Module 5: Microbial and Host Interactions

Question 1

Normal Flora

Answer 1

• bacteria found on skin and mucous membranes

- fairly constant composition

Question 2

Transient Normal Flora

Answer 2

• present for short time only

- caused by antibiotics, hospitalization

Question 3

Contamination

Answer 3

• bacteria present are not normal flora
• bacteria not growing on site
  ex. fecal contamination of hands or wounds

Question 4

Colonization

Answer 4

• bacteria present are growing at site

- no host reaction to bacteria

Question 5

Infection

Answer 5

• bacteria growing at a body site cause an immune reaction

ex. fever, inflammation, pus

Question 6

Pathogenicity

Answer 6

Ability of a microorganism to cause disease

Question 7

Virulence

Answer 7

Degree of pathogenicity of a bacterium

Question 8

Pathogen

Answer 8

Microorganisms capable of causing disease

Question 9

Hyaluronidase

Answer 9

Extra cellular enzyme mainly produced by gram positive bacteria

Question 10

Collagenase

Answer 10

• breaks down collagen in connective tissue

- bacteria spread faster into tissue

Question 11

Hemolysins

Answer 11

Lyse red blood cells

Question 12

Leukocidins

Answer 12

Kill phagocytic white blood cells causing pus or exudate

Question 13

Kinases

Answer 13

Break down fibrin clots formed by the body to isolate infecting bacteria

Question 14

Exotoxins

Answer 14

• mainly produced by gram positive bacteria
• specific site of action in host
• antigenic (causes an immune response)

Question 15

Endotoxins

Answer 15

• produced by gram negative bacteria
• not antigenic
• non specific sites in host affected
• part of cell wall

Question 16

Inflammation

Answer 16

• histamine released at site of infection

- swelling, redness, pain, heat

Question 17

Serous

Answer 17

Watery fluid, few neutrophils

Question 18

Transudate

Answer 18

Noncellular fluid, passive leak from blood or lymph vessels

Question 19

Purulent

Answer 19

WBC’s or PMN’s at the infection site causes pus.

Question 20

Granulomatous Infection

Answer 20

Granuloma at site of infection contains large macrophages

Question 21

Cellulitis

Answer 21

Under the skin loose connective tissue, fluid spreads between layers causing swelling and redness

Question 22

Epidemic

Answer 22

Many people in an area having a disease over a short period of time ex. Bubonic Plague

Question 23

Endemic

Answer 23

Small percentage of population constantly has a disease

ex. Pneumonia

Question 24

Pandemic

Answer 24

World wide epidemic ex.Spanish Flu

Question 25

Epidemiology

Answer 25

Study of when and where diseases occur

Question 26

Endogenous Infection

Answer 26

Infecting bacteria are from your own body | ex. UTI

Question 27

Exogenous Infection

Answer 27

Infecting bacteria come from outside the body | ex. Strep Throat

Question 28

Nosocomial

Answer 28

Infection acquired from the hospital environment

Question 29

Carrier

Answer 29

Person carries potential pathogens without it causing harm

Question 30

Primary

Answer 30

Initial infection caused by bacterium

Question 31

Secondary Infection

Answer 31

An infection following a primary infection and usually caused by a different bacterium

Question 32

Nonspecific Infection

Answer 32

Bacterial cause of infection is not identified

Question 33

Opportunistic

Answer 33

Low grade pathogen causes infection in immunosuppressed or chronically ill patients

Question 34

Acute Infection

Answer 34

Short duration but nasty | ex. salmonella (5-10 days)

Question 35

Chronic Infection

Answer 35

Long lasting | ex. reoccurring yeast infection

Question 36

Localized Infection

Answer 36

Restricted to a small area | ex. skin lesion

Question 37

Disseminated Infection

Answer 37

Infection spread to many body areas | ex. bacteria in bloodstream