15: Microbial Mechanisms of Pathogenicity

Question 1

the ability to cause disease in a host

Answer 1

pathogenicity

Question 2

relative degree of pathogenicity

Answer 2

virulence

Question 3

which is more virulent, neisseria meningitidis or haemophilis influenzae

Answer 3

neisseria meningitidis

Question 4

the avenue by which a microbe gains access to the body

Answer 4

portal of entry

Question 5

what is the portal of entry for malaria plasmodia

Answer 5

bites through the skin

Question 6

what is the portal of entry for aemeobic dysentery

Answer 6

ingestion of cysts

Question 7

mucous membranes line the surface of the eye

Answer 7

conjunctiva

Question 8

easiest and most frequently used portal of entry for pathogenic microbes

Answer 8

mucous membranes of the respiratory tract

Question 9

some microbes can gain access through sweat glands and hair follicles, example

Answer 9

pseudomonas can cause folliculitis

Question 10

when microbes enter the body by means other than the digestive tract

Answer 10

parenteral route

Question 11

some microbes cannot cause disease unless they enter the body through their ______

Answer 11

preferred portal of entry

Question 12

this disease enters the body through a parenteral route and has reverse transcriptase enzyme. what is the disease, and what would you call the syringe

Answer 12

HIV, fomite

Question 13

the initial number of microbes which gain entry and is often decisive in determining whether active disease will follow

Answer 13

infecting dose of microbes

Question 14

the attachment between pathogen and host is accomplished by means of surface molecules on the pathogen called _____ that bind specifically to complementary surface ___ on the cells of certain host tissues

Answer 14

adhesins, receptors

Question 15

the majority of adhesins are what?

Answer 15

glycoproteins or lipoproteins

Question 16

the host’s cell receptors are typically what?

Answer 16

sugars (mannose)

Question 17

mats of microbes that represent another method of adherence and are important because they resits disinfectants and antibiotics

Answer 17

biofilms

Question 18

most important virulence factor for bacterial pathogens

Answer 18

formation of a capsule

Question 19

capsules interfere with ______ and increase the likelihood of microbial survival

Answer 19

phagocytosis

Question 20

a host may make these against an encapsulated bacterium to make it more easily destroyed

Answer 20

anticapsular antibodies

Question 21

components of the ____ may also help a microbe to resist phagocytosis

Answer 21

cell wall

Question 22

component of cell wall in gram negative bacteria that help microbe resist phagocytosis

Answer 22

lipopolysaccharide

Question 23

waxy lipid of mycobacterium tuberculosis that combats digestion after phagocytosis

Answer 23

mycolic acid

Question 24

found on the surface of streptococcus pyogenes that helps to resis phagocytosis

Answer 24

M protein

Question 25

produced and released by some bacteria that contribute to their virulence

Answer 25

enzymes

Question 26

bacterial enzymes which clot fluid portion of blood (plasma)

Answer 26

coagulases

Question 27

what bacteria is very good at producing coagulase

Answer 27

staphylococcus aureus

Question 28

the ____ produced by coagulase may isolate the bacteria from the host defenses

Answer 28

fibrin clot

Question 29

enzyme which break down blood clots

Answer 29

bacterial kinases

Question 30

bacterial enzyme that has been used to help people with heart attack or strokes, what bacteria produces it

Answer 30

streptokinase, streptococcus pyogenes

Question 31

______ is an enzyme which dissolves the cement like material _____ which holds cells together

Answer 31

hyaluronidase, hyaluronic acid

Question 32

promotes the spread of the pathogenic microbes

Answer 32

hyaluronidase

Question 33

_____ is an enzyme which breaks down the protein which forms the framework of muscles and several other tissues ____

Answer 33

collagenase, collagen

Question 34

gram-positive, endospore-forming bacilli that are very good at producing hyaluronidase, collagenase, and hemolysin

Answer 34

clostridium perfringens (gas gangrene)

Question 35

protein that lyses blood cells

Answer 35

hemolysin

Question 36

destroys the protective IgA antibodies on mucous membranes

Answer 36

IgA protease

Question 37

microbes can avoid the immune response by the host by changing the identifying markers on their surface (antigens). Thus, by the time the body mounts an immune response against a pathogen, the pathogen already altered its antigens and is unaffected by the immune response

Answer 37

antigenic variation

Question 38

example of antigenic variation

Answer 38

influenza virus has neurominidase (N spikes) and H spikes that are adhesins and antigens