GRAM POSITIVE COCCI

Question 1

Gram-positive cocci that form clusters

Answer 1

Staphylococcus

Question 2

Gram-positive cocci that form tetrads or sarcinae

Answer 2

Micrococcus

Question 3

Facultative anaerobe, glucose fermenter, resistant to 0.04 U bacitracin, sensitive to furazolidone (≥15mm), modified oxidase negative, sensitive to 200 g/L lysostaphin (10-16mm)

Answer 3

Staphylococcus

Question 4

Aerobe, oxidizer, sensitive to 0.04 U bacitracin (10mm), resistant to furazolidone, modified oxidase positive, resistant to 200 g/L lysostaphin

Answer 4

Micrococcus

Question 5

Other Gram-positive cocci with extremely low virulence and usually considered contaminants that also causes otitis and bacteremia

Answer 5

Micrococcus, Kocuria, Kytococcus, Rothia, Dermacoccus, Aerococcus, Alloiococcus

Question 6

Normal flora colonizers of anterior nares, nasopharynx, perineal area, skin, and mucosa

Answer 6

Staphylococcus aureus

Question 7

Staphylococcus aureus virulence factor that inhibits phagocytosis

Answer 7

Capsule, Slime layer, Biofilm

Question 8

Staphylococcus aureus virulence factor with affinity to Fc of IgG and complement (except IgG III)

Answer 8

Protein A

Question 9

Staphylococcus aureus virulence factor that activates IL-1 and complement

Answer 9

Peptidoglycan

Question 10

Exotoxin of Staphylococcus aureus that disrupts smooth muscle in blood vessels and is toxic to RBC, WBC, platelets, & hepatocytes

Answer 10

Alpha toxin

Question 11

Exotoxin of Staphylococcus aureus that works with alpha toxin and hydrolyzes cell membrane

Answer 11

Beta toxin

Question 12

Exotoxin of Staphylococcus aureus that is cytolytic to RBC (hemolysis)

Answer 12

Delta toxin

Question 13

Exotoxin of Staphylococcus aureus that works with Panton-Valentine Leukocidin and kills WBC

Answer 13

Gamma toxin

Question 14

Exotoxin of Staphylococcus aureus responsible for skin exfoliation

Answer 14

Exfoliatin toxin

Question 15

Heat stable enterotoxin responsible for food poisoning

Answer 15

Enterotoxins A-E, G-I

Question 16

Exotoxin of Staphylococcus aureus that causes Toxic Shock Syndrome (TSS)

Answer 16

Toxic Shock Syndrome Toxin-1 (TSST-1)

Question 17

Coagulase and clumping factor of Staphylococcus aureus

Answer 17

Coagulase (clotting), Clumping factor

Question 18

Enzyme of Staphylococcus aureus that lyses the clot

Answer 18

Fibrinolysin (Staphylokinase)

Question 19

Spreading factor of Staphylococcus aureus involved in joint inflammation

Answer 19

Hyaluronidase

Question 20

Staphylococcus aureus virulence factor that breaks down lipids and nucleic acids

Answer 20

Lipase, Nuclease, Penicillinase

Question 21

Skin diseases caused by Staphylococcus aureus

Answer 21

Scalded Skin Syndrome, Pemphigus neonatorum, Folliculitis, Furuncles, Carbuncles, Acne, Boil, Stye, Impetigo

Question 22

Food poisoning caused by preformed enterotoxins of Staphylococcus aureus

Answer 22

Acute food poisoning (2-6 hours onset)

Question 23

Tissue and systemic diseases caused by Staphylococcus aureus

Answer 23

Wounds, Bacteremia, Endocarditis, Osteomyelitis, Cerebritis, Pyelonephritis

Question 24

Laboratory diagnosis: Medium-large pinhead smooth convex opaque creamy yellow colonies on BAP

Answer 24

Staphylococcus aureus

Question 25

Selective agar for Staphylococcus aureus with yellow colonies and halo

Answer 25

MSA (Mannitol Salt Agar)

Question 26

Chromagar color for MRSA

Answer 26

Mauve-color

Question 27

Positive test for Staphylococcus aureus

Answer 27

VP, Slide and Tube Coagulase, DNase

Question 28

PCR gene used to identify Staphylococcus aureus

Answer 28

nucA gene

Question 29

Gold standard PCR gene for MRSA identification

Answer 29

mecA gene

Question 30

Negative tests for Staphylococcus aureus

Answer 30

PYR, Microdase

Question 31

Staphylococcus aureus complex species

Answer 31

Staphylococcus aureus, Staphylococcus argenteus, Staphylococcus schweitzeri

Question 32

β-Hemolytic, Clumping factor positive, PYR positive, VP positive, Virulence factor is uncertain; probably like S. epidermidis) that causes Endocarditis, Bacteremia, Septic arthritis, UTI, Vascular catheter infections

Answer 32

Staphylococcus lugdunensis

Question 33

β-Hemolytic, Clumping factor positive, PYR positive, VP positive; Also causes Endocarditis, Septicemia, Osteomyelitis, Joint infections, Wounds

Answer 33

Staphylococcus schleiferi

Question 34

Virulence factors is uncertain; probably like S. epidermidis; causes endocarditis, bacteremia, peritonitis, UTI, Wound, Bone, Joints infection; PYR positive, VP positive

Answer 34

Staphylococcus haemolyticus

Question 35

Staphylococcus that is Novobiocin susceptible

Answer 35

S. haemolyticus

Question 36

Causative agent causing common infections such as nosocomial bacteremia from indwelling vascular catheters, endocarditis from prosthetic heart valve, infections from prosthetic joints, postsurgical ocular infection, vascular grafts, bacteremia in neonates under ICU

Answer 36

Staphylococcus epidermidis

Question 37

Coagulase-Negative; virulence factors of Staphylococcus epidermidis

Answer 37

Inhibit phagocytosis: Slime layer, Biofilm, Delta exotoxin

Question 38

Staphylococcus that is sensitive to Novobiocin (>16 mm ZOI)

Answer 38

Staphylococcus epidermidis

Question 39

Common infection sexually-active young women urinary tract infection that is coagulase-Negative and resistant to novobiocin

Answer 39

Staphylococcus saprophyticus