Lecture 7: Infection And Disease

Front 1

Whether or not someone is infected vs. diseased depends on what?

Back 1

The relationship between the host and the parasite.

Front 2

Infection is the ____ or _____ of the body by pathogenic organisms. Who's winning? THe host or the parasite?

Back 2

invasion or colonization of the body by pathogenic organisms. You're winning.

Front 3

DISEASE is any deviation from? Who's winning?

Back 3

the normal healthy state of an organism. Pathogen is winning.

Front 4

A person may be ______ but show no symptoms of ____.

Back 4

infected
disease

Front 5

What is normal flora?

Back 5

normal flora are microorganisms that infect the body without causing disease.

Front 6

Name three places were normal flora can be found.

Back 6

Intestines
Skin
Vagina

Front 7

THe intestines have normal flora that aid in _____ and synthesis of ____.

Back 7

digestion
vitamin K

Front 8

Give examples of the normal flora that exist in intestines.

Back 8

E. coli
Enterobacter, Proteus, Klebsiella, Candida albicans (microorganisms determined by diet)

Front 9

The skin is covered with tons (_#__) of microorganims. What organism can be found on the skin?

Back 9

10^12

Staphylococci

Front 10

What microorganism produces acid through fermentation?

Back 10

Staphylococci

Front 11

Staphylococci, found on the skin, produces acid through fermentation. It helps prevent _____ pathogens from ___

Back 11

acid-hating
colonizing

Front 12

Give an example of a normal flora found on the vagina?

Back 12

Lactobacillus

Front 13

What does lactobacillus feed on?

Back 13

glycogen produced by vaginal epithelium

Front 14

Lactobacillus feeds on glycogen produced by vaginal epithelium. The ___ produced inhibits other microorganisms.

Back 14

acid

Front 15

What are the five steps in the progress of disease?

Back 15

1) Incubation period
2) prodromal
3) Acme
4) Defervescence
5) Convalescence

Front 16

Incubation period

Back 16

timebetween entry of parasite and appearance of symptoms

Front 17

Prodromal

Back 17

host-pathogen battle time.

mild signs or symptoms. This period is characterized by general symptoms such as nausea, fever, headahce, and MALAISE, which indicate that the competition for surpremacy has begun.

Front 18

Acme

Back 18

acute stage of disease (specific symptoms appear).

If pathogen wins, go from prodromal to acme.

Front 19

Defervescence

Back 19

symptoms fade. period of decline.

Front 20

Convalescence

Back 20

body's systems return to normal

Front 21

What is the #1 killer in the world?

Back 21

Acute respiratory diseases: 3.9 million

Front 22

Name some of the most prolific killers in the world.

Back 22

- Acute respiratory diseases
- tropical diseases
- malaria
- childhood diseases
- diarrheal diseases
- HIV/AIDS
- tuberculosis
- other infectious diseases

Front 23

pathogenicity is the ability of a parasite to enter host tissues and cause disease by effecting ____ or ____ change, resulting in altered health and leading to disease

Back 23

physiological
anatomical

Front 24

pathogenicity

Back 24

the ability of a parasite to enter host tissues and cause disease by effecting physiological or anatomical change, resulting in altered health and leading to disease

Front 25

virulence

Back 25

the degree of pathogenicity of a parasite

Front 26

Very pathogenic or really virulent microbes cause serious diseases. Give two microbes that are "highly virulent."

Back 26

Vibrio cholerae (cholera)
Salmonella typhi (typhoid fever)

Front 27

Less pathogenic or moderately virulent cause less serious diseases. Give an example of a moderately virulent microbe.

Back 27

Rhinoviruses (common cold)

Front 28

What kind of microbes do not cause disease?

Back 28

avirulent

Front 29

Avvirulent microbes do not cause disease. They are not pathogenic. MOst organisms have the potential to mutate and become ____

Back 29

virulent

Front 30

_____ microbes only cause disease when host is compromised

Back 30

opportunistic

Front 31

Opportunistic microbes only cause disease when the host is compromised. THey prey on the weak. Give two examples of compromised hosts.

