Chapter 2: Medically Relevant Bacteria (2)

Question 1

Staphylococcus aureus is commonly found in which part of the body?

Answer 1

nose

Question 2

S. aureus is catalase negative or positive?

Answer 2

positive

Question 3

S. aureus is coagulase negative or positive?

Answer 3

positive

Question 4

Staph aureus has what hemolytic pattern?

Answer 4

Beta hemolytic

Question 5

Compare and contrast: α, β, and γ hemolysis?

Answer 5

α: Partial hemolysis (greenish brownish zone)
β: complete hemolysis (clear zone)
γ: no hemolysis (no change)

Question 6

Distinguishing features of Staph aureus?

Answer 6

• ferments mannitol
• salt tolerant

Question 7

Disease Presentations of S. Aureus?

Answer 7

• Infective endocarditis (acute)
• abscesses and mastitis
• TSST: desquamating rash, fever, hypotension
• Gastroenteritis: 2-6 h onset, salt foods, custards
• Supprative lesions, pyoderma, impetigo
• Penumonia: nosocimial, typical, acute
• # 1 osteomyelitis unless HbS mentioned
• septic arthritis

Question 8

S. epidermidis is catalase negative or positive?

Answer 8

positive

Question 9

S. epidermidis is coagulase negative or positive?

Answer 9

negative

Question 10

Hemolysis pattern of S. epidermidis?

Answer 10

γ

Question 11

Distinguishing features of S. epidermidis.

Answer 11

• Novobiocin sensitive (does not like to grow on)
• Biofilm producer

Question 12

3 Staph species?

Answer 12

S. aureus
S. epidermidis
S. saprophyticus

Question 13

Disease presentations associated with S. epidermidis?

Answer 13

• endocarditis in IV drug users
• catheter and prosthetic device infections

Question 14

S. saprophyticus is catalase negative or catalase positvie?

Answer 14

positive

Question 15

S. saprophyticus is coagulase negative or positive?

Answer 15

negative

Question 16

Hemolysis pattern of S. saprophyticus.

Answer 16

γ

Question 17

What are some distinguishing feature of S. saprophyticus?

Answer 17

NovobiocinR

Question 18

What are some disease presentations associated with S. saprophyticus?

Answer 18

UTIs in newly sexually active females

Question 19

Group A strep other name basically?

Answer 19

S. pyogenes

Question 20

S. pyogenes is catalase negative or positive?

Answer 20

negative

Question 21

S. pyogenes is coagulase negative or positive?

Answer 21

negative

Question 22

S. pyogenes hemolytic pattern?

Answer 22

β

Question 23

Distinguishing features of S. pyogenes.

Answer 23

Bacitracin S
PYR (pyrrolidonyl arylamidase)

Question 24

Disease presentations of S. pyogenes?

Answer 24

• pharyngitis
• scarlet fever
• pyoderma/ impetigo
• suppurative lesions
• rheumatic fever
• acute glomerulonephritis

Question 25

Group B strep name?

Answer 25

S. agalactiae

Question 26

Is S. agalactiae catalase negative or positive?

Answer 26

negative

Question 27

Is S. agalactiae coagulase negative or positive?

Answer 27

negative

Question 28

Hemolytic pattern found in S. agalactiae?

Answer 28

β

Question 29

Distinguishing features of S. agalactiae?

Answer 29

* BacitracinR * CAMP+

Question 30

Disease presentations of S. agalactiae?

Answer 30

neonatal septicemia and meningitis

Question 31

Non groupable strep names?

Answer 31

S. pneumoniae and Viridans group.

Question 32

S. pneumoniae catalase negative or positive?

Answer 32

negative

Question 33

S. pneumoniae coagulase negative or positive?

Answer 33

negative

Question 34

Hemolytic pattern of S. pneumoniae?

Answer 34

α

Question 35

Distinguishing features of S. pneumoniae?

Answer 35

* OptochinS * Bile soluble

Question 36

Disease presentation association with S. pneumoniae.

Answer 36

* pneumonia (community acquired) * adult meningitis * otitis media and sinusitis in children

Question 37

Viridans group strep catalase negative or positive?

Answer 37

negative

Question 38

Viridans group strep coagulase negative or positive?

Answer 38

negative

Question 39

Viridans group strep hemolytic pattern?

Answer 39

α/γ

Question 40

Distinguishing features of viridans group strep?

Answer 40

* OptochinR * Bile-insoluble

Question 41

Disease presentation associated with Viridans group strep?

Answer 41

* infective endocarditis * dental caries

Question 42

Group D strep ?

Answer 42

Enterococcus sp.

Question 43

Enterococcus is catalase negative or positive?

Answer 43

negative

Question 44

Enterococcus sp. is coagulase negative or positive?

Answer 44

negative

Question 45

Hemolytic pattern of enterococcus?

Answer 45

α, β, γ

Question 46

Distinguishing features of Enterococcus sp.?

Answer 46

* PYR (pyrrolidonyl arylamidase) * Bile- insoluble * Esculin agar

Question 47

Disease presentations associated with Enterococcus?

Answer 47

* infective endocarditis * urinary and biliary infections

Question 48

Create a gram positive organisms flow chart chart outlining differentiation of Gram positive cocci.

Answer 48

Question 49

Describe Transmission of Staph aureus?

Answer 49

* hands * sneezing * surgical wounds * contaminated food -custard pastries -potato salad -canned meats

Question 50

Predisposing factors of Staph aureus.

Answer 50

* surgery/wounds * foreign body (tampons, surgical packing, sutures) * severe neutropenia (< 500/uL) * IV drug abuse * CGD * cystic fibrosis

Question 51

Pathogenesis of Staph aureus.

Answer 51

* Protein A bind Fc component of IgG, inhibiting phagocytosis * Enterotoxins: fast acting, heat stable * toxic shock syndrome toxin-1 (TSST-1): superantigenn * coagulase: converts fibrinogen to fibrin clot * cytolytic toxin (α toxin): pore-forming toxin, Panton-Valentine leukocidin (PVL), forms pores in infected cells and is acquired by bacteriophage; assocated with increased virulence, MRSA strains * Exfoliatins: skin exfoliating toxins (involved in scalded skin syndrome (SSS) and bullous impetigo