Brock Biology Of Microorganisms Chapter 21

Front 1

Virulence

Back 1

The qualitative measure of pathogenicity

determined by invasiveness, toxicity and other factors

Front 2

Opportunistic Pathogen

Back 2

causes diseases in teh absence of normal host resistance

Front 3

True or False: Most of microbes are nonpathogenic and do not cause harm

Back 3

True

Front 4

Infection

Back 4

Any situation where a microbe is established and growing in a host

Host is not necessarily harmed in infection

Front 5

Disease

Back 5

Damage or injury to the host that impairs host function

Front 6

Differing Environments for infection

Back 6

Skin (Dry environment)

Lungs (Oxygenated Environment)

Large Intestine (anaerobic environment)

Front 7

Mucous Membranes

Back 7

Common site where infection begin

Front 8

Mucus

Back 8

viscous glycoprotein that covers mucous membranes

may be loosely or tightly associated with the mucosal surface

Front 9

What determines if tissue infection occurs?

Back 9

The type of microbe association with mucosal surface

Front 10

True or False: Human skin is generally not a favorable place for microbial growth

Back 10

True

Front 11

Transient Microbes

Back 11

unable to multiply on the skin and usually die

most are gram (-) as they cannot compete with gram (+) bacteria

Front 12

Resident Microbes

Back 12

survive and multiply on skin

most are gram (+)

gram (+) better suited for dry environments

Front 13

What factors increase resident microflora?

Back 13

1) Weather

2) Age

3) Hygiene

Front 14

Lysozymes

Back 14

found in saliva

can cleave glycosidic linkages in teh peptidoglycan of bacteria

Front 15

Dental Plaque

Back 15

bacteria growth on tooth surfaces in thick layers

begins as glycoprotein that grows into a thick layer

caused by species of streptococcus

Front 16

Oral Microbes

Back 16

produce large amounts of organic acids that cause decalcification of tooth enamel (cavities)

can also lead to gingivitis

Front 17

Acidity in intestine

Back 17

Very acidic in the duodenum portion and becomes more neutral in pH toward its distal end

distl end of samall intestine and entire large intestine are both neutral in pH therefore microbes more prevalent in these neutral environments

Front 18

Microflora in Colon

Back 18

Mostly obligate anaerobes, although some faculative aerobes

composition of microflora and diet have a large influence on what metabolic compounds are produced

Front 19

Four microbes most commonly found in Upper respiratory tract

Back 19

1) Staphylococci

2) Streptococci

3) Diphtheroid bacilli

4) gram (-) cocci

Front 20

Microbes in Upper Respiratory Tract

Back 20

potentially harmful bacteria are often part of the nasal flora of healthy individuals

do not cause disease if the other resident microbes out compete the potentially harmful types and limit pathogen growth

Front 21

Microbes in lower respiratory tract

Back 21

has no resident microglora

ciliated epithelial tissue push microbes and debris away from the trachea bronchi and lungs

Front 22

What is responsible for bacterial adherence to host tissue cells

Back 22

macromolecules like polysaccharides, proteins or glycoproteins

these are usually synthesized and secreted by the bacteria and extend outward forming slime layers or capsule structures

Front 23

Four types of nutrients for pathogen

Back 23

Vitamins, amino acids, sugars, organic acids

Front 24

Erythritol

Back 24

important growth factor

helps brucella abortus gorw in cattle

Front 25

Iron

Back 25

greatly influences microbial growth

Transferrin and lactoferrin proteins in animals bind iron tightly

Front 26

Siderophores

Back 26

proteins that remove iron bound to transferrin

Front 27

Toxicity

Back 27

ability of an organism to cause disease by means of a toxin that inhibits host cell function or kills host cells

Front 28

Invasiveness

Back 28

ability of an organism to grow in a host tissue in such large numbers that the pathogen inhibits host function

Front 29

Attenuation

Back 29

the loss of virulence by a microbe or a strain

Front 30

Three toxins produced by Salmonella

Back 30

1) Enterotoxin

2) Endotoxin

3) Cytotoxin

Front 31

Enterotoxin

Back 31

extracellular toxin that damages the host small intestine

Front 32

Endotoxin

Back 32

LPS layer toxin that beocmes toxic when solubilized

Front 33

Cytotoxin

Back 33

toxin that inhibits host cell protein synthesis by inducing a leak of calcium ions forom the host cell

Front 34

How does salmonella establish infection?

Back 34

Through intracellular parasitism

grow inside clelse that line the intestins as well as in phagocytic cells of the host immune system

Front 35

Virulence Factors

Back 35

extracellular proteins produced by pathogens that aid in teh establishment and maintenance of a disease

Front 36

Hyaluronidase

Back 36

breaks down hyaluronic acid in host cells

"intercellular cement"

Front 37

Streptokinase

Back 37

dissolves clots

produced by streptococcus pyogenes

Front 38

coagulase

Back 38

promotes clot formations

produced by s. aureus