Q

first crystallized viral particles

A

Wendell Stanley

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61
Q

a period of the infection process during which a pathogenic agent is dormant in the host and cannot be cultured

A

latent state

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62
Q

an organism’s ability to cause disease

A

pathogenicity

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63
Q

how easily an organism causes disease

A

infectivity

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64
Q

a measure of the degree, or severity of disease

A

virulence

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65
Q

a measure of virulence; the number of bacteria or virions required to kill 50% of an experimental group of hosts

A

Lethal Dose 50% (LD50)

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66
Q

the route of transmission an organism takes

A

infection cycle

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67
Q

two main forms of transmission

A

horizontal transmission and vertical transmission

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68
Q

a mode of transmission in which an infectious agent is transferred from one person or animal to the next

A

horizontal transmission

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69
Q

a mode of transmission whereby the agent is transferred from an infected parent to offspring

A

vertical transmission

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70
Q

how can vertical transmission occur in humans

A

transplacental transmission or during birth

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71
Q

the process by which certain pathogens in maternal blood can pass through the placenta and infect the fetus

A

transplacental transmission

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72
Q

modes of horizontal transmission (5)

A

direct contact
airborne transmission
indirect contact
vehicles
vectors

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73
Q

pathogens that spread horizontally from person to person by physical contact with skin, blood, or bodily fluids

A

direct contact

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74
Q

in disease, the transfer of a pathogen via dust particles or on respiratory droplets produced when an infected person sneezes or coughs

A

airborne transmission

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75
Q

a broad term that covers all types of transmission that are not directly passed from person to person (fomites, food, and water)

A

indirect contact

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76
Q

an inanimate object on which pathogens can be transmitted from one host to another

A

fomites

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77
Q

the transfer of a pathogen when an infected person deposits it on a surface or in food or drink that another person touches or consumes

A

vehicle transmission

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78
Q

an organism that maintains a virus or bacterial pathogen in an area by serving as a high-titer host

A

reservoirs

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79
Q

a vector that conveys pathogens to a susceptible individual or food without the pathogen needing to replicate in the vector

A

mechanical vector

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80
Q

an infectious disease that is primarily seen in animals but can be transmitted to humans either by vector or other means

A

zoonotic disease

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81
Q

the transfer of a pathogen from parent to offspring via infection of the egg cells

typically seen in insects

A

transovarial transmission

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82
Q

a person who harbors a potential disease agent but has no symptoms of disease

A

asymptomatic carrier

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83
Q

portals of entry

A

respiratory
oral
ocular
urogenital
parenteral
wound

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84
Q

agents that are transmitted only by mosquitos or ticks; injection into the bloodstream

A

parenteral route

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85
Q

applies when the immune response to a pathogen is a contributing cause of pathology and disease

A

immunopathogenesis

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86
Q

a trait of a pathogen that enhances a pathogen’s disease-producing capability

toxins, attachment proteins, capsules, and other devices used by pathoge

A

virulence factors

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87
Q

true or false: if you become infected with a pathogen, you will become diseased

A

false

88
Q

what are the requirements for Molecular Koch’s Posulates

A
  1. the phenotype under study should be associated with pathogenic strains of a species
  2. specific inactivation of the suspected virulence gene(s) should lead to a measurable loss in virulence or pathogenicity. the genes should be isolated by molecular methods
  3. reversion or replacement of the mutated gene should restore pathogenicity
88
Q

an organism that can carry infectious agents from one animal to another

A

vectors

88
Q

a type of genomic island in which the stretch of DNA contains virulence factors and may have been transferred from another genome

A

pathogenicity island

88
Q

a measure of how easily a disease spreads

A

basic reproduction number (R0)

89
Q

replication of pathogen in host

A

infection

90
Q

factors that influence infection after exposure

A

(host and pathogen) genetics
risk factors to developing disease
prior exposure to pathogen

91
Q

measures the proportion of infected people who develop disease

A

case-to-infected ratio (CI)

92
Q

how do you calculate R0

A

determine the ratio of new cases to existing cases

93
Q

a measure of virulence

A

case-fatality-ratio (CFR)

94
Q

what is the CFR equation

A

CFR = M / (Ir + Ip + Id)

M= mortality
Ir = infected + recovered
Ip = infected and presented
Id= infected and died

95
Q

what does a pathogen need to do to cause disease

A
  • make contact w/ appropriate host tissues/cells
  • outcompete the resident microbiota for resources
  • survive host defense mechanisms
  • multiply and eventually transmit to a new susceptible hsot
96
Q

how do we identify virulence factors?

