Intro to Bacteria I (lec 1)

Question 1

Size ranges for:

Bacteria

Viruses

Yeast

Answer 1

Bacteria: 0.2 - 2.0 µm

Viruses: 0.15 - 0.3 µm

Yeast: 4 -20 µm

Question 2

Bacteria Shapes:

Sphere

Rod

Curved Rod

Spiral Rod, flexible

Spiral Rod, rigid

Short Rod

Variety in one species

Answer 2

Sphere = Coccus

Rod = Bacillus

Curved Rod = Vibrio

Spiral Rod, flexible = Spirochete

Spiral Rod, rigid = Spirillum

Short Rod = Coccobacillus

Variety in one species = Pleomorphic

Question 3

Cocci Bacterial Arrangements:

Pair

Chain

Grape-like Cluster

Group of Four

Answer 3

Pair = Diplo

Chain = Strepto

Grape-like Cluster = Staphylo

Group of Four = Tetrad

Question 4

Bacterial Cytoplasmic Membrane composed of?

Does NOT include?

Answer 4

lipid bilayer w/ proteins

No Sterols

Question 5

What bacteria do not have a Cytoplasmic Membrane?

Answer 5

Mycoplasma spp
Ureaplasma spp
(respiratory, urogenital)

No cell wall means PCN/cephalosporins not effective

Question 6

Fxns of Cytoplasmic Membranes? (4)

Answer 6

1) Active Transport
2) Synthesis of cell wall precursors
3) Secretion of enzymes and toxins
4) Energy Generation (oxidative phosph thru ETC)

Question 7

Purpose of Cell Wall?

Answer 7

1) Maintain shape
2) Prevents lysis
(bacteria is hypertonic to body’s hypotonic environment)

Question 8

Cell Wall made of?

Answer 8

Peptidogylcan:

repeating NAG/NAM disaccharide
peptide crosslinked

Question 9

G+ bacteria retain which stain?

Answer 9

crystal violet

Question 10

G- bacteria retain which stain?

Answer 10

safranin

Question 11

Parts of G- Cell Envelope? (4)

Answer 11

1) glycocalyx
2) outer membrane
3) periplasm
4) cytoplasmic membrane

Question 12

Outer Membrane of G- made of?

Answer 12

Fxn’l bilayer:

Inner Layer = identical to cytoplasmic membrane
Outer Layer = Phospholipids and Lipopolysaccharides (LPS)

Question 13

Periplasm of G- made of?

Answer 13

Space b/w cytoplasmic memb and outer memb:

1) Thin peptidoglycan layer
2) Transport proteins
3) Hydrolytic enzymes

Question 14

Structure of LPS (in G -outer layer)? (3)

Answer 14

1) O antigen
2) Core Polysaccharide
3) Lipid A

Question 15

O-Antigen of LPS is?

Characteristic?

Used for?

Answer 15

long, linear repeating units of carbs

highly variable (species and strain specific)

identification (serotyping)

Question 16

Definition:

Antigen

Immunogen

Answer 16

Antigen:
molecule that binds to antibody or antigen receptors on T and B cells

Immunogen:
antigen that initiates immune response (antibody formation by T and B cells)

Question 17

Core Polysaccharide of LPS is?

Purpose?

Answer 17

branched polysaccharide (9-12 sugars)

links Lipid A to O-Anitgen

Question 18

Lipid A of LPS found where?

Is?

Does?

Answer 18

outer layer of phospholipid layer of outer memb

Virulence factor - endotoxin

causes clinically significant inflamm response

Question 19

Definition of Virulence Factor?

Answer 19

structure or substance that enhances pathogenesis

Question 20

What is SIRS?

Answer 20

Systemic Inflammatory Response Syndrome

causes release of system-wide cytokines (regulatory molecules of immune system)

Question 21

SIRS clinical manifestation?

Answer 21

2 or more of following:

1) temp > 38º or < 36º
2) tachycardia > 100 bpm
3) tachypnea > 20 bpm
4) leukocytosis > 12,000/mm^3
5) leukopenia < 4,000/mm^3

Question 22

What is Septic Shock?

What induces Septic Shock?

Answer 22

SIRS + sepsis
sxs (U) fever, hypotension

LPS or endotoxins

Question 23

Exotoxin is?

Endotoxin is?

Answer 23

exo = secreted protein

endo = structural LPS

Question 24

G- Cell Envelope Porins are what kind of protein?

Do what?

Answer 24

Channel (span outer memb)

Control diffusion of small molecules:
sugars
AA
metal ions
antibiotics

Question 25

G+ Cell Envelope made of?

Answer 25

Cytoplasmic memb

Peptidoglycan

Question 26

G+ Cell Wall made of?

Answer 26

Peptidoglycan
Teichoic acids (attach bacteria to other CWs and surfaces)

Question 27

2 types of Teichoic Acids in G+ CW?

Answer 27

Wall Teichoic Acid (WTA):
bound to peptidoglycan

Lipoteichoic Acids (LTA):
anchors cell wall to cytoplasmic membrane

Question 28

G+ bacteria endotoxin is?

Answer 28

teichoic acids - when shed

Question 29

Acid Fast bacteria Cell Envelope made of? (3)

Answer 29

1) Cell memb
2) Peptidoglycan
3) Mycolic Acid

Question 30

Mycolic Acid is?

Does?

Answer 30

polymers of long-chain fatty acids (waxy coat),
covalently linked to peptidoglycan (G+ structure)

Makes cell resistant to:
desiccation
some antibiotics
phagocytosis

Question 31

Acid-Fast Staining process?

Answer 31

Primary Stain: Carbol Fuchsin (red)

Acid-Alcohol Wash: Stays red = acid-fast, turns blue = nonacid-fast

Question 32

Glycocalyx is made of?

Found where?

What types of bacteria have it?

Answer 32

polysaccharide w/ glycoproteins

outside CW

G+ and G-

Question 33

Glycocalyx is source of antigens for which 2 bacteria?

Answer 33

K-antigen for e. coli

Vi-antigen for salmonella

Question 34

Fxn of Glycocalyx? (4)

Answer 34

1) protection against desiccation and phagocytosis
2) barrier to toxic hydrophobic molecules (antibiotics)
3) adheres to cells and surfaces (biofilm)
4) source of immunogenic material for vaccines

Question 35

Glycocalyx is virulence factor for what type of bacteria?

Answer 35

strep pneumo

w/o Glycocalyx it is avirulent

Question 36

2 forms of Glycocalyx?

Answer 36

1) slime layer

2) capsule

Question 37

Properties of Slime Layer? (3)

Answer 37

1) loose, non-uniform
2) form biofilm
3) for diffuse

Question 38

Properties of Capsules? (2)

Answer 38

1) rigid, uniform

2) closely surrounds cell