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Miocrobiology > Micro Exam 3 - Ch 13 > Flashcards

Micro Exam 3 - Ch 13 Flashcards

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1
Q

What are normal resident microbiota?

A

Microbes that engage in mutual or commensal associations with human

Aka indigenous, microflora, normal flora, and commensals

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2
Q

What is infection?

A

A condition in which pathogenic microbes penetrate host defenses, enter tissues, and multiply

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3
Q

What is a pathogen?

A

Microbe acting as an infectious agent

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4
Q

What is an infectious disease?

A

An infection that causes damage or disruption to tissues and organs

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5
Q

What are transient microbes? What are resident microbes?

A

Transient microbes are microbes that occupy the body for only short periods

Resident microbes become more established

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6
Q

What is microbial antagonism?

A

When the microbiota benefits the host by preventing overgrowth of harmful microbes

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7
Q

What is an endogenous infection?

A

An infection that occurs when normal flora is introduced to a site that was previously sterile

or one where the pathogen is already in your body

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8
Q

Where in the body has microbes? (5)

A

respiratory tract
digestive tract
reproductive/urinary system
eyes
skin

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9
Q

Are babies sterile?

A

They are sterile before birth, but will get normal microbiota when the fetal membrane breaks, they are handled, and when they receive breast milk

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10
Q

What is the difference between transient and resident microbes on skin?

A

Transients cling to the surface, but do not grow there. They are influence by hygiene.

Residents ones are less influenced by hygiene. They are primarily bacteria and yeast.

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11
Q

7 Major Factors a Pathogen Must Overcome to Cause Disease

A
  1. Gain Access
  2. Attach to body of hose
  3. Invade Deeper Into Tissue
  4. Evade Host Defense
  5. Multiply in Host
  6. Exit Host
  7. Maintain Reservoir
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12
Q

What are the 4 major portals of entry for bacteria?

A

Skin
Mucous Membranes
Placenta
Parenteral Route

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13
Q

What are 2 enzymes that help bacteria invade deeper into tissue?

A

Hyaluronidase and Collagenase

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14
Q

What are 5 things that help bacteria attach firmly?

A

Fimbriae, Capsules, Surface Proteins, Viral Spikes, Hooks

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15
Q

What are exoenzymes?

A

Extracellular enzymes produced by bacteria that dissolve barriers and penetrate through or between cells to invade underlying tissues

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16
Q

What are toxins?

A

(Primarily exotoxins)
Secretions by bacteria that damage target cells, which die and begin to slough off

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17
Q

What are the two kind of bacterial toxins? Describe.

A

Endotoxin- Not secreted, released after host cell is damaged. Made of gram-negative cell walls.

Exotoxin- secreted by living bacterial cell into the infected tissue. Strong specificity for target cell.

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18
Q

What is a toxoid?

A

An inactivated toxin used in vaccines

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19
Q

What is an antitoxin?

A

An antibody that reacts specifically with a toxin

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20
Q

Exotoxin vs Endotoxin: Toxicity

A

Exo: Toxic in small amounts

Endo: Toxic in higher qualities

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21
Q

Exotoxin vs Endotoxin: Effects on the Body

A

Exo: Specific to cell type (blood, liver, or nerve)

Endo: Systemic and less specific (fever, inflammation, weakness, shock)