A
  • compare genomes of related virulent/avirulent pathogens
  • identify genes in the virulent strain that are absent from a virulent strain
  • use molecular koch’s postulates
97
Q

used to prove a gene encodes a virulence factor

A

molecular koch’s postulates

98
Q

measures the dose that it takes a microbe to cause infection (but does not kill host)

A

infectious dose 50 (ID50)

99
Q

form, elevation, margin, size, texture, and opacity

A

colony characteristics

100
Q

bacteria arranged in a spherical shape

A

coccus (pl. cocci)

101
Q

cocci cells are arranged based on what

A

plane of cell division

102
Q

chains of spherically shaped cells

A

streptococcus

103
Q

grapelike clusters of spherically shaped cells

A

staphylococcus

104
Q

rod-shaped cells

A

bacillus (pl. bacilli)

105
Q

rigid, short spiral-shaped cells

A

spirillum (pl. spirilla)

106
Q

flexible, long spiral-shaped cells

A

spirochetes

107
Q

comma-shaped cells

A

vibrio (pl. vibrios)

108
Q

most bacteria are typically between what size in length?

A

0.5-5.0 micrometers

109
Q

what are the constraints on small cells?

A

cells must be big enough to have essential genetic material and machinery

110
Q

smallest known bacterial cells
0.2 micrometers
smallest known genomes (~650 genes)

A

Mycoplasma

111
Q

cannot reproduce outside their host cell, meaning that the parasite’s reproduction is entirely reliant on intracellular resources

A

obligate intracellular parasite

112
Q

large cells are constrained by the limits of

A

diffusion

113
Q

how does E. fishelsoni compensate for its large size?

A
  • with a highly folded membrane that increases surface area
  • multiple genome copies to make materials at different locations
  • vesicles help to excrete waste
114
Q

includes everything that surrounds the cells cytoplasm
(plasma membrane, cell wall, specialized outer layers)

A

cell envelope

115
Q

how do bacterial cell membranes closely resemble eukaryotic cell membranes

A
  • regulate traffic
  • detect signals from the environment
  • contains cholesterol-like structures to help maintain membrane fluidity
116
Q

cholesterol-like structure in bacteria that helps maintain membrane fluidity

A

hopanoid

117
Q

fatty acid chain saturation change in response to what stimuli

A

temperature and pH

118
Q

saturated fatty acid chains can pack very tightly and are more present in what environment

A

hotter

119
Q

unsaturated fatty acid chains are present in what type of environment

contain kinks due to cis bonds

A

cooler environments

120
Q

cyclopropane fatty acids help resist what type of change and how do they maintain this?

A
  • pH
  • decrease permeability of membrane to protons, helping bacteria to survive in acidic environments
121
Q

some archaeal membranes are ______________ that withstand very high temperatures

A

monolayers

122
Q

the bacterial cell wall is made up of

A

peptidoglycan

123
Q

the bacterial cell wall helps prevent lysis in what type of tonic environment?

A

hypotonic

124
Q

qualities of gram positive bacteria

A
  • stains purple
  • teichoic acids
  • many layers (up to 30) of peptidoglycan
  • only one membrane
125
Q

qualities of Gram negative bacteria

A
  • Lipopolysaccharides
  • stains pink
  • inner and outer membrane with a periplasm in the middle
  • 1 or 2 layers of peptidoglycan
  • porins
  • lipoproteins
126
Q

scaffolds for enzymes that remodel peptidoglycan in Gram-positive bacteria

A

teichoic acids

127
Q

what are lipopolysaccharides (LPS) composed of? (most internal to external)

A
  • Lipid A
  • Core polysaccharide
  • O antigen
128
Q

why is LPS a virulence factor?

