Group B Streptococci

Question 1

What are examples of Group B streptococci?

Answer 1

1. Strep Virdans

2. Strep agalactiae

Question 2

Characteristics of Streptococci virdans?

Answer 2

Gram positive cocci in pairs or chains
part of human flora
catalase negative
Facultative anaerobes

Question 3

Optochin resistant organism?

Answer 3

Strep. Viridans

Question 4

Optochin sensitive organism?

Answer 4

Strep. Penumoniae

Question 5

Bile resistant organism?

Answer 5

Enterococcus (group d)

Question 6

Bacitracin resistant organism?

Answer 6

Strep. agalactiae (group b)

Question 7

Bacitracin sensitive organism?

Answer 7

Strep. Pyogenes

Question 8

Microbiological properties of Strep. agalactiae?

Answer 8

• Gram positive, cocci
• encapsulated
• Group B lancefield antigen
• CAMP test positive

Question 9

Which organisms are B-hemolytic?

Answer 9

Strep. Pyogenes and Strep. Agalactiae

Question 10

Which organism is Gamma-hemolytic?

Answer 10

Enterococcus

Question 11

Which organisms are Alpha-hemolytic?

Answer 11

Strep. pneumonia and Strep. Viridans

Question 12

Strep Viridans includes what organisms?

Answer 12

Strep. mutans, songuis, milleri, mitis

Question 13

What is the most important VF of Strep. Agalactiae?

Answer 13

Capsule is imp. VF

Question 14

What capsule types are associated with early onset neonatal disease?

Answer 14

Type 1a, III and V

Question 15

Which capsule is commonly associated with Late onset disease?

Answer 15

Type III

Question 16

Which capsule types are most common in adults?

Answer 16

1a and V

Question 17

Which toxin from Strep. Agalactiae is toxic to neutrophils?

Answer 17

CylE pre forming toxin

Question 18

What is the epidemiology of Strep. Agalactiae?

Answer 18

• Most common cause of septicemia and meningitis in newborns.
• 25% of pregnant women have Group B Strep (GBS) in vagina or rectum

Question 19

Presence of GBS between what weeks of gestation are of most concern?

Answer 19

Weeks 35-37

Question 20

What are the stages of neonatal infection?

Answer 20

1. Colonization of pregnant mother
2. Ascending placental and Uterine infection
3. Pneumonia/Lung injury
4. Bacteremia and Sepsis syndrome
5. BBB penetration and meningitis

Question 21

Strep. Agalactiae infections in pregnant women results in what?

Answer 21

• Postpartum endometritis
• Wound infection
• UTI

Question 22

Strep Agalactiae lab diagnosis to detect vaginal carriage in pregnant women?

Answer 22

PCR-based assays

Question 23

What tests do you use to identify Isolates?

Answer 23

Positive CAMP test

Hippurate hydrolysis

Question 24

The CAMP test examines what?

Answer 24

examines interaction of presumptive GBS with S.aureus in co-culture.

Question 25

A positive CAMP test is indicated by what?

Answer 25

Enhanced hemolysis closest to S. aureus (characteristic arrowhead pattern)

Question 26

GBS enhances S.aureus hemolysis how?

Answer 26

by secreting diffusible CAMP factor

Question 27

What is the drug of choice for GBS?

Answer 27

Penicillin

Question 28

What drugs can you use to serious infections with GBS?

Answer 28

Ampicillin with an aminoglycosides or a cephalosporin

Question 29

If patient is allergic to penicillin or ampicillin what can you give to a patient who has GBS?

Answer 29

Clindamycin or vancomycin

Question 30

For high risk babies, what is given to the mothers before delivery?

Answer 30

Penicillin is given to mother 4 hours before delivery

Question 31

Strep. mutans and Strep. sanguis are found where?

Answer 31

Commensal found in oral cavity, GIT and genitourinary tract

Question 32

characteristics of Strep. mutans and Strep. sanguis?

Answer 32

- Gram positive cocci chain - Indistinguishable from S. pyogenes in gram smear. - Optochin resistant - Nosocomial (hospital acquired)

Question 33

Pathogenesis of Strep. mutans and sanguis?

Answer 33

S. mutans Dextran mediated adherence glue the oral flora onto the tooth enamel or damaged heart valve and to each other (vegetation)

Question 34

What are the diseases Strep. mutans and sanguis causes?

Answer 34

1. Native valve subacute bacterial endocarditis | 2. Dental caries (tooth decay)

Question 35

What are the clinical manifestations of Native valve subacute bacterial endocarditic?

Answer 35

Murmur, anorexia, night sweats, weight loss, etc.

Question 36

RANDOM!! | what causes acute bacterial endocarditis? what causes prosthetic valve endocarditis?

Answer 36

Staph. Aureus Staph. Epidermidis

Question 37

What is the treatment for Strep. mutans and sanguis?

Answer 37

Penicillin G with aminoglycosides for endocarditis.