Virulence GPC

Question 1

Cytolytic toxins Staph aureus

Answer 1

Alpha, beta, gamma, delta, and PVL
Extracellular proteins that affect RBCs and leukocytes
Hemolysins and leukocidins

Question 2

PVL toxin

Answer 2

Panton-Valentine leukocidin
Lethal to PMNs
Suppresses phagocytosis
Most common with community acquired staph.

Question 3

Staph enzymes

Answer 3

Coagulase
Protease
Hyaluronidase
Lipase

Question 4

Coagulase virulence factor

Answer 4

Staph.aureus

Path. Uncertain

Question 5

Hyaluronidase virulence factor

Answer 5

Hydrolyzes hyaluronic acid in intracellular connective tissue that permits spread of bacteria

Question 6

Protein A virulence factor

Answer 6

Staph aureus

Binds Fc portion of IgG and block phagocytosis

Question 7

SSS

Answer 7

Scalded skin syndrome

Caused by staph. aureus exfoliative toxin

Question 8

TEN

Answer 8

Toxic epidermal necrolysis
Linked to Drug reactions
High mortality rate

Question 9

TSST-1

Answer 9

Toxic shock syndrome toxin
Systemic toxin in localized S. aureus infection
High temp., Rash, vomiting/diarrhea, hypotensive

Question 10

S. aureus enterotoxins A, D, B

Answer 10

Stap food posioning
Ingestion of toxin from contaminated food
Rapid symptoms: diarrhea, vomiting, cramps = resolve 24/48 hrs

Question 11

Strep pyogenes virulence

Answer 11

M protein
Protein F 
Lipoteichoic acid
Streptolysin O
Streptolysin S
DNAse (a, b, c, d)
Streptokinase
Hyaluronidase
erythrogenic exotoxcin

Question 12

M protein

Answer 12

Resists phagocytosis
Adherence to mucosal cells
(Strep pyogenes)

Question 13

Protein F

Answer 13

(GAS bacteria)
Fibronectin binding prot.
Adhesion molecule- attachment to host epithelial cells

Question 14

Lipoteichoic acid

Answer 14

Securea attachment to oral mucosal cells w/ M protein and protein F

Question 15

Hyaluronic acid capsule

Answer 15

S. pyogenes
Weakly immunogenic
Prevents opsonized phag.
Masks antigens

Question 16

Streptolysin O

Answer 16

S. pyogenes
Hemolysis on sheep blood agar
Active in reduced form in anaerobic environment
Lyses leukocytes, platelets, RBCs
Highly immunogenic (used for antibody test)

Question 17

Streptolysin S

Answer 17

S. pyogenes
Nonimminogenic
Oxygen stable
Lyses leukocytes

Question 18

Streptokinase

Answer 18

(GAS & some grp. C & G)

Lyses fibrin clot

Question 19

Hyaluronidase

Answer 19

Spreading factor

Enzyme that solubilizes hyaluronic acid of connective tissue

Question 20

Streptococcal pyrogenic exotoxins

Answer 20

Cause scarlet fever
SpeA, B, C, F
Superantigens

Question 21

Superantigens

Answer 21

Strep pyogenes
Stimulate Tcell proliferation by binding with MCH II on antigen presenting cells and beta chains on Tcell receptor
Produces IL-1, TNF, cytokines which mediate disease

Question 22

SpeA

Answer 22

Strep pyrogenic exotoxin
Superantigen
Overstimulation of immune response

Question 23

S. pneumoniae virulence factors

Answer 23

Capsule
Hemolysin
IgA protease
Neuraminidase
Hyaluronidase

Question 24

Enterococcus virulence factors

Answer 24

Can grow in extreme conditions
Resistant to antimicrobials
Extracellular surface adhesion proteins
Extracellular serine protease
E. faecalis: gelatinase, toxin- 2 subunit cytolysin