A
  • the composition of the O-antigen varies in different strains, making it resistant to host defense mechanisms
  • Lipid A is an endotoxin (can overactivate immune response, leading to organ failure and septic shock)
129
Q

steps to Gram-staining

A
  1. crystal violet
  2. iodine
  3. ethanol
  4. safranin
130
Q

the cell wall has what type of charge

A

negative

131
Q

crystal violet has what type of charge

A

positive charge

132
Q

safranin has what charge

A

negative

133
Q

what genera of bacteria are Gram positive?

A
  • Staphylococcus
  • Streptococcus
  • Listeria
  • Clostridium
134
Q

what genera of bacteria are Gram-negative

A
  • Neisseria
  • Escherichia
  • Salmonella
  • Campylobacter
  • Borrelia
  • Treponema
135
Q
  • an organized, crystalline-like layer of protein or glycoprotein found in archaea and bacteria
  • contributes to cell shape and helps protect cell from osmotic stress, bacteriophages, and predatory bacteria
A

S-layer

135
Q
  • a well organized layer of polysaccharides, tightly associated
  • acts as a virulence factor and adheres to surfaces and host cells, aids in biofilm formation, protection from dessication, evasion of phagocytosis by white blood cells
A

capsule

136
Q
  • diffuse, unorganized layer of extracellular material (polysaccharides, glycoproteins, glycolipids); loosely associated
  • adheres to surface and host cells, aids in biofilm association, protection from dessication, evasion of phagocytosis by white blood cells
A

slime layer

137
Q

virulence factors that help bacteria form biofilms

A

capsules and slime layers

137
Q

specialized, surface-attached, collaborative communities that are hard to treat

A

biofilms

138
Q

how do nutrients cross the cell membrane in gram positive cells

A
  • simple diffusion
  • facilitated diffusion
  • active transport
139
Q

use ATP directly to move molecules against their electrochemical gradient

A

primary active transport

140
Q

steps to primary active transport

A
  1. solute binds to its cognate periplasmic binding protein, and the complex then binds to the membrane transporter
  2. the ATPase activity of one component powers the opening of the channel and movement of the solute into the cell
140
Q

what is an example of primary active transport

A

ABC (ATP-Binding Cassette) Transporters

141
Q

use the energy stored in a gradient (one molecule moving from high-to-low) to transport molecules

A

secondary active transport

142
Q

examples of secondary active transport

A

symporters and antiporters

143
Q
  • a mechanism of transport across a membrane in which two different molecules move in the same direction
  • one molecule moves up the electrochemical gradient because the movement of the other molecule is more favorable
A

symporters

144
Q
  • membrane transporters that co-transport two or more dissimilar molecules in the opposite direction across a membrane
  • the movement of one ion or molecule is against its electrochemical gradient and is powered by the movement of another ion or molecule with its electrochemical gradient
A

antiporters

145
Q
  • a bacterial active transport mechanism that uses metabolic energy
  • goes down the electrochemical gradient in a favorable way
  • unique to bacteria
A

group translocation

146
Q

example of group translocation

A

phosphotransferase system (PTS)

147
Q

how do nutrients from the environment enter Gram negative cells?

