Micro 116 Test 3

Front 1

Host

Back 1

Organism which provides nutrients to another organism.

Front 2

Parasite

Back 2

Organism which lives at the expense of its host.
Parasite is smaller than host and is metabolically dependent upon it.

Front 3

Disease

Back 3

An upset in the homeostasis of the host resulting in generation of observable changes. (Signs & Symptoms)

Front 4

Sign

Symptom
Which is objective, subjective?

Back 4

Sign is objective evidence of damage to the host. (HA)
Symptom is subjective evidence of damage to the host. (fever, rash)

Front 5

Infectious disease

Back 5

One in which detrimental changes in health of the host occur as a result of damage caused by the parasite.

Front 6

Pathogen

Back 6

Microorganism that is capable of causing disease.

Front 7

Virulence

Back 7

A measure of pathogenicity, or the ability to cause disease.

Front 8

Virulent

Back 8

Microorganisms that readily cause disease.

(only small #'s of the microbe are needed to initiate and sustain infection.)

Front 9

Opportunistic

Back 9

Microorganisms that may or may not cause disease.
Generally colonize but do not infect the host when usually found associated with the host (called normal microbiota).
Can cause disease if they are introduced to a site where they do not usually reside, especially inside host tissues.

Front 10

Avirulent

Back 10

microorganisms that do NOT cause disease.

Front 11

Attenuated

Back 11

microorganisms with reduced ability to cause disease. Human generated.
Vaccines! (takes microbes and select virulence for vaccines.

Front 12

Pathogenicity

Back 12

Ability or tendency of a microbe to cause disease.

Front 13

Koch's Postulates

Back 13

1. Present (in every case but absent from healthy host)
2. Isolated (grown in pure culture)
3. Cause (able to cause disease when a pure culture is innoculated into a healthy host.)
4. re-isolated (from the host that was inoculated w/ the pure culture.
**this is not possible in opportunistic disease.
*** Also, NOT possible w/ viruses b/c cant culture on a petri dish.

Front 14

To cause disease, a pathogen Must:

Back 14

1. Contact (the host)
2. Colonize (adhere & grow or multiply on host)
3. Infect (proliferate in host cells or tissues)
4. Evade (avoid the hosts defense system)
5. Damage (the host by chemical or physical means)

Front 15

virulence factors

Back 15

resp. for the pathogenecity of a microorganism b/c they influence its ability to cause disease by affecting its invasiveness and /or its toxigenicity.

Front 16

Pathogen

Back 16

a microbe that causes disease and highly virulent pathogens are more likely to cause disease.
(depends on toxigenicity)

Front 17

Factors responsible for pathogenicity (5)

Back 17

1. Adhesins
2. Invasins
3. Evasins
4.Toxins

Front 18

Adhesions

Back 18

Adhesins promote attachment to host cells and tissues, which allows bacteria to contact and colonize host surfaces.
ex) pili, capsules, type III secretion, hemagglutinins, hyphal tips

Front 19

Invasins

Back 19

Invasins promote entrance into and or movement thru tissues or cells, which allows bacteria to infect the host.
ex) digestive enzymes, fibrinolysin, hyaluronidase, hemolysins, type III secretion sys, hyphal extension

Front 20

Evasins

Back 20

Evasins protect pathogen from host defense factors, especially phagocytes, which allows bacteria to evade the host defense system and makes it more possible for them to grow w/in the tissues.
ex) capsules, hyphae, catalase, coagulase, M protein, leukocidins, anti-phagosomal factors, immune system blockades.

Front 21

Toxins

Back 21

Toxins are a general category that includes any molecule that can promote damage to the cells or tissues of the host caused, in this case by bacteria.
2 types: Endotoxins and Exotoxins

Front 22

Exotoxins

Back 22

toxic proteins that are secreted by living microbes.

Front 23

Endotoxins

Back 23

Lipopolysaccharide (LPS) portion of the outer membrane of gram neg bacterial cell walls which is released when the bacteria disintegrate and causes fever and/or endotoxin shock, depending on its concentration in the bloodstream.

Front 24

Damage caused by viruses

Back 24

1. Lytic infections
2. Persistent Infections
3. Latent Infections
4. Transformation (benign and malignant tumors)

Front 25

Benign tumor

Back 25

Noninvasive (enclosed in capsule of host tissue and does not spread to other tissues.

Front 26

Malignant (Metastatic) tumor

Back 26

Invasive (tumor cells spread to other tissues and proliferates there and spreads throughout the body)

Front 27

Epidemiology

Back 27

the study of the occurrence of disease, and deals specifically with studying the cause of diseases and how infectious diseases are spread from person to person (transmission).

Front 28

Epidemic

Back 28

"upon the people" commonly refers to unusually high incidence of a disease in a community (population) at one time.

Front 29

Prevalence

Back 29

the total number of cases in a population at a given time.

Front 30

Incidence

Back 30

the number of new cases in a population at one time.

Front 31

Who is the father of epidemiology?

Back 31

John Snow (looked for commonalities in an epidemic.)

Front 32

Pandemic

Back 32

"all the people" indicates an epidemic involving more than one continent or a worldwide epidemic.

Front 33

Endemic

Back 33

"in the people" a disease is constantly present, usually at low incidence in a population.

Front 34

Outbreak

Back 34

appearance of several cases of a disease usually in a short period of time, in an area previously experiencing no cases or only sporadic (scattered or isolated) cases of the disease. ("mini" epidemic)

Front 35

Morbidity

Back 35

disease, sickness, clinical illness

Front 36

mortality

Back 36

death

Front 37

reservoir

Back 37

a site in which infectious agents remain viable (alive) and from which infection of individuals may occur.

Front 38

Carrier

Back 38

an infected individual which is not showing obvious signs or symptoms of clinical disease, but which is shedding the etiologic agent for a long period of time (greater than six months)

Front 39

Zoonoses

Back 39

diseases which occur primarily in animals but are occasionally transmitted to people (plague, Lyme disease, rocky mountain spotted fever)

Front 40

Vector

Back 40

Living agent which transmits infectious agent (tick, flea, fly, mosquito)

Front 41

Fomite

Back 41

NON-Living abject that transmits infectious agents (pencil, doorknob)

Front 42

Vehicles

Back 42

Food, water and air that can transmit infectious disease.

Front 43

Stages in Transmission of Infectious Diseases

Back 43

1. Escape from old host
2. Travel to new host
3. Entry to new host

Front 44

Modes of Transmission of Infectious Diseases

Back 44

1. Direct (close or intimate contact)
Ex) sex, shaking hands
2. Indirect (from fomites or vectors!)