Streptococcus and Enterococcus

Question 1

What is the oxygen requirement for Streptococcus spp.?

Answer 1

Facultatively anaerobic

Question 2

What is required for the growth of Streptococcus spp.?

Answer 2

Blood or enriched medium

Question 3

What is the Lancefield Classification used for?

Answer 3

Classification of Streptococci by group specific antigen (C carbohydrate)

Question 4

Which species of strep is classified under the group A Lancefield?

Answer 4

Streptococcus agalactiae

Question 5

Which species of strep is classified under the group B Lancefield?

Answer 5

Streptococcus pyogenes

Question 6

What is one method for non-cultural identification of Streptococcus?

Answer 6

Slide Agglutination Test

Question 7

What is the most common clinical presentation of Group A strep infection?

Answer 7

Bacterial Pharyngitis (strep throat)

Question 8

What are two complications associated with Streptococcus pyogenes?

Answer 8

• Rheumatic fever
• Acute Glomerulonephritis (AGN)

Question 9

What disease is characterized by a diffuse red rash that begins on the upper chest?

Answer 9

Scarlet Fever

Question 10

What type of test is used for throat swab culture from a child with strep throat?

Answer 10

Blood agar plate

Question 11

What Gram staining result is typical for Streptococcus pyogenes?

Answer 11

Many Gram-positive cocci in chains or pairs

Question 12

What is one virulence factor of Streptococcus agalactiae?

Answer 12

Capsule which can prevent phagocytosis

Question 13

What is a common clinical infection caused by Streptococcus agalactiae in newborns?

Answer 13

Meningitis

Question 14

What should be removed before specimen collection from the cervix/vagina?

Answer 14

Mucus

Question 15

What type of infections can Group D Streptococci cause?

Answer 15

• Urinary tract infections
• Endocarditis
• Wound infections
• Abscesses

Question 16

What is a characteristic of Enterococcus spp. in terms of their location?

Answer 16

Found in the intestinal tract

Question 17

What type of hemolysis can Enterococcus spp. exhibit?

Answer 17

Alpha-, beta-, or non-hemolytic

Question 18

What is the main virulence factor associated with Streptococcus pneumoniae?

Answer 18

Capsule

Question 19

What disease is Streptococcus pneumoniae a common cause of?

Answer 19

Pneumonia

Question 20

Fill in the blank: Streptococcus pyogenes is known as Group ___ streptococci.

Answer 20

B

Question 21

True or False: Streptococcus agalactiae can cause pneumonia in newborns.

Answer 21

True

Question 22

What test is used for presumptive identification of Streptococcus pyogenes?

Answer 22

Bacitracin test

Question 23

What is the appearance of Streptococcus pyogenes colonies on sheep blood agar?

Answer 23

Small, smooth, translucent with a well-defined zone of beta hemolysis

Question 24

What are common clinical infections caused by S. pneumoniae?

Answer 24

• Pneumonia
• Otitis Media
• Sinusitis
• Bacterial Meningitis
• Endocarditis
• Peritonitis
• Bacteremia

S. pneumoniae is a common pathogen and can be part of the normal respiratory flora.

Question 25

What is the procedure for sputum specimen collection?

Answer 25

Rinse mouth, cough deeply into a sterile container, refrigerate if delayed ## Footnote Specimens should be collected in sterile, screw-cap containers.

Question 26

What is the microscopic morphology of S. pneumoniae?

Answer 26

Gram-positive lanceolate shaped diplococci, can appear singly or in chains ## Footnote This morphology is key for identification in laboratory settings.

Question 27

Describe the colonial morphology of S. pneumoniae.

Answer 27

Glistening wet, mucoid, dome shaped and round colonies, displaying alpha-hemolysis ## Footnote Autocatalysis can result in a depression in the colonies.

Question 28

What biochemical tests are used to identify S. pneumoniae?

Answer 28

* Catalase * Bile Esculin * Optochin Susceptibility * Bile Solubility ## Footnote These tests differentiate S. pneumoniae from viridans streptococci.

Question 29

What characterizes viridans streptococci?

Answer 29

Gram-positive cocci, often alpha-hemolytic, found in the mouth ## Footnote They are opportunistic pathogens, causing disease in immunocompromised hosts.

Question 30

What diseases are commonly associated with viridans streptococci?

Answer 30

* Subacute bacterial endocarditis * Meningitis * Dental caries * Osteomyelitis * Empyema ## Footnote Viridans streptococci are oropharyngeal commensals that can cause these infections.

Question 31

What is the colonial morphology of viridans streptococci?

Answer 31

Small colonies, grey, dry, translucent, alpha-hemolytic or non-hemolytic ## Footnote This appearance aids in their identification in the laboratory.

Question 32

What is the clinical significance of the S. anginosus group?

Answer 32

Can cause bacteremia, abscess formation, endocarditis, respiratory infections, osteomyelitis, septic arthritis, cellulitis ## Footnote Group C and G are normal flora, while group F is found in the oral cavity.

Question 33

What biochemical tests are used for the S. anginosus group?

Answer 33

* PYR - * Hippurate - * CAMP - * VP + * BGUR - ## Footnote These tests help differentiate between species in the group and assess their biochemical characteristics.

Question 34

True or False: S. mutans is a beta-hemolytic streptococcus.

Answer 34

False ## Footnote S. mutans is an alpha-hemolytic viridans streptococcus.

Question 35

Fill in the blank: S. sanguis is known for producing a _______ color on blood agar.

Answer 35

green ## Footnote This green color is due to its alpha-hemolytic properties.