A
  • through the outer membrane: porins and TonB-dependent transporters
  • through the inner membrane: same as Gram positive cells
148
Q
  • passive water-filled pores that have less specificity
  • act via facilitated diffusion
  • allows small (<600 Da) solutes to diffuse, driven by their concentration gradient (from high to low) [ex: amino acids and glucose]
A

porins

149
Q
  • active transporter
  • energy intensive
  • undergoes a conformational change
  • used for very limited nutrients (high specificity and affinity)
  • linked to inner membrane via TonB
  • needs another active transporter
A

TonB-dependent receptor

150
Q

TonB-dependent receptors use energy from

A

proton motive force transmitted from inner to outer membrane

151
Q

the force that promotes movement of protons across membranes down the electrochemical gradient

A

proton motive force

152
Q
  • often a limiting nutrient
  • a key part of the ETC and an important cofactor for certain enzymes
A

iron

153
Q

have an extremely high affinity for iron, function primarily to scavenge iron

A

siderophores

154
Q

siderophores utilize what type of transport

A

ABC transporters

active

155
Q

steps to iron transport

A
  1. the siderophore called enterochelin is secreted and binds iron
  2. the complex is transported to the periplasm through an outermembrane protein FepA
  3. a periplasmic binding protein escorts the complex to an ABC transporter
  4. the enterocherlin-iron complex enters the cell
  5. inside the cell, the iron is released and reduced to iron
156
Q

specialized appendages of bacteria

A
  • pili/fimbriae
  • sex pili
  • flagella
157
Q
  • protein-based (pilin) finger-like appendages
  • responsible for adherence
  • can act as a virulence factor
A

pili / fimbriae

158
Q
  • thin protein appendage
  • connects cells during conjugation (horizontal gene transfer)
A

sex pilus

159
Q
  • not common in coci
  • rigid spiral filament of protein monomers called flagellin, extends from the cell surface
  • responsible for cell motility powered by proton motive force
  • spins like a propeller
A

flagella

160
Q

spirochetes have what kind of flagella

A

endoflagella

161
Q
  • wraps around cell body within periplasm
  • better at moving through viscous envronments
A

endoflagellum

162
Q

bacteria house their DNA in what rather than a defined nucleus

A

nucleoid region

163
Q

what allows for the condensing of DNA into a nucleoid region

A

DNA-binding domains

164
Q

critical for cell shape and division

A

bacterial cytoskeleton

165
Q
  • forms a ring inside almost all bacteria
  • tubulin homolog
  • critical for cell division
  • responsible for contraction and separation, remodeling of peptidoglycan
A

FtsZ

166
Q
  • forms a coil inside rod-shaped and elongated cells
  • actin homolog
  • critical for cell shape determination
A

MreB

167
Q
  • forms a polymer along the inner side of crescent-shaped bacteria
  • intermediate filament homolog
  • critical for cell shape determination
A

crescentin (CreS)

168
Q
  • protein “vesicles” filled with air
  • provide buoyancy to cells for movement in response to light and nutrients
  • present in aquatic organisms/photosynthetic bacteria
A

gas vesicles

169
Q
  • protein “vesicles” that contain CO2 and RubisCO
  • responsible for carbon fixation
A

carboxysomes

170
Q
  • built when carbon sources are abundant / responsible for carbon storage
  • store nutrients in nutrient-limited environments
  • lipid polymers
A

inclusion bodies (PHB granules)

171
Q
  • consist of magnetite enclosed by a lipid membrane
  • directed motility based on a magnetic field (magnetotaxis)
A

magnetosomes

172
Q
  • dormant structure composed of DNA, ribosomes, and severall tough protective coverings
  • ensure survival through periods of environmental stress
A

endospores

173
Q

how has human control of infectious disease made incredible progress in the last century?

A
  • improvements in sanitation and hygiene
  • antimicrobial drugs (antibiotics, antifungals, antivirals)
  • vaccines
174
Q

compounds produced naturally in nature that adversely affects other microbes

A

antibiotics

175
Q

harms target organism but does not affect humans; drug should affect microbial physiology that does not exist, or is greatly modified in humans

