Module 7

Question 1

what is parasitic symbiosis

Answer 1

One party benefits while the other suffers

Question 2

what is mutualistic symbiosis

Answer 2

both party’s benefit

Question 3

what is commensal symbiosis

Answer 3

one party benefits while the other is neutral

Question 4

what is a non pathogen

Answer 4

microorganism that does not cause disease
may be apart of the normal flora

Question 5

what is an opportunitstic pathogen

Answer 5

capable of causing diseases only when the hosts resistance is impaired
immunocompromised

Question 6

what is a pathogen

Answer 6

a microorganism capable of causing disease

Question 7

what is pathogenicity

Answer 7

the ability of an infectious agent to to cause disease

Question 8

what is toxigenicity

Answer 8

the ability of a microorganism to produce a toxin that contributes to the development of disease

Question 9

what is adherence

Answer 9

the process by which a pathogen can stick to the surfaces of host cells

Question 10

what is infection

Answer 10

multiplication of an infectious pathogenic agent within the body - even if person is asymptomatic

Question 11

what is invasion

Answer 11

the process where by bacteria, parasites, fungi and viruses enter host cells or tissues and spread

Question 12

what is a carrier

Answer 12

a person or animal with asymptomatic infections that can be transmitted to another person or animal

Question 13

what is virulence

Answer 13

the quantitative ability of an agent to cause disease
virulent agents cause disease when introduced into the host in small numbers
virculence is the enchanced ability for adherence, invasion and toxigenicity

Question 14

what are the four stages of infection

Answer 14

incubation
prodrome
specific illness period
recovery period

Question 15

what is the incubation period

Answer 15

time between exposure and symptoms

Question 16

what is the prodrome period

Answer 16

generalized symptoms

Question 17

what is the specific illness period

Answer 17

illness specific symptoms

Question 18

what is the recovery period

Answer 18

symptoms resolve and return to health

Question 19

what are the aspects of pathogenesis

Answer 19

colonization and transmission
adherence
invassiveness
toxins

Question 20

what is colonization

Answer 20

establishment of a pathogen at an appropriate site of entry

Question 21

where does colonization normally happen

Answer 21

anything with exposure to outside -> eyes, nose, mouth, lungs
urogenetial tract

Question 22

what do body surfaces at sites of microbial infection do to protect body from infection

Answer 22

have defense mechanisms to prevent attachment and shed microbes
successful microorganisms possess mechanisms for attaching to and moving along surfaces

Question 23

describe respiratory/salivary transmission

Answer 23

hard to control
cover when sneeze/cough

Question 24

describe fecal-oral transmission

Answer 24

control with public health measures
wash hands/access to clean water

Question 25

describe venereal transmission

Answer 25

hard to control as social factors involved increase public awareness/education

Question 26

describe vector transmission

Answer 26

person to bug to another person malaria, zika, lyme disease

Question 27

descrive vertebrate resevoir

Answer 27

vertebrate to vertebrate to person rabies

Question 28

vector-vertebrate resevoir

Answer 28

vertebrate to bug to person the plague...

Question 29

routes of infection for the fetus/newborn

Answer 29

prenatal/congenital perinatal postnatal

Question 30

describe infectious dose

Answer 30

measures virulence amount needed for 50% of sample population to be infected

Question 31

what does a pathogen need for adherence

Answer 31

receptor --> specific carb or peptide residues on host cell ashesin --> macromolecule on the pathogen surface that interacts with the host cell receptor

Question 32

describe surface spread

Answer 32

comes and goes within 7 days innate immune defenses employed common cold

Question 33

describe systemic spread

Answer 33

lasts more than 1 week adaptive immune defenses employed measles

Question 34

what are pathogenic factors for invasiveness

Answer 34

hyalurnidase lipases coagulase collagenase

Question 35

what are the two main types of toxins

Answer 35

endotoxin exotoxin

Question 36

describe endotoxins

Answer 36

gram - part of the cell not used for immunization eg. lipopolysaccharide

Question 37

describe exotoxins

Answer 37

on gram - and + can be released can be used for immunization can be specific to bacteria strains eg. tetanus

Question 38

how do microbes evade the innate immune system

Answer 38

evade mechanical barriers evade phagocytosis

Question 39

how do microbes evade adaptive immune defenses

Answer 39

concealment of antigens antigenic variation immunosuppression

Question 40

how do pathogens evade mechanical barriers

Answer 40

fluid and mucous can remove most viruses, bacteria and protozoa from the surface of epithelial cells specific receptors or mechanical means to bind firmly to epithelial surface

Question 41

how do pathogens evade phagocytosis

Answer 41

kill phagocyte by releasing toxins prevent phagocyte from engulfing microorganism (capsule) prevent the fusion between phagosome and lysosome escape from phagosome to cytoplasm: allow replication of microbe resistance to killing when inside phagolysome - production of antioxidants that neutralize hydrogen peroxide

Question 42

describe concealment of antigens: latency

Answer 42

if a microbe can remain inside a cell without its antigens being displayed on the surface, it cannot be recognized --> even if antibody-mediated or cell-mediated response has been put into action, the microbe inside such a cell is unaffected --> persistenet latent viruses act this way --> during reactivation: re-exposure occurs and boostig of immune responses is inevitable

Question 43

describe concealmet of antigens: microbes in privileged tissue sites

Answer 43

certain microbes colonize in tissues that are out of reach from circulating lymphocytes or have alternate drainage (not lymph) only effective if microbe does not induce innate immune inflammatory response Brain, anterior of eye, testes, placenta

Question 44

describe genetic mutation

Answer 44

some pathogen antigens can repeatedly change their imporant surface structures so that host immunity is less effective can occur during course of infection or spread of a microbe in community --> reduces effectiveness fo T and B memory cells and requires new immune responses to new antigens of the flu virus

Question 45

describegene recombination

Answer 45

sudden alterations in antigens take place by the exchange of genetic info between 2 subtypes of microbes

Question 46

describe immunosupression

Answer 46

many viral and bacterial infections cause immunosupression that is normally temporary but can be long term

Question 47

describe temporary immunosupression

Answer 47

release of immunosuppressive molecules that interfere with complement reduction in MHC I expression by infected cells

Question 48

describe long term immunosuppression

Answer 48

interference with signalling between immune cells and cytotoxic cells

Question 49

describe resistance to anti-microbial treatments

Answer 49

the microbe alters a function or acquires a new functional molecule that helps it resist the drug

Question 50

describe immune function in pregnancy

Answer 50

pregnancy hormones result in reduced cellular immunity but maintain Ab immunity fetal tissue protected from immune rejection by specific functions of placenta and immune regulation some viruses can cross placenta, fetus only has maternal IgG antibodies and innate function

Question 51

describes immune function in newborns

Answer 51

newborns have maternal IgG and IgA from milk --> rapidly develop B cell immunity on their own and eventually T cell mediated immunity Can be treated with immune globulins and some anti-microbial or anti-viral drugs