Bacteriology Part 1

Question 1

What is a bacterium?

Answer 1

single celled microorganism of kingdom prokaryota

Question 2

what does it mean that bacteria are prokaryotes?

Answer 2

= no nucleus

Question 3

in what conditions do bacteria grow?

Answer 3

aerobic, anaerobic, microaerophilic conditions

Question 4

what kind of cell wall do gram positive bacteria have?

Answer 4

thick cell wall

Question 5

What antigenic property is on the cell wall of gram positive bacteria?

Answer 5

lipoteichoic acid

used to recognize antigen and trigger immune response

Question 6

What does the cell wall contain?

Answer 6

peptidoglycan

Question 7

gram negative bacteria have what kind of cell wall and plasma membrane?

Answer 7

Thin cell wall in between two plasma membrane layers (sandwich)

Question 8

What is on the outer layer of gram negative bacteria?

Answer 8

Lipopolysaccharide layer 
(LPS-virulence factor)

Question 9

what type of cell wall do mycobacteria have?

Answer 9

Thin cell wall

Question 10

What is on mycobacteria’s cell wall? (2 things)

Answer 10

1) Mycolic acid (virulence factor)

2) Glycolipids

Question 11

What is lipopolysaccharide?

Answer 11

is a toxin, lipid A component, present on cell surface of gram negative bacteria, that activates immune response, and can be harmful to the host

Question 12

Gram staining: what determines how much color you have?

Answer 12

how thick the cell wall of the bacteria is

Question 13

Gram positive stains what color?

Answer 13

violet/blue; picks up crystal violet, and iodine

Question 14

Gram negative stains what color?

Answer 14

pink; picks up safranin

Question 15

Types of staining:

Answer 15

1) Gram staining

2) Acid staining

Question 16

acid fast staining is due to the presence of what?

Answer 16

mycolic acid

Question 17

Acid fast staining: positive bacteria have gram positive or negative cell wall? And how does it stain?

Answer 17

Gram positive cell wall
stains pink
retains Carbol Fuchsin
b/c it has mycolic acid in cell wall

Question 18

Acid fast staining: Negative gram bacteria stains?

Answer 18

stains blue

due to absence of mycolic acid

Question 19

Flagella: what’s it used for? (3)

Answer 19

1) Locomotion
2) Motility
3) identification

Question 20

What is the flagella called for bacteria that have it in the periplasmic space? What bacteria can you find it in?

Answer 20

Endoflagella

Spirochetes

Question 21

Pilli/ Fimbriae

Answer 21

• threadlike located on bacterial surface
• helps attach bacteria to host cell surface
• contributes to antigenicity

Question 22

In what animal example can you find pilli / fimbriae bacteria?

Answer 22

Neonatal pigs

Question 23

What is a capsule?

Answer 23

The capsule is a thick polysaccharide layer OUTSIDE the cell wall

Question 24

What is the capsule used for? (4)

Answer 24

1) Sticking cell together
2) Food reserve
3) Protection against desiccation and chemicals
4) Helps bacteria evade phagocytosis

Question 25

What are endospores?

Answer 25

highly resistant dormant form of gram positive bacteria

Question 26

What are endospores used for?

Answer 26

Survival mechanism of GRAM POSITIVE bacteria

Question 27

When are endospores produced?

Answer 27

When bacteria are exposed to adverse conditions or food is depleted

Question 28

What orientation do endospores have? (3)

Answer 28

central terminal subterminal

Question 29

How can BACTERIAL GROWTH be measured? (4)

Answer 29

1) colony counting 2) turbidimetry 3) flow cytometer 4) hemocytometer chamber

Question 30

Can bacteria's need for oxygen be used for identification?

Answer 30

yes!

Question 31

Oxygen required for growth (3)

Answer 31

- aerobic - microaerophilic - capnophilic

Question 32

oxygen not required or used for growth (2)

Answer 32

- obligate anaerobe | - aerotolerant anaerobe

Question 33

oxygen not required but can be used for growth (1)

Answer 33

facultative anaerobe

Question 34

All bacteria have a cell wall except:

Answer 34

Mollicutes (Mycoplasma)

Question 35

Bacteria have a single circular chromosome except:

Answer 35

Leptospira has 2!

Question 36

Bacteria have circular DNA except:

Answer 36

Borrelia Burgdorferi:has linear chromosome