Microbiology: Ch. 13

Front 1

microbes that engage in mutual or commensal associations

Back 1

normal (resident) flora, indigenous flora, microbiota

Front 2

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

Back 2

infection

Front 3

any deviation from health, disruption of a tissue or organ

Back 3

disease

Front 4

disease caused by microbes or their products

Back 4

infectious disease

Front 5

Which areas of the body harbor resident microbes?

Back 5

most areas of the body that are in contact with the outside environment

Front 6

Which organ has the highest numbers of bacteria?

Back 6

large intestine

Front 7

Which parts of the body are microbe-free?

Back 7

internal organs, tissues, and fluids

Front 8

bacterial flora benefiting the host by preventing overgrowth of harmful microbes

Back 8

microbial antagonism

Front 9

At what point is an infant introduced to normal flora at which point initial colonization occurs?

Back 9

after the breaking of the fetal membrane; uterus and contents are normally sterile and remain so until just before birth

Front 10

capable of causing disease in healthy persons with normal immune defenses; i. e. influenza virus, plague bacillus, malarial protozoan

Back 10

true pathogens

Front 11

cause disease when the host's defenses are compromised or when they grow in part of the body that is not natural to them; i.e. Pseudomonas sp. & Candida albicans

Back 11

opportunistic pathogens

Front 12

What does the severity of the disease depend upon?

Back 12

the virulence of the pathogen

Front 13

the characteristic or structure that contributes to the ability of a microbe to cause disease

Back 13

virulence factor

Front 14

characteristic routes that microbes follow to enter the tissues of the body

Back 14

portals of entry

Front 15

microbes that originate from sources outside the body

Back 15

exogenous agents

Front 16

microbes that already exist on or in the body (normal flora)

Back 16

endogenous agents

Front 17

the minimum number of microbes required for an infection to proceed

Back 17

infectious dose (ID)

Front 18

Do microbes with small IDs have greater or lesser virulence?

Back 18

greater virulence; i.e. 1 Measles virus will cause an infection, but it takes 100,000,000 Cholera cells to cause an infection

Front 19

the ability of microbes to gain a stable foothold at the portal of entry; dependent on binding between specific molecules on host and pathogen

Back 19

adhesion

Front 20

Where does the initial response of host defenses come from?

Back 20

phagocytes

Front 21

term used to describe the avoidance of phagocytosis

Back 21

antiphagocytic factors; (i.e.) a species of Staph & Strep produce leukocidins, which are toxic to white blood cells

Front 22

cell structures that make phagocytosis difficult

Back 22

slime layer or capsule-(glycocalyx)

Front 23

traits used to invade and establish themselves in the host, also determine the degree of tissue damage that occurs-severity of disease

Back 23

virulence factors

Front 24

enzymes that digest epithelial tissues and permit invasion of pathogens

Back 24

exoenzymes

Front 25

the capacity to produce toxins at the site of multiplication

Back 25

toxigenicity

Front 26

lipid A of LPS of Gram-negative bacteria

Back 26

endotoxins

Front 27

proteins secreted by Gram-positive and Gram-negative bacteria

Back 27

exotoxins

Front 28

4 stages of clinical infections

Back 28

1.) Incubation period
2.) Prodromal stage
3.) Perioid of invasion
4.) Convalescent period

Front 29

time from the initial contact with the infectious agent to the appearance of first symptoms; agent is multiplying but damage is insufficient to cause symptoms; several hours to several years

Back 29

incubation period

Front 30

vague feelings of discomfort; nonspecific complaints

Back 30

prodromal stage

Front 31

multiplies at high levels, becomes well established; more specific signs and symptoms

Back 31

period of invasion

Front 32

as person begins to respond to the infection, symptoms decline

Back 32

convalescent period

Front 33

pattern of infection in which microbes enter the body and remain confined to a specific tissue

Back 33

localized infection

Front 34

pattern of infection in which the infection spreads to several sites and tissue fluids usually in the bloodstream

Back 34

systematic infection

Front 35

pattern of infection in which infectious agents break loose from a local infection and are carried to other tissues

Back 35

focal infection

Front 36

an infection in which several microbes grow simultaneously at the infection site (polymicrobial)

Back 36

mixed infection

Front 37

also known as an initial infection

Back 37

primary infection

Front 38

another infection by a different microbe

Back 38

secondary infection

Front 39

an infection that comes on rapidly, with severe but short-lived effects

Back 39

acute infection

Front 40

infections that progress and persist over a long period of time

Back 40

chronic infections

Front 41

objective evidence of disease as noted by an observer. (i.e.) fever, chest sounds, rash, etc.

Back 41

sign

Front 42

subjective evidence of disease as sensed by the patient. (i.e.) chills, pain, nausea, etc.

Back 42

symptom

Front 43

What are the earliest symptoms of disease as a result of the activation of the body defenses?

Back 43

fever, pain, soreness, swelling

Front 44

a sign of inflammation caused by the accumulation of fluid

Back 44

edema

Front 45

a sign of inflammation caused by walled-off collections of inflammatory cells and microbes

Back 45

granulomas and abscesses

Front 46

a sign of inflammation caused by swollen lymph nodes

Back 46

lymphadenitis

Front 47

What is a sign of an infection in the blood?

