Lecture 1 Flashcards

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1
Q

What are the 3 domains of life?

A

Archaea, Bacteria, and Eukarya

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2
Q

What are archaea?

A

microorganisms that live in extreme environments

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3
Q

Can archaeal microorganisms cause microbial diseases?

A

Possible but not many is known

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4
Q

What domains of life represent the prokaryotes?

A

bacteria and archaea

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5
Q

What are the 3 main differences between prokaryotes and eukaryotes?

A

membrane-bound organelles, nucleus, and size (eukarya = bigger)

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6
Q

What are the main differences between gram (-) and gram (+) bacteria?

A

gram+ = NO periplasm and stains purple/blue; thick peptidoglycan || gram– = peptidoglycan, periplasm, outermembrane, stains pink/red

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7
Q

What is a characteristic of an outer membrane in terms of gram staining?

A

outer-membrane prevents most stains from penetrating

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8
Q

What affects the penetration of stains?

A

presence of outer membrane

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9
Q

What is a periplasm?

A

space located between the peptidoglycan layer and the 2 membranes (outer and cytoplasmic)

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10
Q

Which bacteria has a thinner cell wall?

A

gram–

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11
Q

What are the 4 types of bacteria?

A

gram+, gram–, mycoplasma, and acid-fast

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12
Q

What is unique about the outer structure of mycoplasmas?

A

they ONLY have the cytoplasmic membrane, no cell wall or outer-membrane

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13
Q

What is the outer structure of acid-fast bacterium?

A

very similar to gram+, has basic components = peptidoglycan and cytoplasmic membrane

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14
Q

What does cell morphology refer to?

A

the shape the bacteria takes and how it colonizes

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15
Q

Who discovered the microscope at what year?

A

Robert Hooke in 1600s

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16
Q

Why is it important to know when the microscope was first discovered?

A

science of microbiology began to develop after the discovery of the microscope

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17
Q

When is the Golden Age of Microbiology?

A

1850-1910

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18
Q

What are some contributions Louis Pasteur made to science?

A

discoveries in microbiology and immunobiology, vaccines, pasteurization (steriliztion technique)

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19
Q

Who is the Father of Microbiology?

A

Louis Pasteur

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20
Q

Who is the Father of Medical Microbiology?

A

Robert Koch, general physician

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21
Q

What was the Germ Theory of Disease?

A

linked infectious diseases to certain pathogenic microorganisms proving that those microorganisms are the cause of those IDs

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22
Q

What are Koch’s Postulates?

A

proved infection caused by particular microbe caused death ||| took samples from dead animal > isolated specific colonies > infect animal with those colonies > animal died > was able to isolate same specific colonies

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23
Q

What were the contributions Robert Koch made?

A

Germ Theory of Disease, Koch’s Postulates, pure culturing techniques

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24
Q

What are antibiotics?

A

a chemical substance produced by a microorganism that kills or inhibits the growth of another microorganism

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25
Q

What are antimicrobials?

A

targets all microbes

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26
Q

What is an antitoxin?

A

antibody counteracts toxin

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27
Q

What is bacteremia?

A

presence of bacteria in the blood

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28
Q

What is bacterial envelope?

A

cell envelope from cytoplasmic membrane and other

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29
Q

What is a chronic infection?

A

persistent/long-term infection

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30
Q

What is commensalism?

A

A benefits B but B neither benefits/harms A

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31
Q

What is an endospore?

A

a bacterial cell developed into spore

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32
Q

What is a fomite?

A

an object that can be contaminated with infectious microbes and serve in their transmission

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33
Q

What is hemolysin?

A

protein that lyses RBCs

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34
Q

What is an infection?

A

invasion into host tissues/organs/cells by a pathogen

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35
Q

What is an inflammation?

A

part of body that has become reddened/swollen/hot

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36
Q

What is an opportunist?

A

pathogens that take advantage of an opportunity not normally available

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37
Q

What is an outbreak?

A

sudden start of something

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38
Q

What is a parasite?

A

organism living in/on another organism and benefiting other organism at its expense

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39
Q

What is pathogenicity?

A

ability of an organism to cause a disease

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40
Q

What are R-plasmids?

A

plasmids with antibiotic resistance genes

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41
Q

What are siderophores?

A

molecule that binds/transports iron in microbes

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42
Q

What is a toxin?

A

microbial product that damages the target cell

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43
Q

What is a toxoid?