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22
Q

Exotoxin vs Endotoxin: Chemical Composition

A

Exo: Small proteins

Endo: Lipopolysaccharide of cell wall

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23
Q

Exotoxin vs Endotoxin: Heat Denaturation @ 60 C

A

Exo: Unstable

Endo: Stable

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24
Q

Exotoxin vs Endotoxin: Toxoid Formation

A

Exo: Can be converted to toxoid

Endo: CAN NOT be converted to toxoid

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25
Exotoxin vs Endotoxin: Immune Response
Exo: Stimulates antitoxins Endo: DOES NOT stimulate antitoxins
26
Exotoxin vs Endotoxin: Fever Stimulation
Exo: Usually Not Endo: Yes
27
Exotoxin vs Endotoxin: Manner of Release
Exo: Secreted from live Endo: Released from cell wall during lysis
28
What are 5 portals of exit for bacteria?
Respiratory tract / salivary glands Skin cells Fecal Matter Urogenital Tract Blood
29
What are true pathogens?
Microbes that are capable of causing disease in a healthy person with normal immune defenses IE/ Influenza virus, plague bacillus, malarial protozoan
30
What are opportunistic pathogens?
Microbes that cause disease when the host's defenses are compromised or when they grow in part of the body that is not natural to them IE/ Pseudomonas sp. or Candida albicans
31
What does the severity of disease depend on?
The virulence of the pathogen Virulence factor - characteristic or structure that contributes to the ability of a microbe to cause disease
32
What are the 4 stages of clinical infections?
1. Incubation Period 2. Prodromal Stage 3. Period of invasion 4. Convalescent period
33
What is the incubation period?
Time from initial contact with the infection agent to the appearance of first symptoms The agent is multiplying, but haven't reached levels to cause symptoms Could be hours to years
34
What is the prodromal stage?
Vague feelings of discomfort, nonspecific complaints
35
What is the period of invasion?
The agent has multiplied to high levels and become well-established Specific signs and symptoms appear
36
What is the convalescent period?
As the person begins to respond to the infection, the symptoms decline or subside
37
What is the difference between a sign and a symptom?
Sign- objective evidence of disease by the OBSERVER Symptom- subjective evidence of disease by the PATIENT
38
What are the earliest symptoms of disease?
The activation of the body defenses Fever, pain, soreness, swelling
39
What are 3 signs of inflammation?
Edema - accumulation of fluid Granulomas and Abscesses - walled off collections of inflammatory cells and microbes Lymphadenitis - swollen lymph nodes
40
What is latency?
After the initial symptoms in certain chronic diseases, the microbe can periodically become active and produce a recurrent disease
41
What is a chronic carrier?
A person with a latent infection who sheds the infectious agent
42
What is sequelae?
Long-term or permanent damage to tissues or organs
43
What is epidemiology?
Study of the frequency and distribution of disease and other health-related factors in defined human populations
44
What is a reservoir? What are the three types?
Primary habitat of pathogen in the natural world Human, animal, non-living
45
What is a carrier?
Individual who inconspicuously shelters a pathogen and spreads it to others
46
What is an asymptomatic carrier?
Someone who shows no symptoms
47
What is a passive carrier?
Contaminated healthcare provider that transfers them to another patient
48
What is an incubation carrier?
A person who spreads the infectious agent during the incubation period
49
What is a convalescent carrier?
When someone recuperates without symptoms
50
What is a chronic carrier?
Individual who shelters the infectious agent for a long period
51
What is a vector?
A live animal (other than a human) that transmits an infectious agent from one host to another Majority are arthropods like fleas, mosquitoes, flies, and tick but it can also be larger animals like birds.
52
What are biological vectors?
Vectors that actively participate in a pathogen's life cycle
53
What are mechanical vectors?
Vectors that are NOT necessary to the life cycle of an infectious agent and merely transports it without being infected
54
What is zoonosis?
Infection indigenous to animals naturally transmissible to humans (dead-end host) At least 150 zoonoses exist worldwide (70% of all new emerging diseases) Impossible to eradicate without eradicating the animal reservoir
55
What are three types of transmission?
Indirect Contact - Respiratory and Fomites Direct Body Contact Vehicle Contact
56
What are the 4 types of vehicle contact?
Fecal-oral route Arthropods Airborne - Droplet Nuclei & Aerosols Food/Water
57
What can be airborne?
Droplet nuclei, aerosols
58
What three things do epidemiologists consider?
Virulence Portals of exit and entry Course of disease
59
What is prevalence?
The total number of existing cases with respect to the entire population. Usually represented by a percentage of the population.
60
What is incidence?
Measures the number of new cases over a certain time period, as compared with the general healthy population.
61
What is the mortality rate? Morbidity rate?
Mortality = the total number of deaths in a population due to a certain disease Morbidity = number of people afflicted with a certain disease
62
What is endemic occurrendce?
Disease that exhibits a relatively steady frequency over a long period of time in a particular geographic locale
63
What is a sporadic occurence?
When occasional cases are reported at irregular intervals
64
What is epidemic occurence?
When prevalence of a disease is increasing beyond what is expected
65
What is pandemic occurence?
an epidemic across continents
66
What are three patterns in outbreaks of epidemics?