Back 31

HIV/AIDS patients compromised
Young children & babies

Front 32

HIV/AIDS patients are compromised and more susceptible to which two opportunistic microbes?

Back 32

- Pneumocystis jiroveci
- Toxoplasma gondii (cats carry this)

Front 33

Diseases can be transmitted by either direct or indirect methods. Give 3 direct methods.

Back 33

- Close personal contact (contact w/ animals)
- Exchange of bodily fluids
- Direct exposure to airborne droplets(by respiratory droplets)

Front 34

Give 3 indirect methods for transmission of disease.

Back 34

- Ingesting contaminated food/water
- contact w/ fomites (inanimate objects that carry disease organisms. ex: fork, waterbottle)
- Arthropods (flies, mosquitoes)

Front 35

what are fomites?

Back 35

inanimate objects that carry disease organisms. ex: fork, waterbottle

Front 36

Living organims that carry disease agents from one host to another, such as arthropods, are called vectors. What are the two vectors?

Back 36

Mechanical vector (disease on legs of arthropod)

Biological vector (insect is infected)

Front 37

Mechanical vector

Back 37

arthropod passively transports microorganisms on its legs and other body parts.

Front 38

biological vector

Back 38

arthropod itself is diseased

Front 39

For a disease to keep going there must be a continuing source of disease microorganisms in nature. This continuing source of disease microorganisms is called a ____

Back 39

reservoir

Front 40

A reservoir could be a ___, an ____, or a _____

Back 40

thing
animal
person

ex: cats w/ toxoplasmosis

Front 41

A ___ is a special type of reservoir

Back 41

carrier

Front 42

Generally, a carrier is one who has ____ from the disease but _____.

Back 42

recovered
continues to shed the disease agents

Front 43

Give an example of a carrier, a special type of reservoir.

Back 43

Typhoid Mary
She didn't know she carried typhoid fever. was a cook. whole family that she served got it.

- ppl who have recovered from typhoid fever become carriers for many weeks after the symptoms of disease have left. Their feces may spread the disease to others via contaminated food or water.

Front 44

Give an example of a carrier, a special type of reservoir.

Back 44

Typhoid Mary
She didn't know she carried typhoid fever. was a cook. whole family that she served got it.

- ppl who have recovered from typhoid fever become carriers for many weeks after the symptoms of disease have left. Their feces may spread the disease to others via contaminated food or water.

Front 45

What is the field of science that evaluates origin, cause, spread, and control of disease?

Back 45

epidemiology

Front 46

endemic disease

Back 46

steady frequency of a disease in a particular area

An endemic disease is one that occurs at a low level in a certain geographic area.

Front 47

epidemic disease

Back 47

sudden, high incidence of a disease. outbreak is a contained epidemic.

An epidemic disease breaks out in explosive proportions within a population. Influenza often causes epidemics. This should be contrasted with an outbreak, which is a more contained epidemic. An abnormally high # of measles cases in one US city would be classified as an outbreak.

Front 48

Pandemic dsease

Back 48

world epidemic. ex: AIDS

Front 49

Morbidity

Back 49

measure of those who GET a particular disease.

total # of ill people/total # of people

Front 50

What is the fraction for morbidity?

Back 50

total # of ill people/total # of people

Front 51

mortality

Back 51

measure of those who DIE from a particular disease

total # of deaths/ # of ill ppl

Front 52

Describe chickenpox in terms of morbidity and mortality

Back 52

chicken pox: high morbidity, low mortality

Front 53

Describe AIDS in terms of morbidity and mortality.

Back 53

AIDS: low morbidity, high mortality

Front 54

What is the difference between morbidity and mortality?

Back 54

morbidity= get a disease
mortality= die from a disease

Front 55

Establishment of disease. What is different with each sisease?

