Bacterial Anatomy

Question 1

What type of shape are cocci bacteria?

Answer 1

Spherical

Question 2

What are the types of cocci bacteria?

Answer 2

A. Diplococci- two associated cocci

B. Streptococci- chains

C. staphylococci- clusters

J. sarcinae- packet of 8 arising from alternating cell divisin planes

Question 3

What is the shape of bacili bacteria?

Answer 3

rods

Question 4

What are the types of bacili bactera?

Answer 4

F. Fusiform- tapered end

G. Filamentous

H. Vibrios- comma chaped

I. Spirilla- snakelike

• Clavate or Coryneform- club shaped end

Question 5

Which bacteria are ovoid or ellipsoid?

Answer 5

Coccobacilli

Question 6

Which bacteria are flexible envelopes and corkscrew appearance?

Answer 6

Spirochetes

Question 7

Division of one plane produces?

Answer 7

dipococci or streptococci

Question 8

Division in two planes produces?

Answer 8

Tetrad

Question 9

Division in 3 planes produces?

Answer 9

sarcina or staphylococcus

Question 10

What is a nucleoid?

Answer 10

central condensed region that includes DNA

Question 11

Intracytoplasmic granules

Answer 11

includsion bodies or metachromatic granules for storage of energy polymers such as glycogen

Question 12

ribosomes

Answer 12

ribonucleoprotein complexes upon which protein synthesis occurs

Question 13

What is the most important distinctin among gram- vs gram +

Answer 13

thickness of the bacterial cell wall.

based onthe gram stain

Question 14

What are the step of the gram stain?

Answer 14

1. stain with crystal violet (purple) and iodine
2. destain w/ acetone
3. counterstain with safranin (red)

Question 15

What stain will gram positive bacteria be?

Answer 15

purple

Question 16

What color stain will gram negative bacteria be?

Answer 16

red (counterstain)

Question 17

what are some gram + bacteria?

Answer 17

staphylococcus aureus

streptococcus pneumonia

clostridium botulinum

Question 18

what are features of gram +?

Answer 18

1. cytoplasmic membrane: phospholipid bilayer/integral proteins for E and transport/

                                      Do not contain sterols 

2. peptidoglycan cell wall: impt in inflammatory response/40 layers thick/affected by antibiotics
3. Li[pteichoic acids: in all gram +/similar to lipopolysaccharides in gram -/important for (-) charge promotion
4. teichoic acids: non-toxic/contribute to virulance

Question 19

What are some examples of gram - bacteria?

Answer 19

Neisseria gonorrhea

escherichia coli

salmonella typhimurium

Question 20

what are some features of gram - bacteria?

Answer 20

1. cytoplasmic membrane: smiliar to gram +
2. peptidoglycan cell wall: one layer thick/ does not retain gram stain after txt w/ ethanolic iodine
3. periplasmic space: btw inner and out membranes/contain peptidoglycan layer and hydrolytic enzymes/detox enzymes like b-lactamase (inactivate penicilin)
4. Outer membrane: less permeable and different from cytoplasmic membrane/ only polar molecules can diffuse/ other pass through pores (porins, <~700da pass, some AB pass, resistance from porin)/most antibiotics can’t get through/contains LPS or endotoxin
5. LPS: contains Lipid A which is responsible for toxicity, can cause endotoxic shock/core oligosaccharide/repeating or O antigen

Question 21

Structures of gram +

Answer 21

Question 22

Structures of gram -

Answer 22

Question 23

What is an example of an acid fast bacteria?

Answer 23

Mycobacterium (tuberculosis and leprae)

Can stain + which gram stain because of waxes (mycolic acids) in cell wall.

Question 24

What do the walls of mycobacterium (Acid fast bact) contain?

Answer 24

mycolic acids

murein

polysaccharide

lipids

Question 25

What are the steps in an acid fast stain

Answer 25

1. stain with carbol-fushin (Red) and heat
2. destain with 3% HCL and Alcohol
3. counterstain wil methylene blue

Question 26

What are some bacteria that lack cell wall?

Answer 26

1. mollicutes (mycoplasma)
2. L-forms or L-phase
   - derived from gram- or+
   - loss of peptidoglycan coat
   - can be selected clinically by use of ab

Question 27

what are examples of gram + cocci?

Answer 27

streptococcus

staphylococcus

Question 28

what are some examples of spirochetes?

Answer 28

borrelia

treponema

Question 29

what are examples of gram - cocci?

Answer 29

Neiserria

Moraxcella

Question 30

what are some examples of gram + rods

Answer 30

listeria

corynebacteria

clostridium

basilis

Question 31

what are some examples of gram - rods?

Answer 31

everything else except neisseria

Question 32

capsule

Answer 32

1. polysacc coat in gram-/+
   - slime: weakly adherent
   - microcapsule: thin coat
   - biofilm: growth within layers of polysacc
2. may contribute to virulence
   - antiphagocytic
   - interferes with complement
   - growth in a biofilm prevents access of host cells or Antibiotic

Question 33

How is a capsule visualized?

Answer 33

by exclusion of indian ink

Question 34

how is bacteria serotyped?

Answer 34

via quellung rxn

Question 35

sex pili

Answer 35

facilitate transfer of DNA btw bacteria during conjugation

serves as receptors for bacteriphage

Question 36

Fimbriae or somatic pili

Answer 36

allow bacteria to adhere to surfaces

impt. in infect by some bact (N. Gonorrhea)

Question 37

flagella

Answer 37

mobility,

counterclockwise or clockwise rotation depend on environ.

couterclockwise (positive chemotaxis)

shorter and thinner than flagella

Question 38

Types of Flagella

Answer 38

Question 39

what happens to bacteria when they lose virulence factor?

Answer 39

becomes non-pathogenic

colonizes without infection

carrier state (reservoir for disease-causing orgsm)

can restore virulance–> pathogenicity