Point-source epidemic - from a single source Common-source epidemic - all cases from exposure to the same source Propagated epidemic - sustained increase overtime, meaning it's moving from person to person
67
What do the graph curves look like for each outbreaks of epidemics?
Point-source = 1 big, mountain like triangle Common-source= A large triangle with breaks in between Propagated= A few here and there leading up to a Large triangle
68
What are nosocomial infections?
Aka health-care-associated infections (HAIs) Diseases that are acquired or developed during a hospital stay From surgical procedures, equipment, personnel, and exposure to drug-resistant microorganisms
69
What are the most common nosocomial infections?
Ones that come from surgical incisions and lead to sepsis Respiratory tract and Surgical incisions are most common Then GI tract/diarrhea
70
Resident microorganisms are generally present in sinuses. T/F
False
71
Microbes that do not colonize the human host, but instead are lost rapidly after contact are referred to as
transient
72
The human body usually supports resident biota in which areas?
Tissues with contact to outside Body fluids in exposed body cavities
73
In the human large intestine, the growth of pathogenic bacteria such as Salmonella and Shigella is prevented by the bacterium
E Coli
74
Which of the following indicates a relationship in which resident microorganisms prevent the overgrowth of intruder microorganisms when competing for survival in a common environment?
Microbial antagonism
75
The human microbiome is the collective total of all DNA sequences from the Blank______.
normal resident microbiota
76
The uterus and its contents are Blank______ during embryonic and fetal development.
normally sterile
77
The only areas of the gastrointestinal tract that harbor numerous permanent resident microbes are the Blank______.
large intestine oral cavity rectum
78
Which of the following intestinal microbes is not a member of the coliform group?
Bifidobacterium
79
A broad concept that describes an organism's potential to cause infection or disease is
pathogenicity
80
Name 3 coliforms
Citrobacter Enterobacter Escherichia coli
81
The ability of a particular microbe to establish itself in the host and cause damage determines its
Virulence
82
Any characteristic or structure of a microbe that contributes to an infection or disease state is a(n) ________ factor
Virulence
83
Which two factors determine the virulence of a particular pathogen?
Its ability to cause damage to the host tissues Its ability to establish itself in the host
84
What is the minimum number of microbes that must enter the body to cause infection?
Infectious dose
85
What will happen if the inoculum is less than the infectious dose?
Infection and disease will not occur.
86
When a microbe that is not part of the normal biota enters the body, it is likely to first encounter which type of host defense?
Phagocytes
87
Species of Streptococcus and Staphylococcus produce substances that are toxic to white blood cells which are called
leukocidins
88
The exoenzyme that digests the mucous coating on mucous membranes is called
mucinase
89
The exoenzyme that digests the main protein component in skin and hair is called
keratinase
90
Which exoenzymes is responsible for breaking down the fibers in connective tissue?
Collagenase
91
An enzyme that digests hyaluronic acid, which is the "glue" that holds host cells together, is called
hyaluronidase
92
An exoenzyme that causes the clotting of blood or plasma is called
coagulase
93
The role of streptokinase and staphylokinase is to:
dissolve fibrin clots.
94
Toxins that act on the intestine are called _______ while toxins that act on the kidneys are called _____
enterotoxin, nephrotoxin
95
Which of the following exoenzymes is responsible for digesting the "cement" that holds host cells together?
Hyaluronidase
96
In what 3 ways do exotoxins usually affect host cells?
Disrupting intracellular function Causing lysis of cell Damaging the cell membrane
97
What is a type of bacterial exotoxin that disrupts the cell membrane of red blood cells?
Hemolysin
98
LPS is found in the outer membrane of gram- _______ cells.
negative
99
Endotoxin causes a variety of systemic effects, including ______. (5)
Hemorrhage Diarrhea Fatal shock Fever Inflammation`
100
The death and disintegration of cells and tissues is referred to as ______.
Necrosis
101
Put the stages of infection in order
1. Incubation 2. Prodromal 3. Invasion 4. Convalescent
102
What are the signs and symptoms of inflammation?
Signs: Abscesses Lymphadenitis Edema Symptoms: Pain, Soreness
103
A pathogen is considered unsuccessful if it does not have a specific
portal of exit
104
A protective, nonspecific response to tissue damage is known as
Inflammation
105
An infectious disease that normally occurs in animals but humans can acquire through direct or indirect contact with infected animals is called a(n
zoonosis
106
An infection that occurs primarily when a compromised person is invaded by his or her own microbiota is a(n) ______disease
noncommunicable
107
Which are NOT examples of direct transmission? (3)
Aerosol formation Contaminated vehicles Droplet nuclei
108
Any inanimate object that can serve as a vehicle for the spread of disease when contacted by an infected individual is called a(n)
fomite
109
Which types of transmission involve air as the vehicle? (2)
Aerosols Droplet Nuclei
110
By law, a(n) ________ disease must be brought to the attention of local, district, state or national agencies by medical personnel aware of the condition.
notifiable or reportable
111
The index case is the Blank______.
first case that brings an infection to the attention of medical authorities
112
What did Dr. John Snow do?
proved cholera wasn't spread through "bad air"

Miocrobiology (17 decks)

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