STAPHYLOCOCCI

Question 1

Binds IgG
Prevents complement activation
Prevents opsonization and phagocytosis

Answer 1

Protein A

Question 2

Builds an insoluble fibrin capsule

Answer 2

Coagulase

Question 3

Toxic to hematopoietic cells

Answer 3

Hemolysins

Question 4

Specific for WBC

Answer 4

PV Leukocidin

Question 5

Detoxifies hydrogen peroxidase

Answer 5

Catalase

Question 6

Inactivates penicillin derivatives

Answer 6

Penicillinase

Question 7

Hydrolyzes hyaluronic acid

Spreading Factor

Answer 7

Hyaluronidase

Question 8

Dissolves fibrin clots

Answer 8

Fibrinolysin (Staphylokinase)

Question 9

Spread in fat containing areas of the body

Answer 9

Lipase

Question 10

Causes EPIDERMAL SEPARATION

Answer 10

Exfoliatin Toxin (SSS) - scalded skin syndrome (Ritter disease)

cleaves desmoglein (epidermis) - stratum granulosum

Question 11

Superantigens causing FOOD POISONING

Answer 11

Enterotoxins (heat stable)

Question 12

Superantigens causing TOXIC SHOCK SYNDROME

Answer 12

Toxic Shock Syndrome Toxin (TSST-1)

Question 13

Caused MARKED NECROSIS of the skin and hemolysis

Answer 13

Alpha toxin

Question 14

(+) generalized macular and papular lesions w/ areas of skin necrosis

large areas of skin at the back and abdomen, including lips are noted to be sloughing off

fever (+)
alteration of sensorium

Answer 14

toxic epidermal necrolysis (TEN)

Question 15

Spectrum of Disease (Pyogenic)

Answer 15

Skin and Soft Tissue Infections - bullous impetigo, folliculitis, furuncles, carbuncles, cellulitis, hidradenitis suppurative, mastitis

Acute Endocarditis - MCC; native valve (tricuspid) in IV drug abusers

Pneumonia

Osteomyelitis and Septic Arthritis

Question 16

Spectrum of Disease (Toxigenic)

Answer 16

Gastroenteritis - acute onset of (4hrs) and diarrhea d.t. ingestion of PREFORMED HEAT-STABLE ENTEROXIN; salad made with mayonnaise

Question 17

febrile, hypotensive w/ scarlatiniform rash with areas of desquamation in her arms w/c were insignificant

(+) abdominal pain and LBM

on D4 of menses and uses tampons for the first time

Answer 17

Toxic Shock Syndrome

Question 18

Treatment Methicillin Sensitive SA (MSSA)

Answer 18

Penicillinase resistant penicillins

-Nafcillin, Oxacillin, and Dicloxacillin

Question 19

Treatment Methicillin Resistant SA (MSRA)

Answer 19

contain altered PBP

VANCOMYCIN - DOC

Question 20

Treatment Vancomycin Resistant SA (MSRA)

Answer 20

LINEZOLID - DOC

Question 21

8/M, (+) fever, cough and respiratory distress

CXR - hazy infiltrates in bilateral lower lung fields w/ area of cystic lucency in the middle lobe

AFB (-) sputum smear

Most likely causative agent

Answer 21

Staphylococcus aureus

PNEUMATOCELE

Question 22

(+) painful erythematous and honey colored crusted lesions around his mouth

Culture - gram (+) cocci in clusters

beta-hemolytic, coagulase (+) and appear golden on the blood agar plate

Which of the ff helps the bacterium bind to immunoglobulin and prevent phagocytosis when invading its host?

Answer 22

Protein A

Question 23

Methicillin resistance in S. aureus is carried in which gene?

Answer 23

mecA

Question 24

Catalase (+)
Coagulase (-)
Novobiocin sensitive

Answer 24

Staphylococcus epidermidis

Question 25

Catalase (+)

Coagulase (+)

Answer 25

Staphylococcus aureus

Question 26

MCC of:
prosthetic valve endocarditis 
septic arthritis in prosthetic joints
ventriculoperitoneal shunt
infections
indwelling catheters

Answer 26

Staphylococcus epidermidis

Question 27

Catalase (+)
Coagulase (-)
Novobiocin resistant

Answer 27

Staphylococcus saprophyticus

Question 28

2nd MCC of UTI in sexually active women

Answer 28

Staphylococcus saprophyticus