Aerobic Gram Positive Cocci

Question 1

What is catalase?

Answer 1

An enzyme that breaks down hydrogen peroxide into water and oxygen.

Question 2

Is Staphylococcus catalase positive or negative?

Answer 2

Catalase positive.

Question 3

Is Streptococcus catalase positive or negative?

Answer 3

Catalase negative.

Question 4

What is the function of coagulase?

Answer 4

Coagulase converts fibrinogen to fibrin, leading to clot formation.

Question 5

Which organism is primarily identified by the coagulase test?

Answer 5

Staphylococcus aureus.

Question 6

What does DNase do?

Answer 6

DNase is an enzyme that degrades DNA.

Question 7

True or False: Bacitracin is an antibiotic that inhibits cell wall synthesis.

Answer 7

True.

Question 8

What is the purpose of the bacitracin sensitivity test?

Answer 8

To differentiate Streptococcus pyogenes from other beta-hemolytic streptococci.

Question 9

What does the CAMP test detect?

Answer 9

The presence of the CAMP factor produced by Streptococcus agalactiae.

Question 10

True or False: Optochin is used to differentiate Streptococcus pneumoniae from other alpha-hemolytic streptococci.

Answer 10

True.

Question 11

What is the Lancefield classification used for?

Answer 11

To categorize beta-hemolytic streptococci based on carbohydrate composition of antigens.

Question 12

What Lancefield group is Streptococcus pyogenes classified into?

Answer 12

Group A.

Question 13

What Lancefield group is Streptococcus agalactiae classified into?

Answer 13

Group B.

Question 14

Fill in the blank: Staphylococcus species are typically _____ hemolytic.

Answer 14

beta or non-hemolytic.

Question 15

What is the primary pathogenic species of Staphylococcus?

Answer 15

Staphylococcus aureus.

Question 16

What type of hemolysis does Streptococcus pneumoniae exhibit?

Answer 16

Alpha hemolysis.

Question 17

True or False: All Staphylococcus species are coagulase positive.

Answer 17

False.

Question 18

What is the clinical significance of DNase production?

Answer 18

It helps in identifying pathogenic strains of Staphylococcus aureus.

Question 19

What test can be used to identify Streptococcus pneumoniae?

Answer 19

Optochin sensitivity test.

Question 20

Fill in the blank: The presence of _____ is a key factor in identifying Streptococcus agalactiae.

Answer 20

CAMP factor.

Question 21

What is the main virulence factor of Staphylococcus aureus?

Answer 21

Protein A.

Question 22

Which organism is known for causing necrotizing fasciitis?

Answer 22

Streptococcus pyogenes.

Question 23

What is the appearance of a positive coagulase test?

Answer 23

Clot formation in the test tube.

Question 24

True or False: Bacitracin is effective against Streptococcus pneumoniae.

Answer 24

False.

Question 25

What test differentiates Staphylococcus saprophyticus from Staphylococcus epidermidis?

Answer 25

Novobiocin sensitivity test.

Question 26

What does a positive CAMP test indicate?

Answer 26

The organism is likely Streptococcus agalactiae.

Question 27

What is the primary role of the Lancefield classification system?

Answer 27

To identify groups of streptococci based on their carbohydrate antigens.

Question 28

Fill in the blank: Optochin sensitivity is used to differentiate Streptococcus pneumoniae from _____.

Answer 28

Streptococcus viridans.

Question 29

True or False: All beta-hemolytic streptococci are Lancefield group A.

Answer 29

False.

Question 30

Which Staphylococcus species is often associated with urinary tract infections?

Answer 30

Staphylococcus saprophyticus.

Question 31

What type of agar is used to perform the bacitracin sensitivity test?

Answer 31

Blood agar.

Question 32

Fill in the blank: The coagulase test is typically performed on _____ species.

Answer 32

Staphylococcus.

Question 33

What is the significance of DNase production in Staphylococcus aureus?

Answer 33

It indicates the organism's ability to degrade DNA and is a marker for virulence.

Question 34

What type of hemolysis is exhibited by Streptococcus pyogenes?

Answer 34

Beta hemolysis.

Question 35

What is the primary method of identifying Streptococcus pneumoniae?

Answer 35

Optochin sensitivity test.

Question 36

Fill in the blank: Lancefield groups are designated by letters from _____ to _____.

Answer 36

A to V.

Question 37

What is the main differentiating factor between Staphylococcus epidermidis and Staphylococcus aureus?

Answer 37

Coagulase production.

Question 38

What does a negative DNase test indicate?

Answer 38

The organism does not produce DNase.

Question 39

True or False: Streptococcus pneumoniae is optochin resistant.

Answer 39

False.

Question 40

What type of infections is Streptococcus agalactiae commonly associated with?

Answer 40

Neonatal infections.

Question 41

What is the genus of Enterococcus?

Answer 41

Enterococcus

Question 42

Are Enterococcus species gram-positive or gram-negative?

Answer 42

Gram-positive

Question 43

Which type of hemolysis is typically associated with Enterococcus?

Answer 43

Gamma hemolysis

Question 44

True or False: Enterococcus can be part of the normal intestinal flora.

Answer 44

True

Question 45

What color does Enterococcus produce on bile esculin agar?

Answer 45

Black

Question 46

What is bacitracin used for in microbiology?

Answer 46

To differentiate between streptococci species.

Question 47

Fill in the blank: Enterococcus faecalis is a common species found in _______.

Answer 47

Human intestines

Question 48

What type of infections are commonly associated with Enterococcus species?

Answer 48

Urinary tract infections

Question 49

Which Enterococcus species is most frequently isolated from clinical specimens?

Answer 49

Enterococcus faecalis

Question 50

True or False: Enterococcus is resistant to many antibiotics.

Answer 50

True

Question 51

What is the primary distinguishing factor between alpha, beta, and gamma hemolysis?

Answer 51

The ability to lyse red blood cells and change the color of the agar.

Question 52

Which hemolytic pattern shows complete lysis of red blood cells?

Answer 52

Beta hemolysis

Question 53

What is the significance of bile esculin hydrolysis?

Answer 53

It indicates the ability of an organism to grow in the presence of bile and to hydrolyze esculin.

Question 54

Which hemolytic pattern is characterized by no lysis of red blood cells?

Answer 54

Gamma hemolysis

Question 55

What test can be used to differentiate Enterococcus from Streptococcus?

Answer 55

Bile esculin test

Question 56

Fill in the blank: Enterococcus species are known for their _______ resistance.

Answer 56

Vancomycin

Question 57

What is a common characteristic of Enterococcus in laboratory culture?

Answer 57

They can grow in high salt concentrations.

Question 58

True or False: Enterococcus can be pathogenic in immunocompromised individuals.

Answer 58

True

Question 59

What type of bacteria are Enterococcus often confused with due to similar morphology?

Answer 59

Streptococcus

Question 60

Which Enterococcus species is often associated with endocarditis?

Answer 60

Enterococcus faecalis

Question 61

What is the role of bacitracin in differentiating Streptococcus species?

Answer 61

It inhibits the growth of certain bacteria, helping to identify species.

Question 62

Fill in the blank: Enterococcus is a facultative _______.

Answer 62

Anaerobe

Question 63

What is the main clinical concern regarding Enterococcus species?

Answer 63

Antibiotic resistance

Question 64

Which of the following is a characteristic of beta-hemolytic bacteria? A) Partial lysis B) No lysis C) Complete lysis

Answer 64

C) Complete lysis

Question 65

True or False: All Enterococcus species are pathogenic.

Answer 65

False