Back 55

portal of entry

Front 56

Tetanus occurs only when anaerobic ____ is introduced into a deep puncture wound.

Back 56

Clostridium tetani

Front 57

Why don't ingested spores cause disease?

Back 57

stomach nis not a portal of entry. For example, it needs to be a deep puncture wound for tetanus to occur. But even if microbe finds right portal, proliferation may take time.

Front 58

What are the five steps to establishment of disease?

Back 58

dose
entry
target
damage
exit

Front 59

dose

Back 59

An infectious dose of microorganisms penetrates the host's defensive barrier. need a certain # of organisms to cause disease.

Front 60

entry

Back 60

microorganisms enter the sterile environment of the host's tissues through portal of entry.

Front 61

target

Back 61

microorganisms move into a specific target tissue, such as an organ.

Front 62

damage

Back 62

after moving into an organ, they cause tissue damage, leading to disease

Front 63

exit

Back 63

microorganisms leave the host through a portal of exit to infect another host.

Front 64

Name two factors that establish a disease

Back 64

dose
tissue penetration

Front 65

dose is the # of ______ to establish disease

Back 65

parasites needed

Front 66

dose is the number of parasites needed to establish disease. A little (few hundred thousand) of _____

Back 66

Mycobacterium tuberculosis

Front 67

dose is the number of paraistes needed to establish disease. A lot (millions) of ____

Back 67

vibrio cholerae

Front 68

Tissue penetration. Pathogens are more invasive. Genes for cell penetration exist on the chromosome of certain bacteria. These gense appear to code for surface proteins that assist penetration. Pathogens use their invasive tendencies to gain access to privvileged niches denied to nonpathogens. For example, pathogenic ______ enetrates to sites in the small intestine that are not available to other ____.

Back 68

E. coli O157:H7
E. coli

Front 69

There are other mechanisms that tissue penetration. ______ remains on the surface and makes _____.

Back 69

Bordetella pertussis

toxins

Bordetella pertussis forms pseudomembrane, blocks airway, produces whooping cough

Front 70

Adhesion allows ____ of pathogens on the right tissue

Back 70

localization

Front 71

Adhesion is mediated by proteins called ___.

Back 71

adhesins

Front 72

adhesins are ___, which are usually found on: ____, ____, ____

Back 72

proteins

- outer surface of bacterial cell wall or mycoplasma membrane (M protein of Streptococcus)
- fimbrae or pili
- flagella

Front 73

Give an example of an adhesin that is found on the outer surface of a bacterial cell wall or mycoplasma membrane

Back 73

M protein of Streptococcus

Front 74

What are two methods that allow for cell internalization, the ability to be taken up by host cell?

Back 74

- Phagocytic host cells (bacteria gets eaten)

- Bacterial-induced endocytosis (pathogen goes to human host, which will think its food, internalize it through endocytosis)

Front 75

Cell-to-Cell Transport. What two organisms can use the host cell's actin for cell-to-cell invasion?

Back 75

Listeria
Shigella

Front 76

Listeria and Shigella use host cell's actin to move through host cytoplasm. These pathogens synthesize an ___ that propels the organism through the cell's cytoplasm.

Back 76

actin tail

Front 77

How do the listeria and shigella that form actin tails get to the next host?

Back 77

Cadherin bridge junction

Front 78

Cell-to-cell transport allows bacterial invasion to occur without the bacteria ____.

Back 78

leaving the cellular environment.

Bacterial invasion in the comfort of infected host cell.

avoid immune system.

Front 79

virulence, or _______, encode proteins involved in penetration, adhesion, internalization, or cell-to-cell transport.

Back 79

pathogenicity genes

Front 80

Virulence or pathogenicity genes encode protiens involved in ____, ____, _____, or _____.

Back 80

penetration
adhesion
internalization
cell-to-cell transport

Front 81

What's the term for genes that are clustered in a pathogen's chromosome?

