ID Intro

Question 1

3 variables affecting development of infection and disease

Answer 1

1. Host
2. Environment
3. Agent

Question 2

Gram stain fxn

- how do G + and - look?

Answer 2

Differentiates Gram + from Gram - bacteria

Gram Positive

• large peptidoglycan layer (up to 90% of cell wall)
• holds the dye
• Purple

Gram Neg

• thin peptidoglycan layer
• Pink

Question 3

Two main bacteria in each group

1. GPC
2. GPR
3. GNC
4. GNR

Answer 3

Gram + cocci (GPC)

1. Staph
2. Strep

Gram + rods (GPR)

1. Listeria
2. Clostridium

Gram - cocci (GNC)

1. Neisseria
2. Moraxella

Gram - rods (GNR)

1. E. coli
2. Pseudomonas

Question 4

How are infectious agents recognized by the immune system?

Answer 4

Security against a particular disease

Use PRR to Recognize MAMPS and DAMPS

Question 5

What unique properties are found only in Gram + and only in Gram -

Answer 5

Gram + : teichoic acid
(found in thick cell wall/cell membrane)

Gram - : Endotoxin/LPS
(a lipopolysaccharide found w/in outer membrane, outside of thin peptido wall)

Question 6

Non staining organisms with no cell wall.

List some others.

Answer 6

1. Mycoplasma
2. Chlamydia
   ____________
   Other:
   Legionella (poor)
   Mycobacteria
   Spirochetes
   Rickettsia

Question 7

Lactose fermenting GNR

Answer 7

#1 E. coli
Klebsiella
Enterobacter
Citrobacter
Arizona

Question 8

Classic Non lactose fermentting GNR

Answer 8

Pseudomonas aerugonosa

Salmonella

Shigella

Question 9

Gram neg Cocci

GNC

Answer 9

Neisseria sp

• gonorrheae
• meningitidis

Moraxella catarrhalis

Acinetobacter

(can be present after everything has been killed)

Question 10

GPC
Pairs/clusters

Pairs/Chains

Pairs

Which ones are catalase +?

Answer 10

Pairs/clusters
- staph

Pairs/Chains
- strep

Pairs
- either

Staph is cat +, strep is -

Question 11

Which of the staph is coag + and -?

Answer 11

+ : S. aureus

• : S. epidermidis, saprophyticus, lugdane

Question 12

GPR
small
large

Answer 12

small:
*Listeria (preggos at risk)
Diphteroids

Large:
*Clostridium sp.
bacillus

Question 13

Sources of anaerobes

Answer 13

Normal flora are often anaerobes

1. oral
2. lung
3. intestines
4. Female GU

3% of + blood culture

Question 14

Pattern recognition receptors (PRR):

1. Transmembrane (surface)
2. Cytosolic
3. Extracellular

Answer 14

Transmembrane (surface)
- TLRs

Cytosolic
- NOD, TLR

Extracellular
- CD14, LBP

Question 15

Noninfectious fever

Answer 15

The C-C-C-C-C-Causes

1. Cancer
2. Chemicals
3. Collagen vascular
4. Clot
5. Central fever
6. Consider

Question 16

Cell wall synthesis is target for which drugs?

Answer 16

B lactams (PCN, Ceph)

Glycopeptides (bacitracin, vanco)

Question 17

Cell membrane is target for which drugs?

Answer 17

Polymyxins

Question 18

Outer membrane regulates what 3 things?

Answer 18

B lactamases
Permeability
Efflux

Question 19

Steps of gram staining

Answer 19

1. Heat slide (kill and bind bact)
2. Crystal violet (stain)
3. Iodine (mordant that binds the crystal violet to Gram + cell wall)
4. Decolorizer (acetone alcohol to remove stain from G- cells)
5. Safrinin (counterstain)

Question 20

Coagulase + staphylococci

Answer 20

S. aureus

Question 21

Bacteria associated with endocarditis (4)

Answer 21

1. S. viridans
2. enterococcus
3. S. aureus
4. S. pneumoniae

Question 22

Bacteria associated with meningitis (4)

Answer 22

1. S. pneumoniae
2. N. meningitidis
3. Listeria
4. H. influenzae

Question 23

5th sign of inflammation

Answer 23

functio laesa

- impaired fxn

Question 24

Techoic acid and Endotoxin/LPS are found in which bacteria?

Answer 24

Teichoic acid:
- GP

Endotoxin/LPS (outer membrane)
- GN

Question 25

Fxn of Teichoic acid

Answer 25

Induces TNF and IL-1 | - Found in GP

Question 26

Which drugs have high oral bioavailability?

Answer 26

Quinolones TMP/SMX Metronidazole

Question 27

True / False Infxs dis can be acute or chronic Infxs dis are NOT always contagious Colonization is NOT equal to disease

Answer 27

True to all

Question 28

Bacteremia is typically caused by which org?

Answer 28

Staph! its bad ~ 100% - if S. epi is present, its prob just a contaminant.