Microbiology Test 3

Front 1

What are microorganisms usually found associated with human body tissue?

Back 1

Normal microbial flora

Front 2

What cause disease either by infection, intoxication, or allergy?

Back 2

Pathogens

Front 3

What is the ability to cause damage or disease?

Back 3

Pathogenicity

Front 4

What is the quantitative measure of pathogenicity?

Back 4

Virulence

Front 5

What causes disease only in the absense of normal host resistance?

Back 5

Opportunistic pathogen

Front 6

What is the situation in which a microbe is established and growing in a host, whether or not the host is harmed?

Back 6

Infection

Front 7

What is dmaage or injury to the host that impairs host function?

Back 7

disease

Front 8

At what site do infections normally begin at?

Back 8

mucous membranes

Front 9

The composition of normal flora on the skin is influenced by what factors?

Back 9

environmental factors such as weather and host factors such as age and personal hygeine.

Front 10

Most normal flora on skin are composed of what types of cells?

Back 10

G+

Front 11

Saliva contains what type of enzymes?

Back 11

antimicrobial enzymes

Front 12

Bacteria colonize tooth surfaces by first attaching to acidic _______ deposited there by saliva.

Back 12

glycoproteins

Front 13

Extensive growth of oral microorganisms, especially streptococci, results in a thick bacterial layer know as?

Back 13

dental plaque

Front 14

As plaque continues to develop on a tooth, ______ bacterial species begin to grow.

Back 14

anaerobic

Front 15

As dental plaque accumulates, the microorganisms produce high concentrations of acid that results in decalcification of the tooth enamel known as?

Back 15

dental caries

Front 16

The lactic acid bacteria _______ and ________ mutans are common agents in dental caries.

Back 16

Streptococcus sobrinus and streptococcus mutans

Front 17

Microbial populations in the GI tract are influenced by what?

Back 17

diet and the physical conditions in that area

Front 18

What prevents many organisms from colonizing in the GI tract?

Back 18

The acidity of the stomach and the duodenum(1st part) of the small intestine (pH=2)

Front 19

Intestinal microorganisms carry out a variety of essential metabolic reactions that produce various compounds such as?

Back 19

-vitamins
-gas, organic acids, odor
-enzymes

Front 20

A restricted group of organisms colonizes the upper respiratory tract. Give some examples.

Back 20

staphylococci, streptococci, diphtheroid bacilli, and G- cocci.

Front 21

The _____ respiratory tract lacks microflora in healthy individuals.

Back 21

lower

Front 22

What two microorganisms usually cause UTIs in women?

Back 22

E. coli and P. mirabilis

Front 23

The vagina of the adult female is weakly acidic and contains significant amounts of _____.

Back 23

glycogen

Front 24

What organism ferments glycogen in the vagina producing lactic acid?

Back 24

Lactobacillus acidophilus

Front 25

What is the relative ability of a pathogen to cause a disease?

Back 25

Virulence

Front 26

How is virulence measured?

Back 26

By experimental studies of the LD50(lethal dose 50) which is the amount of an agent that kills 50% of the animals in a test group

Front 27

What would be an example of a highly virulent organism?

Back 27

Streptococcus pneumoniae

Front 28

What is the decrease or loss of virulence?

Back 28

Attenuation

Front 29

What is it called when an organism causes disease by means of a toxin that inhibits host cell funtion or kills host cells?

Back 29

Toxicity

Front 30

What is the ability of a pathogen to grow in host tissue at densities that inhibit host function(can cause damage without producing a toxin)?

Back 30

Invasiveness

Front 31

Pathogen invasion starts at the site of adherence and may spread throughout the host via the ________ or _______ systems.

Back 31

circulatory or lymphatic

Front 32

What is it called when a pathogen must gain access to host tissues and multiply before damage can be done?

Back 32

specific adherence

Front 33

Bacterial adherence can be facilitated by what?

Back 33

-extracellular macromolecules that are not covalently attched to the bacterial cell surface(slime layer, capsule)
-fimbriae and pili

Front 34

What is most important in affecting pathogen growth?

Back 34

the availability of nutrients

Front 35

Pathogens produce enzymes that enhance virulence by breaking down or altering host tissue to provide access to nutrients. What would be an example of this type of enzyme?

Back 35

hyaluronidase

Front 36

Pathogens also produce enzymes that protect the pathogen by interfering with normal host defense mechanisms. An example of this enzyme would be?

Back 36

coagulase

Front 37

What are proteins released from the pathogen as it grows?

Back 37

Exotoxins

Front 38

What are three categories of exotoxins?

Back 38

cytolytic toxins, AB toxins, and superantigen toxins

Front 39

How do cytolytic toxins work?
Toxins thatlyse red blood cells are called what?

Back 39

- by degrading cytoplasmic membrane integrity, causing cell lysis and death.
- hemolysins

Front 40

How to AB toxins work? What are some examples?

Back 40

- By binding to host cell receptor( B subunit) and transferring damaging agent (A subunit) across the cell membrane.
- diptheria toxin, tetanus toxin, and botulinum toxin

Front 41

What two organisms produce potent AB exotoxins that affect the nervous system?

Back 41

Clostridium tetani and Clostridium botulinum

Front 42

What is a type of exotoxin whose activity affects the small intestine and generally cause massive secretions of fluid into the intestinal lumen causing vomiting and diarrhea? List an example

Back 42

Enterotoxins (cholera toxin)

Front 43

What type of toxin consists of the lipopolysaccharide portion of the cell envelope of certain G- bacteria? (toxic when solubilized)

Back 43

Endotoxins

Front 44

The prescence of endotoxins can be detected by what?

Back 44

the Limulus amoebocyte lysate(LAL) assay.

Front 45

What is a host called that consist of one or more inactive resistance mechanisms and has an increased probability of infection?

Back 45

Compromised host

Front 46

What are some common risk factors that canlead to compromised host?

Back 46

-Age(very young or very old)
-Stress
-Diet
-Certain genetic conditions

Front 47

What are some reasons as to why hosts have an innate resistance to most pathogens?

Back 47

-natural host resistance
-tissue specificity
-physical and chemical barriers