Back 81

pathogenicity islands

Front 82

Pathogenicity islands

Back 82

genes are clustered in pathogen's chromosome. The cluster of genes responsible for virulence. These blocs of genetic information could move from a pathogenic strain into an avirulent organism, converting it to a pathogen.

Front 83

Expression of genes takes place only if?

Back 83

there are a sufficient number of pathogens present

Front 84

What is quorum sensing?

Back 84

Turning on virulence factor only if enough "buddies" (pathogens) around. can sense buddies by chemical messenger.

Front 85

What is the mechanism of quorum sensing?

Back 85

pathogens secrete homoserine lactone (messenger)

Front 86

What do the pathogens in quorum sensing secrete as a messenger?

Back 86

homoserine lactone

Front 87

What happens when there is a lot of homoserine lactone secreted?

Back 87

When critical level of homoserine lactone is high enough, corresponding to having enough pathogens), virulence genes are expressed.

Front 88

The virulence of a parasite depends to some degree on its ability to produce a series of extracellular _____ that hep the pathogen resist body defenses.

Back 88

enzymes

The enzymes act on host cells and interfere with certain functions or barriers meant to retard invasion.

Front 89

What is the source of coagulase?

Back 89

staphylococci

Front 90

What is the action and effect of caogulase?

Back 90

action: forms a fibrin clot
effect: allows resistance to phagocytosis

Front 91

What is the source of streptokinase?

Back 91

Streptococci

Front 92

What is the action and effect of streptokinase?

Back 92

action: dissolves a fibrin clot.

effect: prevents isolation of infection

Front 93

What is the source of hyaluronidase?

Back 93

Pneumococci
Streptococci
Staphylococci

Front 94

What is the action and effect of Hyaluronidase?

Back 94

action: digests hyaluronic acid

effect: allows tissue penetration

Front 95

What is the source of leukocidin?

Back 95

Staphylococci
Streptococci
Certain rods

Front 96

What is the action and effect of leukocidin?

Back 96

action: disintegrates phagocytes

effect: limits phagocytosis

Front 97

What is the source of hemolysins?

Back 97

clostridia
Staphylococci

Front 98

What is the action and effect of hemolysins?

Back 98

action: dissolves red blood cells

effect: induces anemia and limits oxygen delivery

Front 99

Pathogenicity can also depend on ____ or ____ produced by pathogenic microorganisms.

Back 99

poisons or toxins

Front 100

EXOTOXINS. Proteins from Gram-______ bacteria released into environment--gets into ______ and _____.

Back 100

positive

blood and cirulation

*Exotoxins are target-cell specific- neurotoxin, enterotoxin

Front 101

ENDOTOXINS. Gram-_____ cell wall component that is relased upon disintegration of bacteria. Lipid of ____ of the outermembrane is the endotoxin.

Back 101

negative

LPS (lipopolysaccharide)

Front 102

EXOTOXINS.
Source?
Location in bacterium?
Chemical composition?

Back 102

Gram-positive

cytoplasm

protein

Front 103

EXOTOXINS.

Antibodies elicited?
Conversion to toxoid?
Liberation of toxin?

Back 103

Yes

Possible

On production by the cell

Front 104

EXOTOXINS.

Representative effects?

Back 104

Interfere with synaptic activity
Interrupt protein synthesis
Increase capillary permeability
Increase water elimination

Front 105

ENDOTOXINS.
Source?
Location in bacterium?
Chemical composition?

Back 105

Gram-negative bacteria
Cell wall
Lipid-polysaccharide-peptide

Front 106

ENDOTOXINS.
Antibodies elicited?
Conversion to toxoid?
Liberation of toxin?

Back 106

No
Not possible
On disintegration of the cell

Front 107

ENDOTOXINS.
Representative effects?

Back 107

Increase body temperature
Increase hemorrhaging
Increase swelling in tissues
Induce vomiting, diarrhea