Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > Lecture 11: Pathogenicity & Epidemiology > Flashcards

Lecture 11: Pathogenicity & Epidemiology Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is the ability to cause disease

A

Pathogenicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the extent of pathogeniciy?

A

Virulence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the virulence factors?

A

adhesion factors
extracellular enzymes
toxins
antiphagocytic factors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the exo enzymes/ secreted enzymes?

A

Coagulase: coagulate blood

Kinases: Digest fibrin clots

Hyaluronidase: Hydrolyses hyaluronic acid

Collagenase: Hydrolyzes collagen

IgA proteases: destroy IgA antibodies

Siderophores: take iron from host iron-binding proteins

Antigenic variation: alter surface proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the adhesion factors on microbes?

A

Surface lipoproteins or glycoproteins called ligands bind to receptors on host cells

Ability to change or block the ligand or its receptor can prevent infection

Inability to make attachment proteins or adhesions renders the microorganisms avirulent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are substances that contribute to pathogenicity?

A

Toxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Ability to produce a toxin

A

Toxigeniciity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Presences of toxin the host’s blood

A

Toxemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Inactivated toxin used in a vaccine

A

Toxoid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Antibodies against a specific toxin

A

Antitoxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the characteristics of exotoxins that are extracellular and secretal?

A

Source: mostly Gram+

Metabolic product: by-products of growing cell

Chemistry: protein

Fever?: No

Neutralized by antitotoxin: yes

LD50: Small

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where are exotoxins produced?

A

Inside mostly gram-positive bacteria as part of their growth and metabolism.

They are then secreted or released following lysis into the surrounding medium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Type I, type II, and type III toxins

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Explain type 1 toxins: superantigens

A

Cause an intense immune response due to (overhwelming amount of) cytokine released by hosts

Fever, nausea, vomiting, diarrhea, shock, death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Explain II toxins

A

Membrane-disrupting toxins

Lyse host’s cells:
Makes protein channels in the plasma membrane (eg leukocidins, hemolysins)

Disrupts phospholipid bilayer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Explain III A-B toxins

A
  1. Bacterium produces and releases exotoxin
  2. B (binding) component of exotoxin binds to host cell receptor and exotoxin enters cell
  3. A (active) component of exotoxin alters cell function by inhibiting protein synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe endotoxins characteristics

A

Source: Gram negative

Metabolic product: present in LPS of outer membrane

Chemistry: Lipid A

Fever?: Yes

Neutralized by antitoxin: no

LD50: relatively large

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe endotoxins

A

Endotoxins are part of the outer portion of the cell wall of gram-negative bacteria. They are liberated when the bacteria die and the cell wall breaks apart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe antiphagocytic factors

A

Certain factors prevent phagocytosis by the host’s phagocytic cells

-Bacterial capsule: composed of same chemicals found in host’s body
-Slippery - difficult for phagocytes to engulf the bacteria

-Antiphagocytic chemicals
-some prevent fusion of lysosome and [phagocytic vesicles
-Leukocidins directly destroy phagocytic white blood cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the cytopathic effects of viruses?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Pathogenic properties of fungi

A

Fungal waste products may cause symptoms

Chronic infections provoke an allergic response

some fungi have toxins called mycotoxins

can also have capsule that prevents phagocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Pathogenic properties of protozoa

A

presence of protozoa

protozoan waste products may cause symptoms

avoid host defenses by
-growing in phagocytes
-antigenic variation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Pathogenic properties of helminths (parasites0

A

use host tissue
presence of parasite interferes with host function
parasites metabolic waste can cause symtoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Principles of epidemiology

A

Pathology: study of disease

Etiology: study of the cause of a disease

-Pathogenesis: development of disease
-Infection: colonization of the body by pathogens
-Disease: an abnormal state in which the body is not functionally normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Pathogenic properties of algae

A

neurotoxins produced by dinoflagellates
-saxitoxin
- paralytic shellfish poisoning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Normal microbiota or macrobiota

A

permanently colonize the host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Mechanisms of pathogenicity (chart)

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Transient microbiota

A

present for hours, days, weeks, or months
-cannot persist in the body
-competition from other microorganism
-elimination by the body’s defenses cells
-chemical or physical changes in the body

can’t colonize in the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Symbiosis

A

close, long-termed reactions between two organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Commensalism

A

one organism is benefited and the other is unaffected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Mutualism

A

both organisms benefit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Parasitism

A

one organism is benefited at the expense of the other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Relationship between normal microbiota and the host is an example of?

A

Mutualism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Probiotics

A

Living microbes applies to or ingested into the body intended to exert a beneficial effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Normal microbiota and the host

A

Normal microbiota protect the host by:
-occupying niches that pathogens might occupy
-producing acids
-producing bacteriocins

Some normal microbiota are opportunistic pathogens

33
Q

Microbial antagonism

A

Competition between microbes

33
Q

Contamination vs infection

A

Contamination- mere presence of microbes in or on the body

Infection - an organism has evaded the body’s external defenses, multiplied, and become established in the body

34
Q

Resident/normal/ permanent microbiota

A

see chart

34
Q

Portals of entry

A

Sites through which pathogens enter the body

-skin (broken)
-mucous membranes (nose, eyes, ears, mouth, vagina, anus, penus, urethra)
-placenta
-parenteral route (insect bite, injection, needle)

34
Q

Locations of normal microbiota in humans

A

chart

When does a person acquire normal flora?
-essentially through birth
-food, people, environment - mature normal flora