A

selective toxicity

176
Q

antibiotics that target cell wall synthesis

A
  • penicillins
  • cephalosporins
  • bacitracin
  • vancomycin
177
Q

antibiotics that target protein synthesis

A
  • chloramphenicol
  • tetracyclines
  • aminoglycosides
  • macrolides
  • lincosamides
178
Q

antibiotics that target cell membrane integrity

A
  • polymyxin
  • daptomycin
  • amphotercin
  • imidazoles (fungi)

these drugs are typically topical agents

179
Q

antibiotics that target nucleic acid function

A
  • nitroimidazoles
  • nitrofurans
  • quinolones
  • rifampin
  • some antiviral compounds, especially antimetabolites
180
Q

antibiotics that target intermediary metabolism of bacteria

A
  • sulfonamides
  • trimethoprim
181
Q

antibiotics can typically be classified as

A
  • broad spectrum
  • narrow spectrum
182
Q

a type of antibiotic that targets a wide range of microbes

A

broad spectrum

183
Q

a type of antibiotic that has a narrow range of the organisms they affect

A

narrow spectrum

184
Q

in regards to arresting bacteria/killing them, antibiotics can be classified as

A

bacteriostatic or bactericidal

185
Q
  • does not lyse cell and prevents septic shock form gram negative cells
  • not very useful if pt is immunocompromised
  • arrests growth, does not kill bacteria
  • gives immune system time to catch up
A

bacteriostatic antibiotics

186
Q
  • lyses cell
  • kills bacteria
  • brings potential for lipid A toxicity
A

bactericidal drugs

187
Q
  1. NAG and NAM precursors are made in the cytoplasm
  2. they are carried across the cell membrane by a lipid carrier: bactoprenol
  3. precursors are polymerized to the existing cell wall structure by transglycosylases
  4. the peptide side chains are cross-linked by transpeptidases
A

peptidoglycan synthesis

188
Q

drugs that target peptidoglycan are typically seen as

A

bactericidal

189
Q

what drug inhibits NAG and NAM precursors from being made in the cytoplasm

A

cycloserine

190
Q

what drug prevents NAG and NAM precursors from being carried across the cell membrane by bactoprenol

A

bacitracin

191
Q

what part of penicillin chemically resembles the D-Ala-D-Ala part of peptidoglycan

A

B-lactam ring

192
Q

mechanism of penicillin

A
  1. target bacterial penicillin binding proteins (PBP)
  2. interfere with transpeptidation (D-Ala-D-Ala is the substrate of transpeptidase)
  3. competitive and irreversible covalent bond forms
  4. unstable cell wall
  5. cell death
193
Q

active against gram positive bacteria

A

penicillin G

194
Q

active against gram positive bacteria and is acid resistant

A

penicillin V

195
Q

B-lactamase resistant

A

methicillin

196
Q

active against a broad range of bacteria

A
  • carbenicillin
  • amoxiciliin
197
Q
A
198
Q

active against a broad spectrum of bacteria and is acid resistant

A

ampicillin

199
Q
  • antimetabolites that interfere with bacterial metabolism
  • bacteriostatic
A

sulfa drugs

200
Q

static drugs that interfere with the bacterial ribosome

A
  • macrolides (erythromycin and azithromycin)
  • chloramphenicol
  • tetracyclines (doxycycline)
201
Q

block transfer of the peptide

A

macrolides (erythromycin and azithromycin)

202
Q

obstructs formation of the peptide bond

A

chloramphenicol

203
Q

interfere with the binding of the tRNA with the mRNA codon

A

tetracyclines (doxycycline)

204
Q
  • interferes with elongation causing misreading
  • produces junk proteins
  • bactericidal
A

aminoglycosides (streptomycin and gentamycin)

205
Q

how do bacteria become resistant to antibiotics

A
  • prevent entry into cell or destroy antibiotic
  • prevent binding to target by altering target or modifying antibiotic
  • reverse binding by disoldging the antibiotic bound to target
206
Q

how can antibiotic resistance be acquired from other microbes

A

horizontal gene transfer

207
Q
  • microbes that produce antibiotics in nature must also be resistant and competitors must have defense mechanisms
  • have genes encoding resistance proteins
A

intrinsic resistance

208
Q

selective pressure from what promotes survival of antibiotic resistant strains

A

overuse of drugs

209
Q

bacteria exhibit a high frequency of

A

random mutations and recombination

Microbio (3 decks)

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