lesson 1

Question 1

number of bacterial species can reside in animal hosts, either as a

Answer 1

commensals or as potential pathogen

Question 2

can interact with host tissues in ways that result in disease

Answer 2

pathogenic bacteria

Question 3

1. acquired soon after birth
2. able to adhere to body surfaces.
3. form stable polymicrobial communities that are present as ‘normal microflora’ lives skin and in the hollow organs whose surfaces and cavities are open to the environment

Answer 3

commensal organism

Question 4

can exist as a commensal in the rumen but when it’s transfers to the liver of feedlot cattle it can act as a pathogen that causes hepatic abscesses

Answer 4

Fusobacterium necrophorum

Question 5

virulence factors includes adhesins, toxins and capsules whose genes are expressed only when their products are required in a process called?

Answer 5

phase variation

Question 6

Animals may be exposed to infection from 2 sources of infection

Answer 6

endogenous or exogenous sources

Question 7

arise when bacteria that live on the skin or mucous membranes as harmless commensals take advantage of impaired antimicrobial defenses of the host and behave as opportunistic pathogens

Answer 7

endogenous infection

Question 8

are example of obligate intracellular pathogens

Answer 8

1. Chlamydiae
2. rickettsiae

Question 8

are example of facultative intracellular pathogen that can invade and replicate in non-phagocytic epithelial cells.

Answer 8

1. Brucella species
2. uropathogenic E. coli
3. Salmonella species
4. Listeria monocytogenes

Question 9

this type of fimbriae can attach to urinary bladder.

Answer 9

Type I fimbriae of uropathogenic E. coli

Question 9

This type of fimbriae attach to epithelial cells in the kidney

Answer 9

P fimbriae

Question 10

The capsule of Bacillus anthracis is
composed of ________ _____; it is anti-phagocytic and is regarded as an essential
virulence factor

Answer 10

polyglutamic acid

Question 11

integral constituents of the bacterial cell wall not released until the microorganisms are lysed

Answer 11

endotoxins

Question 12

produced and secreted by viable bacteria

Answer 12

exotoxins

Question 13

________ stimulate the production of prostaglandins and leukotrienes which are mediators of inflammation.

Answer 13

Cytokines

Question 14

subunit that possesses toxic enzymatic activity

Answer 14

A subunit

Question 15

subunit that is responsible for binding the exotoxin to specific receptors on the host cell membrane and may help in the transfer of the B subunit across the cell

Answer 15

B subunit

Question 16

toxins that has A–B subunit structure

Answer 16

tetanus toxin and botulinum toxins

Question 17

the principal challenge for the host is to?

Answer 17

detect the pathogen & mount a rapid defensive response

Question 18

The cells of the innate immune system express
various________ ______ ______capable of detecting conserved molecular ‘patterns’ that are unique to microorganisms and are not expressed by the
hosts

Answer 18

pattern recognition receptors

Question 19

Pattern recognition receptors is also called ?

Answer 19

pathogen associated molecular patterns

Question 20

if the pathogen is not excreted i the faeces the host is describe as ?

Answer 20

latent carrier

Question 21

if the pathogen is excreted i the faeces & is continiously or intermittently the host is cosidered as?

Answer 21

active carrier

Question 22

route that is by the passage through intercellular spaces, this can be taken by bacteria that are able to disrupt the intercellular tight junction.

Answer 22

paracellular route

Question 23

during this time bacteria are present transiently the bloodstream without replicating.

Answer 23

Bacteraemia

Question 24

while this time pathogenic microorganism multiply & persist in the bloods stream producing systemic disease.

Answer 24

Septicaemia

Question 25

the pathogens enter the epithelial cells through the _____ formed by the host cell membranes in response to signals generated by the pathogens.

Answer 25

membrane-bound vacuoles

Question 26

this type of induced uptake mechanism is induced by specific ligand-receptor interactions at the cell membrane

Answer 26

zipper mechanism

Question 27

this type of induced uptake mechanism is induced by effector molecules delivered into the cell by a type 3 secretory system.

Answer 27

trigger mechanism

Question 28

_____ usually have a short severe clinical course, often a matter of days, & the invadimg bacteria are usually cleared from the body bu the hosts immune response.

Answer 28

acute infections

Question 29

_____ produce clinical effects or less intensity

Answer 29

subacute infections

Question 30

_____ tend to occur when the host fails to eliminate the pathogen

Answer 30

chronic infections

Question 31

Endotoxins is composed of 3 parts:

Answer 31

1. Hydrophobic glycolipid (LIPID A)
2. Hydrophilic polysaccharide composed of (oligosaccharide )
3. Opolysaccharide (O antigen)

Question 32

toxicity redsides in?

Answer 32

Lipid A portion

Question 33

Toll- like receptor is composed of:

Answer 33

1. mononuclear phagocytosis
2. neutrophils
3. platelets
4. dendritic cells
5. B-lymphocytes

Question 34

Release of cytokines induce & stimulate _____ that divide & produce antibodies:

Answer 34

Induced:
1. fever
2. active macrophages
3. clotting factor XII
Stimulate:
1. B cells

Question 35

Categories of exotoxins:

Answer 35

1. toxins that act on the extracellular matrix
2. toxins that act on the plasma membrane of their target cells, where they interfere w/ transmembrane signaling pathways or alter membrane permeability
3. toxins that act inside the cells where they modify signaling pathways or the activities of the cytoskeleton
4. toxins that cause dysfunction of the immune system called “superantigens”

Question 36

TLR’s is expressed in: 6 immune cells & 3 non-immune cells

Answer 36

Immune cells:
1. macrophages
2. dendritic cells
3. neutrophils
4. mast cells
5. b cella
6. specific t cells
non-immune cells:
1. epithelial cells
2. endothelial cells
3. fibroblast

Question 37

this ______ is competent to detect microorganism

Answer 37

Innate immune system

Question 38

this ______ detect the molecular signatures of microbial pathogens, they orchestrate the innate immune response, & they help the adaptive immune response.

Answer 38

TLR’s

Question 39

this pathogen in cattle herds, can establish long term residence in both latent carriers & active carriers.

Answer 39

Salmonella dublin

Question 40

______ bacteria produces high lethal toxins that kill the host, which then becomes an anaerobic substrate in which the bacteria multiply & from which they can be disseminated spores.

Answer 40

Clostridium species

Question 41

this type of foriegn recognition is expressed in the surface by the microbes.

Answer 41

PAMPS

Question 42

while this type of recognition is expressed by own cell, example injured cells that is needed to be removed or get rid off.

Answer 42

DAMPS

Question 43

the strain of this microorganism is enterotoxigenic, it adhere to the epithelial cells of the small intestine in newborn farm animals, not invasive but they induced profuse quantities of watery diarrhoea.

Answer 43

Escherichia coli

Question 44

_____ can contaminate a wound in any region of the body, producing a neurotoxins.

Answer 44

Clostridium tetani

Question 45

secretes a number of toxin that degrade the epithelial barrier & allow the opportunistic pathogen to enter the sub epithelial barrier & allow the opportunistic pathogen to enter sub epithelial tissues.

Answer 45

pseudomonas aeruginosa

Question 46

occur after direct or indirect transmission form an infected animal or from the environment.

Answer 46

Exogenous infection