midterm 1

Question 1

commensalism?

Answer 1

only bacteria or the human get the benefits

Question 2

mutalism?

Answer 2

both bacteria and human gets benefits

Question 3

colonization?

Answer 3

ability of the microbe to stay attached to the body surface and replicate

Question 4

what allows microbiota to attach to host cells?

Answer 4

adhesins

Question 5

what is a pathogen?

Answer 5

-any bacterium, virus, fungus, protozaon, or worm that causes disease in humans
-“culprit”

Question 6

what is pathogenicity?

Answer 6

-the ability of an organism to cause disease
-includes the mechanisms/factors that allow the microorganism to evade
-eg. biofilms, release of toxins, ability to attach, etc
-“tool kit”

Question 7

what are parasites?

Answer 7

are microbes that cause harm inducing infections

Question 8

infection?

Answer 8

-when pathogen or parasite enters, colonizes, and begins to replicate
-low amounts of pathogens
-most infections don’t cause symptoms and go unnoticed

Question 9

disease?

Answer 9

-pathogen has replicated to a significant extent where specific s/s are present

Question 10

acute vs chronic infection?

Answer 10

-acute: lasts 3 weeks or less, symptoms develop and resolve rapidly
-chronic: last longer than 3 weeks, and symptoms develop gradually and resolve slowly

Question 11

what are primary pathogens?

Answer 11

-pathogens that cause disease after infection, in a healthy host
-moderate to high virulence
-rapidly reproduce/increase in number

Question 12

what are opportunistic pathogens?

Answer 12

-causes disease in immunocompromised hosts
-low virulence

Question 13

what is the latent stage?

Answer 13

-when the s/s of the pathogen have subsided, but the pathogen still lingers, but isnt actively replicating
-pathogen cannot be found in culture

Question 14

what is virulence?

Answer 14

-the severity of the disease
-high virulence: ebola
-low virulence: cold

Question 15

what can virulence be measured by?

Answer 15

-lethal dose: how much of the dose will kill 50% of the population
-infectious: how much of the dose that can infect 50 % of the population
-in most cases, the infectious dose is lower because it takes less to infect than to kill

Question 16

what is invasion?

Answer 16

entry of a pathogen into the cell

Question 17

what is invasiveness?

Answer 17

ability of the bacterial pathogen to enter multiple cells, rapidly entering through the tissues

Question 18

what is the host range?

Answer 18

-are the organisms the pathogens can cause an infection in
-the receptor has to be specific to the adhesins for the pathogen to start working
-if the host range is narrow, only certain organism with specific receptor can be infected (eg. salmonelall enterica typhi infects only humans)
-if the host range is broad, multiple organism have the receptor that the adhesins (on the pathogen) can attach to (eg. salmonella enterica typhimurim infects animals and humans)

Question 19

disease?

Answer 19

-disruption of normal structure or function of the body that can be recognized by set of s/s

Question 20

infectious disease

Answer 20

-specific disease caused by a pathogen that can be transfered from one host to another
-to know if a microorganism is the cause of an infectious disease you need to use Koch’s postules: 1) microorganism is found in unhealthy people and not in healthy people, 2) micro must be isolated and grown in a culture, 3) micro should disease when introduced to a healthy person, 4)when re-isolated from the newly infected person the same microorganism will be the causative agent
-postules : one pathogen = one diseae

Question 21

what are signs and symptoms and syndrome?

Answer 21

-signs: objective findings that an be observed by examination
-symptoms: subjective findings only experienced by the person
-syndrome: collection of s/s that occur together and collectively characterize a condition (eg. flu - fever, cough,fatigue, muscle aches)

Question 22

immunopathology?

Answer 22

-the immune systems reaction to pathogen/harmful substances, causing tissue/organ damage

Question 23

sequelae?

Answer 23

pathological consequences that occur after the disease resolves

Question 24

what are the stages of an acute infectious disease?

Answer 24

-incubation: time between the entry and s/s
-prodromal: non specific s/s
-illness: specific s/s, when the pathogens have replicated a whole lot
-decline: when s/s starting decrease and the immune system has the upper hand
-convalescence: s/s are minimal or absent, and its period of recovery
-long term: body develops resistance to the disease or the pathogen can become dormant and isnt actively replicating (stage of latency)

Question 25

morbidity vs mortality?

Answer 25

-morbidity: percent of people who are sick from the disease -mortality: percent of people who are dead from the disease

Question 26

infection cycle?

Answer 26

-process by which pathogens are transmitted from one host to another -has multiple stages: resevoir, portal of exit, mode of transmission, portal of entry, and susceptible host

Question 27

horizontal vs verticle transmission

Answer 27

-horizontal: transmission of pathogen within the same generation of species -vertical: tranmission of pathogen from parent to offspring

Question 28

direct vs in direct tranmission?

Answer 28

-direct contact transmission: pathogens spread directly from person to person or person to animal direct physical contact -non direct: pathogens spreading indirectly, and there's something in between the infectious agent and the next host