Streptococci

Question 1

what are some characteristics of streptococci bacteria

Answer 1

gram positive (peptidoglycan), facultative anaerobes, non-spore forming

Question 2

what are the 3 ways to classify stretococcus

Answer 2

hemolysis patterns
lancefield group
species

Question 3

what are the 3 types of hemolysis patterns

Answer 3

alpha - partial hemolysis and green discoloration
beta - complete hemolysis
gamma - no hemolysis

Question 4

what is the most prevalent disease of Group A streptococcal diseases

Answer 4

acute pharyngitis (strep throat)

Question 5

how would you prevent acute rheumatic fever (ARF)

Answer 5

by treating primary disease of strep throat w/ penicilan

-ARF only comes after strep throat does not spontaneously come

Question 6

what is the only site of infection post acute rheumatic fever (ARF)

Answer 6

pharynx

Question 7

what disease follows strep throat, is caused by a group a streptococcus, and causes smoky urine

Answer 7

Acute post-streptococcal glomerulonephritis (APSGN)

Question 8

how are group A streptococcus infections transmitted, what age group is most susceptible

Answer 8

person to person, school aged children

Question 9

Group A infections cant penetrate intact skin so the must bind to mucous membrane using ______ ?

Answer 9

adhesins

Question 10

what do GAS adhesins bind to on epithelial surfaces

Answer 10

fibronectin

Question 11

what are streptococcus 2 most important virulence factors

Answer 11

streptokinase, and hylauropeptidase

Question 12

what is the role of streptokinase

Answer 12

it allows bacteria to degrade/lyse blood clots

Question 13

what are group a streptococcus 3 mechanisms to avoid phagocytosis

Answer 13

• M protein
• hyaluronic acid capsule
• C5a peptidase

Question 14

what is C5a peptidase and how does it work

Answer 14

an anti-phagocytosis mechanism of GAS, and it inactivates phagocyte chemotaxins

Question 15

what is M protein and how does it work

Answer 15

an anti-phagocytosis mechanism of GAS, and it binds to host proteins preventing normal immune defense

Question 16

what is the hyaluronic acid capsule and how does it work

Answer 16

an anti-phagocytosis mechanism of GAS, and it makes the strep “slippery” so phagocytes have tough time attaching to it

Question 17

what activates macrophages, causes T cells to release cytokines, and is responsible for the red rash of scarlet fever

Answer 17

superantigens

Question 18

Group A and Group B streps both have what hemolysis pattern

Answer 18

Beta

Question 19

what are some characteristics of Group B streps

Answer 19

• inhabit GI and female genital tracts
• have a polysaccharide capsule
• aerobic

Question 20

Group D streps exhibit what kind of hemolysis pattern

Answer 20

alpha or gamma

Question 21

enterococci and neneneterococci are what group of streps

Answer 21

Group D streps or the normal fora of GI and genitourinary tracts

Question 22

what is the “worlds toughest pathogenic bacteria” and why

Answer 22

enterococci, because its resistant to most antibiotics and penicilan only inhabits this bacteria NOT KILL it

Question 23

what strep is the most common cause of subacute bacterial endocarditis

Answer 23

viridans streptococci

Question 24

what strep type is known as the “mutans” group and is responsible for dental caries

Answer 24

Viridans streptococci

Question 25

how do viridans streps cause dental plaque

Answer 25

form polymers on sucrose then ferment sugar to lactic acid (demineralizes enamel)
-remain active at low pH