A

inactivated toxin used in vaccine development

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44
Q

What can toxoids be used for?

A

as an antigen for vaccine development

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45
Q

What are vaccines?

A

substance used to stimulate antibody production

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46
Q

What is virulence?

A

severity/harmfulness of a disease

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47
Q

What is a virulence factor?

A

agents produced by pathogen for pathogenesis

48
Q

What is zoonosis?

A

diseases that can be transmitted from animals to humans

49
Q

What are the 6 stages of an infectious disease (ID)?

A

EESMDO - encounter > entry > spread > multiplication > damage > outcome

50
Q

When do we first encounter microbes and what does this mean?

A

at birth = means fetus lives in a sterile environment

51
Q

What do “congenital infections” mean?

A

infections before birth

52
Q

When would one contract a congenital infection?

A

when mother has an infectious disease that can be passed to newborn child prior to delivery

53
Q

What are some examples (3) of congenital infections?

A

AIDs, HIV, syphillus

54
Q

Does encounter always mean it will lead to an infectious disease, why or why not?

A

No due to host cell defensess

55
Q

What are some factors that contribute to one’s susceptibility of contracting an infectious disease?

A

gender, overall health, how many microbes we encounter, and age

56
Q

What are the 2 types of encounter?

A

exogenous and endogenous

57
Q

What does an exogenous encounter mean?

A

the microbial agent is from the environment

58
Q

What does an endogenous encounter mean?

A

the microbial agent is present in or on the human body (normal flora)

59
Q

What does “ingress” mean?

A

entry without crossing epithelial barriers (ie: via toxins); damage caused by the product of a pathogen (ie: botulism)

60
Q

What does “penetration” mean?

A

whole pathogen enters into a tissue after crossing epithelial barrier

61
Q

What are some ways “penetration” entry can occur?

A

via receptors, insect bites, cuts/wounds, organ transplants or blood infusions

62
Q

What is the common form of entry?

A

penetration

63
Q

How does “ingress” entry work?

A

pathogen stays outside of the cell but sends one of its microbial factors it produces

64
Q

How do exogenous pathogens enter our bodies?

A

through one of the openings we have (ie: nose, mouth, vagina, cuts/wounds)

65
Q

What is “spread”?

A

pathogens want to infect more than one part/side of the body so they scatter (“spread”) to those parts starting from the origin of entrance

66
Q

What does spread depend on?

A

anatomical factors such as bloodstream which can take them to different parts of the body

67
Q

Do all microbes spread the same way?

A

No, some evolved different microbe-specifc mechanisms to spread = takes them from one site to another

68
Q

Why do microbes spread?

A

look for the best environment to multiply and flourish = why they use host (provides protection from extreme environments)

69
Q

What is “multiplication”?

A

the reason why they spread; make new progeny

70
Q

How does multiplication play a key role in infectious diseases?

A

if microbe doesn’t multiply to enough high numbers to cause an infectious disease = will have no symptoms = no existence of a disease

71
Q

What is an asymptomatic infection?

A

when multiplication numbers remain low

72
Q

When will multiplication of microbes develop into a disease?

A

when the multiplication reaches a certain high number and remains at that number = will release toxins = continue to damage the host

73
Q

When can recovery or cure occur?

A

when the damage and multiplication number significantly decreases

74
Q

What is key to determine the outcome of an infectious disease?

A

the multiplication number and type of damage

75
Q

What is the normal microbiota composed of?

A

the different types of microorganisms frequently found in or on the bodies of healthy individuals; they are non-pathogenic with some exceptions

76
Q

What is the reason why not everyone has the same microbiota?

A

due to different exposure, diet, what nutrients we have inside of us || what our bodies supply dictate which microorganisms can survive/thrive there

77
Q

Define “normal microbiota”

A

commensal organisms that coexist with humans without causing harm

78
Q

What are transient members of the normal microbiota?

A

pathogenic microbes found in normal microbiota of some individuals

79
Q

What does it mean when a microbe becomes “opportunistic”?

A

when these microbes find the opportunity to cause/develop an infectious disease

80
Q

What are the sites colonized by normal microbiota?

A

skin, respiratory tract, digestive tract, urinary tract, genital system

81
Q

What are the sterile sites of the body?

A

any site not following the tube from the mouth/nose to anus/vagina/urethra

82
Q

Why do we have normal flora in/on our bodies?