How does a bacteria attach itself to the host?
-Capsule, fimbriae, etc.,

35
Q

Opportunistic pathogens

A

Normal microbiota that can cause disease under certain circumstances

Conditions that provide opportunities for pathogens
-immune suppression
-Changes in the normal microbiota- changes in the relative abundance of normal microbiota may allow opportunity for a member to thrive and cause disease
-introduction of normal microbiota into unusual site in the body

36
Q

Skin

A

outer layer of packed, dead, skin cells

usually a barrier to pathogens

pathogens can enter
-through opening or cuts
-some can burrow into or digest the outer layers of skin

37
Q

Parenteral route

A

not a true portal of entry, since its via injection or insertion

pathogens deposited directly into tissues beneath the skin or mucous membranes

37
Q

Mucous membrane

A

line the body cavities that are open to the environment

provides a moist, warm environment

respiratory tract is the most commonly used site of entry
- entry is through the nose, mouth or eyes

gastrointestinal tract
- pathogens must be able to survive the acidic pH of the stomach

38
Q

Pathogenic organisms

A

portal of entry

attachment or adhesion to cause infection
- bacteria viruses, and protozoa (parasites)

Infection - the invasion of the host by a pathogen

Disease - results only if the invading pathogen alters the normal functions of the body, also referred to as morbidity

39
Q

Koch’s postulates

A

see chart

used to prove the cause of an infectious disease

40
Q

Sign

A

a change in a body that can be measured or observed as a result of disease

41
Q

Exceptions to Koch’s postulates

A
41
Q

Classifying infectious diseases

A
42
Q

Symptom

A

a change in body function that is felt by a patient as a result of disease

43
Q

Syndrome

A

a specific group of signs and symptoms tha accompany a disease

44
Q

Communicable disease

A

a disease that is spread form one host to another (also contains contagious disease)

45
Q

Contagious disease

A

a communicable disease that is easily spread

46
Q

Non-communicable disease

A

a disease that is not transmitted from one host to another

47
Q

Severity of duration of a disease

Acute disease

A

symptoms develop rapidly

48
Q

Severity of duration of a disease

Chronic disease

A

disease develops slowly

49
Q

Severity of duration of a disease

Subacute disease

A

Symptoms between acute and chronic

50
Q

Severity of duration of a disease

Latent disease

A

disease with a period of no symptoms when the patient is inactive

51
Q

Extent of host’s involvement:

Local infection

A

pathogens limited to a small area of the body

51
Q

Extent of host’s involvement:

Systemic infection

A

an infection throughout the body

52
Q

Extent of host’s involvement:

Focal infection

A

Systemic infection that began as a local infection

53
Q

Extent of host’s involvement:

Bacteremia

A

Bacteria in the blood

54
Q

Extent of host’s involvement:

Septiicemia

A

Growth of bacteria in the blood

55
Q

Extent of host’s involvement:

Toxemia

A

toxins in the blood

56
Q

Extent of host’s involvement:

Viremia

A

viruses in the blood

57
Q

Extent of host’s involvement:

Primary infection

A

acute infection that causes the initial illness

58
Q

Stages of infections

A

following infection, sequence of events called the disease process occurs

Many infectious diseases have five stages following infection:

  1. Incubation period: no signs or symptoms
  2. Prodromal period: vague, general symptoms
  3. Illness: most severe signs and symptoms
  4. Decline: declining signs and symptoms
  5. Convalescence: no signs or symptoms
58
Q

Extent of host’s involvement:

Subclinical disease

A

No noticeable signs or symptoms (inapparent infection)

58
Q

Extent of host’s involvement:

Secondary infection

A

Opportunistic infection after a primary (predisposing) infection

59
Q

Predisposing factors

A

Make the body more susceptible to disease
-inherited traits such as the sickle-cell gene
-climate and weather
-fatigue
-age
-lifestyle
-male/female - short urethra in females
-chemotherapy

60
Q

Movement of the pathogens out of the host

A

Pathogens leave host through portals of exit

see chart

61
Q

Reservoirs of infections

A

continual sources of infection

humans: carriers may have inapparent infections or latent diseases

animals: some zoonoses may be transmitted to humans

nonliving things (soil)

62
Q

Transmission of disease: contact

A

Directo contact: close association between infection and susceptible host

Indirect contact: spread\ by fomites (touching surface that is contaminated)
- or droplet transmission via airborne droplets

63
Q

Relative frequency of nosomial infections

A

see pie chart

63
Q

Nosocomial infections

A

Are acquired as a result of a hospital stay

5-15% of all hospital patients acquire nosocomial infections

see chart

63
Q

Transmission of diseases: vehicle and vector

A

Vehicles: transmission by an inanimate reservoir (food, water)

Vectors: arthropods, especially fleas, ticks, and mosquitoes
- Mechanical arthropod carries pathogen on feet
-Biological pathogen reproduces in vector (intermediate hosts)

63
Q

Transmission of disease

A

see chart

64
Q

Occurrence of disease:

Prevalence

A

Fraction of a population having a specific disease at a given time

64
Q

Epidemology

A

The study of where and when diseases occur and how they are transmitted in a population

64
Q

Emerging new diseases and contributing factors

A
65
Q

Occurrence of disease:

Incidence

A

fraction of a population that contracts a disease during a specific time period

66
Q

Occurrence of disease:

Pandemic disease

A

worldwide epidemic -

disease that occur in a large area and also occur occasionally

66
Q
A
67
Q

Occurrence of disease:

Epidemic disease

A

disease that occur in a large area and also occur occasionally

67
Q

Occurrence of disease:

Sporadic disease

A

disease that occurs occasionally in a population

68
Q

Occurrence of disease:

Endemic disease

A

Disease constantly present in a population

Disease acquired by many hosts in a given area in a short time

68
Q
A

Microbiology (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions