Module 5

Question 1

Koch’s Postulates

Answer 1

Robert Koch proved bacteria can cause disease.

Question 2

Koch’s Postulates 4 requirements

Answer 2

1) Microorganism must be found in every case to be called the Causative Agent.
2) Microorganism must be grown in a pure culture
3) Disease must be reproduced when pure culture is injected into healthy host
4) Microorganism must be recoverable from the injected host

Question 3

Normal Flora

Answer 3

Bacteria normally found on outer surfaces and mucous membranes of the body

Question 4

Transient Normal Flora

Answer 4

Bacteria different from usual flora and present for short time

Question 5

Contamination

Answer 5

• Presence of bacteria in/on body site
• Not part of normal flora
• Bacteria not growing

Question 6

Colonization

Answer 6

Contamination, but bacteria are growing

No host reaction

Question 7

Infection

Answer 7

Bacteria growing in/on a body site

Causing host reaction

Question 8

Pathogenicity

Answer 8

Ability of a microorganism to cause disease

Question 9

Virulence

Answer 9

Degree of pathogenicity

Question 10

Pathogen

Answer 10

Microorganism capable of causing disease

Question 11

Nonpathogen

Answer 11

Microorganism not capable of causing disease

Very few microorganisms can be classified this as most are capable of causing some sort of infection

Question 12

6 Factors contributing to pathogenicity

Answer 12

Capsules
Hyaluronidase
Collagenase
Hemolysins
Leukocidins
Kinases

Question 13

Capsules

Answer 13

prevent phagocytes from attaching to bacteria

Question 14

Hyaluronidase

Answer 14

Extracellular enzyme mainly produced by Gram positive bacteria
Dissolves hyaluronic acid (compound in connective tissue matrix)
Allows bacteria to spread throughout tissue

Question 15

Collagenase

Answer 15

Breaks down collagen (in connective tissue)

Allows bacteria to spread faster in connective tissue

Question 16

Hemolysins

Answer 16

Lyse RBCs

Decreases host’s immunity

Question 17

Leukocidins

Answer 17

Kills phagocytic cells creating pus

Question 18

Kinases

Answer 18

Break down fibrin clot (formed by body to isolate infection)

Bacteria break through clot and spread

Question 19

2 types of bacterial toxins

Answer 19

exotoxins and endotoxins

Question 20

Exotoxins

Answer 20

Mainly produced by Gram Positive bacteria
Excreted from living bacterial cells
Mainly protein molecules
Antigenic (causes an immune response)
May be converted to toxoids for immunization
Have a specific site of action in host

Question 21

Endotoxins

Answer 21

Produced my Gram Negative bacteria
Part of the cell wall (Lipopolysaccharide of outter membrane)
Released when cell walls are lysed (from antibiotics)
Do not form toxoids for immunization
Nonspecific sites of action in the host
Symptoms: aches, malaise, fever, decreased blood pressure, shock

Question 22

Signs of bacterial infection

Answer 22

Fever, lymph node swelling, inflammation, exudate, Granulomatous infection, cellulitis`

Question 23

Lymph Node Swelling

Answer 23

System accumulates and drains waste fluids
Nodes may become infected/swollen due to increase of antibody-producing cells
Neck, under arms, groin

Question 24

Inflammation

Answer 24

Damaged cells release histamine

Results in dilation of blood vessels, fluid and phagocytes move in

Question 25

Exudate

Answer 25

Accumulation of fluid at site of infection | Purulent exudate, serous exudate, transudate

Question 26

Purulent exudate

Answer 26

AKA Polymorphonuclear neutrophils (PMNs) | Many WBC, neutrophils, pus

Question 27

Serous exudate

Answer 27

Watery fluid is few polymorphonuclear neutrophils (PMNs) and less protein

Question 28

Transudate

Answer 28

noncellular fluid (leadage from blood or lymph vessels)

Question 29

Granulomatous Infection

Answer 29

Granuloma formed at site of infection Collections of macrophages -results in increased capacity for phagocytosis and digestion

Question 30

Epidemic

Answer 30

Many people in an area having a disease over a short period of time

Question 31

Endemic

Answer 31

Disease constantly present in a small percentage of the population

Question 32

Pandemic

Answer 32

World-wide epidemic

Question 33

Epidemiology

Answer 33

the study of when/where disease occurs and how it is spread

Question 34

Endogenous Infection

Answer 34

Infecting bacteria come from the host's own body

Question 35

Exogenous Infection

Answer 35

Infecting bacteria come from outside the hosts body

Question 36

Nosocomial Infection

Answer 36

Hospital acquired infection

Question 37

Carrier

Answer 37

Potential pathogen carried by a host (no signs of infection)

Question 38

Primary Infection

Answer 38

Initial infection caused by a microorganism

Question 39

Secondary Infection

Answer 39

Infection following a primary infection caused by a different microorganism

Question 40

Nonspecific infection

Answer 40

Microbial cause not identified

Question 41

Opportunistic Infection

Answer 41

Caused by Low Grade Pathogen | typically in patients with lowered immune system

Question 42

Disseminated Infection

Answer 42

Spread to most parts of the body