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Microbiology > Microbial Interactions with Humans > Flashcards

Microbial Interactions with Humans Flashcards

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1
Q

What are the 8 sites known to host a microbiome

A
  1. Skin and adjacent mucous membranes
  2. Upper respiratory tract
  3. Gastrointestinal tract (including mouth)
  4. Outer portion of urethra
  5. External genitalia
  6. Vagina
  7. External ear canal
  8. External eye (lids, conjunctiva)
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2
Q

What are the 6 newly discovered sites that host a microbiome?

A
  1. Lungs (lower respiratory tract)
  2. Bladder (and urine)
  3. Breast and breast milk
  4. Amniotic fluid and fetus
  5. Brain (DNA detected)
  6. Bloodstream (DNA detected)
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3
Q

What are the sites that only DNA has been detected?

A

Brain, Bloodstream

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4
Q

What is virulence?

A

The relative severity of a disease caused by a particular microbe

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5
Q

What are the 5 steps of infection?

A
  1. Portal of entry
  2. Attachment interactions
  3. Surviving host defense
  4. Damaging the host/causing disease
  5. Exiting the host
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6
Q

Describe the Portal of entry step

A

The route that a microbe takes to enter the tissues of the body to initiate an infection.
: Through mucous membrane, skin, parenteral route

Exogenous - Organisms coming from OUTSIDE the body

Endogenous - Organisms coming from somewhere in the same human

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7
Q

Describe the Attachment interactions step

A

Use ADHESION which is a process which microbes gain a more stable foothold on host tissues.

Bacterial, fungal and protozoal pathogens attach most often through fimbrae, surface proteins and adhesive slimes or capsules.

Viruses attach by specialized receptors

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8
Q

Explain the surviving host defenses step

A

Antiphagocytic factors are used by some pathogens to avoid phagocytes (white blood cells)

Some like Streptococcus and Staphylococcus produce leukocidins which are toxic to WBC

OR some microbes secrete a capsule or slime layer to prevent being engulfed

or they can survive within the WBC

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9
Q

What are the 3 ways a microbe can damage their host?

A
  1. Directly through the action of enzymes or toxins (both endo and exotoxins)
    - Microbial enzymes and exo- endotoxins disrupt host cell structure or connections between host cells.
  2. Indirectly by inducing the hosts defenses to respond excessively or inappropriately
  3. Epigenetic changes made to host cells by microbe (such as histones, altering the host genes that are expressed)
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10
Q

What are exotoxins and what do they cause?

A

They’re secreted proteins that are the most potent toxins produced by microbes

Damaging the cell membrane and causing lysis or disrupting intracellular function.

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11
Q

Describe the exiting the host step

A

Pathogens depart through the portal of exit

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12
Q

What do exoenzymes do?

A

They break down and inflict damage on tissues, other enzymes dissolve the host’s defense barriers and promote the spread or microbes to deeper tissues.

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13
Q

What are enterotoxins?

A

Bacterial toxins that affect the GI tract (small intestine)

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14
Q

What are endotoxins

A

Also lipopolysaccharides (LPS) on gram-negative bacteria, initiates a host inflammatory response cause fever, diarrhea, decreased number of immune cells

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15
Q

What is an infectious dose?

A

The minimum number of microbes necessary to cause an infection to proceed.

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16
Q

Whats the 7 difference between exotoxins and endotoxins

A

Exotoxins -

  1. Proteins from gram + and -, toxic in small amounts
  2. SPECIFIC mode of action (binds to a specific cell receptors or structures)
  3. HIGHLY toxic
  4. Can be converted to a toxoid: FORMALDEHYDE will DESTROY toxicity
  5. Can be killed by antitoxins
  6. Does NOT cause Fever
  7. unstable

Endotoxins -

  1. LPS only on Gram -, released on cell lysis
  2. GENERAL/SYSTEMIC : fever, diarrhea, vomiting
  3. RARELY fatal
  4. Immune réponse not sufficient to neutralize toxin
  5. No toxoid potential
  6. INDUCES fever in host
  7. stable
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17
Q

What is a toxoid?

A

a chemically modified toxin from a pathogenic microorganism, which is no longer toxic but is still antigenic and can be used as a vaccine.

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18
Q

What are the 4 cardinal signs of inflammation?

A
  1. Redness (blood flow to an area)
  2. Pain
  3. Heat (local area, fever)
  4. Swelling
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19
Q

What is a reservoir?

A

The primary habitat in the natural world where a pathogen makes its home

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20
Q

What are examples of reservoirs?

A

Living:
Animals, humans (carriers),
Arthropods

Nonliving: 
Soil 
Air 
Water 
The built environment
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21
Q

When is a host communicable?

A

When an infected host can transmit the infectious agent to another host and establish infection in that host.

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22
Q

What does it mean for an agent to be contagious?

