Dr. Bailey Study Guide 1

Question 1

6 Steps in the infectious disease process

Answer 1

1) Encounter
2) Entry
3) Spread
4) Multiplication
5) Damage
6) Outcome

Question 2

Encounter with microbe

Answer 2

The different natural reservoirs of infectious microbes

Does not necessarily mean infection

Question 3

Entry

Answer 3

Pathogens going into the body

Question 4

Spread

Answer 4

Pathogens must adhere to the host, multiply, and spread

Question 5

Different mechanisms for microbe spreading

Answer 5

Lateral propogation

Dissemination

Question 6

Lateral propogation

Answer 6

Microbes multiply then spread to distant sites

Question 7

Dissemination

Answer 7

Microbes spread then multiply

Question 8

Damage

Answer 8

How a host responds

Question 9

Processes for entering into a host

Answer 9

1) Ingress of microorganisms into body that are contiguous with the outside capsule
2) Penetration of a microorganism into deeper tissues after crossing an epithelial barrier (insect bites, cuts, transplants, etc)

Question 10

Body parts that are “external”

Answer 10

Nose
Mouth
Respiratory tract
Alimentary canal
Anus
Female genital tract
Urinary Tract

Question 11

Steps for bacteria to enter epithelia

Answer 11

Attachment

Internalization

Question 12

Strict aerobes

Answer 12

Must have oxygen to grow

Question 13

Obligate anaerobes

Answer 13

Cannot tolerate oxygen

Question 14

Facultative anaerobes

Answer 14

Can grow with or without oxygen

Most medically important bacteria

Question 15

Oligotrophs

Answer 15

Can grow with limited nutrients

Question 16

What must microbes overcome in order to spread

Answer 16

Host defenses

Question 17

Microaerophiles

Answer 17

Require some oxygen, but lower levels of oxygen

Question 18

Mesophils

Answer 18

Grow in mild temperatures (15-45 degrees C)

Question 19

Inoculum size

Answer 19

The number of organisms it takes to cause disease

Important in establishing an infection

Question 20

4 Possible outcomes of a host-parasite interaction

Answer 20

1) Host wins and clears infection
2) Parasite overcomes the host
3) The hist and parasite adapt to eachother
4) Neither host or parasite win

Question 21

How long can a chronic infection last

Answer 21

Indefinately

Question 22

Damage to the host can be caused by…

Answer 22

The infectious agent or immune response or both

Question 23

The great majority of microorganisms are..

Answer 23

Commensal

Question 24

Gram positive bacteria

Answer 24

Have a thick cell wall made up of muerin

Question 25

Muerin

Answer 25

A peptidoglycan made up of long chains of N-acetylmuramic acid and N-acetylglucosamine linked together by short polypeptides

Question 26

Gram negative bacteria

Answer 26

Have a thin layer of muerin between two membranes

Question 27

Outer membrane of Gram-negative bacteria

Answer 27

Made up of Lipopolysaccharide (LPS) that is species-specific

Question 28

Lipopolysaccharide

Answer 28

On outer membrane of Gram- cell walls. Toxic in even in purified form. Made up of a lipid region that faces towards the cell, and a polysaccharide that faces out.

Question 29

Bactericidal agents

Answer 29

Kill bacteria

Question 30

Bacteriostatic agents

Answer 30

Inhibit bacteria growth

Question 31

How do Penicillins and other beta-lactams work?

Answer 31

Bactericidal agents that affect the cell wall

Question 32

How do antibiotics often work

Answer 32

By targeting bacterial ribosomes. Can target either the 30S or 50S subunits

Question 33

2 subunits to bacterial ribosomes

Answer 33

30S | 50S

Question 34

30S ribosomal subunit

Answer 34

Primarily responsible for the translation of mRNA

Question 35

Teichoic acid

Answer 35

Surface structure found on both Gram+ and Gram- bacteria not embedded in cell membrane (Lipoteichoic acid when it is) Thicker in Gram+

Question 36

Importance of bacteria cell surface structures

Answer 36

Cells of the immune system recognize them

Question 37

Toll-like receptor 4 recognizes

Answer 37

LPS

Question 38

Toll-like receptor 2 recodnizes

Answer 38

Peptidoglycan

Question 39

Toll-like receptor 2 and 4 together reecognizes

Answer 39

Teichoic acids

Question 40

50S ribosomal subunit

Answer 40

Resonsibel for joining amino acids together and moving the complex along the mRNA molecule

Question 41

Sulfonamides and trimethoprim inhibit...

Answer 41

Folic acid metabolism

Question 42

Aminoglycosides, tetracyclines, and erythromycin inhibit

Answer 42

Protein syntesis

Question 43

Metronidazole inhibits

Answer 43

DNA synthesis

Question 44

Pili or fimbriae

Answer 44

Specialized structures on the surface of bacteria that are involved in adhesion to cells or other surfaces

Question 45

Sex pili

Answer 45

Specialized pili that link a donor cell to a recipient during transfer of DNA

Question 46

Flagella

Answer 46

Surface structures used for locomotion.

Question 47

Flagella counterclockwise movement

Answer 47

Locomotion of a cell

Question 48

Flagella clockwise movement

Answer 48

Tumbling

Question 49

Flagellar movement is used by bacteria for..

Answer 49

Chemotaxis - the movement towards a substance that attract and away from substances that repel

Question 50

Obligate intracellular parasites

Answer 50

Can only grow inside host cells

Question 51

Theraputic index

Answer 51

The ratio between the effective dose and toxic use of the antibiotic

Question 52

Antibiotics tend to target structures that...

Answer 52

are unique in bacteria compared to structures found in host cells

Question 53

Sulfa drugs

Answer 53

Interact with an enzyme to prevent the production of a metabolite

Question 54

Mechanisms of antibiotic resistance

Answer 54

- Synthesizing enzymes that inactivate a drug - Inhibiting uptake of a drug - Increasing secretion of the drug (pumping it out of the cell) - Modifying the target of the drug

Question 55

Drug resistant genes

Answer 55

Often found on plasmids that can readily be transferred from one bacteria to another

Question 56

In order to survive as an infectious agent, bacteria must...

Answer 56

1) Avoid being washed away 2) Find a nutritionally compatible niche 3) Survive host defenses 4) Transfer to a new host

Question 57

Damage to a host as a result of an infection can be caused by....

Answer 57

- cell death - pharmacological alteration of metabolism - mechanical causes - host responses - bacterial toxins

Question 58

Many structures on the microbial surface consists of...

Answer 58

Repeated molecules - referred to as pathogen associated molecular patterns

Question 59

Pattern recognition receptors

Answer 59

Recognize pathogen associated molecular patterns

Question 60

Bacteria are often classified by...

Answer 60

Their surface antigens (aka serotype) O refers to LPS H refers to flagella K refers to a capsule