A

help with absorption of nutrients, metabolic function, immune stimulation (cross-reactivity), keeping out invaders (bacteriocin)

83
Q

What is cross-reactivity when it comes to immune stimulation?

A

antigen/antibody interaction

84
Q

What is a bacteriocin?

A

protein produced by one bacterial strain targeted against those of a closely related strain; doesn’t damage organs

85
Q

What is a benefit of colonizing certain parts of our organ systems?

A

to prevent other pathogens and microorganisms from entering our bodies

86
Q

What is at least one member of the normal microbiota that can cause cancer in some individuals and why?

A

H. pylori because it is a transient member that can become opportunistic

87
Q

What are some ways/mechanisms have our bodies developed to prevent pathogens from entering and colonizing?

A

secretions that contain antimicrobials such as that in tears and saliva

88
Q

What are the 2 bacterial species of the normal microbiota on the skin?

A

staphylococcus and corynebacteria

89
Q

What factors influence the skin microbiota?

A

weather, age (skin composition), personal hygiene

90
Q

Which type of bacteria survive better in dry conditions and why and what does this mean?

A

Gram+ survive better in dry conditions due to their thick cell wall therefore we most often find gram+ species on skin

91
Q

Which part of the respiratory tract is colonized by microbes and which part is sterile?

A

upper is colonized by microbes and lower is sterile

92
Q

What species colonize the normal microbiota of the respiratory tract?

A

Staphylococcus, Corynebacteria, Streptococcus, Haemophilus, Neisseria

93
Q

How is the oral cavity a complex environment?

A

two different types of surfaces bacteria can grow = bones and epithelial tissue

94
Q

How is bone in the oral cavity an additional bonus to the colonization of microbes?

A

bone is a great surface for microbes to colonize

95
Q

Which part of the body will give the normal microbiota the most nutrients?

A

oral cavity = where we uptake food and fluids = easily allows microbes to multiply

96
Q

What is an example of an antimicrobial that is secreted by the oral cavity?

A

lysozyme

97
Q

What species are present in the normal microbiota of your oral cavity?

A

Actinomyces, Borrelia, Streptococcus

98
Q

What is the GI tract composed of?

A

Stomach, small and large intestines

99
Q

What characterizes the stomach?

A

very low pH (~2)

100
Q

Which part of the body has the largest biomass of bacteria (number?)? Does this mean an increase in variety of species present?

A

GI tract at 10^4; not variety in species

101
Q

What species are present in the normal microbiota of your GI tract?

A

Heliobacter, Escherichia

102
Q

Which part of the urinary tract is colonized by normal microbiota and which is sterile?

A

upper is sterile and lower is colonized by normal microbiota (urethra)

103
Q

Where is the location of a UTI infection and which species is mainly responsible for it?

A

bladder and Escherichia

104
Q

What species are present in the normal microbiota of your urinary tract?

A

Streptococcus and Escherichia

105
Q

In what gender and body part of the human body can be colonized by normal microbiota? What characterizes this area?

A

Female’s vagina at a weakly acidic pH

106
Q

What species are present in the normal microbiota of a vagina?

A

Streptococcus, Escherichia, Lactobacilus

107
Q

What is the Human Microbiome Project?

A

sequenced 16S rRNA to identify the types of microbes in body sites of 242 healthy individuals

108
Q

What were the findings of the Human Microbiome Project?

A

discovered which species were more dominant in which areas of the body

109
Q

What is H. pylori a member of what organ?

A

stomach

110
Q

How can we have a sterile organism that lack a normal microbiota to study the normal microbiota?

A

generate a sterile animal in the lab and determine what effect the microbiota has on the physiology of the host and pathogenesis

111
Q

What is a side effect on the normal microbiota when taking antibiotics?

A

antibiotics will not only target the pathogen but also the normal microbiota as well

112
Q

What is a new concept that challenges the old one when linking an infectious disease to the presence of a pathogen?

A

perhaps an infectious disease can occur by the absence of a good microbe from your normal microbiota that allowed a bad microbe to take over and flourish due to use of antibiotics

113
Q

In the Human Microbiome Project, why were there more samples taken from women?

A

female body is more complex

114
Q

How many microbes are in our normal microbiota (based on the Human Microbiome Project)?

A

100x more than our total body cells

115
Q

On average, how many species are present on our normal microbiota?

A

about 10,000