Module 5

Question 1

What is normal flora?

Answer 1

Bacteria normally found at a body site.

Question 2

What is transient normal flora?

Answer 2

It is not the same organism as NF and is only present for a short amount of time.

Question 3

What is contamination?

Answer 3

The presence of bacteria where it normally isn’t without any growth.

Question 4

What is the difference between colonization and infection?

Answer 4

There is no host reaction in colonization.

Question 5

What is pathogenicity?

Answer 5

The ability of bacteria to cause disease.

Question 6

What is virulence?

Answer 6

The degree of pathogenicity.

Question 7

What is a nonpathogen?

Answer 7

Microorganisms not capable of causing disease.

Question 8

What are some examples of virulence factors and their functions?

Answer 8

Capsules- prevent phagocytosis
Hyaluronidase- dissolves connective tissue making it easier to spread
Collagenase- breaks down collagen making it easier to spread
Hemolysins- lyse RBCs, decreases host immunity
Leukocidins- kills phagocytotic cells
Kinases- breaks down fibrin clots making it easier to spread

Question 9

What bacteria is hyaluronidase mostly found in?

Answer 9

Gram positive

Question 10

Which bacteria produce exotoxins?

Answer 10

Gram positive

Question 11

Which bacteria produced endotoxins?

Answer 11

Gram negative

Question 12

What are the characteristics of exotoxins?

Answer 12

Excreted from living cells.

Antigenic so can be converted to toxoids for immunizations.

Have a specific target

Question 13

What are the characteristics of endotoxins?

Answer 13

Part of the cell wall and are only released when cells lyse.

Not antigenic.

Have nonspecific action sites.

Question 14

What are the body’s defence mechanisms against infection?

Answer 14

Fever, lymph node swelling, inflammation, exudate, granulomatous infection, and cellulitis.

Question 15

What types of exudate are there and what are their characteristics?

Answer 15

Purulent- contains WBCs

Serous- watery fluid with few WBCs

Transudate- no cellular fluid, passive vessel leakage

Question 16

What is the function of a granulomatous infection?

Answer 16

To walk off the infection site by macrophages fusing together.

Question 17

What’s the difference between an epidemic and an endemic?

Answer 17

Epidemic- many people have the disease in a small period of time

Endemic- a disease that’s constantly present in the population in a small percentage

Question 18

What is epidemiology?

Answer 18

The study of when and where diseases occur and how they’re spread.

Question 19

What is the difference between a endogenous and exogenous infection?

Answer 19

Endo- bacteria originate from the host’s body

Exo- bacteria originate from outside the host’s body

Question 20

Where is a nosocomial infection obtained?

Answer 20

The hospital

Question 21

What is a disseminated infection?

Answer 21

An infection that spreads throughout most of the body.

Question 22

What are Koch’s postulates?

Answer 22

1. Found in every case
2. Isolated from host and grown by itself
3. Reproduced when injected in a healthy host
4. Recoverable from new host