ch 1 Staphylococci

Question 1

Staphylococci is gram ___

Answer 1

gram postive coccus

Question 2

Staphylococci motlition

Answer 2

non-motile

Question 3

s.aureus is

Answer 3

nasal carrier

Question 4

identification straphylococci

Answer 4

Gram positive, cocci in clusters shape (grapes).

Question 5

micrococci

Answer 5

gram postive cocci in trated

Question 6

Staphylococci Catalase

Answer 6

+ve

Question 7

Staphylococci Oxidation Fermentation Test

Answer 7

facultative anaerobic

Question 8

Staphylococci Oxidase

Answer 8

negative

Question 9

Staphylococci Bacitracin

Answer 9

Resistant

Question 10

Staphylococci Lysostaphin

Answer 10

sensitive

Question 11

Micrococci Catalase

Answer 11

postive

Question 12

Micrococci Oxidation Fermentation Test

Answer 12

aerobic

Question 13

Micrococci Bacitracin

Answer 13

sensitive

Question 14

Micrococci Lysostaphin

Answer 14

resistant

Question 15

Mannitol Salt Agar It is

Answer 15

a selective medium for S. aureus.

Question 16

Selective agent:

Answer 16

7-9% NaCl

Question 17

Indicator:

Answer 17

phenol red.

Question 18

is an enzyme which catalyzes the dissociation of hydrogen peroxide (H2O2) to oxygen and water.

Answer 18

Catalase

Question 19

Catalase Test Substrate:

Answer 19

H2O2

Question 20

Catalase Test End product (

Answer 20

positive result): gas bubbles (O2)

Question 21

is an enzyme that converts fibrinogen to fibrin, which means that it can coagulate plasma. The test is used to distinguish between S. aureus from coagulase-negative Staphylococci.

Answer 21

Coagulase

Question 22

Coagulase Test
Substrate:

Answer 22

plasma fibrinogen.

Question 23

DNase Test substrate

Answer 23

DNA

Question 24

can be used to differentiate between potentially pathogenic S. aureus and other Staphlococcus by looking for the presence of the exo-enzyeme DNase. After growth for 24-48 hrs 1N HCL is added to the agar plate.

Answer 24

DNase agar

Question 25

DNase Positive result:

Answer 25

zone of clearance around the colony.

Question 26

Dnase Negative result:

Answer 26

no zone of clearance around the colony.

Question 27

It is a rapid latex agglutination test for identification of Staphylococcus aureus. Latex particles coated with human fibrinogen for detection of clumping factor and coated with specific IgG for detection of protein A and surface antigens characteristic of S. aureus.

Answer 27

Staphaurex

Question 28

is a major cause of nosocomial infection worldwide. It is resistant to I
a number of widely used antibiotics due to acquisition of penicillin binding Msft
protein 2a encoded by mecA gene and production of β-lactamases

Answer 28

MRSA

Question 29

Treatment of MRSA

Answer 29

Vancomycin

Question 30

Virulence factors of S. aureus:

Answer 30

Enterotoxin
Adhesins
Catalase
7- Coagulase

Question 31

Diseases by s.aureus

Answer 31

abscess
pneumonia
urinary tract infection,
Food poisoning

Question 32

Treatment if S. aureus sensitive to methicillin (MSSA).

Answer 32

Floxacillin

Question 33

Micrococci Oxidase

Answer 33

postive