mod 7

Question 1

symbiosis.

Answer 1

“living together”

Question 3

symbiosis

Answer 3

living togetehr
relationship

Question 4

parasitism. meaning and example

Answer 4

one party benefit, other harmed

ex. virus. H1N1 and human cell

Question 5

mutualism
meaning and example

Answer 5

both parties benefit

ex. bacteria in vagina

Question 6

Commensalism
meaning and example

Answer 6

one benefit one doenst notice

ex. shark and remora fish
ex. staph. epidermis on human skin

Question 7

microbiome

Answer 7

millions of bacterial flora on/in humans
help with immunity, digestion, etc
can prevent colonization of more parasitic pathogens, produce metabolites

Question 8

microbiome shift during pregnancy

Answer 8

gut bacteria becomes more diverse to support metabolism and immune function

vaginal bacteria also becomes more diverse, increase in lactobacilli’s species who produce lactic acid and protect and protect vaginal tract/baby from infection

Question 9

microbiome vaginal vs c section birth

Answer 9

during vaginal delivery newborn exposed to birthing persons bacteria in birth canal, which helps babies microbiome ( seeps through skin and ingested into gut)

miss this opportunity during c section, gains hospital and microbiome and from surrounding adults skin, can lead to late establishment of gut microbiome.

Question 10

Dysbiosis

Answer 10

imbalance or disruption of normal gut biome - can lead to bacterial vaginoses, preterm birth, bowel disease etc

Question 11

non pathogen

Answer 11

non disaese causing agent, can be part of normal flora

Question 12

opportunistic pathogen

Answer 12

agent capable of causing disease when hosts resistance is impared (etc infection or immunocompromised)

Question 13

pathogen

Answer 13

microorganism capeable of causing disease

Question 14

pathogenicity

Answer 14

ability of infectious agent to cause disease

Question 15

adherence

Answer 15

process by which pathogen sticks to surface of cells

Question 16

Infection

Answer 16

Multiplication of infectious agent within the body (can be symptomatic or asymptomatic)

Question 17

Invasion

Answer 17

process by which bacteria/parasite/fungi/virus enter host cell and spread within body

Question 18

carrier

Answer 18

perosn/animal with asymptomatic infection that can be transferred

Question 19

virulence

Answer 19

quantitative ability of an agent to cause disease, virulent agents cause disease when introduced into host in small numbers

Question 20

Stages of infectious disease (4)

Answer 20

1. incubation 2. prodrome 3. specific illness period 4. recovery

Question 21

describe 4 stages of illness

Answer 21

1. incubation- time fromm exposure to apperance of symptoms
2. prodrome- time of non specific symptoms
3. specific illness- characteristic features of disease occur
4. recovery- symptoms resolve and health restored

Question 22

3 possibilities after recovery period

Answer 22

1. cleared and fine 2. chronic carrier 3. latent infection 4. subclinical (asymptomatic)

Question 23

Pathogenesis- colonization and transmission

Answer 23

establishment of pathogen at point of entry

Question 24

routes of entry (6)

Answer 24

1. respiratory/saliva 2. fecal oral 3. venereal (sexual) 4. vector 5. vertebrate reservior 6. vector-vertabrate resevior

Question 25

3 routes of infection for infant

Answer 25

1. prenatal (inutero) 2. perinatal (during birth) 3. postnatal

Question 26

ID and LD

Answer 26

ID- infectious dose, little number means % of pop that will be infected, a measure of virulence, can be affected by other environmental factors LD- lethal dose, how many will die

Question 27

pathogenesis - adherence - requires what 2 things?

Answer 27

1. receptor- on host cell, usually specifc carbohydrate or peptide 2. adhesin- on pathogen, macromolecule (lipoprotein or glycoprotien) which interacts with host cell receptor these reactions are usually very specific, only occur in one area in one species

Question 28

2 examples of adherence

Answer 28

1. HIV- special glycoprotien (gp41/120) adhesion on envelope and binds to CD4 receptor and CCr5 on helper T without CCr5 or mutant form - not susceptible to HIV 2. Ecoli- produces proteins (adhesions) that bind to sugars (receptors) on host cell, can be blocked by proanthocyanidins (found In cranberry juice)

Question 29

pathogenesis- invasivness

Answer 29

ability to spread and penetrate hosts defenses

Question 30

pathogenesis- invasivness surface infection vs systemic infection

Answer 30

surface- epithelial layer and fail to spread deeper, local spread on mucosal surface, usually comes and goes within 7 days, innate immune response ex. common cold systemic- spread through body, blood and lymph, lasts more than week, adaptive immune response, ex. measles

Question 31

pathogenesis- invasivness pathogenic factors

Answer 31

- hyaluronidase- break up connective tissue for penetration - lipase- penetrate oily glands - coagulase - collagenase

Question 32

pathogeneisis- bacterial toxins

Answer 32

exotoxins (released from cell) endotoxin (part of cell)

Question 33

exotoxins

Answer 33

- usually polypeptides released by bacteria - antigenic, stim IR, induce specific antibodies called antitoxins - specific to bacteria strain - can be modified to form toxoid which are antigenic but not toxic, can be used for vaccines

Question 34

exotoxins in disease examples

Answer 34

- cholera toxin cause diharea by causing intestine to produce sodium, bicarb, water - diptheria toxin cause cell death by stopping protein synthesis - tetnus toxin cause muscle spasm by blocking inhibitory motor neuron pathways

Question 35

endotoxins

Answer 35

- part of outer cell wall (in gram neg bacteria) (LPS) - non specific, cant make toxoid

Question 36

How do microbes ivade immune response

Answer 36

1. evade innate barriers (mechanical barriers and phagocytosis) 2. evade adaptive ( hide antigens, cupress immune resp, change antigens) 3. resistance to antimicrobial drugs

Question 37

pregnancy hormones reduce what IR? babys recieve what AB? till when?

Answer 37

reduce cellular immunity, maintain antibody IgG from placenta, IgA from milk, till birth, rapidly form T and B cells