3A - Bacteria

Question 1

Outcome of an infection by microorganism dependent upon

Answer 1

pathogenicity and virulence of the organism and the resistance of the host

Question 2

Resistance of a host (Innate defenses)

Answer 2

Physical cellular defenses (acute inflammation, monocyte macrophage system, normal bacterial flora, complement)

Question 3

Resistance of a host (adaptive defenses)

Answer 3

passive immunity from colostrum, active immunity from T and B lymphocytes

Question 4

Bacterial pathogenicity is determines by its ablilty to

Answer 4

infect and to damage cells

Question 5

Ability to infect cells done by

Answer 5

adhesion, multiplication, colonization, tissue invasion, circumvention of the animal’s defenses

Question 6

ability to damage cells by

Answer 6

toxins (endo/exo). cytolysis, invasion of extracellulr matrix

Question 7

surface structures of bacteria

Answer 7

flagella, fimbriae, pili, glycocalyx

Question 8

Flagella

Answer 8

• Flagellum- single / Flagella- pleural
        Function
                ‣ Motility
                ‣ Toward stimulus
                ‣ Away from stimulus
        ◦ Functions by rotation 
        ◦ Helical in shape

Question 9

Pili

Answer 9

◦ Pili are similar to fimbriae but they are usually longer and there is less of them
◦ They may also be used for attachment but morei mportantly they are used for gene transfer
◦ Pili are often important receptors for viruses and are best seen under the electron microscope when they are coated with virus

Question 10

Attachment pili

Answer 10

play an important role in causing urinary tract infections allowing the bacteria to resist the flushing action of urine and attach to the mucus membranes

Question 11

Twitching motility

Answer 11

the ability to glide along a solid surface with extension and retraction of the pilus
function of the pili

Question 12

Conjugation

Answer 12

sexual reproduction via pili(gene transfer)

important in the transfer of antibiotic resistance and other virulence genes

Question 13

Glycocalyx

Answer 13

◦ External polysaccharide or protein coating outside of the cell wall
◦ Protect bacteria from the immune system and from the environment
‣ Allow Attachment
‣ Anti-phagocytic
‣ Resist drying
‣ Reservoir for nutrients
‣ Depot for waste

Question 14

Slime layer

Answer 14

glycoproteins molecules are loosely associated with the cell wall.
• Protection from dehydration and loss of nutrients
one of two forms of glycocalyx

Question 15

Capsule

Answer 15

polysaccharides are more firmly attached to the cell wall.
• Gummy, sticky consistency and provide protection, adhesion to solid surfaces and to nutrients in the environment.
one of two forms of glycocalyx

Question 16

Bacterial mucoid

Answer 16

• like glycocalyx

Capsule, Slime layer, Biofilm

Question 17

Bacterial Cell Wall

Answer 17

◦ Rigid and stops the bacterial cell from bursting
◦ Defines the shape
◦ Acts as an environmental barrier

Question 18

Coccus

Answer 18

Round ball shape

Question 19

Coccobacillus

Answer 19

Elongated ball shape

Question 20

Vibrio

Answer 20

Elbow noodle shape

Question 21

Bacillus

Answer 21

Rod shape

Question 22

Spirillum

Answer 22

corkscrew shape

Question 23

Spirochete

Answer 23

exaggerated corkscrew + pole through the middle

Question 24

Peptidoglycan

Answer 24

found in the cell wall
◦ Peptidoglycan is only present in bacteria and is a strong stimulant of the immune system
◦ Made up of polysaccharides and a few amino acids
◦ Gram –ve bacteria have an outer cell membrane outside of the peptidoglycan layer