Back 47

changes in the number of circulating white blood cells

Front 48

an increase in white blood cells

Back 48

leukocytosis

Front 49

a decrease in white blood cells

Back 49

leukopenia

Front 50

condition in which microorganisms are multiplying in the blood and present in large numbers

Back 50

septicemia

Front 51

form of septicemia in which small numbers of bacteria are present in the blood but not necessarily multiplying

Back 51

bacteremia

Front 52

form of septicemia in which a small number of viruses are present but not necessarily multiplying

Back 52

viremia

Front 53

What is an asymptomatic (subclinical) infection?

Back 53

although infected, the host doesn't show any signs of disease; because of the inapparent infection, the person doesn't seek medical attention

Front 54

the specific avenue by which a pathogen departs; blood, urine, feces, etc.

Back 54

portals of exit

Front 55

the term describing the ability of a microbe to become periodically active and produce a recurrent disease after the initial symptoms have passed

Back 55

latency

Front 56

a person with a latent infection who sheds the infectious agent

Back 56

chronic carrier

Front 57

long-term or permanent damage to tissues or organs

Back 57

sequelae

Front 58

the primary habitat of a pathogen in the natural world; (i.e.) human or animal carrier, soil, water, plants

Back 58

reservoir

Front 59

the individual or object from which an infection is actually acquired

Back 59

source

Front 60

an individual who inconspicuously shelters a pathogen and spreads it to others; may or may not have experienced disease due to the microbe

Back 60

carrier

Front 61

3 types of asymptomatic carriers

Back 61

incubation carriers, convalescent carriers, chronic carriers

Front 62

an asymptomatic carrier that spreads the infectious agent during the incubation period

Back 62

incubation carrier

Front 63

an asymptomatic carrier who is recuperating without symptoms

Back 63

convalescent carrier

Front 64

an asymptomatic carrier who shelters the infectious agent for a long period

Back 64

chronic carrier

Front 65

a carrier such as a contaminated healthcare provider who picks up pathogens (externally) and transfers them to other patients

Back 65

passive carrier

Front 66

a live animal (other than human) that transmits an infectious agent from one host to another

Back 66

vector

Front 67

What are the majority of vectors?

Back 67

arthropods; fleas, mosquitoes, flies, and ticks

Front 68

Examples of larger vectors?

Back 68

mammals, birds, lower vertebrates

Front 69

types of vectors that actively participate in a pathogen's life cycle

Back 69

biological vectors

Front 70

a type of vector that is not necessary to the life cycle of an infectious agent and merely transports it without being infected

Back 70

mechanical vector

Front 71

an infection indigenous to animals but naturally transmissable to humans (humans don't transmit the disease to others)

Back 71

zoonosis

Front 72

characteristics of zoonosis

Back 72

at least 150 exist worldwide; make up 70% of all new emerging disease worldwide; impossible to eradicate the disease without eradicating the animal reservoir

Front 73

disease type in which an infected host can transmit the infectious agent to another host and establish infection in that host

Back 73

communicable disease

Front 74

term used for a highly-communicable disease

Back 74

contagious

Front 75

an infectious disease that does not arise through transmission from host to host

Back 75

non-communicable disease

Front 76

How do non-communicable diseases occur?

Back 76

primarily when a compromised person is invaded by his or her own normal microflora or through contact with an organism in a natural, non-living reservoir

Front 77

a pattern of transmission through physical contact or fine aerosol droplets

Back 77

direct contact

Front 78

a pattern of transmission that passes from infected host to intermediate conveyor and then to another host

Back 78

indirect contact

Front 79

diseases that are acquired or developed during a hospital stay

Back 79

nosocomial infections

Front 80

How are nosocomial infections acquired?

Back 80

from surgical procedures, equipment, personnel, and exposure to drug-resistent microorganisms

Front 81

Characteristics of nosocomial infections

Back 81

most commonly involve urinary tract, respiratory tract, and surgical incisions

Front 82

What is the most common organism involved in a nosocomial infection?

Back 82

Gram-negative intestinal flora; E. coli, Pseudomonas, Staph

Front 83

stringent measures to prevent the spread of nosocomial infections from patient to patient, from patient to worker, and from worker to patient

Back 83

universal precautions

Front 84

What are universal precautions based upon?

Back 84

the assumption that all patient specimens could harbor infectious agents, so must be treated with the same degree of care

Front 85

the study of the frequency and distribution of disease and health-related factors in human populations

Back 85

epidemiology

Front 86

collecting, analyzing, and reporting data on rates of occurrence, mortality, morbidity and transmission of infections

Back 86

surveillance

Front 87

the total number of existing cases with respect to the entire population usually represented by a percentage of the population

Back 87

prevalence

Front 88

measures the number of new cases over a certain time period, as compared with the general healthy population

Back 88

incidence

Front 89

the total number of deaths in a population due to a certain disease

Back 89

mortality rate

Front 90

the number of people afflicted with a certain disease

Back 90

morbidity rate

Front 91

a disease that exhibits a relatively steady frequency over a long period of time in a particular geographic locale

Back 91

endemic

Front 92

term used when occasional cases of a disease are reported at irregular intervals

Back 92

sporadic

Front 93

term used when prevalence of a disease is increasing beyond what is expected

Back 93

epidemic

Front 94

an epidemic across continents

Back 94

pandemic

Front 95

What are Koch's postulates used for?

Back 95

determining the causative or etiologic agent of infectious disease