host-parasite interaction

Question 1

association of two organisms living together; where both (host and organism) benefit from one another may be described as mutualism

Answer 1

symbiosis

Question 2

relationship where the organism benefits but there is no beneficial or harmful effect to the host

Answer 2

commensalism (ex. proteus mirabilis)

Question 3

one species (microbe) benefits at the expense of the other (host) (ex. entamoeba histolytica)

Answer 3

parasitism

Question 4

microorganisms that are commonly found on or in body sites of healthy persons are called…

Answer 4

normal, usual, indigenous flora

Question 5

microorganisms that colonize an area for months or years represent

Answer 5

resident microbial flora

Question 6

microorganisms that are present at the site temporarily represent

Answer 6

transient flora (“visit”)

Question 7

more organisms inhabit moist areas than dry areas; and are dominated by…

Answer 7

diphtheroids

Question 8

human milk has a high lactose concentration and maintains pH of…

Answer 8

5.0 to 5.5; an environment supportive of bifidobacterium spp.

Question 9

composition of the flora on the skin depends on the activity of

Answer 9

sebaceous or sweat glands

Question 10

organisms concentrate the most in areas that are moist

Answer 10

such as armpit, groin, and perineum

Question 11

this gland secrete substances metabolized by the skin bacteria, releasing odorous amines

Answer 11

apocrine sweat glands

Question 12

found in moist areas such as axillae and between the toes

Answer 12

aerobic diphtheroids

Question 13

colonize the deep sebaceous glands

Answer 13

p. acnes

Question 14

reside in hair follicles and colonize the sebaceous glands because they are resistant to skin lipids and fatty acids

Answer 14

staphylococcus epidermidis, propionibacterium spp.

Question 15

predominant genus of mouth bacteria

Answer 15

streptococcus

Question 16

upper respiratory is composed of

Answer 16

mouth
nasopharynx
oropharynx
larynx

Question 17

lower respiratory composed of

Answer 17

trachea
bronchi
pulmonary parenchyma

Question 18

mouth, nasopharynx, oropharynx are colonized predominantly with viridans strep

Answer 18

such as streptococcus mitis, strep mutans, strep milleri, strep sanguis, moraxella catarrhalis, neisseria spp., and diptheroids

Question 19

gastrointestinal tract comprises of

Answer 19

esophagus
stomach
small intestine
colon

Question 20

microorganism resistant to acid ph of the stomach

Answer 20

spore-forming bacteria
cysts of parasites
helicobacter pylori

Question 21

microorg present in large intestine

Answer 21

pseudomonas aeroginosa
gram-pos cocci
yeasts

Question 22

colonized in its outermost segment by organism found on the skin

Answer 22

urethra

Question 23

before puberty and postmenopausal women, vaginal flora primarily consists of…

Answer 23

yeast
gram-neg bacilli
gram-pos cocci

Question 24

ability of a microbe to prduce disease in a susceptible individual

Answer 24

pathogenicity

Question 25

organisms recognized to cause disease in healthy immunocompetent individuals

Answer 25

true pathogens

Question 26

pathogenic in nearly all situation; and clinical significance is well established

Answer 26

yersinia pestis and bacillus anthracis

Question 27

colonizes the upper respiratory tract of healthy individuals without causing disease

Answer 27

haemophilus influenzae

Question 28

organisms under usual conditions do not cause disease but can induce an infectious process in patients with prostetic devices

Answer 28

staphylococcus epidermidis

Question 29

oppurtunistic pathogens

Answer 29

h. influenzae and S. epidermidis

Question 30

an infection that occurs as the result of medical treatment or procedures

Answer 30

iatrogenic infection

Question 31

relative ability of a microorg to cause a disease or the degree of pathogenicity

Answer 31

virulence

Question 32

virulence encompass functions such as

Answer 32

inhibiting phagocytosis facilitating adhesion to host cells or tissues enhancing intracellular survival after phagocytosis damaging tissue thru the production of toxins and extracellular enzymes

Question 33

encapsulated strains of... are associated with highly invasive infections and are known to be more virulent than nonencapsulated strains

Answer 33

s.pneumoniae h. influenzae

Question 34

another bacterial structure that protects organisms from phagocytosis is

Answer 34

protein A

Question 35

protein A in the cell wall of staphylococcus aureus helps the organism avoid phagocytosis by

Answer 35

interfering with the binding of the host's antibodies to the surface of the organism

Question 36

antibodies bind to antigens via their

Answer 36

Fab or antigen-binding portion

Question 37

protein A binds to the Fc portion of igG

Answer 37

preventing opsonization and phagocytosis by turning the antibody around on the surface

Question 38

streptococci prduce... that lyse rbc and induce toxic effects on wbc and macrophage

Answer 38

hemolysin

Question 39

pathogenic staphylococci release... that cause lysosomal discharge into cell cytoplasm

Answer 39

leukocidins

Question 40

staphylococcal leukocodins... is lethal to leukocytes and contributes to the invasiveness of the organism

Answer 40

panton-valentine

Question 41

cell surface structures that mediate attachment are called

Answer 41

adhesins

Question 42

main adhesins in bacteria are the

Answer 42

fimbriae (pili)

Question 43

causes traveler's diarrhea

Answer 43

e.coli