Micro Ch 21: Interactions Of Host And Pathogen

Front 1

What is a portal of entry?

Back 1

A portal of entry is the site at which pathogenic microbes gain access to tissue that can be infected.

Front 2

Name some portals of entry in humans.

Back 2

Some portals of entry in humans include the mouth and nose, the GU tract, cuts in the skin, mosquito bites that penetrate into the blood, and the placenta.

Front 3

Distinguish the survival abilities of intracellular and extracellular pathogens.

Back 3

Intracellular pathogens cause infection because the microbes have developed the ability to escape phagocytic killing mechanisms. Extracellular pathogens cause infection by their ability to remain outside of phagocytic cells.

Front 4

Define and distinguish primary and opportunistic pathogens.

Back 4

Primary pathogens can invade and infect healthy hosts. Opportunistuc pathogens are normally nonpathogens that cannot be warded off by individuals whose immune systems are compromised.

Front 5

What individuals are generally predisposed to infection with opportunistic pathogens?

Back 5

Tissue transplant pts and people with immunodeficiencies (AIDS pts, for example) are often predisposed to infection with opportunistic pathogens.

Front 6

Differentiate a virulent organism from a virulence factor.

Back 6

A virulent org is one that causes a dz. Virulence factors are enzymes and toxins that allow an org to evade the host immune system.

Front 7

How do the concepts of infectious dose and virulence differ from each other?

Back 7

Infectious dose refers to the number of bact cells required to establish infection; virulence refers to the bacterium's ability to infect a host in spite of the host's defenses.

Front 8

Give two factors that allow different microbes to attach or adhere to target cells.

Back 8

Fimbraie and lipoteichoic acid of gram pos cells are factors that allow different microbes to attach or adhere to target cells.

Front 9

How do endotoxins and exotoxins differ?

Back 9

Endotoxins are released only when the microbe is damaged or lysed. Exotoxins are purposefully secreted from the microbe.

Front 10

What does botulinum toxin do?

Back 10

After it is eaten in food, the botulinum toxin penetrates the intestinal wall and blocks transmission of nerve-muscle signals.

Front 11

What kind of toxin is LPS (lipopolysaccharide)? In what kind of bacteria do you find LPS?

Back 11

LPS is an endotoxin found in the gram neg bacterial lipid A

Front 12

What virulent effect does LPS have on its host? I

Back 12

The host recognizes lipid A and tries the destroy the infection by cooking it with higher and higher body temperatures (fever). If the host overreacts, brain damage, cardiovascular shock, and hemorrhaging can occur.

Front 13

Describe an exoenzyme that functs in virulence.

Back 13

The exoenzyme functions to destroy host connective tissue, which facilitates bacterial spreading.

Front 14

What do hemolysins do?

Back 14

Hemolysins are toxins that cause RBC hyaluronidase s to lyse so that RBC contents become available as microbial nutrient sources.

Front 15

Systemic infection

Back 15

Infection spread via the blood or lymphatic systems

Front 16

Focal infection

Back 16

Infection spread from a specific locale

Front 17

Acute infection

Back 17

severe infection begins abruptly

Front 18

Chronic infection

Back 18

infection appears gradually and lasts for an extended period of time

Front 19

Subacute infection

Back 19

infection with intermediate duration and symptoms

Front 20

Primary infection

Back 20

infection caused by the organism that intiated infection

Front 21

secondary infection

Back 21

infection caused by the organism that initiated infection

Front 22

subclinical, asymptomatic, or apparent infection

Back 22

Infection that though present and growing, does not manifest symptoms

Front 23

Abscess

Back 23

Discrete infection that blocks the entry of immune system cells

Front 24

Bacteremia

Back 24

bacteria in the blood

Front 25

Septicemia

Back 25

Actively growing bacteria in the blood

Front 26

Viremia

Back 26

virus in the blood

Front 27

Leukocytosis

Back 27

increased number of wbcs

Front 28

leukopenia

Back 28

decreased number of wbcs

Front 29

What is latency?

Back 29

When microbes persist in a dormant state, although symptoms of the infection subside

Front 30

Name some common microbes that become latent.

Back 30

Turbercle bacilli, herpes simplex, HIV, hep B, and Epstein-Bar viruses

Front 31

What potential danger does a chronic carrier present to other people?

Back 31

Because the chronic carrier may be asymptomatic, he may not know the disease is in his system and can therefore unknowingly spread the disease to others.

Front 32

What are sequelae?

Back 32

Sequelae are specific conditions that follow an illness episode, such as heart valve damage after a bout of strep sore throat.

Front 33

When do sequelae occur?

Back 33

Sequelae occur after the initial infection has run its course.

Front 34

What is the CDC? What does the CDC publish?

Back 34

Centers for Disease Control and Prevention in Atlanta, Georgia. The CDC publishes information about new outbreaks of illnesses. new pathogens, and how to control and prevent disease in the Morbidity and Mortality Weekly Report.

Front 35

Why is an infection control nurse so important?

Back 35

An infection control nurse is important because he or she acts to identify and control the spread of outbreaks as quickly as possible.

Front 36

Communicable

Back 36

Infection passes from one host to another

Front 37

Contagious

Back 37

Highly communicable infection

Front 38

Transmission (horizontal and vertical)

Back 38

The spread of dz from one individual to another or from parent to progeny (vertical)

Front 39

Fomite

Back 39

an inanimate object from which a microbe may be contacted

Front 40

Aerosols

Back 40

Microbe-containing droplets released into the air by coughing or sneezing.

Front 41

Fecal-oral route

Back 41

Microbes left on the hands after defecation/urination, subsequently transmitted to food or other objects having oral contact; or any fecal contamination of food or water.