2/8: streptococcus, enterococcus, pneumococcus, stayphylococcus

Question 1

____ one of the first microbes identified to cause disease

Answer 1

streptococci

Question 2

____ discovery lead to hygienic and aseptic practices in hospitals

Answer 2

streptococci

Question 3

____ over 100 species

Answer 3

streptococci

Question 4

Is streptococci spore forming?

Answer 4

NO

Question 5

Is streptococci motile?

Answer 5

NO

Question 6

Streptococci were originally classified into lancefield groups which classified them based on ____

Answer 6

classified based on major cell-wall carbohydrate antigens (groups a-h)

Question 7

Pyogenic strep =

Answer 7

pus forming

Question 8

Streptococci can also be classified based on hemolysis pattern. What are the 3 subgroups?

Answer 8

alpha hemolysis
beta hemolysis
gamma hemolysis

Question 9

Alpha hemolysis group of streptococci = ___

Answer 9

partial hemolysis and green discoloration of hemoglobin

Question 10

Beta hemolysis group of streptococci = ___

Answer 10

clear zone of complete hemolysis

Question 11

Gamma hemolysis group of streptococci = ___

Answer 11

no zone of clearance at all

Question 12

According to the lancefield group classificartion of streptococci, group A = ___

Answer 12

streptococci pyogenes

Question 13

Streptococci pyogenes is transmitted via ___

Answer 13

GAS spreading by direct human contact of respiratory droplets

Question 14

Streptococci pyogenes can infect ___

Answer 14

EXCLUSIVELY HUMANS

primarily in respiratory tract, blood, skin

Question 15

Streptococci pyogenes has a hallmark feature of ____

Answer 15

pus formation

remember pyogenes = pus forming

Question 16

What does the M PROTEIN of streptococci pyogenes do?

Answer 16

M cells bind to keratinocytes and prevents opsonization by complement

this resmebts mysoins (coiled strcture) the hypervariable region can have antibodies produced to it but there are over 200 serotypes and immunity to one doesn’t cross to another

Question 17

The type of ____ determines what disease the GAS causes in streptococci pyogenes

Answer 17

M PROTIEN

Question 18

Protein F of streptococci pyogenes does what?

Answer 18

binds to fibronectin

Question 19

What does the hyaluronic acid capsule of the streptococci pyogenes do?

Answer 19

hyaluronic acid capsule = anti phagocytic

camouflages teh bacteria

interferes with adherence to epithelial cells, so hyaluronidase is secreted to digest the capsule and allow bacterial spread thorugh the tissue

Question 20

Although the hyaluronic acid capsule of streptococci pyogenes is antiphagocytic and camouflages the bacteria, it also inhibits adherence to epithelial cells.

What does streptococci pyogenes do to overcome this?

Answer 20

secretes hyaluronidase to digest the hyaluronic acid capsule

this allows bacteria to adhere to epitheilial cells and spread throughout tissue

Question 21

What does C5a peptidase of streptococci pyogenes do?

Answer 21

degrades C5a, blocks chemotaxis of phagocytes