MICROEX2 Staph Key Terms

Question 1

Staphylococcus aureus
Pathogen?
Normal Flora?
Reservoir?

Answer 1

Usually considered pathogen
Normal flora when found in respiratory specimens
Reservoir in nasal vestibule

Question 2

Staphylococcus epidermis
Pathogen?
Normal Flora?
Reservoir?

Answer 2

Not generally considered a pathogen unless found in obvious association with disease
Yes (opportunistic, nosocomial)
Skin surface, musous membranes

Question 3

Staphylococcus saprophyticus
Pathogen?
Normal Flora?
Reservoir?

Answer 3

Pathogenic in UTIs
yes (opportunistic)
Skin, urogenital tract

Question 4

What do colonies of Staphylococcus aureas look like on blood agar?

Answer 4

Large creamy/gold

Question 5

What color are Micrococcus sp. colonies on blood agar?

Answer 5

yellow

Question 6

Staphylococcus aureus is resistant to:

Answer 6

Heat
Dessication
High Salt concentration
Alcohol

Question 7

Protein A

Answer 7

Staphylococcus aureus
Major antigenic component, antiphagocytis and anti-complementary properties
Lowers host resistance to other organism

Question 8

Coagulase

Answer 8

Staphylococcus aureus
Produces a fibrin clot at site of infection
neutralizes bactericidal effects or normal serum

Question 9

Alpha toxins and hemolysins

Answer 9

Staphylococcus aureus
Nreaks down RBCs
Inactivates leukocytes
Increases tissue cell permeability
May be dermonecrotic

Question 10

Does Staphylococcus aureus have a capsule?

Answer 10

Yes

Question 11

Leukocidins and hemolysins…

Answer 11

Staphylococcus aureus
Toxin
Inactivate antiphagocytis cells

Question 12

Enterotoxin

Answer 12

Staphylococcus aureus
Toxin
causes disruption in Na/K pump in bowels producing diarrhea and vomiting

Question 13

Exfoliative

Answer 13

Staphylococcus aureus
Toxin
Causes skin depolymerization and peeling

Question 14

TSST

Answer 14

Staphylococcus aureus
Toxin
Causes toxic shock syndrom

Question 15

Agressins

Answer 15

a class of enzymes which collectively act on host tissue to establish infections and relate to virulence

Question 16

Hyaluronidase

Answer 16

Staphylococcus aureau
Aggressin
Loosens tissue via delopymerization; related to septicemia

Question 17

Name 5 toxins associated with Staphylococcus aureus

Answer 17

Leukocidins
Hemolysins
Enterotoxins
Exfoliative Toxins
TSST-1

Question 18

Name 4 agressins associated with Stapylococcus aureus

Answer 18

Hyaluronidase
Lipase
DNAse
Staphylokinase

Question 19

Lipase

Answer 19

Staphylococcus aureus
Agressin
Acts on oils and fats in skin; related to furuncles and carbuncles

Question 20

DNAse

Answer 20

Staphylococcus aureus
Agressin
degrades host DNA

Question 21

Staphylokinase

Answer 21

Staphylococcus aureus
Agressin
desolves fibrin clots; inactivates plasminogen (may be used as anticlotting medicine)

Question 22

Toxic Shock Syndrome

Answer 22

Staphylococcus aureus
Caused by TSST-1
Causes fever, vomiting, diarrhea, desquamation, hypotension
May be life threatening is progresses to uncontrolled shock and sepsis

Question 23

Furruncles

Answer 23

Staphyloccoccus aureus

Boils; limited subcutaneous involvement

Question 24

Carbuncles

Answer 24

Staphylococcus aureus
Multiple furnuncles, usually more deep seated in skin with multiple drainage sites
genetic predisposition, common in diabetics

Question 25

Bacteremia

Answer 25

``` Staphylococcus aureus Bacteria are present in blood but do not reproduce in blood May cause Endocarditis 50% fatality Petechia and positive blood cultures ```

Question 26

Osteomyelitis

Answer 26

Staphylococcus aureus Infection of bone May be from fracture, bruises; may involve marrow Most common in children < 12 Usually found in ends of long bones or in spinal column

Question 27

Impetigo

Answer 27

Staphylococcus aureus Usually nosocomial bullous (blister), exfoliative bacterial dermatitis Produces septic lesions

Question 28

Food Poisoning

Answer 28

``` Staphylococcus aureus Enterotoxins (Type A and B) producess sudden onset of nausea, diarrhea and vomiting 2-6 hours after picnics NO FEVER ```

Question 29

Micrococcus species are usually considered a ...

Answer 29

contaminant