A

Highly communicable , especially through direct contact

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23
Q

What does it mean for an agent to be noncommunicable?

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A

When an infectious disease does not arise through transmission of the infectious agent from host to host.

When a compromised person is invaded by his or her own microbiota (EAR INFECTION). Or when a person gets in contact with a nonliving resivoir.(MYCOSES)

24
Q

What are the 5 different patterns of transmission?

Study These Flashcards
A
  1. Vertical
  2. Horizontal
  3. Indirect
  4. Direct
  5. Vector/Vehicle
25
Define Vertical transmission
Transmission is from parent to offspring via the ovum, sperm, placenta, or milk
26
Define horizontal transmission
Disease is spread through a population from one infected individual to another
27
Define direct horizontal transmission
Involves very close proximity or actual physical contact between two hosts
28
Define indirect horizontal transmission
Infectious agent must pass from an infected host to an intermediate conveyor (a VEHICLE which is a nonliving material) from there to another host. EX: doorknobs, water, air, soil, food
29
Describe the two vector transmission Vectors are living Vehicles are nonliving Fomite is an inanimate object
Mechanical vector - insect carry microbes to host in its body parts Biological vector - insects INJECTS microbes into host ; part of microbe life cycle completed in insect . The microbe lives and multiples within the insect.
30
What is prevalence and Incidence of disease?
Prevalence - total number of existing cases in a given population Incidence - the number of new cases over a certain time period
31
What is Ro?
Reproduction rate , how many people will 1 person infect?
32
The Case fatalility rate is
the number of people who die from the disease, the higher the number the more deadly you know the disease is
33
Why are reportable disease important?
They help districts etc keep track of the diseases out there
34
What are some of the reportable diseases?
Anthrax, leprosy, smallpox, syphilllus, TB, Lyme disease, zika virus, yellow fever
35
An adaptive response in which microorganisms begin to tolerate an amount of drug that would ordinarily be inhibitory is called drug ______.
resistance
36
Drug resistance arises when ______.
- an organism gains the genetic information for resistance from another organism - a spontaneous mutation occurs in the organism's DNA code
37
Drugs can be identified from noncultivable bacteria by ______.
harvesting antibiotics directly from soil
38
What are the advantages to the consumption of probiotics?
- They can be helpful for managing food allergies. | - They are safe to consume.
39
What are the categories of major drug side effects?
- Allergic reactions - Toxic damage to tissue - Normal flora disruption
40
Summarize the problems that have led to the worldwide problem of managing antimicrobial drugs.
increase in superinfections physicians use a "shotgun" approach to treat minor infections development of resistance in "bystander" microbes
41
One consequence of widespread use of ______-spectrum antibiotics is the development of resistance in ______ microbes that are part of the normal biota.
broad ; bystander
42
The human body typically begins to be colonized by its normal biota _______.
before birth
43
Resident biota are found in/on the ________.
skin , mouth , nasal passages, large intestine
44
The effect of "good" microbes against invading microbes is called _______.
microbial antagonism
45
Microbial hyaluronidase, coagulase, and streptokinase are examples of _______.
exoenzymes
46
What are the stages of an infection?
Incubation period - the time the initial contact with the infectious agent Prodromal stage - general symptoms such as fatigue and muscle aches Acute phase (Height of infection) - marked by fever Convalescent period - symptoms decline, patients strength and health gradually return Continuation period - only some infections have this phase. The organisms lingers within the patient or the organism is gone but symptoms continue.
47
The objective, measurable evidence of disease evaluated by an observer is termed a(n) _______.
sign
48
The subjective evidence of disease sensed by the patient is termed a(n) _______.
symptom
49
Long-term or permanent damage to tissues or organs resulting from a specific disease are called _______.
sequelae Meningitis: deafness Strep throat : rheumatic heart disease Lyme disease: arthritis Polio: paralysis
50
What is latency?
A dormant state of microbes in certain chronic infectious diseases
51
A _______ is the presence of small numbers of bacteria in the blood bu not multiplying.
bacteremia
52
A _______ is an infection indigenous to animals that can, on occasion, be transmitted to humans.
zoonosis
53
_______ carriers are shedding and transmitting pathogens while they are recovering from an infectious disease.
Convalescent
54
The study of the frequency and distribution of a disease in a defined population is _______.
epidemiology
55
The principal government agency responsible for tracking infectious diseases in the United States is the ________.
Centers for Disease Control and Prevention
56
The number of persons afflicted with an infectious disease is the _______ rate.
morbidity
57
Ninety people developed diarrhea, fever. and abdominal cramps in the aftermath of a wedding. On diagnosis it was determined that they were suffering from salmonella, and after taking their histories, they all reported that they had eaten the chicken at the reception. This is an example of ________
point-source epidemic

Microbiology (13 decks)

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